The present invention relates to the field of biotechnology. Specifically, the present application relates to a human papillomavirus chimeric protein, and a pentamer or a virus-like particle formed thereby, as well as use of the human papillomavirus chimeric protein, the human papillomavirus chimeric pentamer or the human papillomavirus chimeric virus-like particle in the preparation of a vaccine for the prevention of papillomavirus infection and infection-induced diseases.
Human papillomaviruses (HPVs) are a class of envelope-free small DNA viruses that infect epithelial tissues. More than 200 types of the virus have been identified and classified into α, β, γ, μ, and η genera according to the amino acid homology of L1, the main coat protein of human papillomavirus. They are also classified into mucosa types and skin types according to the different sites of infection. Mucosa type HPVs mainly infect the genitourinary, perianal and oropharyngeal mucosa and skin. They all belong to the α genus, and are further classified into oncogenic HPVs with transforming activity and low-risk HPVs (LR-HPVs) that induce benign hyperplasia. Oncogenic HPVs include 12 common high-risk types (including HPV16, -18, -31, -33, -35, -39, -45, -51, -52, -56, -58, -59, etc.), 1 probable high-risk type (HPV68), and more than 10 very rare possible high-risk types (HPV26, -30, -34, -53, -66, -67, -69, -70, -73, -82, -85, etc.). Studies have found that all oncogenic HPV-positive cancerous tissues show specific E6*I mRNA expression, decreased expression of tumor suppressor gene Rb/P53 and cyclin CDI, and increased expression of p16INK 4a, indicating that the oncogenic risk from infection with any type of oncogenic HPV is the same. There are about 12 types of low-risk HPVs (HPV6, -7, -11, -13, -32, -40, -42, -43, -44, -54, -74, -91, etc.), of which HPV6 and -11 types induce a total of 90% of perianal and genital condylomata acuminata and most of the recurrent respiratory papillomas. Skin-type HPVs mainly infect skin tissues other than the above sites, some of which (HPV2, -27, -57) induce skin verrucous hyperplasia, and other types (HPV5, -8, -38, etc.) are associated with the occurrence of squamous cell carcinoma and basal cell carcinoma of skin.
Malignant tumors that have been identified as related to oncogenic HPV infection are cervical cancer, vaginal cancer, vulval cancer, penile cancer, anal and perianal cancer, oropharyngeal cancer, tonsil cancer and oral cancer, among which cervical cancer is the most harmful. Cervical cancer is the third highest incidence of malignant tumor in women in the world, with an annual incidence of about 527,000, including 285,000 in Asia and 75,000 in China. The 12 common high-risk types of HPV induce a total of 95.2%-96.5% of cervical cancer, and the rest more than 10 probable and possible high-risk types induce a total of about 3.29% of cervical cancer. HPV type 16 is a prevalent high-risk type worldwide, with the highest detection rate in HPV-related tumors such as cervical cancer, perianal cancer, penile cancer, vulval cancer, and in precancerous lesions. HPV16 and HPV 18 have a detection rate of 50-60% and ˜20% in cervical cancer worldwide, respectively. The 12 common high-risk types of HPV induce a total of 95.2%-96.5% of cervical cancer, and the rest more than 10 probable and possible high-risk types induce a total of about 3.29% of cervical cancer.
HPV L1 virus-like particles (L1 VLPs) mainly induce type-specific neutralizing antibodies and protective responses, and the protective range of the vaccine can only be expanded by increasing the types of L1 VLPs. The three HPV vaccines on the market are all L1 VLP vaccines, namely the divalent vaccine by GSK (Cervarix, HPV16/-18), the tetravalent vaccine (Gardasil, HPV6/-11/-16/-18) and the nine-valent vaccine (Gardasil-9, HPV6/-11/-16/-18/-31/-33/-45/-52/-58) by Merck, of which the nine-valent vaccine with the widest protection range only covers limited 7 high-risk types and 2 low-risk types (HPV6/-11), and cannot prevent the skin types. In addition, the protection range of L1 VLP vaccines cannot be expanded by unlimitedly increasing the types of L1 VLPs. Therefore, L1 VLP vaccines can hardly meet the requirements of prevention of HPV infection-related diseases.
The secondary capsid protein L2 of HPV has no immune activity in its native state, but the N-terminal polypeptide of L2 can induce cross-neutralizing antibodies and cross-protection responses, although the immunogenicity is weak, the titer of the induced antibody is low; and the types cross-neutralized by monotypic L2 antiserum is limited. At present, a variety of conserved epitope peptides that can induce neutralizing antibodies have only been found in 16 L2N, in which aa. 17-38 is its main neutralizing epitope region, and the monoclonal antibody RG-1 recognizing this region cross-neutralizes the most types. Therefore, this region is also called RG-1 epitope peptide, in which aa. 21-31 is the core sequence of its neutralizing epitope. The homologous region of aa. 21-31 is always retained in studies related to RG-1 epitope peptides, regardless of the length of the sequence.
