Inhibition of CD40 signaling pathway in antigen presenting cells by T suppressor cells

摘要: Abstract Understanding the mechanism which underlies induction of immunologic tolerance is crucial to development strategies for treatment autoimmune diseases and allograft rejection. Although concept that T suppressor cells (Ts) downregulate immune response has long been accepted, existence a distinct population lymphocytes mediates suppression not convincingly demonstrated. In previous studies, we have utilized human cell lines (TCLs) analyze suppressive effects CD8 + CD28 − in allogeneic, peptide specific xeno-specific responses. each case, inhibit proliferation CD4 helper (Th) with cognate antigen specificity. These display critical functional characteristics cells. Similar cytotoxic (Tc) by Th, this process depends on presenting (APC) acting as “bridge” between MHC-class I class II A possible explanation Ts-mediated their ability modulate function APCs. The present studies show Ts directly CD40 signaling pathway APC contact-dependent renders bridging APCs incapable inducing Th activation. state supports order interact determines outcome