Patent Application
20210322530
The present application relates to a composition for preventing or treating Mycoplasma spp. infection, particularly to a composition for preventing or treating Mycoplasma synoviae.
Mycoplasma spp. is currently known as the smallest prokaryote capable of self-replicating extracellularly. They are spherical with a diameter of 0.3 to 0.9 μm, or filament-like with a length of 1 μm. As fastidious bacteria, they are difficult to culture and their growth rate is very slow. It is known that several types of Mycoplasma spp. are associated with a number of human or animal diseases.
Studies have shown that poultry can be infected with dozens of types of Mycoplasma spp., including Mycoplasma synoviae, a disease-causing microorganism listed in the OIE (World Organization for Animal Health) document regarding Mycoplasma diseases. Thus, Mycoplasma synoviae is an important pathogen to be taken into consideration for the prevention or treatment in poultry.
Mycoplasma synoviae may cause synovitis or arthritis. Mycoplasma synoviae infection in broiler chicken will result in lower feed efficiency, higher mortality rate and poultry carcasses condemnation rate. Mycoplasma synoviae infection in breeder chickens and layer chickens will result in lower egg production rate and higher embryo mortality rate. Mycoplasma synoviae infection in chickens will be more likely to result in secondary infection caused by viral or bacterial pathogens, causing significant financial losses for poultry farmers. Manufacturers of veterinary vaccines worldwide have developed live and inactivated vaccines for the poultry industry; however, culturing Mycoplasma synoviae is difficult and costly. Therefore, there remains a need in this field for vaccines that can be used for preventing and treating Mycoplasma synoviae infection.
Accordingly, one object of the present disclosure is to provide antigens suitable for being used in Mycoplasma synoviae subunit vaccines, thereby producing subunit vaccines to reduce disease prevention costs.
Another object of the present disclosure is to provide a subunit vaccine with multiple antigens that can be used for preventing and treating Mycoplasma synoviae infection. Such vaccine provides better protection than single-antigen vaccines.
To this end, the present disclosure provides a composition for preventing Mycoplasma synoviae infection, comprising: active ingredients, which comprise Tuf, NOX, MS53-0285 and a combination thereof, wherein said Tuf has a sequence of SEQ ID NO: 01, said NOX has a sequence of SEQ ID NO: 02, and said MS53-0285 has a sequence of SEQ ID NO: 03; and a pharmaceutically acceptable adjuvant.
Preferably, said active ingredients are at least two proteins selected from the group consisting of: Tuf, NOX and MS53-0285. More preferably, said active ingredients include Tuf, NOX and MS53-0285.
More preferably, said active ingredients have a concentration of 40 to 900 μg/mL based on the total volume of said composition.
Possibly, said pharmaceutically acceptable adjuvant is a complete or incomplete Freund's adjuvant, alumina gel, surfactant, polyanion adjuvant, peptide, oil emulsion, or a combination thereof.
Preferably, said composition further comprises a pharmaceutically acceptable additive. Possibly, said pharmaceutically acceptable additive is a solvent, stabilizer, diluent, preservative, antibacterial agent, antifungal agent, isotonic agent, absorption delaying agent, or a combination thereof.
Preferably, said symptoms caused by Mycoplasma synoviae infection are tracheal lesion, air sac lesion, arthritis or a combination thereof.
Preferably, said symptoms caused by Mycoplasma synoviae infection are at least arthritis provided that said active ingredients include Tuf. Preferably, said symptoms caused by Mycoplasma synoviae infection are at least air sac lesion provided that said active ingredients include NOX and MS53-0285, or a combination thereof. More preferably, said symptoms caused by Mycoplasma synoviae infection are at least tracheal lesion provided that said active ingredients include MS53-0285.
Preferably, said symptoms caused by Mycoplasma synoviae infection are tracheal lesion, air sac lesion and arthritis provided that said active ingredients comprise Tuf, NOX and MS53-0285.
The present disclosure also provides an expression vector, comprising: a nucleotide sequence of SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6 or a combination thereof; expression elements including a promoter and a ribosome binding site; and a fusion partner sequence.
