In vitro effects of an antitumor antibiotic, @entity43801 , on the XXXX immune system.

@entity19 @entity43801 @entity5 @entity2047
Effects of an antitumor antibiotic, @entity43801 (AF) on the @entity19 immune system were studied. Unlike lectins, AF did not induce any proliferative response of splenocytes. Furthermore, AF significantly inhibited proliferative response of splenocytes in response to lectins, such as concanavalin A, lipopolysaccharide, or phytohemagglutinin above 5 micrograms/ml. In concanavalin A-induced T-lymphocyte response, AF selectively inhibited the formation of @entity2047 ( @entity2047 ) receptors, which was observed above 0.4 micrograms/ml. On the other hand, the inhibitory effect on the proliferative response to @entity2047 of T-lymphocytes, which had already obtained @entity2047 receptors, was observed above 10 micrograms/ml. @entity2047 production of splenocytes in response to concanavalin A was also suppressed by AF above 2 micrograms/ml and only 3% of @entity2047 was produced in the presence of AF, 10 micrograms/ml. However, AF-activated macrophages and their glycolysis was significantly stimulated. Activation of macrophages by AF was also confirmed by stimulation of interleukin 1 production and tumoricidal activity. However, natural killer activity of splenocytes was suppressed at the concentration where significant activation of tumoricidal activity of macrophages was observed. Therefore, AF had a dual effect on the immune system. Macrophages were activated to produce interleukin 1 and to kill @entity5 cells. On the other hand, functions of lymphocytes were suppressed.
