Heavy-metal mitogenesis: thymocyte activation by Zn++ requires 2-mercaptoethanol and lipopolysaccharide as cofactors.
Thymocytes from Balb/C mice were activated in vitro by Zn++ as noted by the several-fold increases in 3H-thymidine incorporation at 144 h of culture. Thymocyte activation by Zn++ required the presence of 2-mercaptoethanol (2-ME) and bacterial lipopolysaccharide (LPS) in concentrations as low as 1.0 ng/ml. Thymocytes were not stimulated by these agents in the absence of Zn++. Bovine serum products, thought to contain trace amounts of LPS, appeared to satisfy this LPS requirement. Interleukin 1 (IL 1) could not replace LPS as a cofactor. Thymocytes did not respond to Hg++ under the culture conditions used here. Thymocyte subpopulation studies showed that cell preparations enriched for peanut lectin receptor-negative, mature thymocytes were activated by Zn++ and required LPS for the response.
D000818:Animals; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008623:Mercaptoethanol / Q000494:pharmacology; D008628:Mercury / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008934:Mitogens; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D015032:Zinc / Q000494:pharmacology*
D008070:Lipopolysaccharides; D008934:Mitogens; D008623:Mercaptoethanol; D008628:Mercury; D015032:Zinc