TRD

T-lymphocytes recognize antigens via a mechanism that resembles that used by immunoglobulins produced by B cells. There are 2 main mature T-cell subtypes, those expressing alpha and beta chains, and those expressing gamma and delta chains. Unlike secreted Ig molecules, T-cell receptor chains are membrane bound and act through cell-cell contact. Gamma-delta T cells may also recognize antigens directly without presentation by the major histocompatibility complex.