Identification of CD4+ T-cell Epitopes on Mycobacterium Tuberculosis- Secreted MPB51 Protein in C57BL/6 Mice
Introduction & Objective: Both CD4+ type 1 helper (Th1) cells and CD8+ T cells play effective roles in protection against Mycobacterium tuberculosis infection. DNA vaccine encoding MPB51 can induce Th1-type immune responses and protective immunity upon challenge with M.tuberculosis. This study a...
| Main Authors: | , |
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| Format: | Article |
| Language: | fas |
| Published: |
Hamadan University of Medical Sciences
2006-03-01
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| Series: | پزشکی بالینی ابن سینا |
| Subjects: | |
| Online Access: | http://sjh.umsha.ac.ir/article-1-514-en.html |
| Summary: | Introduction & Objective: Both CD4+ type 1 helper (Th1) cells and CD8+ T cells play effective roles in protection against Mycobacterium tuberculosis infection. DNA vaccine encoding MPB51 can induce Th1-type immune responses and protective immunity upon challenge with M.tuberculosis. This study address to identify T-cell immunodominant epitopes on MPB51 in C57BL/6 mice.
Materials & Methods : We cloned DNA encoding MPB51 molecule in pCI plasmid. After constructing MPB51 DNA-covered gold cartridge, C57BL/6 mice were immunized by using a gene gun system. Two weeks after the last immunization, the immune spleen cells were cultured in the presence of a synthetic overlapping library peptides covering the mature MPB51 sequence or medium alone. Intracellular and cell culture supernatant gamma interferon (IFN-g) production was analyzed using flow cytometry and ELISA, respectively.
Results : Mapping of T-cell epitopes on MPB51 molecule was performed in the spleen lymphocytes restimulated by 20-mer overlapping synthetic peptides of mature MPB51 sequence. Flow cytometric analysis with intracellular IFN-g and the T-cell phenotype revealed that P171-190 and P191-210 peptides contain immunodominant CD4+ T-cell epitopes. Further analysis by using T-cell subset depletion and serial peptide dilution revealed that P171 and p191 are H2-Ab-restricted dominant and subdominant CD4+ T cell epitopes, respectively.
Conclusion: This study proved that vaccination with plasmid DNA encoding M. tuberculosis-secreted MPB51 protein not only induce CD4+ T cells immune response but also is an appropriate method for identifying immunogenic peptides. |
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| ISSN: | 2588-722X 2588-7238 |