Patent Application
20120220028
The present invention relates to an enhancer for promoter and the use thereof.
There has been a demand for the establishment of a technique for gene therapy on lymphoid cells in order to treat various diseases targeting lymphoid cells, such as leukemia and human immunodeficiency virus (HIV) infection. The present inventors have found out an HHV-6B MIE promoter from human herpesvirus-6 (HHV-6), one kind of herpesvirus, as a promoter for introducing a desired gene into lymphocyte cells, and filed the application thereof (Patent Document 1).
Such a virus promoter can be used alone, but is desired to be combined with an enhancer to enhance its action.
In this regard, with respect to eukaryotic promoters, various introns have been known to have enhancer functions. However, with respect to promoters of viruses such as herpesvirus, the enhancer function of the intron has not been known well.
A CMV promoter has been known to be poor in its activity in lymphoid cells. Even if an enhancer of Patent document 2 is used, it is unknown whether the activity increases in cells other than CHO cells.
Patent Document 1: International Publication No.
Patent Document 2: Japanese PCT National Phase Laid-Open Publication No. 2008-536506
The present invention intends to provide an enhancer for a viral promoter such as a promoter that can induce expression selectively and strongly in immunocompetent cells or blood cells, such as lymphocytes and the like.
The present invention has solved the above problem by unexpectedly finding that an intron for a major immediate early gene (MIE) of HHV-6B has such an enhancer activity.
This may be significant in that, even though all introns do not have enhanced expression effects, an intron having such an effect has been found newly. This may be also significant in that, even though most of past studies have been intended for eukaryotes, an intron of HHV-6 is shown by the present inventors (it may be the fist time at least for HHV-6, particularly HHV-6B) and the effect thereof is remarkable.
The CMV promoter has been known to be poor in its activity in lymphoid cells. Even if an enhancer of Patent document 2 is used, it is unknown whether the activity increases in cells other than CHO cells. Even if the activity increases in lymphoid cells, such an increase is not always favorable because the original activity is small. In that respect, the 6MIE promoter by itself shows higher activity than the CMV promoter in cultured cells from T-cell lines such as Molt-3, Jurkat, and SupT1. A combination of this 6MIE promoter with the present enhancer causes a further increase in activity. Besides, it is found that such a combination has a promoter activity at least 5 times higher than that of the CMV promoter. Thus, it is expected that a foreign gene can be more effectively introduced into lymphoid cells in a specific manner.
Therefore, the present specification provides the following items.
(1) An enhancer for a promoter, comprising: an intron sequence for a major immediate early gene (MIE) of human herpes virus-6 (HHV-6) (hereinafter, referred to as HHV-6B), or a fragment of the intron sequence.
(2) The enhancer for a promoter according to item 1, wherein the intron sequence includes a sequence (SEQ ID No. 2) of at least—12 to +1292 based on a transcription initiation point of IE1 included in the above 6MIE sequence, or a fragment of the sequence.
(3) The enhancer for a promoter according to item 1 or 2, wherein the sequence includes a sequence (SEQ ID No. 3) of −12 to +262 based on the transcription initiation point of IE1 included in the above 6MIE sequence.
(4) The enhancer for a promoter according to any of items 1 to 3, wherein the sequence is the sequence (SEQ ID No. 3) of −12 to +262 based on the transcription initiation point of IE1 included in the above 6MIE sequence.
(5) The enhancer for a promoter according to any of items 1 to 4, wherein the promoter includes a sequence (SEQ ID No. 4) of at least −382 to −983 based on the transcription initiation point of IE1 included in the above 6MIE sequence, or a fragment of the sequence.
(6) A promoter with improved activity, comprising: an intron sequence for a major immediate early gene (MIE) of human herpes virus-6 (HHV-6) or a fragment of the sequence; and a promoter.
(7) The promoter with improved activity according to item 6, further comprising: a sequence (SEQ ID No. 2) of at least −12 to +1292 based on a transcription initiation point of IE1 included in the above 6MIE sequence, or a fragment of the sequence; and an MIE promoter.
(8) The promoter with improved activity according to item 7, wherein the MIE promoter includes a sequence (SEQ ID No. 4) of at least −382 to −983 based on the transcription initiation point of IE1 included in the above 6MIE sequence, or a fragment of the sequence.
(9) A construct for enhancing expression of a gene in a cell, comprising: an intron sequence for a major immediate early gene (MIE) of human herpes virus-6 (HHV-6) or a fragment of the sequence; and a promoter.
(10) The construct according to item 9, wherein the construct includes: a sequence (SEQ ID No. 2) of at least −12 to +1292 based on a transcription initiation point of IE1 included in the above 6MIE sequence, or a fragment of the sequence; and an MIE promoter.
(11) The construct according to item 9 or 10, wherein the cell is a cell of T-lymphocyte or adherent line.
(12) The construct according to items 9, 10, or 11, wherein the cell is selected from the group consisting of Molt-3, Jurkat, MRC-5, MeWo, SupT1, and U373.
(13) A method for enhancing expression of a gene in a cell, comprising the steps of:
1) generating a construct including the enhancer for a promoter as described in any one of items 1 to 5 and a promoter, where the gene is arranged so as to be operatively linked to a sequence;
2) introducing the construct into the cell; and
3) culturing the cell under conditions for expressing the gene.
(14) Use of a sequence (SEQ ID No. 2) of at least −12 to +1292 based on a transcription initiation point of IE1 included in the 6MIE sequence, or a fragment of the sequence, as an enhancer for a promoter.
Hereinafter, preferred embodiments of the present invention are presented. It should be understood that those skilled in the art would appropriately perform the embodiments thereof based on the description of the present invention and the well-known and routinely used technique in the art, and the functions and effects attained by the present invention should be readily understood.
The present invention has provided enhancers for promoters that selectively induce the expression of a protein in immune cells such as T lymphocytes. The use of enhancers for promoters of the present invention has provided methods and pharmaceutical agents for effectively preventing or treating immunological diseases such as innate immune deficiency syndrome. Furthermore, the present invention also provides a technique for efficiently conducting gene therapy.
Hereinafter, preferred embodiments of the present invention will be described. It should be understood that expression of a singular form also includes concept of a plural form thereof unless otherwise mentioned, throughout the present specification. Therefore, it should be understood that an article in a singular form (e.g., “a”, “an”, “the” etc. in the case of English) also includes concept of a plural form thereof unless otherwise mentioned. In addition, it should be understood that the terms used in the present specification are used in the meaning usually used in the art unless otherwise mentioned. Therefore, unless defined elsewhere, all the terminology, and the scientific and technical terms used in the present specification have the same meanings as those that are generally understood by those skilled in the art to which the present invention pertains. In the case of contradiction, the present specification (including definitions) prevails.
The definitions of terms particularly used in the present specification are described below.
As used in the present specification, “HHV” refers to a human herpes virus, of which there are types 1, 2, 3, 4, 5, 6, 7, 8 and the like.
As used in the present specification, the term “herpesvirus” includes all of HHV-6A, HHV-6B, and HHV-7, and both their wild-types and recombinant types unless otherwise mentioned. As used in the present specification, the term “HHV-6 (human herpes virus-6)” includes HHV-6A and HHV-6B, and both their wild-types and recombinant types unless otherwise mentioned. HHV6 belongs to the same subgenus p as that of cytomegalovirus HHV-5, and HHV-6B is a causative virus of exanthema subitum. It is said that approximately all Japanese will have been infected therewith by the age of two years old.
The terms “protein”, “polypeptide”, “oligopeptide”, and “peptide” used in the present specification are used in the same meaning in this specification, and each refers to a polymer of amino acids in arbitrary length.
The term “polynucleotide”, “oligonucleotide”, and “nucleic acid” used in the present specification are used in the same meaning in this specification, and each refers to a polymer of nucleotides in arbitrary length. Unless otherwise indicated, a particular nucleic acid sequence also implicitly encompasses conservatively-modified variants thereof (e.g., degenerate codon substitutions) and complementary sequences as well as the sequence explicitly indicated. Specifically, degenerate codon substitutions may be produced by generating sequences in which the third position of one or more selected (or all) codons is substituted with mixed-base and/or deoxyinosine residues (Batzer et al., Nucleic Acid Res. 19:5081 (1991); Ohtsuka et al., J. Biol. Chem. 260:2605-2608 (1985); Rossolini et al., Mol. Cell. Probes 8:91-98 (1994)).
In the present specification, “gene” refers to a factor that defines a genetic trait. A gene is typically arranged in a given sequence on a chromosome. A gene that defines the primary structure of a protein is called a structural gene. A gene that regulates the expression of a structural gene is called a regulatory element. In the present specification, “gene” may refer to “polynucleotide”, “oligonucleotide”, and “nucleic acid” and/or “protein”, “polypeptide”, “oligopeptide” and “peptide”. In the present specification, “open reading frame” or “ORF” in relation to a gene, refers to a reading frame which is one of three frames obtained by sectioning the base sequence of a gene at intervals of three bases, and has a start codon and a certain length without appearance of a stop codon, and has the possibility of actually coding a protein. The entire base sequence of the genome of herpesvirus has been determined, identifying at least 101 genes. Each of the genes is known to have an open reading frame (ORF).
In the present specification, “RNAi” is an abbreviation of RNA interference and refers to a phenomenon where a factor for causing RNAi, such as double-stranded RNA (also called dsRNA), is introduced into cells and mRNA homologous thereto is specifically degraded, so that the synthesis of gene products is suppressed, and techniques using the phenomenon. In the present specification, RNAi may have the same meaning as that of a factor which causes RNAi.
In the present specification, “a factor causing RNAi” refers to any factor capable of causing RNAi. In the present specification, “a factor causing RNAi to a gene” indicates that the factor causes RNAi relating to the gene and that the effect of RNAi is successfully achieved (e.g., suppression of expression of the gene). Examples of such a factor causing RNAi include, but are not limited to, RNA containing a double-stranded portion having a length of at least 10 nucleotides or variants thereof, which have a sequence having at least about 70% homology with a portion of the nucleic acid sequence of a target gene or a sequence hybridizable thereto under stringent conditions. Here, this factor may be preferably DNA containing a 3′ protruding end, where more preferably the 3′ protruding end has a length of 2 or more nucleotides (e.g., 2 to 4 nucleotides in length).
