title: Quantification of non-specific immunosuppressive factors.
abstract: A simple, reproducible and quantitative method for evaluating certain non-specific immunological inhibitors in a variety of biological fluids is described. Human lymphocytes were stimulated with PHA in the presence of colchicine. Phytohaemagglutinin stimulated a large percentage of cells and colchicine's selective blockage of mitosis limited the stimulated cells to one S phase. These conditions effectively established a maximum amount of DNA synthesis within each culture. Quantification of suppression was then achieved by measuring a decrease from this maximum. The PHA-colchicine assay was successfully used to quantify inhibition by normal plasma, normal mouse sera, mouse neonate sera, murine Ehrlich's and sarcoma I ascitic fluids and an immunoregulatory alpha-globulin peptide preparation. Because of the ability to obtain a specific inhibitory activity for the suppressive factors, this assay was particularly suited for following the isolation of inhibitors during the fractionation of suppressive substances from complex fluids.
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000276:immunology; D001681:Biological Assay / Q000379:methods; D001769:Blood; D002286:Carcinoma, Ehrlich Tumor / Q000276:immunology; D003078:Colchicine / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007166:Immunosuppressive Agents / Q000032:analysis*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D010455:Peptides / Q000276:immunology; D010835:Phytohemagglutinins / Q000494:pharmacology; D012513:Sarcoma, Experimental / Q000276:immunology; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors
chemical_list: D007166:Immunosuppressive Agents; D010455:Peptides; D010835:Phytohemagglutinins; D003078:Colchicine; D013936:Thymidine