Abstract
Fifteen overlapping synthetic peptides, spanning the entire amino acid sequence of the Mycobacterium tuberculosis 19-kDa protein, were used to identify epitopes recognized by murine T cells. Five of the 15 peptides tested were able to elicit in vitro lymph node T cell proliferative responses in C57BL/10 mice primed by footpad inoculation with homologous peptide. Analysis in congenic strains of mice revealed H-2 restriction in the response to four peptides. However, one peptide, 19.7 (residues 61 to 80), induced T cell responses in all four haplotypes tested. This peptide was also unique in being able to stimulate lymph node cells from C57BL/10 mice immunized with recombinant 19-kDa protein, killed M. tuberculosis, or live bacillus Calmette Guerin infection. T cell lines specific for peptide 19.7 were of the CD4 phenotype. Significantly, sequence analysis revealed that residues 61 to 80 of the 19-kDa protein exhibited considerable homology with a single 20-amino acid sequence (residues 120 to 140), but not with any other region of the 28-kDa protein expressed in Mycobacterium leprae. This finding is the first evidence of epitope-restricted homology between otherwise structurally unrelated microbial Ag.
Original language | English |
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Pages (from-to) | 2706-2712 |
Number of pages | 7 |
Journal | Journal of Immunology |
Volume | 147 |
Issue number | 8 |
Publication status | Published - 15 Oct 1991 |
Keywords
- Amino Acid Sequence
- Animals
- Antigens, Bacterial/immunology
- Epitopes/analysis
- H-2 Antigens/genetics
- Haplotypes
- Immunization
- Lymphocyte Activation
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Mycobacterium bovis/immunology
- Mycobacterium leprae/immunology
- Mycobacterium tuberculosis/immunology
- Peptide Fragments/immunology
- Structure-Activity Relationship
- T-Lymphocytes/immunology