The present disclosure further provides an expression vector, comprising: a nucleotide sequence translated as a protein of Tuf, NOX, MS53-0285 or a combination thereof, wherein said Tuf has a sequence of SEQ ID NO: 01, said NOX has a sequence of SEQ ID NO: 02, and said MS53-0285 has a sequence of SEQ ID NO: 03; expression elements including a promoter and a ribosome binding site; and fusion partner sequences.
Preferably, said fusion partner is DsbC from E. coli, MsyB from E. coli, FklB from E. coli or a combination thereof.
Preferably, said expression vector has a sequence of SEQ ID NO: 07, SEQ ID NO: 08, or SEQ ID NO: 09.
The present disclosure further provides the use of protein for producing a composition for preventing and treating Mycoplasma synoviae infection, wherein said protein comprises Tuf, NOX, MS53-0285 or a combination thereof; wherein said Tuf has a sequence of SEQ ID NO: 01, said NOX has a sequence of SEQ ID NO: 02, and said MS53-0285 has a sequence of SEQ ID NO: 03.
In view of the foregoing, the present disclosure discloses antigens used for preventing and treating Mycoplasma synoviae infection and as active ingredients for subunit vaccines. The results of the present disclosure not only provide a novel option for preventing Mycoplasma synoviae infection, but also discloses that “cocktail” subunit vaccines combining two or more antigens (i.e. containing two or more antigens as active ingredients) have a better immunity-inducing effect.
The development results of the present disclosure prove that Tuf, NOX and MS53-0285 can be used as active ingredients in subunit vaccines for preventing and treating Mycoplasma synoviae infection. The phrase “preventing and treating Mycoplasma synoviae infection” herein refers to reduce infection level of Mycoplasma synoviae in poultry, such as alleviating diseases caused by Mycoplasma synoviae infection. Said diseases include but not limited to tracheal lesion, air sac lesion or arthritis (such as footpad swelling or footpad inflammation). From a scientific point of view, it is impossible to demonstrate whether the subjects are not infected with said disease-causing microorganisms at all. Therefore, it can be understood by a person having ordinary skill in the art that in the field of disease prevention, the act of “preventing and treating” does not intend to keep the subject from being infected with any of said disease-causing microorganisms.
In one aspect, the present disclosure relates to a composition for preventing and treating Mycoplasma synoviae infection. In one preferred embodiment, the composition is a subunit vaccine. In one preferred embodiment, the composition comprises Tuf as active ingredients, and said Tuf has a sequence of SEQ ID NO: 01. In another preferred embodiment, the composition comprises NOX as active ingredients, and said NOX has a sequence of SEQ ID NO: 02. In yet another preferred embodiment, the composition comprises MS53-0285 as an active ingredient, and said MS53-0285 has a sequence of SEQ ID NO: 03.
A person having ordinary skill in the art can readily understand that as long as the antigen determinants on said proteins are not affected, said amino acid sequence can be altered to a certain degree and still falls within the scope of the present invention. For example, a few amino acids in said sequence may be altered by a person having ordinary skill in the art, but the immunity-inducing effect as described herein can still be generated. Alternatively, based on the needs of a person having ordinary skill in the art, other sequences may be added into said sequence to facilitate production without affecting the immunity-inducing effect as described herein. In this regard, the modified sequence should still falls within the scope of the present invention.
In one embodiment, when said active ingredients include Tuf, said symptoms caused by Mycoplasma synoviae infection are at least arthritis. Nevertheless, the fact that said active ingredients include Tuf does not suggest that they are ineffective in preventing other diseases, but rather that they are more effective in preventing arthritis.
In one embodiment, when said active ingredients include NOX, MS53-0285 or a combination thereof, said symptoms caused by Mycoplasma synoviae infection are at least air sac lesion. Nevertheless, the fact that said active ingredients include NOX, MS53-0285 or a combination thereof does not suggest that they are ineffective in preventing other diseases, but rather that they are more effective in preventing air sac lesion.
In one embodiment, when said active ingredients include MS53-0285, said symptoms caused by Mycoplasma synoviae infection are at least tracheal lesion. Nevertheless, the fact that said active ingredients include MS53-0285 does not suggest that they are ineffective in preventing other diseases, but rather that they are more effective in preventing tracheal lesion.
In one embodiment, when said active ingredients include Tuf, NOX and MS53-0285, said symptoms caused by Mycoplasma synoviae infection are at least tracheal lesion, air sac lesion and arthritis.
