Mechanism of T-Dependent Cytotoxicity: Role of Papain-Sensitive Non Class I MHC Target Molecules and Expression of Target Antigen for Cytotoxicity
Cell mediated cytotoxicity (CMC) has been shown to play a major role in resistance to viral infections, tumor rejection and allograft rejection. The mechanism by which the cytotoxic phenomenon operates has been the subject of many investigations, but still remains elusive. Several approaches have been used, such as chemical inhibitors which allow for the dissection of lysis into three steps, namely, binding and/or recognition, programming for lysis, and the killer cell independent lysis stage (1). Other approaches have made use of blocking antibodies which allow for the characterization of surface molecules involved in lysis (2). These studies suggest that lysis is a complex phenomenon requiring several interactions between the lymphocyte and the target cell before lysis is achieved. The nature of these interactions and the biochemical nature of the molecules involved has been studied in part. For instance, it is clear that H2 antigens on target cells are recognized by the CTL receptor. Likewise, several molecular species on CTL have also been implicated in cytotolysis such as Lyt23 and the LFA family of molecules (3–5).
KeywordsTarget Cell Effector Cell Sodium Periodate 51Cr Release Target Cell Membrane
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