The RG-1 types that have been reported for vaccine research include HPV type 4 RG-1, HPV type 6 RG-1, HPV type 16 RG-1, HPV type 17 RG-1, HPV type 31 RG-1, HPV type 33 RG-1, HPV type 45 RG-1, HPV type 51 RG-1, HPV type 58 RG-1, etc. [C. Schellenbacher et al., The Journal of investigative dermatology 2013, 133(12):2706-13: H. Seitz et al., Vaccine 2014, 32(22):2610-2617: B. Huber et al., PLOS One 2015, 10(3):e0120152; B. Huber et al., PLOS One 2017, 12(1): e0169533; X. Chen et al., Oncotarget 2017, 8(38):63333-63344; X. Chen et al., Human Vaccines & Immunotherapeutics 2018, 14(8):2025-2033; PCT/CN2017/075402], and the employed means include VLP surface display, bacterial protein surface display (bacterial thioredededin Trx, flagellar protein, cholera toxin mutant CRM197), targeted IgγR modified antibody and tandem fusion of multiple types of L2 polypeptides containing the RG-1 epitope. However, studies have shown that a variety of RG-1 epitope peptide-related vaccines have poor activity results. For example, the three type 16 cVLPs surface displaying HPV type 4 RG-1, HPV type 6 RG-1 or HPV type 17 RG-1 induced very low titer of HPV16 neutralizing antibody, and the titer of cross-neutralization was not detected [B. Huber et al., PLOS One 2017, 12(1):e0169533; X. Chen et al., Oncotarget 2017, 8(38):63333-63344]. The 18cVLP displaying HPV type 45 RG-1 induced very low titer of HPV18 neutralizing antibody (only 1/100 of type 18 L1VLP), and only cross-neutralized the oncogenic types HPV45, −70 and −39 with very low titer, the highest was only 100 [B. Huber et al., PLOS One 2015, 10(3):e0120152]. The Trx fusion protein antiserum surface displaying type 51 RG1 had a narrow cross-neutralization range, and the highest titer of cross-neutralizing antibody was only 500 [H. Seitz et al., Vaccine 2014, 32(22):2610-2617]. In contrast, the type 16 RG1-cVLP reported by Schellenbacher et al. as well as the type 31 RG1-cVLP, type 33 RG1-cVLP and type 58 RG1-cVLP previously reported by the inventors had better immunoactivity, and the titer of HPV16 neutralizing antibody induced by the backbone type VLP was as high as 105 (comparable to that induced by type 16 L1 VLP), and the corresponding RG-1 epitope-induced L2-dependent cross-neutralizing antibodies had a wide neutralization range and relatively high titers (the highest was up to 6400) [C. Schellenbacher et al., The Journal of investigative dermatology 2013, 133(12):2706-13; X. Chen et al., Oncotarget 2017, 8(38):63333-63344; X. Chen et al., Human Vaccines & Immunotherapeutics 2018, 14(8): 2025-2033; PCT/CN2017/075402].
The above data suggest that the RG-1 epitope peptides derived from different HPV types have very different immunogenicity. The inventors compared the immunogenicity of type 58 RG-1 and type 6 RG-1 in a previous publication, and found that type 58 RG-1 epitope peptide antiserum cross-neutralized more types (13 types) and had higher titers (the highest was up to 3200), while type 6 RG-1 epitope peptide antiserum neutralized fewer types (9) types) and had very low titers (the highest was only 100) [X. Chen et al., Oncotarget 2017, 8(38):63333-63344]. This indicated that although the RG-1 epitope peptide region was strongly conserved among different types, the different types of RG-1 had different immunogenicity. Therefore, the immune activity of a chimeric protein vaccine constructed with 17-36 homologous polypeptide selected from any type of L2 cannot be expected.
In another aspect, the HPV16 cVLP vaccine study reported by Schellenbacher and Wang showed that when inserting a type 16 RG-1 epitope peptide into the surface region of a type 16 L1 VLP vector, due to the difference in the flanking sequence, the insertion site and insertion method of the type 16 RG-1 core epitope peptide sequence, the immune activity of the multiple different type 16 RG1-cVLPs obtained was significantly different. Among them, the cVLP with insertion of type 16 RG-1 into the DE loop region of type 16 L1 had the best activity, and the cVLP with insertion of type 16 RG-1 core sequence into the h4 region of type 16 L1 had the poorest activity. In addition, Chen and Boxus both reported the cVLP of type 33 RG-1, but different vectors, HPV16 L1 VLP and 18 L1 VLP were used respectively. Although both reports chose the DE loop as the insertion site, but the insertion region differed by 1 amino acid, and the epitope peptide length differed by 2 amino acids. The two type 33 RG1-cVLPs induced very significantly different activity of the type 33 RG-1-dependent cross-neutralizing antibodies. Type 33 RG1-cVLP antiserum could cross-neutralize at least 12 types (2 types of which had a titer >1000), while type 33 RG1-18cVLP antiserum only cross-neutralized 7 types, of which 6 types had a much lower neutralization titer (4 types of which had a titer <100) than the 33RG1-16cVLP antiserum.
Therefore, there is a current need to develop a vaccine based on HPV L1 and HPV L2 chimeric proteins that can produce high-titer neutralizing antibodies against more types of HPV viruses.
In order to solve the above technical problems, the inventors selected a variety of different lengths of type 59 RG-1 epitope peptides for research on HPV cVLPs. The results showed that the HPV type 18 cVLP obtained in the present invention had very strong immunogenicity, and induced serum neutralizing antibodies that could neutralize multiple types of HPV of the α7 subgenus at high titer.
