title: An NK-like cell limits the adoptive response from "pre-progenitor" B cells.
abstract: Evidence is presented that a dividing, Thy 1 . 2 positive and NK 1 . 2 positive cell with a suppressive effect on adoptive responses is present in the spleens of normal and athymic mice, and that its function may be enhanced by non-specific antigenic stimulation. NK cells may thus exert a controlling function on the proliferation and differentiation of B cells. The main experimental observation is that under certain assay conditions incubation of spleen cells with 3H-TdR in order to kill dividing, non-specifically activated 'pre-progenitor' B cells may actually give a marked increase rather than a decrease in a subsequent hapten-specific primary adoptive response. An activated 'suppressor' population was proposed as the reason for this effect. This anomalous effect may be avoided and the cycle state of the B cells assessed by prior elimination of cells bearing Thy 1 antigen, together with the use of a more reliable hydroxyurea incubation to kill dividing B cells.
mesh_terms: D000818:Animals; D000941:Antigens / Q000008:administration & dosage; D000961:Antilymphocyte Serum / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006736:Horses; D007116:Immunization, Passive; D007694:Killer Cells, Natural / Q000276:immunology / Q000502:physiology*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D050378:T-Lymphocytes, Regulatory / Q000145:classification / Q000276:immunology
chemical_list: D000941:Antigens; D000961:Antilymphocyte Serum