Inhibition of tumor-induced lymphocyte blastogenesis by a factor or factors associated with peripheral leukocytes

A factor or factors concentrated on leukocytes of cancer patients depress the proliferative response of lymphocytes to stimulation with autologous tumor. Inhibitory activity with material eluted from cells resides in neither high nor lower molecular weight fractions but in a combination of the two. The finding suggests that in vitro inhibition of lymphocyte proliferation to autochthonous tumor occurs because of antigen-antibody complexes.