In the present specification, “corresponding” amino acid and nucleic acid refer to an amino acid and a nucleic acid, respectively, in a given polypeptide and nucleic acid molecule, which have, or are anticipated to have, a function similar to that of a predetermined amino acid and nucleic acid in a polypeptide and nucleic acid molecule as a reference for comparison. For example, in the case of ubiquitin, the corresponding amino acid and nucleic acid refer to an amino acid contributing in a similar manner to the catalytic activity and present in a similar location as in the sequence (for example, glycine at the C-terminus) which is responsible for linking lysine, and a nucleic acid encoding the same. For example, in the case of a nucleic acid sequence, the corresponding amino acid and nucleic acid may be the nucleic acid sequence or a similar portion which exerts a similar function to the particular portion which it encodes.
In the present specification, “corresponding” gene, promoter, and intron refer to a gene in a given species, which have, or are anticipated to have, a function similar to that of a predetermined gene in a species as a reference for comparison. When there are a plurality of genes having such a function, it refers to a gene having the same evolutionary origin. Therefore, a gene corresponding to a given gene may be an ortholog of the given gene. Therefore, genes corresponding to those such as herpes virus type 6B and tumor antigen, can be found in other organisms (for example, herpes virus type 7). Such a corresponding gene can be identified by techniques well-known in the art. Therefore, for example, a corresponding gene in a given animal can be found by searching a sequence database of the animal (e.g., herpes virus 6B) using the sequence of a reference gene (e.g., MIE promoter sequence, intron sequence, or the like of herpes virus 6A) as a query sequence. Alternatively, wet experiments can be used for screening a library to find out the same.
In the present specification, “isolated” substance (e.g., a biological factor, such as a nucleic acid or a protein) refers to a substance substantially isolated or purified from other substances (preferably, biological factors) in the environment in which such a substance is naturally-occurring (e.g., in the cells of an organism) (for example, the “isolated” substance means that, in the case of the nucleic acid, factors other than nucleic acids and nucleic acids containing nucleic acid sequences other than that of the nucleic acid of interest; and, in the case of the protein, factors other than proteins and proteins containing amino acid sequences other than that of the protein of interest). The term “isolated” nucleic acid and protein encompasses nucleic acids and proteins purified by standard purification techniques. Therefore, the isolated nucleic acid and protein encompasses chemically synthesized nucleic acids and proteins.
In the present specification, “purified” substance (e.g., a biological factor such as a nucleic acid or a protein) refers to one from which at least a portion of naturally accompanying factors has been removed. Therefore, ordinarily, the purity of a purified substance is higher than that of a substance in a normal state (i.e., concentrated).
In the present specification, “purified” and “isolated” mean that the same type of a substance is present preferably at least 75% by weight, more preferably at least 85% by weight, even more preferably at least 95% by weight, and most preferably at least 98% by weight.
In the present specification, “homology” in relation to a gene refers to the proportion of identity between two or more gene sequences. Therefore, the greater the homology between two given genes, the greater the identity or similarity between their sequences. Whether or not two genes have homology is determined by comparing their sequences directly or by a hybridization method under stringent conditions in the case of nucleic acid. When two gene sequences are directly compared with each other, these genes have homology if the DNA sequences of the genes have representatively at least 50% identity, preferably at least 70% identity, more preferably at least 80%, 90%, 95%, 96%, 97%, 98%, or 99% identity with each other.
In the present specification, “stringent hybridization conditions” refers to conditions commonly used and well-known in the art. By conducting a colony hybridization method, a plaque hybridization method, a Southern blot hybridization method, or the like using a polynucleotide selected from the polynucleotides of the present invention as a probe, such a polynucleotide can be obtained. Specifically, a polynucleotide to be hybridized under stringent conditions refers to a polynucleotide that can be identified by performing hybridization at 65° C. in the presence of 0.7 to 1.0 M NaCl using a filter on which DNA derived from a colony or plaque is immobilized, and washing the filter at 65° C. with a 0.1 to 2-fold concentration SSC (saline-sodium citrate) solution (1-fold concentration SSC solution is composed of 150 mM sodium chloride and 15 mM sodium citrate). Hybridization can be conducted in accordance with a method described in an experiment book, for example, Molecular Cloning 2nd ed., Current Protocols in Molecular Biology, Supplement 1-38, DNA Cloning 1: Core Techniques, A Practical Approach, Second Edition, Oxford University Press (1995). Here, sequences hybridizing under stringent conditions exclude, preferably, sequences containing only A or T. “Hybridizable polynucleotide” refers to a polynucleotide that can hybridize to other polynucleotides under the above-described hybridization conditions. Specific examples of the hybridizable polynucleotide include a polynucleotide having a homology of at least 60% to the base sequence of DNA encoding a polypeptide having an amino acid sequence specifically disclosed in the present specification, preferably a polynucleotide having a homology of at least 80%, and more preferably a polynucleotide having a homology of at least 95%.
In the present specification, the identity comparison and homology calculation of base sequences are performed using a sequence-analyzing tool BLAST with the default parameters. An identity search may be conducted, for example, using NCBI BLAST 2.2.9 (published on May 12, 2004). The value of identity in the present specification usually refers to a value as a result of alignment with the BLAST as described above using the default parameters. However, if the change of parameters results in higher values, then the highest value is employed as the value of identity. When a plurality of regions is evaluated for identity, the highest value is employed as the value of the identity.
In the present specification, “search” indicates that a given nucleic acid base sequence is utilized to find other nucleic acid base sequences having a specific function and/or property either electronically or biologically, or using other methods. Examples of the electronic search include, but are not limited to, BLAST (Altschul et al., J. Mol. Biol. 215:403-410 (1990)), FASTA (Pearson & Lipman, Proc. Natl. Acad. Sci., USA 85:2444-2448 (1988)), Smith and Waterman method (Smith and Waterman, J. Mol. Biol. 147:195-197 (1981)), and Needleman and Wunsch method (Needleman and Wunsch, J. Mol. Biol. 48:443-453 (1970)), and the like. Examples of the biological search include, but are not limited to, stringent hybridization, a microarray in which genomic DNA is attached to a nylon membrane or the like or a microarray (microarray assay) in which genomic DNA is attached to a glass plate, PCR and in-situ hybridization. In the present specification, it is intended that promoters used in the present invention encompass a sequence corresponding to those identified by such an electronic or biological search.
In the present specification, “expression” of a gene, a polynucleotide, a polypeptide, or the like, indicates that the gene or the like is affected by a predetermined action in vivo to be changed into another form. Preferably, it indicates that genes, polynucleotides, or the like are transcribed and translated into polypeptides. In one aspect of the expression, genes may be transcribed into mRNA. More preferably, these polypeptides may have post-translational processing modifications.
In the present specification, amino acids may be referred to with the generally known three-letter abbreviation or the one letter-abbreviation proposed by the IUPAC-IUB Biochemical Nomenclature Commission. Nucleotides may also be referred to with the generally known one-letter abbreviations which are generally accepted.
In the present specification, “fragment” refers to a polypeptide or polynucleotide having a sequence length ranging from 1 to n−1 with respect to the full length of a polypeptide or polynucleotide (having a length of n). The length of the fragment can be appropriately changed depending on the purpose. For example, in the case of polypeptides, the lower limit of the length of the fragment includes 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, 50 or more amino acids. Lengths represented by integers which are not herein specified (e.g., 11) may also be appropriate as a lower limit. For example, in the case of polynucleotides, the lower limit of the length of the fragment includes 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, 50, 75, 100, 200, 300, 400, 500, 600, 600, 700, 800, 900, 1000 or more nucleotides. Lengths represented by integers which are not herein specified (e.g., 11) may also be appropriate as a lower limit.
The polypeptide used in the present invention may have at least one (for example, one or several) amino acid substitutions, additions and/or deletions in the amino acid sequence, as long as it has a substantially identical function as a naturally-occurring polypeptide.
In the present specification, “variant” refers to a substance, such as a polypeptide, polynucleotide, or the like, which differs partially from the original substance. Examples of such a variant include a substitution variant, an addition variant, a deletion variant, a truncated variant, and an allelic variant. The term “allele” refers to a genetic variant located at a locus identical to a corresponding gene, where the two genes are distinguishable from each other. Therefore, the term “allelic variant” refers to a variant which has an allelic relationship with a given gene. The term “species homolog or homolog” refers to one that has an amino acid or nucleotide homology with a given gene in a given species (preferably at least 60% homology, more preferably at least 80%, at least 85%, at least 90%, and at least 95% homology). A method for obtaining such a species homolog is clearly understood from the description of the present specification. The term “orthologs” (also called orthologous genes) refers to genes in different species derived from a common ancestry (due to speciation). For example, in the case of a hemoglobin gene family having a multigene structure, human and mouse-α hemoglobin genes are orthologs, while the human-α hemoglobin gene and the human-β hemoglobin gene are paralogs (genes arising from gene duplication). Orthologs are useful for estimation of molecular phylogenetic trees. Therefore, the orthologs of the present invention may be useful in the present invention.
In the present specification, “functional variant” refers to a variant which retains a biological activity (in particular, promoter activity) which the sequence of standard is responsible for.
In the present specification, “conservative (or conservatively modified) variant” applies to both amino acid and nucleic acid sequences. With respect to particular nucleic acid sequences, conservatively modified variants refer to nucleic acids that encode identical or essentially identical amino acid sequences, and refer to essentially identical sequences if the nucleic acids do not encode amino acid sequences. Because of the degeneracy of the genetic code, a large number of functionally identical nucleic acids encode any given protein. For example, codons GCA, GCC, GCG and GCU all encode amino acid alanine. Thus, at every position where alanine is specified by a codon, the codon can be altered to any of the corresponding codons described without altering the encoded polypeptide. Such nucleic acid variations are “silent alterations (variations)” which represent one species of conservatively modified variation. In a nucleic acid, for example, a conservative substitution can be confirmed by measuring a promoter activity.
