title: Characterization of cell lines enhancing IL-2 production by human phytohemagglutinin-stimulated lymphocytes.
abstract: Certain cell lines were found to significantly enhance IL-2 production by phytohemagglutinin-stimulated T lymphocytes, and the mechanisms involved in mediating such an enhancement have been studied. All B-lymphoblastoid cell lines (B-CL) tested had an enhancing capability, even lines which were immature, surface immunoglobulin negative, or negative for EBV-associated antigens or Fc receptors. Furthermore, a B-CL lacking HLA-A, B, and C, antigens as well as a HLA-DR-deficient mutant line enhanced IL-2 production. Autologous B-CL as well as allogeneic lines were able to augment IL-2 production. Cell lines from patients with T-cell acute lymphoblastic leukemia did not stimulate, while more mature, DR-positive T-cell lines did. Although all HLA-DR positive cell lines, regardless of their derivation, provided enhancement, several lines of evidence, including blocking experiments with anti-DR antibodies, indicated that the reaction was not HLA-DR mediated. The enhancing determinant(s) appeared to be cell associated since CL supernatants were ineffective, and it may serve as an important additional signal to the preactivated IL-2-producer T-cell.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D002460:Cell Line; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D007108:Immune Tolerance; D007376:Interleukin-2 / Q000096:biosynthesis*; D007519:Isoantigens / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008214:Lymphocytes / Q000378:metabolism*; D008222:Lymphokines / Q000276:immunology; D010835:Phytohemagglutinins / Q000494:pharmacology*
chemical_list: D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D007519:Isoantigens; D008222:Lymphokines; D010835:Phytohemagglutinins