Leukocyte components which can inhibit or enhance the uptake of 3H-thymidine by peripheral lymphocytes can be prepared by ultrafiltration of leukocyte extracts followed by gel filtration on Sephadex G-10. A potent inhibitor of lymphocyte transformation is present in an ultrafiltrate fraction having a nominal molecular weight of 5,000–10,000. Three other components having inhibitory, and one component having enhancing, activity on lymphocyte transformation were found in an ultrafiltrate fraction having a molecular weight less than 5,000. The inhibitory components in the latter were principally derived from polymorphs and inhibited both T and B lymphocyte proliferation. Enhancing components were mainly derived from mono-nuclear cells and augmented the proliferation of T cells only.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.