The inventors performed comparative analysis of the neutralization activity of 8 different types of RG-1 epitope immune serum in Example 1. The inventors unexpectedly found that the immune serum of type 59 RG-1 epitope peptide could cross-neutralize at least 17 types, in particular, the titers of neutralizing HPV type 45, 59 and 16 were all above 103. It had the best activity of neutralizing the high-risk HPV types of the α7 subgenus reported so far, and the cross-neutralization activity against HPV16 was comparable to 16RG-1, currently reported as having a relatively stronger immunogenicity.
In view of this, the object of the present invention is to provide a human papillomavirus chimeric protein for the preparation of a vaccine for the prevention of papillomavirus infection and infection-induced diseases.
The present invention is based on the following unexpected findings of the inventors: the insertion of HPV type 59 L2 protein polypeptide into the surface region of the full-length or truncated HPV type 18 L1 protein can improve the immunogenicity of HPV type 59 L2 protein polypeptide. The obtained chimeric protein can be expressed at a high level in an E. coli or insect cell expression system. The chimeric protein can be assembled into VLP, and can induce a broad-spectrum protective immune response against multiple types of HPVs from different genera/subgenera. Relevant experimental results are provided in the examples herein.
Based on the above object, in one aspect, the present invention provides a human papillomavirus chimeric protein, the backbone of which is a HPV18 L1 protein or a mutant of the HPV18 L1 protein, and the backbone is chimeric with at least one polypeptide from a HPV type 59 L2 protein.
That is, in a first aspect of the present invention, the present invention provides a human papillomavirus chimeric protein comprising or consisting of a HPV type 18 L1 protein or a mutant of the HPV type 18 L1 protein, and a polypeptide from a HPV type 59 L2 protein inserted into the surface region of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein, wherein the amino acid sequence of the HPV type 18 L1 protein is as shown in SEQ ID No. 1, and the amino acid sequence of the HPV type 59 L2 protein is as shown in SEQ ID No. 2.
In a preferred embodiment of the human papillomavirus chimeric protein according to the present invention, the mutant of the HPV type 18 L1 protein is a protein obtained by truncating 0-8 amino acids at N-terminus and/or truncating 0-32 amino acids at C-terminus of the HPV type 18 L1 protein.
In a preferred embodiment of the human papillomavirus chimeric protein according to the present invention, the mutant of the HPV type 18 L1 protein is selected from the group consisting of:
In a preferred embodiment of the human papillomavirus chimeric protein according to the present invention, the polypeptide from the HPV type 59 L2 protein is selected from any continuous fragment of 8-33 amino acids in the region of amino acids 1-50 as shown in SEQ ID No. 2. Preferably, the polypeptide from the HPV type 59 L2 protein is a HPV type 59 L2 protein RG-1 epitope peptide or a mutant epitope peptide thereof. Further preferably, the polypeptide from HPV type 59 L2 protein consists of an amino acid sequence selected from the group consisting of amino acids 17 to 32 as shown in SEQ ID No. 2, amino acids 16 to 35 as shown in SEQ ID No. 2, amino acids 17 to 37 as shown in SEQ ID No. 2, amino acids 16 to 37 as shown in SEQ ID No. 2, and a sequence with extension or truncation of 1 to 7 amino acids at N-terminus and/or C-terminus of the above amino acid sequences.
Most preferably, the amino acid sequence of the polypeptide from HPV type 59 L2 protein is as shown in SEQ ID No. 3, SEQ ID No. 4, SEQ ID No. 5 or SEQ ID No. 6.
Optionally, the polypeptide from HPV type 59 L2 protein is a polypeptide obtained by extending or truncating 1-7 amino acids at N-terminus and/or extending or truncating 1-7 amino acids at C-terminus of the amino acid sequence shown in SEQ ID No. 3.
Optionally, the polypeptide from HPV type 59 L2 protein can further be a polypeptide with greater than 60%, preferably greater than 70%, preferably greater than 80%, greater than 90%, and even more preferably greater than 95% of sequence identity with the amino acid sequence as shown in SEQ ID No. 3, SEQ ID No. 4, SEQ ID No. 5 or SEQ ID No. 6.
In a preferred embodiment of the human papillomavirus chimeric protein according to the present invention, the HPV type 18 L1 protein can be from, for example but not limited to, the L1 proteins from HPV18 variant strains, such as ATL15214.1, ATL14646.1, ARS43458.1, ARS43428.1, ARS43449.1, AGU90430.1 in the NCBI database. Preferably, the amino acid sequence of the HPV type 18 L1 protein is as shown in SEQ ID No. 1.
In a preferred embodiment of the human papillomavirus chimeric protein according to the present invention, the polypeptide from the HPV type 59 L2 protein is inserted into the surface region of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein, preferably inserted into the DE loop and/or h4 region of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein. More preferably, the polypeptide from the HPV type 59 L2 protein is inserted between amino acids 134 and 135, or between amino acids 137 and 138, or between amino acids 432 and 433, or between amino acids 434 and 435 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein by direct insertion, alternatively inserted into the region of amino acids 121 to 124, or the region of amino acids 131 to 138, or the region of amino acids 431 to 433, or the region of amino acids 432 to 435 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein by non-isometric substitution.