In the present specification, in order to prepare genes that encode functionally equivalent polypeptides, amino acid additions, deletions, or modifications can be performed in addition to amino acid substitutions. Amino acid substitution(s) refers to the replacement of at least one amino acid of an original peptide with different amino acids, such as the replacement of 1 to 10 amino acids, preferably 1 to 5 amino acids, and more preferably 1 to 3 amino acids of an original peptide with different amino acids. Amino acid addition(s) refers to the addition of at least one amino acid to an original peptide chain, such as the addition of 1 to 10 amino acids, preferably 1 to 5 amino acids, and more preferably 1 to 3 amino acids to an original peptide chain. Amino acid deletion(s) refers to the deletion of at least one amino acid from an original peptide, such as the deletion of 1 to 10 amino acids, preferably 1 to 5 amino acids, and more preferably 1 to 3 amino acids from an original peptide. Examples of amino acid modification include, but are not limited to, amidation, carboxylation, sulfation, halogenation, alkylation, glycosylation, phosphorylation, hydroxylation, and acylation (e.g., acetylation). Amino acids to be substituted or added may be naturally-occurring or normaturally-occurring amino acids, or amino acid analogs. Naturally-occurring amino acids are preferred.
A nucleic acid form of the polypeptide to be expressed in the present specification refers to a nucleic acid molecule that allows expression of a protein form of the polypeptide. Such a nucleic acid molecule may be one in which a part of the sequence of the nucleic acid is deleted or is substituted with other base(s), or may be one in which a part of other nucleic acid sequences is inserted, as described above, as long as a polypeptide to be expressed has substantially the same activity as that of the naturally-occurring polypeptide. Alternatively, other nucleic acids may be linked to the 5′ end and/or 3′ end of the nucleic acid. The nucleic acid molecule may be one that is hybridizable to a gene encoding a polypeptide under stringent conditions and encodes a polypeptide having substantially the same function as that of the polypeptide. Such a gene is known in the art and can be used in the present invention.
Such a nucleic acid can be obtained by the well-known PCR method, and can also be chemically synthesized. This method may be combined with, for example, a site-specific mutagenesis method, a hybridization method, or the like.
In the present specification, “substitution, addition or deletion” for a polypeptide or a polynucleotide refers to the substitution, addition or deletion of an amino acid or its substitute, or a nucleotide or its substitute with respect to the original polypeptide or polynucleotide. Techniques for such substitution, addition, or deletion are well-known in the art, and examples of the technique include site-specific mutagenesis techniques. The number of substitutions, additions, or deletions may be arbitrarily determined as long as it is one or more. The number can be made large as long as a variant having such substitutions, additions or deletions can maintain an intended function. For example, such a number may be one or several, and preferably within 20% or 10% of the full length sequence, or not more than 100, not more than 50, not more than 25, or the like.
In the present specification, “promoter (or promoter sequence)” refers a DNA region that determines the initiation site of transcription of a gene and directly regulates the frequency of transcription, and is a base sequence to which RNA polymerase usually binds to initiate transcription. Accordingly, in the present specification, a portion having the function of a promoter of a gene refers to “a promoter portion”. A promoter region can be deduced by predicting the protein coding region in a genomic base sequence using DNA analysis software. Deduced promoter regions are usually located at the upstream of a structural gene although it varies depending on the structural gene, and is not limited thereto, and may also be the downstream of the structural gene.
In the present specification, “MIE” (gene) refers to a major immediate early gene, which is a gene that is immediately transcribed by a transcription factor derived from a host or a virion after viral infection.
In the present specification, “MIE promoter” or “MIEp” refers to a major immediate early promoter, which is a promoter of a gene that is immediately transcribed by a transcription factor derived from a host or a virion after viral infection. The MIE gene may be identified by RT-PCR using RNA extracted from an infected cell treated with cycloheximide (CHX).
In the present specification, “6MIE” (gene) refers to a major immediate early gene of human herpes virus 6 (HHV-6) (particularly, HHV-6B). In the present specification, “IE1 of 6MIE” refers to a gene that encodes an IE1 protein among proteins encoded by the major immediate early gene of HHV-6. The transcription initiation point of IE1 (SEQ ID NO. 41) of 6MIE is illustrated as +1 in
In the present specification, “6MIE promoter” or “6MIEp” refers to a promoter of a major immediate early gene (MIE) of human herpes virus 6 (particularly HHV-6).
In the present specification, the identification method of a promoter is as follows: that is, some sequences in the vicinity of the structural gene are screened (for example, using an expression cassette described in the examples), and the sequence having a gene expression promoting activity is mapped. Consequently, a sequence having a significant promoting activity may be identified. Usually, it is located at the upstream of the structural gene in many cases, but is not limited thereto.
In the present specification, “MIE promoter of HHV-6B” refers to any sequence having a promoter activity in SEQ ID NO: 1. Preferably, the promoter has position −770 to position −1 from the transcription initiation point in SEQ ID NO: 1. Examples of the sequence include, but are not limited to, SEQ ID NO: 1 or a sequence corresponding thereto. In the expression control of HHV-6B gene, it is preferable to be located in the region at −530 to −383 from the upstream, and preferably in the region of −1007 to −383 from the transcription initiation point, and the base sequence thereof includes sequences set forth in SEQ ID NOs: 5, 6, and the like. Amongst them, it has been elucidated that NF-κB and AP-1 motifs (−541 to −534 from the transcription initiation point as the origin, corresponds to NF-κB motif sequence, and −426 to −416 and −196 to −186 correspond to the AP-1 motif sequence) may be motifs from experiments of base sequence substitution. Therefore, preferably, the MIE promoter of HHV-6B of the present invention includes: (a) a polynucleotide having the base sequence set forth in SEQ ID NO: 1, or a base sequence corresponding thereto or a fragment sequence thereof; (b) a polynucleotide of an allelic variant of the base sequence set forth in SEQ ID NO: 1 or a base sequence corresponding thereto or a fragment sequence thereof; (c) a polynucleotide which hybridizes the polynucleotide of any of (a) and (b) under stringent conditions and has a biological activity; or (d) a polynucleotide of any of (a) to (c) or a polynucleotide which contains the base sequence with at least 70% identity to a complement sequence thereof, and has a biological activity.
In the present specification, “constructive” expression of a promoter refers to a trait in which expression is found at a substantially predetermined amount in any tissue of an organism during any stage in the course of the development of the organism. Specifically, when northern blot analysis is carried out under conditions similar to those in the examples described in the present specification, if substantially the same expression is observed in the same or corresponding site thereof on any time points (e.g., two or more time points such as day 5 and day 15), the expression is regarded as being constructive by the definition in the present invention. Constructive promoters are believed to play a role in the homeostasis of organisms in a normal growth environment. These traits can be determined by extracting RNA from an arbitrary portion of an organism and subjecting the RNA to northern blot analysis to analyze expression amounts or subjecting the expressed protein to western blot to determine the quantity of the protein.
In the present specification, the “enhancer” or “promoter of enhancer” may be used so as to enhance the expression efficiency of a gene of interest. A plurality of enhancers or a single enhancer may be used, or no enhancer may be used. A region in an intron or promoter which enhances the activity of the promoter may also be referred to as an enhancer as long as it has the activity of enhancing the expression efficiency of a gene.
In the present specification, “intron” is a gene region provided as an intervening sequence that is present in DNA and included in a primary transcript, but not included in the final functional mature RNA, and removed by splicing.
In the present specification, “operatively linked” or “operative link” refers to the fact that the expression (operation) of a desired sequence is located under the control of a transcription regulation sequence (e.g., promoter or enhancer) or a translation regulation sequence. In order that a promoter is operatively linked to a gene, the promoter is usually located immediately at the upstream of the gene, but is not necessarily located in a flanking manner.
In the present specification, “nucleic acid construct” and “gene cassette” are interchangeably used to refer to a nucleic acid sequence including: a nucleic acid molecule (for example, DNA, RNA) encoding a gene; and a control sequence (e.g., a promoter) operatively linked thereto (such that it can control expression of the nucleic acid) according to necessity, and also refer to a nucleic acid molecule including: a control sequence (e.g., a promoter); and a heterologous gene operatively linked thereto (i.e., in frame) according to necessity. It is intended that the use of this cassette or the construct optionally in combination with other regulatory elements is encompassed in the present invention. Preferable expression cassettes or nucleic acid constructs are those cleaved by a specific restriction enzyme and are easy for recovery.
When a gene is mentioned in the present specification, “vector” refers to one capable of transferring a polynucleotide sequence of interest into a target cell. Examples of such a vector include those capable of self-replication in a host cell or incorporation into a chromosome, and containing a promoter at a site suitable for transcription of the polynucleotide of the present invention, such as a prokaryotic cell, yeast, an animal cell, a plant cell, an insect cell, an individual animal, and an individual plant. In the present specification, for example, BAC vectors may be used. The BAC vector refers to a plasmid produced based on the F plasmid of E. coli, and is capable of propagating and stably maintaining a DNA fragment of about 300 kb or greater in size, in a bacteria such as E. coli or the like. The BAC vector includes at least a region essential for replication of BAC vectors. Examples of such a region essential for replication include oriS, a replication initiation point of F plasmid, or a variant thereof.
As used in the present specification, “selective marker” refers to a gene that functions as an indicator for selecting a host cell including a nucleic acid construct or a vector. Examples of the selective markers include, but are not limited to, fluorescent markers, luminescent markers and drug selective markers. Examples of the “fluorescent markers” include, but are not limited to, genes encoding fluorescence proteins such as green fluorescent protein (GFP), cyan fluorescent protein (CFP), yellow fluorescent protein (YFP), and red fluorescent protein (dsRed). Examples of the “luminescent markers” include, but are not limited to, genes encoding luminescent proteins such as luciferases. Examples of the “drug selective markers” include, but are not limited to, hypoxanthine guanine phosphoribosyl transferase (hprt), dihydrofolate reductase gene, glutamine synthase gene, aspartate transaminase, metallothionein (MT), adenosine aminase (ADA), AMP deaminase (AMPD1, 2), xanthine-guanine-phosphoribosyl transferase, UMP synthase, P-glycoprotein, asparagine synthase, and ornithine decarboxylase. Examples of a combination of these drug selective markers and a drug to be used include, but not limited thereto, genes that encode proteins, such as a combination of dihydrofolate reductase (DHFR) gene and methotrexate (MTX); a combination of glutamine synthase (GS) gene and methionine sulfoximine (Msx); a combination of aspartate transaminase (AST) gene and N-phosphonacetyl-L-aspartate (PALA); a combination of MT gene and cadmium (Cd2+); a combination of adenosine deaminase (ADA) gene and adenosine, alanosine, 2′-deoxycoformycin; a combination of AMP deaminase (AMPD1, 2) gene and adenine, azaserine and coformycin; a combination of xanthine-guanine-phosphoribosyl transferase gene and mycophenolic acid; a combination of UMP synthase gene and 6-azauridine, pyrazofuran; a combination of P-glycoprotein (P-gp, MDR) gene and multi drugs; a combination of aspartate synthase (AS) gene and β-aspartyl hydroxamic acid or albizziin; ornithine decarboxylase (ODC) gene and α-difluoromethyl-ornithine (DFMO).
As used in the present specification, “expression vector” refers to a nucleic acid sequence including a structural gene and a promoter for regulating expression thereof, and in addition, various regulatory elements in a state that allows them to operate within host cells. The regulatory element may include, preferably, terminators, selective markers such as drug-resistance genes (e.g., kanamycin resistant gene and hygromycin resistant gene), and enhancers. It is well-known in the art that a type of expression vector of an organism such as an animal and a kind of a regulatory element to be used may vary depending on the host cells. As used in the present specification, “recombinant vector” refers to a vector capable of transferring a polynucleotide sequence of interest to a target cell. Examples of such a vector include those capable of self-replication in a host cell or incorporation into a chromosome, and containing a promoter at a site suitable for transcription of the polynucleotide of the present invention, such as a prokaryotic cell, yeast, an animal cell, a plant cell, an insect cell, an individual animal, and an individual plant.
In the present specification, “terminator” refers to a sequence which is located at the downstream of a protein-encoding region of a gene and which is involved in the termination of transcription when DNA is transcribed into mRNA, and the addition of a poly-A sequence. It is known that a terminator contributes to the stability of mRNA, and has an influence on the amount of gene expression. Examples of the terminator include, but are not limited to, a sequence including AATAAA.
In the present specification, “foreign gene” refers to, in a given organism, a gene which does not naturally occur in the given organism. Such a foreign gene may be a gene modified from a gene which naturally occurs in the given organism, or a gene which naturally occurs in an organism that is different from the given organism (e.g., ADA gene), or an artificially synthesized gene, or a complex thereof (e.g., a fusion). An organism containing such a foreign gene may express a genetic product which is not expressed in nature. For example, a recessive gene to be deleted (for example, ADA gene, PNP gene, γc chain gene, TAP gene, MHC II gene, X-linked WASP, CD40 ligand, PI3K-like gene, DNA helicase) may be used as a foreign gene.
In the present specification, the foreign gene may be of cytokine. As used in the present specification, “cytokine” is defined as in the broadest sense used in the art, and a physiologically active substance which is produced from a cell and acts on the same cell or a different cell. Cytokines are generally a protein or a polypeptide, and have a controlling action of immunological response, regulation of endocrine system, regulation of the nerve system, antitumor activity, antiviral activity, regulatory action of cell proliferation, regulatory action of cellular differentiation and the like. In the present specification, cytokines may exist in a protein form or nucleic acid form, or in any other forms, and at the actual time of action, cytokines usually mean a protein form. As used in the present specification, “growth factor” refers to a substance which promotes or controls the growth of a cell. Growth factors are also called as growth- or development-stimulating substances. Growth factors may substitute the action of serum macromolecular substances by addition to a medium in a cell culture or a tissue culture. Many growth factors have been found to function as a control factor of a differentiation state other than growth of a cell. The cytokines typically include interleukins, chemokines, hematopoietic factors such as colony stimulation factors, tumor necrosis factors, and interferons. Examples of the growth factors typically include platelet derived growth factor (PDGF), epidermal growth factor (EGF), fibroblast growth factor (FGF), hepatocytic growth factor (HGF), and vessel endothelial growth factor (VEGF), which show growth activity.
In the present invention, those having homology with the foreign gene of a native form as described above may be used as a foreign gene to be expressed. Examples of the foreign gene with such homology include, but are not limited to, nucleic acid molecules having nucleic acid sequences with an identity or similarity of at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 99%, or polypeptide molecules having amino acid sequence of an identity or similarity of at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 99%, to a comparative foreign gene when conducting comparison using default parameters of Blast.
In the present specification, “expression” of a gene product, such as a gene, a polynucleotide, a polypeptide, or the like, indicates that the gene or the like is affected by a predetermined action in vivo to be changed into another form. Preferably, it indicates that genes, polynucleotides, or the like are transcribed and translated into polypeptides. In one aspect of the expression, genes may be transcribed into mRNA. More preferably, these polypeptides may have post-translational processing modifications.
Accordingly, in the present specification, “reduction” of “expression” of a gene, a polynucleotide, a polypeptide or the like refers to when the factor of the present invention is allowed to act, the amount of expression is significantly reduced compared to that when the factor is not allowed to act. Preferably, the reduction of expression includes a reduction in an amount of polypeptide expression. In the present specification, “increase” of “expression” of a gene, a polynucleotide, a polypeptide or the like refers to when the factor of the present invention is allowed to act, the amount of expression is significantly increased compared to when the factor is not allowed to act. Preferably, the increase of expression includes an increase in an amount of polypeptide expression. In the present specification, “induction” of “expression” of a gene refers to an increase in an amount of expression of the gene by acting a factor on a cell. Accordingly, the induction of expression encompasses that the expression of the gene is observed when the expression of the gene is not observed at all, and that the expression of the gene is increased when the expression of the gene has already been observed.
In the present specification, “specific expression” of a gene refers to expression in a different level (preferably in a higher level) in a specific site or period of time in a plant than that of the other site or period of time. The term specific expression may refer to expression in a certain site (specific site) or may also refer to expression other than the certain site. Preferably, the term specific expression refers to expression in the certain site only.
As used in the present specification, any of methods for introducing a recombinant vector can be used as long as they are methods for introduction of DNA, and examples thereof include a calcium chloride method, an electroporation method [Methods. Enzymol., 194, 182 (1990)], a lipofection method, a spheroplast method [Proc. Natl. Acad. Sci. USA, 84, 1929 (1978)], a lithium acetate method [J. Bacteriol., 153, 163 (1983)], and a method described in Proc. Natl. Acad. Sci. USA, 75, 1929 (1978).
Transitional expression of Cre enzyme, DNA mapping on the chromosomes, and the like, used in a method for removing a genome, genomic locus or the like used in the present specification are well-known in the art as described in “FISH Experimental Protocol: from human/genomic analysis to chromosomal/genetic diagnosis” in Cell Engineering, special issue, Experimental Protocol Series, supervised by Kenichi Matsubara, Hiroshi Yoshikawa, SHUJUNSHA Co., Ltd. (Tokyo), and the like.
In the present specification, “detection” or “quantification” of gene expression (e.g., mRNA expression, polypeptide expression) may be attained by an appropriate method, including a mRNA measurement method and an immunological measurement method. Examples of molecular biological measurement methods include Northern blotting methods, dot blotting methods, and PCR methods. Examples of the immunological measurement methods include ELISA methods where a microtiter plate may be used, RIA methods, fluorescent antibody methods, Western blotting methods, and immunohistological staining methods. Examples of quantification methods include ELISA methods, and RIA methods. A gene analysis method using an array (e.g., a DNA array, a protein array) may also be used. The DNA array is widely reviewed in Cell Engineering, special issue, “DNA Microarray and Up-to-date PCR Method”, edited by SHUJUNSHA Co., Ltd. The protein array is described in detail in Nat. Genet. 2002 December; 32 Suppl:526-32. Examples of methods for analyzing gene expression include, but are not limited to, RT-PCR methods, RACE methods, SSCP methods, immunoprecipitation methods, two-hybrid systems, and in vitro translation methods in addition to the above-described techniques. Other analysis methods are described in, for example, “Genome Analysis Experimental Method, Yusuke Nakamura's Lab-Manual, edited by Yusuke Nakamura, YODOSHA Co., Ltd. (2002), and the like. All of the above descriptions are herein incorporated by reference.
In the present specification, “expression amount” refers to the amount of a polypeptide or mRNA expressed in a subject cell. Examples of such an expression amount include an amount of expression of the polypeptide of the present invention in a protein level evaluated by any appropriate method using the antibody of the present invention, including immunological measurement methods such as an ELISA method, an RIA method, a fluorescent antibody method, a Western blotting method, an immunohistological staining method, and the like, or an amount of expression of the polypeptide of the present invention in a mRNA level evaluated by any appropriate method, including molecular biological measurement methods such as a Northern blotting method, a dot blotting method, a PCR method, and the like. The term “change in amount of expression” indicates that an increase or decrease in an amount of expression of the polypeptide of the present invention in a protein level or in a mRNA level evaluated by any appropriate method including the above-described immunological measurement method or molecular biological measurement method.
As used in the present specification, the terms “transformation”, “transduction”, and “transfection” are used interchangeably unless otherwise mentioned, and refer to introduction of a nucleic acid into host cells. As a transformation method, any technique for introducing DNA into host cells can be used, and examples thereof include various well-known techniques such as an electroporation method, a method using particle gun (gene gun), and a calcium phosphate method.
The term “transformant” refers to the whole or a part of a living organism, such as a cell, which is produced by transformation. Examples of the transformant include prokaryotic cells, yeast, animal cells, plant cells, and insect cells. Transformants may be referred to as transformed cells, transformed tissue, transformed hosts, or the like, depending on the subject, and in the present specification, all of the forms are encompassed; however, a particular form may be specified in a particular context.
Examples of the prokaryotic cells include those of the genera Escherichia, Serratia, Bacillus, Brevibacterium, Corynebacterium, Microbacterium, and Pseudomonas, including Escherichia coli XL1-Blue, Escherichia coli XL2-Blue, Escherichia coli DH1, Escherichia coli MC1000, Escherichia coli KY3276, Escherichia coli W1485, Escherichia coli JM109, Escherichia coli HB101, Escherichia coli No. 49, Escherichia coli W3110, Escherichia coli NY49, Escherichia coli BL21(DE3), Escherichia coli BL21(DE3) pLysS, Escherichia coli HMS174(DE3), Escherichia coli HMS174(DE3)pLysS, Serratia ficaria, Serratia fonticola, Serratia liquefaciens, Serratia marcescens, Bacillus subtilis, Bacillus amyloliquefaciens, Brevibacterium ammmoniagenes, Brevibacterium immariophilum ATCC14068, Brevibacterium saccharolyticum ATCC14066, Corynebacterium glutamicum ATCC13032, Corynebacterium glutamicum ATCC14067, Corynebacterium glutamicum ATCC13869, Corynebacterium acetoacidophilum ATCC13870, Microbacterium ammoniaphilum ATCC15354, Pseudomonas sp.D-0110, and the like.
