H Levine

A defect of immunoregulatory T cell subsets in systemic lupus erythematosus patients demonstrated with anti-2H4 antibody.

The cell surface phenotype of peripheral blood lymphocytes (PBL) of systemic lupus erythematosus (SLE) patients was characterized with the anti-2H4 monoclonal antibody that defines the human suppressor inducer subset. The T4+2H4+ population of cells has been shown to be critical for the activation of T8+ suppressor cells. Patients with SLE has a markedly decreased percentage of T4+2H4+ cells (13 +/- 2%) in their PBL compared with normal controls (21 +/- 1%) (P less than 0.001). This reduction was greatest in patients with active SLE, especially those with renal disease. Serial analysis of patients with SLE and renal disease showed a correlation between percent positive circulating T4+2H4+ cells and disease activity. Moreover, there was a significant correlation between a low percentage of T4+2H4+ cells and decreased suppressor-inducer function in autologous mixed lymphocyte reaction-activated T4+ cells from SLE patients. Thus, a deficiency exists in SLE patients with active renal disease in the T4+2H4+ suppressor-inducer T cell subset.

ACUTE LEUKAEMIA WITH MIXED LYMPHOID AND MYELOID PHENOTYPE

CHAPUIS, B., HELG, C., JEANNET, M., ZULIAN, G., LEUNISSEN, K.M.L., WATERVAL, P.W.G. & VAN HOFF, J.P. (1985) Anaphylactic reaction to intravenous cyclosporin. Lancet, i, 636. PTACHCINSKI, R.J.. GRAY, J., VENKAIARAMANAN, R., BURCKART. G.J., VAN THIEL, D.H. & ROSENTHAL, J.T. (1985) Anaphylactic reaction to intravenous cyclosporin. Lancet, i, 6 3 6 4 3 7. HUBER, p. & GIJMO~SKI, P. (1985) Anaphylactic reaction to intravenous cyclosporin. New England Journal of Medicine, 312, 259. KAHN, B.D., WIDEMAN, C.A., FLETCHNEK, S. & V A N BUREN. C.T. (1984) Anaphylactic reaction to intravenous cyclosporin. Lancet, i, 52.

Human cell lines express multiple populations of Ia-like molecules

Three monoclonal antibodies have been used to isolate Ia-like antigens from three human cell lines; two of which are thought to be homozygous at the HLA-D/DR locus. Complete extraction of the Ia antigens identified by one antibody leaves those recognized by the two remaining antibodies in three parallel sets of experiments, indicating that the antigenic determinants recognized by these antibodies are present on three different populations of Ia molecules from cells of single individuals. These three populations of Ia-like molecules may reflect serologic variants of the product of a single genetic locus or may represent the products of as many as three nonallelic genetic regions. Demonstration of the existence of these multiple populations of Ia-like molecules on presumed homozygous typing cells indicates that this antigenic system is much more complex than has been generally realized. Further study may clarify the relationship between HLA-D/DR type and susceptibility to a variety of diseases and ultimately lead to better matches and improved survival for allogenic transplants. Since the HLA-D region is intimately involved in regulation of the immune response and susceptibility to a variety of diseases, use of monoclonal antibodies specific for discrete Ia antigens, the only identified products of the HLA-D region, may facilitate dissection of its many biological functions.

T-Cell Regulation of Restricted B-Cell Responses

In earlier studies it was shown that synthetic and chemically well-defined Dnp-oligolysines did induce both cellular and humoral immunity in guinea pigs, and that this response was under immune response gene control (1, 2). Sera of guinea pigs of genetic responder strain immunized with synthetic Dnp-oligolysine peptides have been shown to contain highly specific antibodies of restricted heterogeneity which could discriminate Dnp-oligolysines with minimal changes in hapten position, chain length, D-lysine-alanine sub-stituents (3–7). Like specificity has been shown in T-cell responses of responder guinea pigs to these simple antigens since they could also discriminate equally well the homologous immunizing antigen from closely related ones in assays measuring antigen-induced delayed hypersensitivity, tritiated thymidine incorporation, and mediator production (8–9). Non-responder animals, in contrast, lack a T-cell response to these antigens and the antibody produced in the absence of T-cells, while Dnp-specific, could not discriminate one Dnp-oligopeptide from another (6). Exquisite specificity of antibody in animals with highly specific T-cell responses and the lack of it in non-responder guinea pigs immunized to the same antigen suggested that T-cells could select specific B-cell clones to proliferate (10). To test this possibility, studies were undertaken to explore antigen-induced B-cell responses in both strain 2 and 13 guinea pigs in the presence and absence of Dnp-oligolysine-specific T-cells. These experiments will emphasize the role of specific T-cells in the selection and amplification of unique B-cell clones.