Differential sensitivities of primary and secondary T cell responses to antigen structure.
Here we examined T cell responses to two analogs of a chimeric peptide encoding a known B and a known T cell epitope. In one of the analogs, the B cell epitope existed in a random conformation whereas it was restricted within a disulfide-bonded cyclic loop in the other. Immunization of these peptides in mice revealed that the latter peptide was significantly poorer at priming T cells and our preliminary results suggest this could be the result of differential processing of the two analogs. While primary T cell responses were sensitive to the influence of conformation, secondary responses were not discriminatory for the two antigens confirming the differences in activation requirements for primary and secondary T cell responses. Further, our studies also suggest that the priming efficacy of a T cell epitope is influenced by its structural environment.
Nayak
B P
BP
Immunology Group, International Center for Genetic Engineering and Biotechnology, New Delhi, India. bishnu@icgebnd.ernet.in
D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000737:chemistry / Q000276:immunology*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology*