Effects of inhibitors of DNA and protein syntheses on mitogenic factor production by PPD-stimulated guinea pig lymphocytes.

The effects of inhibitors of DNA synthesis and mitosis and of protein synthesis on mitogenic factor production by lymph node cells from guinea pigs sensitized to tuberculin was studied. All inhibitors used in this study were added to the medium at the beginning of culture. Cytosine arabinoside, vinblastine and mitomycin-C reduced markedly the incorporation of tritiated thymidine in DNA, but had no effect on the production of mitogenic factor. Mitomycin-C at higher concentrations, however, induced the partial reduction of mitogenic factor production. On the other hand, puromycin and cycloheximide, inhibitors of protein synthesis, suppressed markedly the production of mitogenic factor. These results indicate that mitogenic factor production requires protein synthesis, but is independent of DNA synthesis.