The influence of T cell development on pathogen specificity and autoreactivity

T cells orchestrate adaptive immune responses upon activation. T cell activation requires sufficiently strong binding of T cell receptors on their surface to short peptides derived from foreign proteins bound to protein products of the major histocompatibility (MHC) gene products, which are displayed on the surface of antigen presenting cells. T cells can also interact with peptide-MHC complexes, where the peptide is derived from host (self) proteins. A diverse repertoire of relatively self-tolerant T cell receptors is selected in the thymus. We study a model, computationally and analytically, to describe how thymic selection shapes the repertoire of T cell receptors, such that T cell receptor recognition of pathogenic peptides is both specific and degenerate. We also discuss the escape probability of autoimmune T cells from the thymus.Comment: 12 pages, 7 figure

Immunological Events Associated with Immunization by Sperm in Incomplete Freund’s Adjuvant

Guinea pigs were immunized with sperm antigen(s) in complete or incomplete Freund’s adjuvant. Those immunized with sperm in CFA developed orchids, made high titers of complement fixing antibody; their lymphocytes could transfer orchitis when inoculated into normal recipients and produced &lt;i&gt;in vitro&lt;/i&gt; migration inhibitory factors. Those immunized with sperm in ICFA did not develop orchitis and made high titers of anaphylactic antibodies; their lymphocytes did not transfer orchitis into normal guinea pigs and did not inhibit migration of macrophages. Lymphocytes from guinea pigs immunized with CFA could transfer orchitis when inoculated into the testes of guinea pigs immunized with ICFA. Hence the lack of disease in guinea pigs immunized with ICFA is not because of a protection of their testes by non-phlogogenic antibodies.</jats:p