As used herein, the term “direct insertion” refers to the insertion of a selected peptide fragment between two adjacent amino acids. For example, direct insertion between amino acids 134 and 135 of SEQ ID No. 1 refers to the direct insertion of the selected peptide fragment between amino acids 134 and 135 of SEQ ID No. 1.
As used herein, the term “non-isometric substitution” refers to the insertion of a selected peptide fragment into the specified amino acid region after deleting the sequence of the specified amino acid region. For example, non-isometric substitution into the region of amino acids 121 to 124 of SEQ ID No. 1 refers to the insertion of the selected peptide fragment between amino acids 121 and 124 of SEQ ID No. 1 after deleting amino acids 122 to 123 of SEQ ID No. 1. Optionally, in the embodiments of direct insertion or non-isometric substitution, the polypeptide from the HPV type 59 L2 protein comprises a linker of 1 to 3 amino acid residues in length at its N-terminus and/or C-terminus.
Optionally, the linker consists of any combination of amino acids selected from the group consisting of glycine (G), serine (S), alanine (A) and proline (P). Preferably, a G (glycine) P (proline) linker is selected for the N-terminus, and a P (proline) linker is selected for the C-terminus.
In a preferred embodiment of the papillomavirus chimeric protein of the present invention, in the embodiment of direct insertion, the amino acid sequence of the polypeptide from the HPV type 59 L2 protein is SEQ ID No. 4 or SEQ ID No. 5, the insertion site is between amino acids 137 and 138 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus, and the amino acid sequence of the obtained papillomavirus chimeric protein is as shown in SEQ ID No. 7, SEQ ID No. 8, SEQ ID No. 9 or SEQ ID No. 10.
In a preferred embodiment of the human papillomavirus chimeric protein of the present invention, in the embodiment of direct insertion, the amino acid sequence of the polypeptide from the HPV type 59 L2 protein is SEQ ID No. 3, the insertion site is between amino acids 432 and 433 or between amino acids 434 and 435 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus, and the amino acid sequence of the obtained papillomavirus chimeric protein is as shown in SEQ ID No. 11, SEQ ID No. 12, SEQ ID No. 13 or SEQ ID No. 14.
In a preferred embodiment of the human papillomavirus chimeric protein of the present invention, in the embodiment of direct insertion, the amino acid sequence of the polypeptide from the HPV type 59 L2 protein is the sequence as shown in SEQ ID No. 4 or SEQ ID No. 6 containing a GP linker at N-terminus and a P linker at C-terminus, the insertion site is between amino acids 134 and 135 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus, and the amino acid sequence of the obtained papillomavirus chimeric protein is as shown in SEQ ID No. 15, SEQ ID No. 16, SEQ ID No. 17 or SEQ ID No. 18.
In a preferred embodiment of the human papillomavirus chimeric protein of the present invention, in the embodiment of non-isometric substitution, after deleting the region of amino acids 132-137 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus, a polypeptide from the HPV type 59 L2 protein is inserted between the amino acids 131 and 138 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus, the polypeptide from HPV type 59 L2 protein has a glycine-proline linker added at its N-terminus, the amino acid sequence of the polypeptide from HPV type 59 L2 protein is as shown in SEQ ID No. 3, and the amino acid sequence of the obtained papillomavirus chimeric protein is as shown in SEQ ID No. 19 or SEQ ID No. 20.
In a preferred embodiment of the human papillomavirus chimeric protein of the present invention, in the embodiment of non-isometric substitution, after deleting the region of amino acids 122-123 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus, a polypeptide from the HPV type 59 L2 protein is inserted between the amino acids 121 and 124 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus. In the embodiment of the direct insertion, the amino acid sequence of the polypeptide from the HPV type 59 L2 protein is as shown in SEQ ID No. 3, and the amino acid sequence of the obtained papillomavirus chimeric protein is as shown in SEQ ID No. 21 or SEQ ID No. 22.
In a preferred embodiment of the human papillomavirus chimeric protein of the present invention, in the embodiment of non-isometric substitution, after deleting the amino acid 432 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus, a polypeptide from the HPV type 59 L2 protein is inserted between the amino acids 431 and 433 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus. In the embodiment of the direct insertion, the amino acid sequence of the polypeptide from the HPV type 59 L2 protein is as shown in SEQ ID No. 3, and the amino acid sequence of the obtained papillomavirus chimeric protein is as shown in SEQ ID No. 23 or SEQ ID No. 24.
In a preferred embodiment of the human papillomavirus chimeric protein of the present invention, in the embodiment of non-isometric substitution, after deleting the amino acids 433-434 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus, a polypeptide from the HPV type 59 L2 protein is inserted between the amino acids 432 and 435 of the HPV type 18 L1 protein or the mutant of the HPV type 18 L1 protein with 32-amino acid truncation at C-terminus. In the embodiment of the direct insertion, the amino acid sequence of the polypeptide from the HPV type 59 L2 protein is as shown in SEQ ID No. 3, and the amino acid sequence of the obtained papillomavirus chimeric protein is as shown in SEQ ID No. 25 or SEQ ID No. 26.