Examples of the animal cells include cord blood mononuclear cells, peripheral blood mononuclear cells, and Sup-T1 cells.
In the present specification, “animal” is used in its broadest sense in the art and refers to vertebrates and invertebrates. Examples of the animals include, but are not limited to, the class Mammalia, the class Aves, the class Reptilia, the class Amphibia, the class Pisces, the class Insecta, and the class Vermes.
In the present specification, “tissue” in relation to organisms refers to an aggregate of cells having a certain similar function. Therefore, a tissue may be a portion of an organ (body organ). Organs (body organs) usually have cells having the same function in many cases, but may have coexisting cells having slightly different functions. Therefore, in the present specification, tissues may have various kinds of cells in a coexisting manner as long as a certain property is shared by the cells.
In the present specification, “body organ (organ)” refers to a structure which has a single independent form and in which one or more tissues are combined together to perform a specific function. In animals, examples thereof include, but are not limited to, stomach, liver, intestine, pancreas, lung, airway, nose, heart, artery, vein, lymph node (lymphatic system), thymus, ovary, eye, ear, tongue, and skin.
In the present specification, “transgenic” refers to incorporation of a specific gene into an organism or an organism incorporated such a gene (e.g., plants or animals (mice, etc.)). Among transgenic organisms, one with a deleted or suppressed gene refers to a knockout organism.
When the organisms of the present invention are animals, the transgenic organisms can be produced by using a production technique of a transgenic organism utilizing a microinjection method (a trace amount injection method), a virus vector method, an ES cell method (embryonic stem cell method), a sperm vector method, a chromosome fragment introducing method (transsomic method), an episome method, or the like. These production techniques of transgenic animal are well-known in the art.
As used in the present specification, “screening” refers to selection of a substance, a host cell, a virus, or the like having a given specific property of interest from a number of candidates using a specific operation/evaluation method. It will be understood that the present invention also encompasses viruses having a desired activity obtained by screening.
In the present specification, “chip” and “microchip” are used interchangeably to refer to a micro-integrated circuit that has versatile functions and constitutes a portion of a system. Examples of the chip include, but are not limited to, DNA chips, protein chips, and cell chips.
The herpesvirus promoters of the present invention can be used as an ingredient of a pharmaceutical composition for the treatment, prevention, and/or therapy of lymphatic or hemic diseases, immune diseases, and infectious diseases.
In the present specification, “effective amount” in relation to a drug refers to an amount which causes the drug to exhibit its intended efficacy. In the present specification, an effective amount corresponding to the smallest concentration may be referred to as a minimum effective amount, among such effective amounts. Such a minimum effective amount is well-known in the art. Typically, the minimum effective amount of a drug has been determined or can be determined as appropriate by those skilled in the art. The determination of such an effective amount can be achieved by the use of an animal model, or the like in addition to actual administration. The present invention is also useful for the determination of such an effective amount.
In the present specification, “pharmaceutically acceptable carrier” refers to a substance which is used for production of a pharmaceutical agent or an agricultural chemical (e.g., an animal drug), and has no adverse effect on effective ingredients. Examples of such a pharmaceutically acceptable carrier include, but are not limited to, antioxidants, preservatives, colorants, flavoring agents, diluents, emulsifiers, suspending agents, solvents, fillers, bulking agents, buffers, delivery vehicles, excipients, and/or agricultural or pharmaceutical adjuvants.
The kind and amount of a drug to be used in the treatment method of the present invention can be easily determined by those skilled in the art based on information obtained by the method of the present invention (e.g., information relating to a disease) in view of the purpose of use, the target disease (kind, severity, etc.), the patient's age, weight, sex, and past history, the form and kind of a site of a subject to be administered, or the like. The frequency of subjecting a subject (patient) to the monitoring method of the present invention can also be easily determined by those skilled in the art in view of the purpose of use, the target disease (kind, severity, etc.), the patient's age, size, weight, and past history, the progression of the therapy, and the like. Examples of the frequency of monitoring the state of a disease include once per day to once per several months (e.g., once per week to once per month). Preferably, monitoring is preferably performed once per week to once per month with reference to the progression.
In the present specification, “instruction(s)” refers to a description of the treatment method of the present invention for a person who performs administration, such as a medical doctor and a patient. The instructions state administration of the pharmaceutical agent of the present invention, for example, immediately after or before radiation therapy (e.g., within 24 hours). The instructions are prepared in accordance with a format defined by a regulatory authority of a country in which the present invention is practiced (e.g., Ministry of Health, Labour and Welfare in Japan, Food and Drug Administration (FDA) in the U.S.), explicitly describing that the instructions are approved by the regulatory authority. The instructions are so-called package insert and are typically provided in paper media; however, the instructions are not limited thereto, and may be provided in the form of electronic media (e.g., web sites provided on the Internet and electronic mails).
In the therapy of the present invention, two or more pharmaceutical agents may be used as required. When two or more pharmaceutical agents are used, these agents may have similar properties or may be derived from similar origins, or alternatively, may have different properties or may be derived from different origins. The method of the present invention can be used to obtain information about a disease level for a method for administering such two or more pharmaceutical agents.
Culturing methods used in the present invention are described and supported in, for example, “Animal Culture Cell Manual, Eeno et al., eds., KYORITSU SHUPPAN Co., Ltd., 1993, the entirety of which is hereby incorporated by reference.
In certain embodiments, a nucleic acid including a sequence encoding an antibody or a functional derivative thereof is administered for the purpose of gene therapy for treating, inhibiting or preventing a disease or disorder related to abnormal expression and/or activity of the polypeptide of the present invention. Gene therapy refers to a therapy performed by administering a nucleic acid, which has been expressed or is capable of being expressed, to subjects. In this embodiment of the present invention, a nucleic acid produces a protein encoded thereby and the protein mediates a therapeutic effect.
Any method available in the art for gene therapy may be used in accordance with the present invention. Illustrative methods are described below.
See the following general review for a method for gene therapy: Goldspiel et al., Clinical Pharmacy 12:488-505 (1993); Wu and Wu, Biotherapy 3: 87-95 (1991); Tolstoshev, Ann. Rev. Pharmacol. Toxicol. 32: 573-596 (1993); Mulligan, Science 260: 926-932 (1993); and Morgan and Anderson, Ann. Rev. Biochem. 62:191-217 (1993); and May, TIBTECH 11(5): 155-215 (1993). Generally known recombinant DNA techniques used for gene therapy are described in Ausubel et al. (eds.), Current Protocols in Molecular Biology, John Wiley & Sons, NY (1993); and Kriegler, Gene Transfer and Expression, A Laboratory Manual, Stockton Press, NY (1990).
The compounds or pharmaceutical compositions of the present invention are preferably tested in vitro, and then in vivo for the desired therapeutic or preventive activity, prior to use in humans. For example, in vitro assays to demonstrate the therapeutic or preventive utility of a compound or pharmaceutical composition include the effect of a compound on a cell line, or a patient tissue sample. The effect of the compound or composition on the cell line and/or tissue sample can be determined utilizing techniques known to those skilled in the art (including, but not limited to, cell lysis assays). In accordance with the present invention, examples of the in vitro assays which can be used to determine whether or not administration of a specific compound is indicated include in vitro cell culture assays. In this assay, a patient tissue sample is grown in a culture, and exposed to a compound or otherwise a compound is administered to the patient tissue sample, and the effect of such a compound on the tissue sample is observed.
The present invention provides methods for treatment, inhibition, and prevention by administration to a subject an effective amount of a component or pharmaceutical composition including the enhancer for a promoter of the present invention. In a preferred aspect, the component including an enhancer for a promoter may be substantially purified (for example, including the state where the effects are restricted, or a substance causing undesirable side effect is substantially free). Subjects may preferably be animals including, but not limited to, cattle, pigs, horses, chickens, cats, dogs, and the like, and preferably mammals, and most preferably humans.
When the nucleic acid molecule or polypeptide of the present invention is used as a pharmaceutical agent, such a composition may further contain a pharmaceutically acceptable carrier and the like. Examples of the pharmaceutically acceptable carrier contained in the pharmaceutical agent of the present invention include any substance known in the art.
Examples of such a suitable formulation material or the pharmaceutically acceptable carrier include, but are not limited to, antioxidants, preservatives, colorants, flavoring agents, diluents, emulsifiers, suspending agents, solvents, fillers, bulky agents, buffers, delivery vehicles, diluents, excipients and/or pharmaceutical adjuvants. Typically, the pharmaceutical agent of the present invention is administered in the form of a composition including an isolated multipotential stem cell or a variant or derivative thereof, with at least one physiologically acceptable carrier, excipient or diluent. For example, an appropriate vehicle may be an injection solution, a physiological solution, or an artificial cerebrospinal fluid. Such a vehicle can be supplemented with other substances commonly used for compositions for parenteral delivery.
The acceptable carriers, excipients or stabilizers used in the present specification are nontoxic to recipients and are preferably inert at the dosages and concentrations to be employed, and examples thereof include, but are not limited to, phosphate, citrate, or other organic acids; ascorbic acid, (alpha-tocopherol; low molecular weight polypeptides; proteins (e.g., serum albumin, gelatin, and immunoglobulins); hydrophilic polymers (e.g., polyvinylpyrrolidone); amino acids (e.g., glycine, glutamine, asparagine, arginine and lysine); monosaccharides, disaccharides, and other carbohydrates (including glucose, mannose, and dextrins); chelating agents (e.g., EDTA); sugar alcohols (e.g., mannitol and sorbitol); salt-forming counterions (e.g., sodium); and/or nonionic surfactants (e.g., Tween, pluronics and polyethylene glycol (PEG)).