In another aspect, the present disclosure relates to a cocktail vaccine used for preventing or treating Mycoplasma synoviae infection. The cocktail vaccine as described herein contains two and more antigens. In a preferred embodiment, the cocktail vaccine as described herein contains two and more antigens from the same type of disease-causing microorganism. In general, combining two or more antigens in a single vaccine does not necessarily contribute synergistically to the immunity-inducing effect of the vaccine. Instead, it may lead to an unfavorable consequence that the immunity-inducing effects of two or more antigens offset each other. In terms of cost, even if the immunity-inducing effects of two or more antigens do no offset each other, it is not worthwhile combining these two or more antigens in a single vaccine when there is no synergistic effect.
In a preferred embodiment, the active ingredients of said cocktail are at least two proteins selected from the group consisting of the following proteins: Tuf, NOX and MS53-0285. More preferably, said active ingredients include Tuf, NOX and MS53-0285. In a possible embodiment, as long as the antigen determinants on the folding from said amino acid sequences are not destroyed, said active ingredients may be fusion proteins having any two or more of said amino acid sequences. In another possible embodiment, said cocktail vaccine uses said proteins that are independent of each other.
In a preferred embodiment, the composition of the present disclosure further comprises a pharmaceutically acceptable adjuvant and/or a pharmaceutically acceptable additive. Said pharmaceutically acceptable adjuvant is used for enhancing the immunity-inducing effect of active ingredients, maintaining the stability of active ingredients, and enhancing the safety of said composition when used as a vaccine. Said pharmaceutically acceptable adjuvant is, including without limitation, a complete or incomplete Freund's adjuvant, alumina gel, surfactant, polyanion adjuvant, peptide, oil emulsion, or a combination thereof. Said pharmaceutically acceptable additive may be, including without limitation, a solvent, stabilizer, diluent, preservative, antibacterial agent, antifungal agent, isotonic agent, absorption delaying agent, or a combination thereof.
In a possible embodiment, the composition of the present disclosure can be made into formulations that are administered orally, nasally, intravenously, intramuscularly or intraperitoneally. In a possible embodiment, the active ingredients in the composition of the present disclosure have a concentration of 40 to 900 μg/mL based on the total volume of said composition. In another possible embodiment, the active ingredients in the composition of the present disclosure have a concentration of 40 to 600 μg/mL based on the total volume of said composition. In the cocktail vaccine of the present invention, the concentration of said active ingredients is the total concentration of all the antigens contained in said cocktail vaccine. In one embodiment, for example, when the cocktail vaccine of the present disclosure contains said Tuf antigens and said NOX antigens as active ingredients, said “concentration of active ingredients” is the total of the concentration of said Tuf antigens and that of said NOX antigens. In another embodiment, when the cocktail vaccine of the present disclosure contains said Tuf antigens, said NOX antigens and said MS53-0285 as active ingredients, said “concentration of active ingredients” is the total of the concentration of said Tuf antigens, that of said NOX antigens, and that of MS53-0285 antigens.
On the other hand, an obstacle to express said active ingredients in prokaryotic expression systems is to purify the expressed active ingredients from the said prokaryotic expression systems. Recombinant proteins expressed in prokaryotic expression systems are typically non-soluble, thereby making the purification process more difficult and costly. In this regard, one advantage of the antigen expression vector of the present disclosure is the ability to express soluble recombinant antigens, thereby simplifying the purification process and reducing its costs.
Thus, in another aspect, the present disclosure relates to an expression vector, which is used for producing said Tuf, NOX or MS53-0285. The expression vectors of the present disclosure comprise nucleotide sequences, expression elements and fusion partner sequences. Said nucleotide sequences can be translated as Tuf, NOX, MS53-0285 or a combination thereof.
Said expression elements refer to elements required for initiating transcription and translation processes in the expression system. Said expression elements should at least include a promoter and a ribosome binding site. Preferably, said expression elements may further include: an operator, enhancer sequences for enhancing translation/transcription, or a combination thereof. In a preferred embodiment, said expression vector is used in an E. coli expression system, and said expression elements can be recognized by E. coli.