In a preferred embodiment of the human papillomavirus chimeric protein of the present invention, the polypeptide as shown in SEQ ID No. 4 is inserted between amino acids 137 and 138 of the mutant of the HPV type 18 L1 protein by direct insertion, and the mutant of the HPV type 18 L1 protein is selected from the group consisting of;
In another aspect, the present invention relates to a polynucleotide encoding the above papillomavirus chimeric protein.
The present invention also provides a vector comprising the above polynucleotide, as well as a cell comprising the vector.
The polynucleotide sequence encoding the above papillomavirus chimeric protein of the present invention is suitable for different expression systems. Optionally, these nucleotide sequences are whole-gene optimized with E. coli codons and can be expressed at high levels in an E. coli expression system: alternatively, they are whole-gene optimized with insect cell codons and can be expressed at high levels in an insect cell expression system.
The present invention also provides a polymer, preferably, the polymer is a papillomavirus chimeric pentamer or chimeric virus-like particle comprising or formed by the above papillomavirus chimeric protein.
The present invention also provides use of the above papillomavirus chimeric protein, the papillomavirus chimeric pentamer or the papillomavirus chimeric virus-like particle in the preparation of a vaccine for the prevention of papillomavirus infection and/or papillomavirus infection-induced diseases, preferably, the papillomavirus infection-induced diseases include but are not limited to cervical, vaginal, vulval, penile, perianal, oropharyngeal, tonsil and oral cancers:
The present invention also provides a vaccine for the prevention of papillomavirus infection and infection-induced diseases, comprising the above papillomavirus chimeric pentamer or chimeric virus-like particle, an adjuvant, as well as an excipient or carrier for vaccines, preferably further comprising at least one virus-like particle or chimeric virus-like particle of mucosa-tropic and/or skin-tropic HPVs. Wherein, the content of these virus-like particles is an effective amount that can separately induce a protective immune response.
Optionally, the adjuvant is an adjuvant for human use.
According to the present invention, the term “insect cell expression system” includes insect cell, recombinant baculovirus, recombinant Bacmid and expression vector. Among them, the insect cell is derived from commercially available cells, the examples of which are listed here but are not limited to: Sf9, Sf21, High Five.
According to the present invention, the term “prokaryotic expression system” includes but is not limited to E. coli expression system. Wherein, the expression host bacteria are derived from commercially available strains, the examples of which are listed here but are not limited to: BL21 (DE3), BL21 (DE3) plysS, C43 (DE3), Rosetta-gami B (DE3).
According to the present invention, examples of the term “full-length HPV type 18 L1 protein” include, but are not limited to, full-length L1 protein with a length equal to the protein No. ATL15070.1 in the NCBI database.
The gene fragment of “truncated HPV type 18 L1 protein” means that it has deletion of nucleotides encoding 1 or more amino acids at its 5′ end and/or 3′ end compared to the gene of wild-type HPV type 18 L1 protein, wherein the full-length sequence of “wild-type HPV type 18 L1 protein” is for example, but is not limited to, the following sequences in the NCBI database: ATL15214.1, ATL14646.1, ARS43458.1, ARS43428.1, ARS43449.1, AGU90430.1, etc.
According to the present invention, the term “excipient or carrier for vaccines” refers to that selected from one or more of the following, including but not limited to pH adjuster, surfactant and ionic strength enhancer. For example, the pH adjuster is for example but not limited to phosphate buffer. The surfactant includes cationic, anionic or nonionic surfactant, and is for example but not limited to polysorbate 80 (Tween-80). The ionic strength enhancer is for example but not limited to sodium chloride.
According to the present invention, the term “adjuvant for human use” refers to an adjuvant that can be applied clinically to the human body, including various adjuvants that have been approved and may be approved in the future, for example, but not limited to, aluminum adjuvant, MF59 and various forms of adjuvant compositions.
According to the present invention, the vaccine of the present invention can be in a patient-acceptable form, including but not limited to oral administration or injection, preferably injection.
According to the present invention, the vaccine of the present invention is preferably used in a unit dosage form, wherein the dose of protein virus-like particles in the unit dosage form is 5 μg to 100 μg, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 μg, as well as the range between any two of the above values, preferably 30 μg to 60 μg.
The present invention will be further illustrated below by the following non-limiting examples. It is well known to those skilled in the art that many modifications can be made to the present invention without departing from the spirit of the present invention, and such modifications also fall within the scope of the present invention. The following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention, as the embodiments are necessarily diverse. The terms used in the present specification are intended only to describe particular embodiments but not as limitations. The scope of the present invention has been defined in the appended claims.
Unless otherwise specified, all the technical and scientific terms used in the present specification have the same meaning as those generally understood by those skilled in the technical field to which the present application relates. Preferred methods and materials of the present invention are described below; but any method and material similar or equivalent to the methods and materials described in the present specification can be used to implement or test the present invention. Unless otherwise specified, the following experimental methods are conventional methods or methods described in product specifications. Unless otherwise specified, the experimental materials used are easily available from commercial companies. All published literatures referred to in the present specification are incorporated here by reference to reveal and illustrate the methods and/or materials in the published literatures.
