The ability of hapten-conjugated cells to induce cell-mediated cytotoxicity is affected by the mode of hapten linkage

Spleen cells from C57 $\text{B}\text{1}\text{6}$ mice were modified with varying concentrations of several haptens coupled in different ways, then assayed for their ability to induce a cytotoxic response against hapten-modified target cells when cocultured with syngeneic spleen cells. Haptens such as TNBS, DNBS, Fl-NCS, and AB-NCS which couple via the ?-amino groups of lysine were all capable of generating high levels of cytotoxicity when tested against hapten-coupled syngeneic tumor. One hapten, DNBM, which coupled via -COOH groups was effective in generating cell-mediated cytotoxicity. By contrast, similar haptens such as ABA and DNBA which couple as diazonium salts via tyrosine and histidine groups were not found to generate cytotoxic responses over wide ranges of concentrations. Possible explanations are discussed.