Examples of the appropriate carriers include neutral buffered saline or saline mixed with serum albumin. Preferably, the product is formulated as a lyophilizate using appropriate excipients (e.g., sucrose). Other standard carriers, diluents, and excipients may be included as desired. Other exemplary compositions include Tris buffer with pH 7.0 to 8.5, or acetate buffer with pH 4.0 to 5.5, which may further include sorbitol or a suitable alternative thereof.
The pharmaceutical agent of the present invention may be administered orally or parenterally. Alternatively, the pharmaceutical agent of the present invention may be administered intravenously or subcutaneously. When systemically administered, the pharmaceutical agent for use in the present invention may be in the form of a pyrogen-free, pharmaceutically acceptable aqueous solution. The preparation of such pharmaceutically acceptable compositions can be easily performed by those skilled in the art in consideration of pH, isotonicity, stability and the like. In the present specification, administration methods may be oral administration, and parenteral administration (e.g., intravenous administration, intramuscular administration, subcutaneous administration, intradermal administration, mucosal administration, intrarectal administration, intravaginal administration, topical administration to an affected site, skin administration). A dosage formulation for such administration may be provided in the form of any formulation. Example of the form of formulation include liquid formulations, injections, and sustained preparations.
The pharmaceutical agent of the present invention may be prepared and stored in the form of lyophilized cake or aqueous solutions by mixing a sugar chain composition having the desired degree of purity with, according to necessity, physiologically acceptable carriers, excipients, or stabilizers (see Japanese Pharmacopoeia 14th edition, or a supplement thereto or the latest edition thereof, Remington's Pharmaceutical Sciences, 18th Edition, A. R. Gennaro, ed., Mack Publishing Company, 1990; and the like).
The amount of a sugar chain composition used in the treatment method of the present invention can be easily determined by those skilled in the art in view of the purpose of use, the target disease (kind, severity, etc.), the patient's age, weight, sex, and past history, the form and kind of a cell, or the like. The frequency of subjecting a subject (patient) to the treatment method of the present invention can also be easily determined by those skilled in the art in view of the purpose of use, the target disease (kind, severity, etc.), the patient's age, size, weight, and past history, the progression of the therapy, and the like. Examples of the frequency of administration include once per day to once per several months (e.g., once per week to once per month). Preferably, administration is preferably performed once per week to once per month with reference to the progression.
(General Techniques Used in this Specification)
Techniques used in the present specification uses well-known and routinely used techniques in the fields of sugar chain science, microfluidics, microfabrication, organic chemistry, biochemistry, genetic engineering, molecular biology, microbiology, genetics, and their relevant fields, which are within the technical scope of the present invention unless otherwise specified. The techniques are sufficiently well described in documents described below and other documents cited in other places in the present specification.
Microfabrication is described in, for example, Campbell, S. A. (1996). The Science and Engineering of Microelectronic Fabrication, Oxford University Press; Zaut, P. V. (1996). Micromicroarray Fabrication: a Practical Guide to Semiconductor Processing, Semiconductor Services; Madou, M. J. (1997). Fundamentals of Microfabrication, CRC1 5 Press; Rai-Choudhury, P. (1997). Handbook of Microlithography, Micromachining & Microfabrication: Microlithography; and the like, the relevant portions of which are herein incorporated by reference.
Molecular biology procedures, biochemistry procedures, microbiology procedures and sugar chain scientific procedures used in the present specification are well-known and routinely used in the art, and are described in, for example, Maniatis, T. et al. (1989). Molecular Cloning: A Laboratory Manual, Cold Spring Harbor and its 3rd Ed. (2001); Ausubel, F. M. et al. eds, Current Protocols in Molecular Biology, John Wiley & Sons Inc., NY, 10158 (2000); Innis, M. A. (1990). PCR Protocols: A Guide to Methods and Applications, Academic Press; Innis, M. A. et al. (1995). PCR Strategies, Academic Press; Sninsky, J. J. et al. (1999). PCR Applications: Protocols for Functional Genomics, Academic Press; Gait, M. J. (1985), Oligonucleotide Synthesis: A Practical Approach, IRL Press; Gait, M. J. (1990). Oligonucleotide Synthesis: A Practical Approach, IRL Press; Eckstein, F. (1991). Oligonucleotides and Analogues: A Practical Approach, IRL Press; Adams, R. L. et al. (1992). The Biochemistry of the Nucleic Acids, Chapman & Hall; Shabarova, Z. et al. (1994). Advanced Organic Chemistry of Nucleic Acids, Weinheim; Blackburn, G. M. et al. (1996). Nucleic Acids in Chemistry and Biology, Oxford University Press; Hermanson, G. T. (1996). Bioconjugate Techniques, Academic Press; Method in Enzymology 230, 242, 247, Academic Press, 1994; Special issue, Experimental Medicine “Experimental method for Gene Introduction & Expression Analysis)”, YODOSHA Co., Ltd., 1997; and the like, and the relevant portions (or possibly the entirety) of which are herein incorporated by reference.
Hereinafter, preferred embodiments will be described; however, the embodiments are provided for illustrative purposes of the present invention. Accordingly, it should be understood that the scope of the present invention is not limited to the preferred embodiments. It should be understood by those skilled in the art that variations and modifications can be easily made within the scope of the present invention with reference to the following preferred embodiments.
In an aspect, the present invention provides an enhancer for a promoter, which comprises an intron sequence for a major immediate early gene (MIE) of human herpes virus-6 (HHV-6) or a fragment of the intron sequence. In particular, it has been found that this enhancer has unexpectedly enhanced the ability of a viral promoter such as an HHV-6B MIE promoter or the like.
It has been found that the HHV-6B MIE promoter, with an HHV7 MIE promoter, and an HHV7 U95 promoter, is unexpectedly enhanced in selectivity to lymphocytes in comparison to HCMV IE promoters. It is understood that the enhancer of the present invention can further enhance such selectivity. Further, it has been found that in adhesive cells (293 cells, Vero cells and the like), the MIE promoter only showed one hundredth the activity of that of HCMV IE promoter, whereas in lymphoid cells such as SupT1 and U937, a several fold increase in expression efficiency is obtained. Such a high level of selectivity or specificity accounts for capability of application to DNA vaccines, and particularly to the development of a pharmaceutical agent that targets lymphocytes as gene therapy. In this regard, it is understandable that the enhancer of the present invention can further enhance such an effect. Moreover, in an expression system in vivo, since activities are diminished even in the case of CMV promoters which have potent activity, due to the action of methylase, it is understood that the enhancer for a promoter of the present invention may be used to secure an amount of expression in vivo in blood cells or lymphocyte cells. In genetic diseases, gene therapy for cancer, or the like, retrovirus vectors are generally used; however, since LTR activity is not so potent as a promoter, the introduction of the enhancer for a promoter of the present invention into the upstream of the gene to be expressed allows potent expression in blood cells. The present invention is useful in gene therapy targeting blood cell diseases such as leukemia. Furthermore, RNAi is used as a method for knocking out gene expression, and the enhancer for a promoter of the present invention is used as an enhancer for a promoter of hair-pin type RNA expression vectors, thereby allowing more efficient effects of inhibition of expression in the blood cells. Macrophages, dendritic cells or the like are purified from native peripheral blood using flow cytometry, and these cells are transfected with plasmids constructed so as to express cancer specific antigen, tumor necrosis factor (TNF) gene and the like under controlling the enhancer for a promoter of the present invention, and reintroduced to the original body after confirmation of expression of a cancer antigen, thereby practicing the gene therapy of cancer as a result of efficient activation of cancer antigen specific CTL via Class I-HLA.
In one embodiment, the promoter to be used in the present invention includes a length of at least 8 contiguous nucleotide sequences, amongst the sequence set forth in SEQ ID NO: 1. Preferably, the promoter of the present invention includes at least the R3 region or the functional variant thereof, amongst the sequence set forth in SEQ ID NO: 1. More preferably, the promoter of the present invention includes a sequence of at least −574 to −427 based on a transcription initiation point; more preferably, a sequence of at least −1051 to −427 based on a transcription initiation point, amongst the sequence set forth in SEQ ID NO: 1.
In one embodiment, the intron sequence of the present invention includes a sequence (SEQ ID No. 2) of at least −12 to +1292 based on a transcription initiation point of IE1 included in the above 6MIE sequence, or a fragment of the intron sequence. It has not been conventionally known that the intron sequence of the present invention has an enhancer effect, and the intron sequence of the present invention has not also been conventionally known as a viral promoter, and thus it is entirely unexpectable.
In a preferred embodiment, the intron sequence of the present invention includes a sequence (SEQ ID No. 3) of −12 to +262 based on a transcription initiation point of IE1 included in the above 6MIE sequence. More preferably, the intron sequence of the present invention is comprised of the sequence (SEQ ID No. 3) of −12 to +262 based on the transcription initiation point of IE1 included in the 6MIE sequence. It is understood that such a sequence may have one or more, or at least one nucleotide substitution, addition and/or deletion as long as it has the enhancer effect.
In one embodiment, a promoter as a target of the enhancer of the present invention includes: (a) a polynucleotide having the base sequence set forth in SEQ ID NO: 1, or a base sequence corresponding thereto or a fragment sequence thereof; (b) a polynucleotide of an allelic variant of the base sequence set forth in SEQ ID NO: 1 or a base sequence corresponding thereto or a fragment sequence thereof; (c) a polynucleotide which hybridizes the polynucleotide of any of (a) and (b) under stringent conditions and has a biological activity; or (d) a polynucleotide of any of (a) to (c) or a polynucleotide which contains the base sequence with at least 70% identity to a complement sequence thereof, and has a biological activity. Here, the biological activity may be a promoter activity and/or an enhancer activity, but is not limited thereto. The promoter activity and the enhancer activity can be determined using techniques well-known in the art. Such techniques are also described in the present specification and illustrated in examples.
In one preferred embodiment, a promoter as a target of the enhancer of the present invention may include substitution, addition, or deletion in the above (a) to (d). The numbers of such substitutions, additions, and deletions may be preferably limited to, for example, 50 or less, 40 or less, 30 or less, 20 or less, 15 or less, 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, or less, or 2 or less. The smaller the numbers of substitutions, additions, and deletions is preferred. However, the larger the number of substitutions, additions, and deletions is allowable as long as the promoter retains its biological activities (preferably, the promoter has similar or substantially the same activities as those of HHV-6B MIE promoter).