HPV35, -39, -51, -53, -56, -59, -68, -82 RG-1 epitope peptides were synthesized using chemical synthesis, and the sequences of the epitope peptides were as shown in Table 1. The polypeptides were synthesized by GL Biochem (Shanghai) Co., Ltd. In order to improve the immunogenicity of the synthetic peptides, each synthetic peptide was coupled with keyhole limpet hemocyanin (KLH) after activation of carboxyl group by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC, CAS No. 25952-53-8). New Zealand white rabbits weighing 2.0-2.5 kg were randomly divided into groups, 2-4 rabbits per group. Four days before immunization, 15 mg of inactivated DH5a (PBS containing 0.5% v/v formaldehyde, treated at 37° C. for 24-48 h) thoroughly mixed with an equal volume of Freund's complete adjuvant was injected subcutaneously at multiple sites on the back for immunostimulation. The first immunization was performed by subcutaneous injection of 1 mg of KLH-polypeptide thoroughly mixed with an equal volume of Freund's complete adjuvant at multiple sites on the back and inner thigh. Booster immunization was performed for 4 times at an interval of 2 weeks, and the antigen of the booster immunization was 0.5 mg of KLH-polypeptide thoroughly mixed with an equal volume of Freund's incomplete adjuvant. Blood was collected 2 weeks after the last immunization and serum was isolated.
Seventeen HPV pseudoviruses were used to detect the titers of neutralizing antibodies in the immune serum, and the results were shown in Table 2. The 59RG-1 epitope peptide had the best immune activity, and its antiserum could neutralize all 17 types used for detection, of which the titers of neutralizing antibodies of HPV45, -59, -16 were all above 103, and the titers of neutralizing antibodies of HPV5, -31, -18, -39, -68, -57 were between 500 and 1000. It was worth noticing that the 59RG-1 epitope peptide antiserum had high levels of neutralizing antibodies against the five α7-HPV used for detection.
Methods of polypeptide synthesis, pseudovirus preparation and pseudoviral neutralization experiments were all publicly available, for example, the patents CN 104418942A and 108676057A.
There were 26 chimeric L1 proteins, namely:
The chimeric protein genes optimized with E. coli codons were digested by NdeI/XhoI and inserted into the commercial expression vector pET22b (produced by Novagen), respectively. The chimeric protein genes optimized with insect cell codons were digested by BamHI/EcoRI and inserted into the commercial expression vector pFastBac1 (produced by Invitrogen), respectively. Expression vectors comprising the chimeric protein genes were obtained. There were a total of 16 expression vectors for E. coli, namely: pET22b-18L1DE137-138/59dES, pET22b-18L1DE137-138/59dE, pET22b-18L1h4432-433/59dE, pET22b-18L1h4434-435/59dE, pET22b-18L1DE134-135/59dES, pET22b-18L1DE134-135/59dE, pET22b-18L1DE131-138/59dE, pET22b-18L1DE121-124/59dE, pET22b-18L1h4431-433/59dE, pET22b-18L1h4432-435/59dE, pET22b-18L1DE137-138/59dES-mut1, pET22b-18L1DE137-138/59dES-mut3, pET22b-18L1DE137-138/59dES-mut5, pET22b-18L1DE137-138/59dES-mut2, pET22b-18L1DE137-138/59dES-mut4, pET22b-18L1DE137-138/59dES-mut6. There were a total of 16 expression vectors for insect cells, namely: pFastBac1-18L1ΔCDE137-138/59dES, pFastBac1-18L1ΔCDE137-138/59dE, pFastBac1-18L1ΔCh4432-433/59dE, pFastBac1-18L1ΔCh4434-435/59dE, pFastBac1-18L1ΔCDE134-135/59dE, pFastBac1-18L1ΔCDE134-135/59dES, pFastBac1-18L1ΔCDE121-124/59dE, pFastBac1-18L1ΔCDE131-138/59dE, pFastBac1-18L1ΔCh4432-435/59dE, pFastBac1-18L1ΔCh4431-433/59dE, pFastBac1-18L1DE137-138/59dES-mut2, pFastBac1-18L1DE137-138/59dES-mut1, pFastBac1-18L1DE137-138/59dES-mut3, pFastBac1-18L1DE137-138/59dES-mut4, pFastBac1-18L1DE137-138/59dES-mut5, pFastBac1-18L1DE137-138/59dES-mut6. The above methods of enzyme digestion, ligation and construction of clones were all well known, for example, the patent CN 101293918 B.
The amino acid sequences of the polypeptides used in the present invention were shown as follows:
The nucleotide sequences encoding the chimeric proteins of the present invention were shown as follows:
Recombinant expression vectors comprising the chimeric L1 genes, namely pFastBac1-18L1ΔCDE137-138/59dE, pFastBac1-18L1ΔCh4434-435/59dE, pFastBac1-18L1ΔCDE134-135/59dE, pFastBac1-18L1ΔCDE121-124/59dE, pFastBac1-18L1ΔCh4432-435/59dE, pFastBac1-18L1DE137-138/59dES-mut1, pFastBac1-18L1DE137-138/59dES-mut2, pFastBac1-18L1DE137-138/59dES-mut3, pFastBac1-18L1DE137-138/59dES-mut4, pFastBac1-18L1DE137-138/59dES-mut5, pFastBac1-18L1DE137-138/59dES-mut6, were used to transform E. coli DH10Bac competent cells, which were screened to obtain recombinant Bacmids. Then the recombinant Bacmids were used to transfect Sf9 insect cells so as to pFastBac1-18L1ΔCDE137-138/59dES, pFastBac1-18LΔCh4432-433/59dE, pFastBac1-18L1ΔCDE134-135/59dES, pFastBac1-18L1ΔCDE131-138/59dE, pFastBac1-18L1ΔCh4431-433/59dE, amplify recombinant baculoviruses within the Sf9 cells. Methods of screening of recombinant Bacmids and amplification of recombinant baculoviruses were all well known, for example, the patent CN 101148661 B.
