In vivo effects of human dialyzable leukocyte lysates : II. Augmentation of the spleen cell proliferative response to antigen in KLH-sensitive mice

The in vivo effects of human dialyzable leukocyte lysate (DLL) upon the subsequent in vitro proliferative response of lymphocytes to antigen was investigated. Twenty-four-hour DLL treatment of KLH-sensitive mice resulted in the augmentation of antigen-stimulated proliferation of 5-day spleen cell cultures. Ampliative effects of DLL treatment were dependent upon the time after antigen priming and the conditions of sensitization. Moderate augmentation was detected 1–4 weeks following suboptimal sensitization. Marked enhancement of the response to antigen was observed in optimally sensitized mice only after the initial proliferation had subsided. DLL augmentation was detected more readily in mice primed with optimal concentration of antigen than in mice sensitized with lower concentrations of KLH.