title: In vitro generation of splenic suppressor cells by trypsin.
abstract: Rat spleen cells were mitogenically stimulated with concanavalin A (Con A) or sodium periodate and cultured for 14-20 hr with trypsin. When these trypsin-activated cells were co-cultured with fresh mitogenically stimulated cells, [3H]-thymidine incorporation into the fresh cells was suppressed. Artifactual and trivial effects of trypsin (e.g. increased release of cold thymidine, decreased cell viability, and a change in thymidine transport) could not account for the suppressor effect. Suppressor activity was not affected by removing B cells or macrophages before trypsin activation nor by treating the trypsinized cells with mitomycin C. Suppressor activity could only be generated when the spleen cells were stimulated with Con A or periodate during culture with trypsin, and supernates from the trypsin-activated cells did not have suppressor activity. The physiological significance of the results and possible mechanisms of action of the suppressor cells are discussed.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D010504:Periodic Acid / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D013936:Thymidine / Q000378:metabolism; D014357:Trypsin / Q000494:pharmacology*
chemical_list: D007376:Interleukin-2; D010504:Periodic Acid; D003208:Concanavalin A; C009288:metaperiodate; D014357:Trypsin; D013936:Thymidine