Sf9 cells were inoculated with the recombinant baculoviruses of the 16 chimeric L1 genes to express the chimeric L1 proteins. After incubation at 27° C. for about 88 h, the fermentation broth was collected and centrifuged at 3,000 rpm for 15 min. The supernatant was discarded, and the cells were washed with PBS for use in expression identification and purification. Methods of infection and expression were publicly available, for example, the patent CN 101148661 B.
Recombinant expression vectors comprising the chimeric L1 genes, namely pET22b-18L1DE137-138/59dES, pET22b-18L1DE137-138/59dE, pET22b-18L1h4432-433/59dE, pET22b-18L1h4434-435/59dE, pET22b-18L1DE134-135/59dES, pET22b-18L1DE134-135/59dE, pET22b-18L1DE131-138/59dE, pET22b-18L1DE121-124/59dE, pET22b-18L1h4431-433/59dE, pET22b-18L1h4432-435/59dE, pET22b-18L1DE137-138/59dES-mut1, pET22b-18L1DE137-138/59dES-mut2, pET22b-18L1DE137-138/59dES-mut3, pET22b-18L1DE137-138/59dES-mut4, pET22b-18L1DE137-138/59dES-mut5, pET22b-18L1DE137-138/59dES-mut6, were used to transform E. coli BL21 (DE3).
Single clones were picked and inoculated into 3 ml of LB medium containing ampicillin and incubated at 37° C. overnight. The bacterial fluid cultured overnight was added to LB medium at a ratio of 1:100 and incubated at 37° C. for about 3 h. When the OD600 reached between 0.8-1.0, IPTG was added to a final concentration of 0.5 μM, and the bacterial fluid was incubated at 16° C. for about 12 h and collected.
1×106 cells expressing the different chimeric L1 proteins described in Examples 4 and 5 respectively were collected and resuspended in 200 μl of PBS solution. 50 μl of 6× loading buffer was added and the samples were denatured at 75° C. for 8 minutes. 10 μl of sample was used for SDS-PAGE electrophoresis and Western blot identification, respectively. The results were as shown in
1×106 cells expressing the 18L1 backbone protein with 32-amino acid truncation at C-terminus, as well as cells expressing the chimeric L1 proteins with the 18L1 with 32-amino acid truncation at C-terminus as backbone, or with the 6 types of 18L1 mutants as backbone, respectively, were collected and resuspended in 200 μl of PBS solution. The cells were disrupted by ultrasonic disruption (Ningbo Scientz Ultrasonic Cell Disruptor, 2 #probe, 100 W, ultrasound 5 s, interval 7 s, total time 3 min) and centrifuged at a high speed of 12,000 rpm for 10 minutes. The lysed supernatant was collected and the L1 content in the supernatant was detected by sandwich ELISA, which was well known, for example, the patent CN104513826A.
Microtiter plates were coated with HPV18 L1 monoclonal antibodies prepared by the inventor at 80 ng/well by overnight incubation at 4° C. The plate was blocked with 5% BSA-PBST at room temperature for 2 h and washed 3 times with PBST. The lysed supernatant was subjected to 2-fold serial dilution with PBS. The HPV18L1 VLP standard was also subjected to serial dilution from a concentration of 2 μg/ml to 0.0625 μg/ml. The diluted samples were added to the plate respectively at 100 μl per well and incubated at 37° C. for 1 h. The plate was washed 3 times with PBST, and 1:3000 diluted HPV18L1 rabbit polyclonal antibody was added at 100 μl per well and incubated at 37° C. for 1 h. The plate was washed 3 times with PBST, and 1:3000 diluted HRP-labeled goat anti-mouse IgG (1:3000 dilution, ZSGB-Bio Corporation) was added and incubated at 37° C. for 45 minutes. The plate was washed 5 times with PBST, and 100 μl of OPD substrate (Sigma) was added to each well for chromogenic reaction at 37° C. for 5 minutes. The reaction was stopped with 50 μl of 2 M sulfuric acid, and the absorbance at 490 nm was determined. The concentrations of HPV18L1 protein and 18L1 chimeric proteins in the lysed supernatant were calculated according to the standard curve.
The results were as shown in Table 3. The expression amounts of 18L1ΔCDE134-135/59dES, 18L1ΔCDE137-138/59dES, 18L1ΔCh4431-433/59dE and 18L1ΔCh4432-435/59dE of the present invention were very high, comparable to that of the HPV18L1 backbone. In addition, the expression amounts of the chimeric proteins with the 18L1 mutants with amino acid substitutions at C-terminus as backbone, namely 18L1DE137-138/59dES-mut1, 18L1DE137-138/59dES-mut4, 18L1DE137-138/59dES-mut5, were all higher than that of the HPV18L1 backbone and the corresponding C-terminal truncated chimeric protein.
