ABSTRACT
OBJECTIVE: To prepare and purify the rabbit anti-TgMIC16 polyclonal antibody, so as to apply it in subcellular localization. METHODS: New Zealand white rabbits were immunized with purified recombinant TgMIC16 mixing with the same volume of Freund's adjuvant for three times, respectively. The rabbit serum was collected on the 14th day after the last immunization. The polyclonal antibody in rabbit serum was purified with Protein A affinity purification column. ELISA and Western blotting were used to detect the antibody titer and specificity of polyclonal antibody. The polyclonal antibody was used to the localization of TgMIC16 by the immunofluorescence method. RESULTS: Indirect ELISA showed that the antibody titer was 1â¶512 000. Western blotting showed that the recombinant TgMIC16 protein was recognized by the specific polyclonal antibody. IFA showed that TgMIC16 was located in the microneme of Toxoplasma gondii. CONCLUSIONS: The rabbit anti-TgMIC16 is prepared and purified, and successfully applied to immunofluorescence localization of TgMIC16 in T. gondii.
Subject(s)
Antibodies , Protozoan Proteins , Recombinant Proteins , Toxoplasma , Animals , Antibodies/isolation & purification , Antibody Specificity , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Protein Transport , Protozoan Proteins/immunology , Protozoan Proteins/metabolism , Rabbits , Recombinant Proteins/isolation & purification , Toxoplasma/metabolismABSTRACT
Toxoplasma gondii is an obligate intracellular protozoan that can invade all eukaryotic cells and infect all warm-blood animals, causing the important zoonosis toxoplasmosis. Invasion of host cells is the key step necessary for T. gondii to complete its life cycle and microneme proteins play an important role in attachment and invasion of host cells. Microneme protein 16 (TgMIC16) is a new protective protein in T. gondii and belongs to transmembrane microneme proteins (TM-MIC). The TM-MICs are released onto the parasite's surface as complexes capable of interacting with host cell receptors. In the present study, we expressed the TgMIC16 protein on the surface of Saccharomyce cerevisiae (pCTCON2-TgMIC16/EBY100) and evaluated it as a potential vaccine for BALB/c mice against challenge infection with the RH strain of T. gondii. We immunized BALB/c mice both orally and intraperitoneally. After three immunizations, the immune response was evaluated by measuring antibody levels, lymphocyte proliferative responses, percentages of CD4+ and CD8+ T lymphocytes, cytokine production, and the survival times of challenged mice. The results showed that the pCTCON2-TgMIC16/EBY100 vaccine stimulated humoral and cellular immune responses. In addition, mice immunized with the pCTCON2-TgMIC16/EBY100 vaccine showed increased survival times compared with non-immunized controls. In summary, TgMIC16 displayed on the cell surface of S. cerevisiae could be used as potential vaccine against toxoplasmosis.
Subject(s)
Antibodies, Protozoan/immunology , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Protozoan Proteins/immunology , Protozoan Vaccines/immunology , Toxoplasma/immunology , Toxoplasmosis/prevention & control , Administration, Oral , Animals , Antibodies, Protozoan/blood , Female , Humans , Immunization , Injections, Intraperitoneal , Male , Mice , Mice, Inbred BALB C , Protozoan Proteins/genetics , Protozoan Vaccines/therapeutic use , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/immunology , Toxoplasmosis/therapy , Vaccines, Synthetic/immunology , Vaccines, Synthetic/therapeutic useABSTRACT
To prepare and purify the rabbit anti-TgMIC16 polyclonal antibody, so as to apply it in subcellular localization.New Zealand white rabbits were immunized with purified recombinant TgMIC16 mixing with the same volume of Freund’s adjuvant for three times, respectively. The rabbit serum was collected on the 14th day after the last immunization. The polyclonal antibody in rabbit serum was purified with Protein A affinity purification column. ELISA and Western blotting were used to detect the antibody titer and specificity of polyclonal antibody. The polyclonal antibody was used to the localization of TgMIC16 by the immunofluorescence method.Indirect ELISA showed that the antibody titer was 1∶512 000. Western blotting showed that the recombinant TgMIC16 protein was recognized by the specific polyclonal antibody. IFA showed that TgMIC16 was located in the microneme of Toxoplasma gondii.The rabbit anti-TgMIC16 is prepared and purified, and successfully applied to immunofluorescence localization of TgMIC16 in T. gondii.
ABSTRACT
In a previous study, we found that rabbit anti-Toxoplasma gondii serum was capable of recognizing truncated T. gondii microneme protein 16 (TgMIC16), indicating that TgMIC16 is an essential antigenic T. gondii protein. However, the broad application of this recombinant protein is limited by its low expression level. In this study, we performed codon optimization of TgMIC16 by changing the codon-adaptation index from 0.22 to 1.0 without altering the amino acid sequence and expressed the optimized gene in three different Escherichia coli strains, followed by comparison of soluble recombinant-protein expression and yield. Our results showed that the recombinant protein rTgMIC16 was expressed as inclusion bodies in all three strains following optimization of induction parameters, and western blot analysis revealed the presence of a ~72-kD recombinant protein as a specific band following purification. A shuffle-expression strain was selected to amplify incubation products and induce expression, resulting in an overall rTgMIC16 yield of ~20 mg/L. These findings provide a basis for further investigation of TgMIC16 to elucidate its functions and interaction partners.
ABSTRACT
The bioinformatics software was used to predict the B cell and T cell epitopes of Toxoplasma gondii microneme 16 (TgMIC16) followed by epitopes display on the yeast of Saccharomyces cerevisiae.B and T cell epitopes of TgMIC16 were predicted by DNAStar and IEDB,and software of SYFPEITHI and BIMAS,respectively.According to the predicted results,the antigenic epitope region was expressed with pCTCON2/EBY100 display system.The expression protein was detected by indirect immunofluorescence (IFA) and flow cytometry.Results showed that there were potential B/T cell epitopes in TgMIC16 and concentrated in the aa343-625 region.The epitope region was successfully displayed on the surface of yeast cells,and the optimal induction time was 24 hours.The study would lay the foundation for the development and efficacy evaluation of the yeast carrier vaccine in the further research.
ABSTRACT
The bioinformatics software was used to predict the B cell and T cell epitopes of Toxoplasma gondii microneme 16 (TgMIC16) followed by epitopes display on the yeast of Saccharomyces cerevisiae.B and T cell epitopes of TgMIC16 were predicted by DNAStar and IEDB,and software of SYFPEITHI and BIMAS,respectively.According to the predicted results,the antigenic epitope region was expressed with pCTCON2/EBY100 display system.The expression protein was detected by indirect immunofluorescence (IFA) and flow cytometry.Results showed that there were potential B/T cell epitopes in TgMIC16 and concentrated in the aa343-625 region.The epitope region was successfully displayed on the surface of yeast cells,and the optimal induction time was 24 hours.The study would lay the foundation for the development and efficacy evaluation of the yeast carrier vaccine in the further research.