In a preferred embodiment, the research of the present disclosure has proved that DsbC from E. coli, MsyB from E. coli, FklB from E. coli, or a combination thereof is preferably used as a fusion partner for expression of said antigens of the present invention, thereby making the recombinant proteins produced in a prokaryotic expression system as soluble form. In a preferred embodiment, in order to facilitate the purification process, said expression vector may further comprise a sequence encoding His-tag, GST-tag or a combination thereof, so that the obtained recombinant proteins can be purified using a nickel ion affinity column or a glutathione affinity column.
In yet another aspect, the present disclosure relates to a use of composition, in which said Tuf, NOX or MS53-0285 are used, for preventing and treating Mycoplasma synoviae infection. No further elaboration is needed for said composition for preventing and treating Mycoplasma synoviae infection since it has been previously described.
The following examples describe the experiments carried out for the development of the present disclosure to further illustrate the features and advantages thereof. It should be understood that the examples listed below are merely exemplary of the invention, and should not be used to limit the scope of the claims.
Gene-specific primers are designed for various antigens (Table 1). A genomic DNA of Mycoplasma synoviae was used as a template and gene-specific primers were combined to amplify target genes.
TUFBAMHIF (SEQ ID NO: 10):
TUFSALIR (SEQ ID NO: 11):
NOXBAMHIF (SEQ ID NO: 12):
NOXSALIR (SEQ ID NO: 13):
MS53BAMHIF (SEQ ID NO: 14):
MS53SALIR (SEQ ID NO: 15):
1. Extracting Genomic DNA of Mycoplasma synoviae
2. Amplifying Target Genes Using Polymerase Chain Reaction (PCR)
3. Recovery and Cloning PCR Products
4. Site-Directed Mutagenesis of Nox Gene
Tm=81.5+0.41(% GC)−675/N−% mismatch,
where “% GC” is the percentage of G or C nucleotides in the primer; “N” is the length of the primer; and “% mismatch” is the percentage of mutated bases in the primer. The primers used for point mutation of nox gene are listed in Table 3 below, including NOXBAMHIF/NOXM2, NOXM1/NOXM4, NOXM3/NOXM6 and NOXM5/NOXSALIR.
5. Site-Directed Mutagenesis of Ms53-0285 Gene
Following the above operations, tuf gene (SEQ ID NO: 04), nox gene (SEQ ID NO: 05) and ms53-0285 gene (SEQ ID NO: 06) were obtained. They can be translated as Tuf (SEQ ID NO: 01), NOX (SEQ ID NO: 02) and MS53-0285 (SEQ ID NO: 03), respectively.
Plasmids having dsbC gene of E. coli were used as backbone for constructing Mycoplasma synoviae antigen expression plasmids. The construction processes of expression plasmids are as follows:
1. Construction of Tuf Expression Vector
2. Construction of NOX Expression Plasmid
3. Construction of MS53-0285 Expression Plasmid
The plasmids for expressing Mycoplasma synoviae antigens were transformed into E. coli BL21 (DE3), respectively. A single colony of the strain expressing the antigens was selected and inoculated in 12 mL of LB medium containing kanamycin (final concentration: 30 μg/mL). The resulting mixture was cultured overnight at 37° C. and at 180 rpm. Then, 10 mL of the liquid culture was added to 1 L of LB medium containing kanamycin (final concentration: 30 μg/mL) and was shake-cultured (37° C., 180 rpm) until OD600 reached about 0.4-0.6. 0.1 mM IPTG was then added at 28° C. to induce protein expression. After for 4 hours of induction, the culture was centrifuged (10,000×g, 10 minutes, 4° C.) and bacterial cell pellet was collected. The bacterial cell pellet was resuspended in 10 mL of phosphate buffer (20 mM sodium phosphate, 500 mM NaCl, pH 7.4) and was disrupted by ultrasonication. The suspension was centrifuged (30,966×g, 30 min) and the supernatant was collected. Finally, the supernatant was filtered through a filter membrane with 0.22 μM pore size. Protein electrophoresis was conducted to observe the expression status and solubility of the recombinant antigens.