An appropriate amount of cell fermentation broth of chimeric L1 was collected and the cells were resuspended with 10 ml of PBS. PMSF was added to a final concentration of 1 mg/ml. The cells were ultrasonically disrupted (Ningbo Scientz Ultrasonic Cell Disruptor, 6 #probe, 200 W, ultrasound 5 s, interval 7 s, total time 10 min) and the disrupted supernatant was collected for purification. The purification steps were carried out at room temperature. 4% β-mercaptoethanol (w/w) was added to the lysate to disaggregate VLP. Then the samples were filtered with 0.22 μm filters, followed by sequential purification with DMAE anion exchange chromatography or CM cation exchange chromatography (20 mM Tris, 180 mM NaCl, 4% β-ME, elution at pH 7.9), TMAE anion exchange chromatography or Q cation exchange chromatography (20 mM Tris, 180 mM NaCl, 4% β-ME, elution at pH 7.9) and hydroxyapatite chromatography (100 mM NaH2PO4, 30 mM NaCl, 4% β-ME, elution at pH 6.0). The purified product was concentrated and buffer (20 mM NaH2PO4, 500 mM NaCl, pH 6.0) exchange was performed using Planova ultrafiltration system to prompt VLP assembly. The above purification methods were all publicly available, for example, the patents CN 101293918 B, CN 1976718 A, etc.
Severe aggregation was found for 18L1h4431-433/59dE, 18L1h4432-435/59dE, 18L1ΔCh4431-433/59dE and 18L1ΔCh4432-435/59dE during the assembly of pure chimeric proteins, while aggregation was not observed for other chimeric proteins after assembly. The assembled chimeric protein solutions were subjected to DLS particle size analysis (Zetasizer Nano ZS 90 Dynamic Light Scattering Analyzer, Malvern), and the results were as shown in Table 4. Among them, the DLS analysis plots of 18L1ΔCDE134-135/59dE, 18L1ΔCDE134-135/59dES, 18L1ΔCDE137-138/59dE, 18L1ΔCDE137-138/59dES were as shown in
The chimeric proteins were purified separately according to the chromatographic purification method described in Example 8. The assembled chimeric proteins were prepared on copper mesh, stained with 1% uranium acetate, fully dried and then observed using JEM-1400 electron microscope (Olympus). The results showed that the chimeric proteins expressed by both E. coli and insect cells could be assembled into cVLPs with a diameter of about 50 nm. Among them, the electron microscopy images of 18L1ΔCDE134-135/59dE, 18L1ΔCDE134-135/59dES, 18L1ΔCDE137-138/59dE, 18L1ΔCDE137-138/59dES cVLPs were as shown in
4-6 weeks old BALB/c mice were randomly divided into groups, 5 mice per group, and 10 μg cVLP in combination with 50 μg Al(OH); and 5 μg MPL adjuvant were used to immunize mice by subcutaneous injection at Weeks 0, 4, 7, 10 for a total of 4 times. Tail vein blood was collected 2 weeks after the 4th immunization and serum was isolated.
24 types of HPV pseudoviruses were used to detect the neutralizing antibody titers of the immune serum. The results showed that after immunizing mice with various cVLPs produced by E. coli and insect cell expression systems, the levels and neutralization range of the induced cross-neutralizing antibodies were different with each other. Among them, as shown in Table 5, the antiserum of 18L1ΔCDE134-135/59dES and 18L1ΔCDE137-138/59dES cVLPs expressed by insect cells could neutralize at least 23 types of pseudoviruses, and the immune serum of 18L1ΔCDE134-135/59dE and 18L1ΔCDE137-138/59dE cVLPs could neutralize at least 19 types of pseudoviruses. It was worth mentioning that the antiserum of 18L1ΔCDE134-135/59dES and 18L1ΔCDE137-138/59dES cVLP could neutralize all 6 α7-HPVs used for detection, in particular for 18L1ΔCDE137-138/59dES cVLP, the antibody titers to cross-neutralize α7-HPVs were all above 250, and it was the cVLP with the strongest cross-neutralization ability against α7-HPVs reported so far.
In addition, after immunizing mice with the above strategy, the cVLPs constructed with 18L1 mutants with 32-amino acid truncation at C-terminus in the present invention could also induce high levels of neutralizing antibodies. Among them, the level of each type of neutralizing antibody induced by 18L1DE137-138/59dES-mut4 was comparable to those induced by 18L1ΔCDE137-138/59dES. It was worth noticing that the HPV39 and HPV59 neutralizing antibody titers of 18L1DE137-138/59dES-mut4 immune serum were both greater than 103 (as shown in Table 5 and
Methods of pseudovirus preparation and pseudoviral neutralization experiments were all publicly available, for example, the patent CN 104418942A.
Number | Date | Country | Kind |
---|---|---|---|
202110002251.3 | Jan 2021 | CN | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/CN2021/120583 | 9/26/2021 | WO |