ABSTRACT
B. Nonspecific Lectin-and Oxidation-Dependent Cytotoxicity (LDCC and ODCC) and CTL Targeting by Antibody
In contrast to the exquisite specificity of CTL-medited lysis,4.24.25 under certain conditions CTL can lyse virtually any TC - both allogeneic, syngeneic and even autologous, nonspecifically. These conditions include:
1. Presence of certain mitogenic lectins, notably Concanavalin A (Con A) and phytohemagglutinin (PHA)26-31
2. The cells are subjected mild oxidation by periodate (NaIO,) or by neuraminidase followed by galactose oxidase (NAG0)32,33
3. Cross-linking CTL and TC through antibodies against the CTL-receptor or receptorassociated determinants such as T3 or T1 134-39
In a recent report,40 however, a pepsin F(abl), fragment of T3 antibody has been shown to be an effective mediator of (nonspecific) CTL-induced lysis, suggesting that physical, antibody-mediated bridging of effector and TC may, in fact, not be necessary at all to induce lysis. Confirmation and extension of the latter report is required, as it appears to contradict an earlier study stressing cell-cell contact for lysis to occur,34 as well as to indicate involvement of a soluble cytocidal mediator that can lyse bystander cells.