Protein purification was then conducted using immobilized-metal ion affinity chromatography by way of the covalent bonding between His tag on the recombinant antigens and nickel ions or cobalt ions. The recombinant antigens were purified by ÄKTA prime plus (GE Healthcare, Sweden) equipped with 5 mL HiTrap™ Ni excel column (GE Healthcare, Sweden). First, said supernatant was introduced into HiTrap™ Ni excel column after the column was equilibrated with 25 mL of phosphate buffer solution. After the sample was fully introduced, 100 mL of a wash buffer solution containing 30 mM imidazole (20 mM sodium phosphate, 500 mM NaCl, 30 mM imidazole, pH 7.4) was used to wash the column to remove non-specific proteins adhered thereon. Finally, 150 mL of an elution buffer solution containing 250 mM imidazole (20 mM sodium phosphate, 500 mM NaCl, 250 mM imidazole, pH7.4) was used to wash off the recombinant antigens from the resin, wherein imidazole of high concentration can compete with the recombinant antigens for binding sites on the resin, thereby causing the recombinant antigens to be washed off. The purified antigen solution was put into Amico™ ultra-15 ultracel-30K centrifuge tube (Merck Millipore, USA) to be centrifuged (2,600×g) at 4° C. until it reached an appropriate volume, and was then stored at 4° C. for further use.
The result is shown in
4-week-old specific pathogen-free chickens (purchased from the Animal Drugs Inspection Branch of the Animal Health Research Institute, Council of Agriculture, Executive Yuan, Taiwan) were used and kept in animal house facilities at the inspection branch. Recombinant Mycoplasma synoviae antigens Tuf, NOX and MS53-0285 were mixed individually with a commercially available adjuvant MONTANIDE™ Gel 01 (Seppic) following the operations manual, so that the final dose of each single-antigen vaccine became 50 μg/0.5 mL. 0.5 mL of these single-antigen vaccines were administered subcutaneously in the back of the neck of 4-week-old chickens. Second vaccination was conducted to chickens reaching 6 weeks of age. After vaccination, the chickens were observed for two weeks. Blood samples were then collected and centrifuged (2,000×g, 4° C., 15 minutes) to obtain serum samples. Mycoplasma synoviae antibodies were assayed using a commercial kit (IDEXX Mycoplasma synoviae Antibody Test Kit).
The results are shown in Table 5 below and in
Next, 8-week-old chickens were challenged with Mycoplasma synoviae through tracheae and footpads. The challenge strain used was ATRI 2014 (hereinafter “MS-f1”), which was isolated from commercial native chicken farm in Taiwan. The challenge strain was cultured in Mycoplasma medium at 32° C. and at 75 rpm for 32 hours.
In trachea challenge, the chickens were held and a feeding tube was inserted into the trachea of the chickens. 1 mL of broth of challenge strain with 106 CCU was then injected using a syringe. Finally, the necks of the chickens were rubbed gently so that the broth could be spread out evenly. In footpad challenge, footpads were disinfected with alcohol wipes and 0.5 mL of broth of challenge strain with 103 CCU was injected therein using a needle. After challenge, blood samples were collected and serum was isolated to assess Mycoplasma synoviae-specific antibodies. Weight, footpad temperature and footpad thickness of the chickens at various time points were also recorded. At the end of the experiment, a dissection was performed to observe the symptoms of tracheae, air sac and footpad swelling among the chickens. Observed results were recorded following the diagnostic criteria for organ dysfunction as described in Table 6 below.
It could be observed from the footpad thickness of the chickens that the group of chickens administered with single-antigen vaccine had milder swelling than the positive group (see
Air sac lesion is another common type of infection as a result of Mycoplasma synoviae infection. Air sacs in healthy chicken should be transparent without being covered with discharges.
Chicken tracheae were further sectioned. H&E staining was performed to observe the changes of mucus thickness on tracheal rings. The results showed that mucosal infection could be effectively prevented among the vaccinated groups, compared to the non-vaccinated challenge chickens, by administering the single-antigen vaccine of the present invention, with MS53-0285 subunit vaccine being the most effective (
It can be understood from the above results that despite slight differences in efficacy, Tuf, NOX and MS53-0285 vaccines of the present disclosure are generally effective in alleviating symptoms induced by Mycoplasma synoviae.
4-week-old specific pathogen-free chickens (purchased from the Animal Drugs Inspection Branch of the Animal Health Research Institute, Council of Agriculture, Executive Yuan, Taiwan) were used and kept in animal house facilities at the inspection branch. Various combinations of antigens (Tuf+NOX, Tuf+MS53-0285, NOX+MS53-0285 and Tuf+NOX+MS53-0285) were mixed individually with commercially available adjuvants to obtain cocktail vaccines. Each antigen in each dose of vaccine (0.5 mL) was 50 μg.
