T cell recognition of Moloney sarcoma virus proteins during tumor regression. I. Lack of a requirement for macrophages and the role of blastogenic factors in T cell proliferation.

The characteristics of the T cell blastogenic response of lymphocytes from Moloney leukemia/sarcoma virus inoculated mice against the virion proteins gp71 and p12 were examined. The proliferative responses to both antigens were independent of a requirement for macrophages as determined by macrophage-depletion experiments, the lack of an effect of antisera against Ia on proliferation and by analysis of the number of cell interactions required for proliferation. The kinetics of antigen-lymphocyte interaction were examined and found to require only 4 to 6 hr for half-maximal activation. Proliferation in response to gp71 or p12 was found to be due to the production of blastogenic factor(s), and using additivity experiments, little if any proliferation appears to be associated with antigen-specific lymphocytes. The production of blastogenic factor(s) does not require proliferation and is temporally displaced from antigen-lymphocyte interaction by 8 to 10 hr.