In a preferred embodiment, identity to one of polynucleotides of any one of the above (a) to (d) or a complementary sequence thereof may be at least about 80%, more preferably at least about 90%, further preferably at least about 98%, and most preferably at least about 99%.
In another preferred embodiment, a promoter as a target of the present invention includes a sequence of at least −382 to −983 based on a transcription initiation point of IE1 included in the above 6MIE sequence or a fragment of the sequence. Although not wishing to be bound by theory, it is because a sequence with a remarkable enhancer effect of the present invention can be found in this region. Furthermore, it should be understood that a region where such an enhancer effect can be found is not limited to the above region.
In another aspect, the present invention provides a promoter with improved activity, including: an intron sequence for a major immediate early gene (MIE) of human herpes virus-6 (HHV-6) (particularly, HHV-6B) or a fragment of the sequence; and a promoter.
In the present specification, the “promoter with improved activity” of the present invention can be understood as any promoter with improved activity higher than that of the promoter used alone.
In one embodiment, it is understood that an intron sequence for a major immediate early gene (MIE) of human herpes virus 6 (HHV-6), which is used in the promoter with improved activity of the present invention, or a fragment of the sequence can employ any embodiment described in the above section “Enhancer for promoter”.
In one embodiment, furthermore, it is understood that a promoter to be used for the promoter with improved activity of the present invention can employ any embodiment described in the above section “Enhancer for promoter”.
In a preferred embodiment, the promoter with improved activity of the present invention includes the sequence (SEQ ID No. 2) of at least −12 to +1292 of IE1 included in the 6MIE sequence, or a fragment of the sequence, and an MIE promoter. Although not wishing to be bound by theory, this is because the use of such a combination provides a promoter with remarkably improved promoter effect, compared with the conventional MIE promoter.
Here, preferably, the MIE promoter used in the present invention includes a sequence (SEQ ID No. 4) of at least −382 to −983 based on a transcription initiation point of IE1 included in the above 6MIE sequence, or a fragment of the sequence.
In another aspect, the present invention provides a construct for enhancing expression of a gene in a cell, including an intron sequence for a major immediate early gene (MIE) of human herpes virus-6 (HHV-6) or a fragment of the sequence and a promoter.
In one embodiment, it is understood that the intron sequence for a major immediate early gene (MIE) of human herpes virus 6 (HHV-6) or a fragment of the sequence can employ any embodiment described in the above section “Enhancer for promoter”.
Furthermore, in one embodiment, it is understood that the promoter used in the construct of the present invention can also employ any embodiment described in the above section “Enhancer for promoter”.
In a preferred embodiment, the construct of the present invention is a construct for enhancing expression of a gene in a cell, and includes the sequence (SEQ ID No. 2) of at least—12 to +1292 based on a transcription initiation point of IE1 included in the above 6MIE sequence, or a fragment of the sequence, and an MIE promoter. Although not wishing to be bound by theory, this is because the use of such a combination provides a construct with remarkably improved promoter effect, compared with the conventional MIE promoter.
In one embodiment, cells as a target of the construct of the present invention are blood cells, particularly cells of T-lymphocyte or adherent line. Examples of the cells of T-lymphocyte line include Molt-3, Jurkat, and SupT1. Examples of the cells of adherent line include MRC-5, MeWo, and U373.
In one embodiment, the nucleic acid construct of the present invention includes a sequence encoding a foreign gene derived from a source different from the promoter and the enhancer thereof which are used in the present invention, where the sequence is operatively linked to a sequence of the promoter used in the present invention.
Examples of such a foreign gene include, but are not limited to, one encoding an RNAi molecule, a pharmaceutical agent, a recessive gene to be deleted, or a selective marker.
Preferably, the selective marker to be used in the present invention may be one that allows selection in a medium of a host in which the nucleic acid construct of the present invention is introduced. For example, the selective marker may be one that allows visual selection in a host in which the nucleic acid construct is introduced, and examples thereof include hypoxanthine guanine phosphoribosyl transferase (hprt) and green fluorescent protein (GFP), cyan fluorescent protein (CFP), yellow fluorescent protein (YFP), and red fluorescent protein (dsRed).
Preferably, it is advantageous that the selective marker included in the nucleic acid construct of the present invention does not substantially exhibit toxicity against the host in which the nucleic acid construct of the present invention is introduced. This is because, no adverse effect is preferred when the present invention is used for therapeutic or preventive purposes.
Examples of those to be included in the nucleic acid construct of the present invention include recessive genes to be deleted. Here, a recessive gene to be deleted refers to any recessive gene which exhibits a diseased condition when deleted. Examples of such a recessive gene include ADA gene (which is related to severe combined immunodeficiency (SCID)), PNP gene (which is related to severe combined immunodeficiency (SCID)), γc chain gene (which is related to severe combined immunodeficiency (SCID)), TAP gene (which is related to MHC I deficiency), MHC II gene (which is related to MHC II deficiency), X-linked WASP (which is related to Wiskott-Aldrich syndrome), CD40 ligand (which is related to X-linked high IgM syndrome), PI3K-like gene (which is related to ataxia telangiectacia), and DNA helicase (which is related to Bloom's syndrome).
In a preferred embodiment, pharmaceutical agents to be included in the nucleic acid construct of the present invention may be proteinous pharmaceutical agents such as cytokines, chemokines, growth factors, protein hormones, and peptide hormones such as IFN-α, IFN-γ, IL-2, IL-12, G-CSF, and GM-CSF.
In another aspect, the present invention provides an expression vector including the nucleic acid construct of the present invention. Such an expression vector includes elements essential to expression, which may not exist in the nucleic acid construct of the present invention, for example, terminators and enhancer sequences other than those of the present invention in an operatively linked manner, which allow expression in the host. In another preferred embodiment, the selective markers may be immortalizing genes (for example bcl-2). Alternatively, the selective markers may be hypoxanthine phosphoribosyl transferase (HPRT), a gene encoding a toxic product, a toxic gene product that is active depending on a condition in combination with a suicide substrate (for example, herpes simplex virus thymidine kinase (HSV-TK) in combination with ganciclovir).
In another aspect, the present invention provides a cell including the construct of the present invention. Such a cell, in the case of a lymphocyte, promotes the expression of a protein encoded by a foreign gene.
Preferably, it is advantageous that the cell of the present invention is heterogenous to the promoter sequence used in the present invention. It can be said that it is one of surprising effects to have a promoter activity even if the cell is heterogenous. A method for introducing the nucleic acid molecule of the present invention into a cell is well-known in the art, and described in detail in the above section. Alternatively, such a cell may be identified by screening a cell containing the nucleic acid molecule in a sample including the cell. The cell containing the nucleic acid molecule of the present invention may preferably be in an undifferentiated state. The cell expressing the nucleic acid molecule of the present invention is usually in an undifferentiated state. Therefore, a cell into which such a nucleic acid molecule has been introduced so as to be expressed in a controllable manner can control the undifferentiated state. Alternatively, such a cell may be used to produce the nucleic acid molecule of the present invention in a large amount. Such production methods are well-known in the art and are described in the documents described in the present specification.
In another aspect, the present invention provides a tissue including the construct of the present invention. Such a nucleic acid sequence is preferably operatively linked to a control sequence. Such a tissue may be an animal tissue, or a tissue of a different organism such as a plant. Alternatively, such a tissue may be used to produce the nucleic acid molecule of the present invention in a large amount. Such production methods are well-known in the art and are described in the documents described in the present specification.
In another aspect, the present invention provides an organ including the construct of the present invention. Such a nucleic acid sequence is preferably operatively linked to a control sequence. Such an organ or body organ may be an animal organ or body organ, or an organ or body organ of a different organism such as a plant. Alternatively, such an organ or body organ may be used to produce the nucleic acid molecule of the present invention in a large amount. Such production methods are well-known in the art and are described in the documents described in the present specification.
In another aspect, the present invention provides an organism including the construct of the present invention. Such an organism may be an animal or a different organism such as a plant. Alternatively, such an organism may be used to produce the nucleic acid molecule of the present invention in a large amount. Such production methods are well-known in the art and are described in the documents described in the present specification.
In another aspect, the present invention provides a method for enhancing expression of a gene in a cell, including the steps of:
1) generating a construct including the enhancer for a promoter of the present invention and a promoter, where the gene is arranged so as to be operatively linked to a sequence;
2) introducing the construct into the cell; and
3) culturing the cell under conditions for expressing the gene.
Alternatively, the present invention provides a kit for enhancing expression of a gene in a cell, including:
1) a construct including the enhancer for a promoter of the present invention and a promoter, where the gene is arranged so as to be operatively linked to a sequence;
2) a reagent for introducing the construct into the cell; and
3) a means for culturing the cell under conditions for expressing the gene. It is understood that the enhancer for a promoter, promoter, construct, cell, and the like used in this method can employ any form described in the sections “Enhancer for promoter”, “Promoter”, and “Construct”. The reagent for introducing the construct into a cell is known in the art, and any of them may be used. A culturing means is also known in the art, and any of them may be used.
In another aspect, the present invention provides use of a sequence (SEQ ID No. 2) of at least −12 to +1292 based on a transcription initiation point of IE1 included in the 6MIE sequence, or a fragment of the sequence, as an enhancer for a promoter. Here, it is understood that the enhancer for a promoter can employ any form described in the section “Enhancer for promoter”.
In one aspect, such a use form may be a pharmaceutical agent.
Therefore, in another aspect, the present invention provides a pharmaceutical composition including the enhancer for a promoter of the present invention, a promoter, and an antigen-encoding sequence. Here, the antigen may be any protein desired to raise an immune response in a host. Examples of such an antigen include, but are not limited to, cancer antigens. Therefore, the pharmaceutical composition of the present invention may preferably be a DNA vaccine.