0.5 mL of said recombinant-antigen vaccine was administered subcutaneously in the back of the neck of 4-week-old chickens. Second vaccination was conducted to chickens reaching 6 weeks of age. After vaccination, the chickens were observed for two weeks. Blood samples were then collected and centrifuged (2,000×g, 4° C., 15 minutes) to obtain serum samples. Mycoplasma synoviae-specific antibodies were detected using a commercial kit (IDEXX Mycoplasma synoviae Antibody Test Kit).
The results are shown in Table 7 below and in
Experiments 4-week-old specific pathogen-free chickens (purchased from the Animal Drugs Inspection Branch of the Animal Health Research Institute, Council of Agriculture, Executive Yuan, Taiwan) were used and kept in animal house facilities at the inspection branch. The recombinant antigens Tuf, NOX and MS53-0285 were mixed with a commercially available adjuvant MONTANIDE™ ISA 71 VG (Seppic) to obtain the cocktail vaccine of the present invention. Each antigen in each dose of vaccine (0.5 mL) was 50 μg. Said adjuvant was mixed with said antigens at a 7:3 mix ratio by weight. Given that the specific gravity of said adjuvant is about 0.816, the vaccine produced in this experiment contained approximately 0.37 mL of adjuvant.
0.5 mL of said recombinant-antigen vaccine was administered subcutaneously in the back of the neck of 4-week-old chickens. Second vaccination was conducted to chickens reaching 6 weeks of age. After vaccination, the chickens were observed for two weeks. Blood samples were then collected and centrifuged (2,000×g, 4° C., 15 minutes) to obtain serum samples. Mycoplasma synoviae-specific antibodies were detected using a commercial kit (IDEXX Mycoplasma synoviae Antibody Test Kit).
The results are shown in Table 8 below and in
Next, 8-week-old chickens were then challenged with Mycoplasma synoviae MS-f1 through tracheae and footpads. After the challenge, blood samples were collected and serum was isolated to assess Mycoplasma synoviae-specific antibodies. Weight, footpad temperature, and footpad thickness of each chicken at various time points were also recorded. At the end of the experiment, a dissection was performed to observe the symptoms of tracheae, air sac and footpad swelling among the chickens. Observed results were recorded following the diagnostic criteria for organ dysfunction as described in Table 6.
The results showed that the triple-antigen vaccine of the present disclosure could alleviate weight loss that occurred on infected chickens (
The recombinant antigens were mixed with a commercially available adjuvant MONTANIDE™ ISA 71 VG (Seppic) to formulate subunit vaccines having recombinant antigens at four concentrations: 150 μg, 100 μg, 50 μs and 20 μs per dose (0.5 mL), respectively. Said adjuvant was mixed with said antigens at a 7:3 mix ratio by weight. Given that the specific gravity of said adjuvant is about 0.816, the vaccine produced in this experiment contained approximately 0.37 mL of adjuvant. Groups were designed as shown in Table 10.
4-week-old specific pathogen-free chickens (purchased from the Animal Drugs Inspection Branch of the Animal Health Research Institute, Council of Agriculture, Executive Yuan, Taiwan) were used and kept in animal house facilities at the inspection branch. Said recombinant-antigen vaccine was administered to the chickens twice every two weeks for vaccination. Two weeks after vaccination, the chickens were challenged with Mycoplasma synoviae MS-f1 through tracheae and footpads. After challenge, blood samples were collected and serum was isolated to assess Mycoplasma synoviae-specific antibodies. Weight, footpad temperature, and footpad thickness of the chickens at various time points were also recorded. At the end of the experiment, a dissection was performed to observe the symptoms of air sac lesion among the chickens. Observed results were recorded following the diagnostic criteria for organ dysfunction as described in Table 5.
The results showed that the four doses of antigen vaccines used in this experiment could all induce antibody production in the chickens. In addition, the four doses that were tested in this experiment were all effective in alleviating symptoms regarding weight and footpad temperature (
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2017/108887 | 11/1/2017 | WO | 00 |
