Similarities between the syngeneic mixed lymphocyte response and lymphoma-induced T cell proliferation in SJL/J mice

In the present study, the syngeneic (autologous) mixed lymphocyte reaction (SMLR) was compared with a strikingly similar lymphoproliferative response that was induced by a syngeneic lymphoma, the reticulum cell sarcomas of SJL/J mice. These two syngeneic responses shared several properties in common, including the nature of both the responding T cell subpopulation (Lyt-1+) and the stimulatory determinants (I-region encoded products). RCS cells stimulated proliferative responses in syngeneic T cells that were markedly higher than those seen in either SMLR (6X greater) or after allogeneic stimulation of the same responder cells (2X greater). This was true at all R/S ratios tested. Indeed, at R/S ratios as high as 100, RCS cells still induced a significant response. As in the SMLR, despite the marked proliferation observed in RCS-induced cultures, there was no development of cytotoxic cells with specificity for "self". The supernatant culture fluids of both responses also contained similar lymphokine activities, including IL-2 and IFN. Moreover, perhaps as a result of IFN production, cytotoxic activity against NK-susceptible target cells was observed in both the SMLR and the RCS-induced response. Here again, the major difference between the two responses was quantitative; RCS-induced responses yielded much higher levels of lymphokine and NK activities than those obtained in SMLR. The marked similarity between these two syngeneic lymphoproliferative responses suggests that the RCS-induced response may actually represent an exaggerated instance of SMLR. It may, therefore, provide a useful tool to probe the significance of syngeneic lymphocyte interactions in vivo, as well as host-tumor relationship.(ABSTRACT TRUNCATED AT 250 WORDS)