title: Depression of colony formation by human thymus-derived lymphocytes with rifampin and other antimicrobial agents.
abstract: Colonies of human lymphocytes with thymus-derived (T) cell characteristics can be induced in phytohemagglutinin-P to grow in a semisolid medium. To expand the data base on the effects of antimicrobial agents on cell-mediated immunity, the effect of 30 antimicrobial agents on T-lymphocyte cloning was studied. All of the drugs were added to the cultures in concentrations ranging from 10(-5) to 10(-14) M, and the results were compared with those in cultures without the drug. Drugs that inhibit protein synthesis at the 50S ribosomal subunit in bacteria--in particular, chloramphenicol, clindamycin, erythromycin, and troleandomycin--suppressed colony formation. However, the most significantly immunosuppressive agent was rifampin; it suppressed colony formation at concentrations of up to 2.5 x 10(-9) M, a value significantly lower than that found in previous in vitro testing and well below therapeutic levels. Screening of drugs by lymphocyte cloning techniques for possible suppression of cell-mediated immunity appears to be a rapid, sensitive, and inexpensive procedure.
mesh_terms: D000328:Adult; D000935:Antifungal Agents / Q000494:pharmacology; D002701:Chloramphenicol / Q000494:pharmacology; D002981:Clindamycin / Q000494:pharmacology; D002999:Clone Cells / Q000187:drug effects; D004917:Erythromycin / Q000494:pharmacology; D006801:Humans; D009161:Mycobacterium / Q000187:drug effects; D012293:Rifampin / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects*; D014217:Troleandomycin / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D002981:Clindamycin; D004917:Erythromycin; D002701:Chloramphenicol; D014640:Vancomycin; D014217:Troleandomycin; D012293:Rifampin