title: Immunosuppression induced by chemicals requiring metabolic activation in mixed cultures of rat hepatocytes and murine splenocytes.
abstract: Primary cultures of adult rat hepatocytes (Fischer 344) were used as an in vitro metabolic activation system in immunotoxicological assays. Rat hepatocytes were isolated by a collagenase perfusion technique and cultured for 20 to 24 hr to allow the formation of a monolayer on collagen-coated plastic petri dishes. Spleen cells isolated from (C57BL/6 X C3H)F1 mice were cocultured with the hepatocytes along with the chemicals. Cyclophosphamide (CP) and Aflatoxin B1 (AFB1) were effectively activated in this coculture system and produced a dose-related suppression of the in vitro antibody responses to LPS, DNP-Ficoll, and SRBC in 3 hr. Neither CP (1 mM) nor AFB1 (10(-4) M) cultured with spleen cells alone produced any effects. Both CP and AFB1 also produced a dose-related suppression of the proliferative responses to LPS, Con A, and PHA. In contrast, up to 100 mM of N-nitrosodimethylamine (DMN) did not suppress any of these assays after a 3-hr incubation in the coculture system. These results indicate that a coculture system can be used to characterize the activity of immunosuppressive chemicals requiring metabolic activation.
mesh_terms: D016604:Aflatoxin B1; D000348:Aflatoxins / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D001711:Biotransformation; D002478:Cells, Cultured; D003520:Cyclophosphamide / Q000378:metabolism / Q000494:pharmacology; D004128:Dimethylnitrosamine / Q000378:metabolism / Q000494:pharmacology; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D005362:Ficoll / Q000031:analogs & derivatives / Q000276:immunology; D007166:Immunosuppressive Agents / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000276:immunology; D008099:Liver / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008934:Mitogens / Q000276:immunology; D051381:Rats; D011916:Rats, Inbred F344; D012756:Sheep; D013154:Spleen / Q000276:immunology*
chemical_list: D000348:Aflatoxins; C031007:DNP-Ficoll; D007166:Immunosuppressive Agents; D008070:Lipopolysaccharides; D008934:Mitogens; D005362:Ficoll; D003520:Cyclophosphamide; D016604:Aflatoxin B1; D004128:Dimethylnitrosamine