In another aspect, the enhancer for a promoter of the present invention provides a pharmaceutical composition for treating a disease, disorder or condition in which a lymphocyte-specific treatment is desired, the composition including the enhancer for a promoter of the present invention, a promoter, and a nucleic acid sequence for the treatment. Here, the target of the pharmaceutical composition may appropriately be any of diseases, disorders, conditions and the like desired to have lymphocyte specific treatment, and examples thereof include acquired immunodeficiency syndromes. Examples of the acquired immunodeficiency syndromes include, but are not limited to, severe combined immunodeficiency (SCID), MHC I deficiency, MHC II deficiency, Wiskott-Aldrich syndrome, X-linked high IgM syndrome, ataxia telangiectacia, and Bloom's syndrome. Although not wishing to be bound by theory, acquired immunodeficiency syndrome is caused by some deficiency in a recessive gene (which is herein also referred to as a recessive gene to be deleted). It is possible to carry out somatic gene therapy in which this gene to be deleted is introduced to bone marrow cells taken from a patient then the cells are reintroduced into the patient. In this case, the HHV-6B MIE promoter to which the enhancer for a promoter of the present invention may target is utilized to expect an increase in efficiency of gene expression in a cell differentiated into T cell, macrophage and the like. Introduction of such a gene construct can be carried out, for example, by using a retrovirus and the like.
In a preferred embodiment, the nucleic acid sequences for the treatment to be used in the present invention include nucleic acid sequences encoding cytokines, nucleic acid sequences encoding chemokines, nucleic acid sequences encoding growth factors, nucleic acid sequences encoding protein hormones, nucleic acid sequences encoding peptide hormones, ribozymes, and RNAi.
In another aspect, the present invention provides use of the enhancer for a promoter of the present invention in production of a pharmaceutical composition for treating a disease, disorder, or condition.
Reference documents such as scientific references, patents and patent applications cited in the present specification are incorporated by reference in their entirety in the present specification to the same extent as that each is specifically described.
As described above, the present invention has been described for easy understanding by showing preferred embodiments. The present invention will be described below based on examples, but the aforementioned description and the following examples are provided only for illustration, and are not provided for the purpose of limiting the present invention. Therefore, the scope of the present invention is not limited to embodiments or examples which are specifically described in the present specification, and is limited only by claims.
Handling of animals used in the following examples was in accordance with the provisions set forth in Osaka University.
It was confirmed that the activity of a major immediate early gene (MIE) promoter of human herpes virus 6 (HHV-6) (6MIEp) was higher than that of the IE promoter (SEQ ID NO. 35) of cytomegalovirus (CMV) in T cells. In this example, a promoter with a prolonged 3′ end of HHV-6B MIE promoter was prepared, and investigation was performed whether a similar effect could be obtained with respect to the intron of IE1.
The upstream region of MIE gene of HHV-B strain HST was amplified using various primers described below (
Variants of the obtained various promoter were inserted into pGL3 basic to construct reporter plasmids, respectively. Various kinds of culture cells (Molt-3, MRC-5, Jurkat, MeWo, SupT1, and U373) were transfected with the constructed reporter plasmids, and their luciferase activities were then measured.
Specifically, on a day before the transfection, adherent line cells were seeded 1×105 cells/well to a 24 well plate and then incubated overnight at 37° C. under 5° 6CO2. Floating line cells were seeded 4×105 cells/well to a 24 well plate immediately before the transfection. Using Lipofectamine 2000 (Invitrogen), various kinds of culture cells (Melt-3, MRC-5, Jurkat, MeWo, SuPT1, and U373) were transfected with 1 μg of various constructed reporter plasmids or empty vectors together with 0.25 μg of Renilla luciferase expression plasmid (pRL-TK) for correcting transfection efficiency. After 24 hours from the transfection, the cells were collected. The cells were lysed with Dual-luciferase reporter assay system (Promega). The amount of luminescence due to firefly luciferase and Renilla luciferase in the cell lysate were measured, respectively. Here, the measurement was conducted with a multi-mode microplate reader LB941 (Berthold). The amount of luminescence due to firefly luciferase obtained by measurement was divided by the amount of luminescence due to Renilla luciferase to correct the transfection efficiency.
Furthermore, the resulting value was divided by the amount of luminescence of the empty vector to obtain a relative value of the promoter activity to the empty vector.
As a result of the reporter assay with luciferase, any of promoters extending to intron 1 showed increased activities in any cells. In contrast, however, promoters extending to introns 2 to 4 showed a decrease in activity (
The results of the reporter assay of promoters reveal that the addition of intron 1 causes an increase in activity. The T-cell line shows higher activity than the CMVIE promoter. In addition, some of adherent line cells, such as MeWo cells and MRC-5 cells, show an increase in activity up to the same level as that of the CMVIE promoter. It is supposed that such an increase in activity may be useful in foreign gene expression.
A polyA tail is added to the 3′-end of mRNA. The polyA tail is considered to stabilize mRNA and promote protein expression. The polyA tail targets a sequence of AAUAAA on the 3′ region of mRNA and is added thereto by polyA polymerase. A region that contains a polyA addition sequence derived from herpes virus is inserted into the downstream of a gene that encodes a protein of interest, attempting to protein expression.
Regions containing portions considered to be polyA addition sequences derived from HHV-6B, U90, and U100 illustrated below were amplified by PCR, respectively. These were inserted into the downstream of DsRed2 gene of pBlueScriptSK(−)-DsRed2 vector (Clontech). Then, 6MIE was used as a promoter to construct plasmids pBleuScriptSK(−)-6 MIE-DsRed2-U90pA (SEQ ID NO. 39) and pBlueScriptSK(−)-6 MIE-DsRed2-U100pA (SEQ ID NO. 40).
The cloned U90pA sequence (complementary strand of 134474 to 134679 of HHV-6B HST genome, the underlined portion is assumed as poly-A addition sequence) is as follows:
The cloned 100pA sequence (complementary strand of 148150 to 148301 of HHV-6B HST genome, the underlined portion is assumed as poly-A addition sequence) is as follows:
Various kinds of culture cells (293T, MeWo, MRC5, and HeLa) were transfected with the obtained plasmids, and expression of DeRed was then confirmed under fluorescence microscope.
Specifically, on the day before the transfection, various kinds of culture cells (293T, MeWo, MRC5, and HeLa) were seeded 2×105 cells/well to a 6-well plate and then incubated overnight at 37° C. under 5% CO2. Transfection of 1 μg pBlueScript plasmid, to which the above expression cassette had been inserted, was conducted using Lipofectamine 2000 (Invitrogen). After overnight incubation at 37° C. under 5% CO2, DsRed expression was confirmed using fluorescence microscope.
Knocking out of gene expression in blood cells was conducted using an IE promoter and an RNAi method together with the enhancer for a promoter of the present invention. IE promoters are advantageous for analysis since they are expressed in blood cells in a large amount.
1) Preparation of Cells (in the Case of Macrophages)
Healthy human peripheral blood was collected, separated and purified by density gradient using Ficoll/Hypaque. The PBMCs were cultured in AIM V serum medium (Life Technologies) supplemented with M-CSF (R&D systems, 100 U/ml). The medium was exchanged every three days, and macrophages at Day 6 or 7 after culture were used for experiments.
2) Production of siRNA Expression Retrovirus Vector
In order to express hair-pin type RNA; a synthetic oligo-DNA including “a sense strand target sequence”, “a loop sequence”, “an antisense strand target sequence” and “a terminator sequence” were produced. Such a sense strand target sequence, loop sequence, antisense target sequence, terminator sequence may be made using a well-known technique in the art. Those skilled in the art can understand that when actually using these, an appropriate sequence may be employed depending on the actual situation.
The above-mentioned DNA was incorporated into a plasmid vector in which the oligo-DNA was linked to the downstream of the IE sequence, gag, pol, and env which are necessary for replication of a retrovirus were deleted, and NeoR gene was included, by making use of restriction enzyme sequences and the like. Plasmid vector produced (10 μl) was added to 100 μl of competent cells and transformation was conducted and the resultant was cultured for 16 hours at 37° C. after plating into LBAmp plate. Colonies obtained by the transformation were cultured on LBApm liquid medium at 37° C. for 16 hours, and plasmids were extracted and purified using conventional methods from the culture solution.
Retrovirus packaging cells expressing gag, pol and env were plated on a disc with a 10-cm diameter, and transfection reagent was opened to transfect the plasmid (10 μg). After 24 to 48 hours, the cells were subjected to serial dilution into a G418 containing medium (500 μg/ml) and passaged.
Every three to four days, the G418 medium was exchanged and cultured for about two weeks in total. The colonies were recovered and at the time where growth was found at a confluent level on a six-well plate, the medium was changed to a G418 free medium and the supernatant was recovered 24 hours later. Subsequently, cells were stocked.
Retrovirus vectors included in the supernatant were subjected to serial dilution, and infected into NIH/3T3 cells, and colonies grown were counted to calculate the infection value.
3) Gene Introduction Experiment Using Retrovirus Vectors
Retrovirus vectors were infected with blood cells such as macrophages prepared in 1). Immediately after washing, the cells were plated so as to be 0.5 to 2.5×104 cells/cm2 in a plate. Twenty four hours after the infection, the medium was exchanged with a G418 containing medium, and every three to four days, the medium was exchanged. About two weeks later, gene introduced cells were obtained. The cells were used to confirm the amount of expression of the knocked out gene of interest.
These experiments were conducted to actually confirm that after gene introduction, lymphocyte specific expression of a foreign gene was knocked out with the promoter used in the present invention.
Instead of the RNAi of Example 3, a nucleic acid molecule encoding a gene (e.g., cytokines such as TGFβ) desired for expression was introduced.
As a result, by conducting the same experiments as in Example 3, after gene introduction, it was confirmed that the enhancer for a promoter of the present invention actually induced the specific expression of a foreign gene in such a manner that the promoter activity was enhanced.
As described above, the present invention has been exemplified using preferred embodiments of the present invention; however, it is understood that the scope of the present invention should be construed only by the claims. It is understood that a content of patents, patent applications and references cited in the present specification should be incorporated into the present specification by reference as if the content itself is specifically described in the present specification.
The present invention has provided an enhancer for a viral promoter. The enhancer for a promoter of the present invention is useful in a method and pharmaceutical agent for effectively preventing or treating immune diseases such as acquired immunodeficiency syndromes. The present invention is also useful in the techniques for efficiently conducting gene therapy.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-205365 | Sep 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/005447 | 9/3/2010 | WO | 00 | 5/16/2012 |
