The regulation of immunoglobulin synthesis after HLA-identical bone marrow transplantation: VI. Differential rates of maturation of distinct functional groups within lymphoid subpopulations in patients after human marrow grafting.

This investigation uses different polyclonal activators of in vitro immunoglobulin production to elicit immunoregulatory profiles of B cells, T cells, T4 cells, and T8 cells from 25 recipients (13 with and 12 without chronic graft-v-host disease [GVHD] ) after HLA-identical marrow transplantation for aplastic anemia or hematologic malignancy. Pokeweed mitogen, Epstein-Barr virus, herpes simplex type 1 virus, and tetanus toxoid were used to induce immunoglobulin production as measured by a plaque assay. Multiple defects in the various lymphoid subsets were found in both groups of patients. There was defective b cell function, lack of T cell or T4 cell subset helper activity, and increased T cell, T4 cell, or T8 cell suppressor activity after stimulation with the various activators. Inconsistent B, T, T4, and T8 cell functions in the marrow graft recipients provide evidence for (a) different functional groups of cells within each subset responsive to different polyclonal activators; (b) a spectrum of immune capabilities within each phenotype lineage; (c) different patterns of immune reconstitution for each lymphocyte subset after marrow grafting; and (d) chronic GVHD altering recovery of in vitro functional responses to the different polyclonal activators.

Regulatory roles of human OKT4/OKT8 subsets in polyclonal immunoglobulin production induced by herpes simplex type 1 virus.

T cells, OKT4 cells and OKT8 cells from the peripheral blood of normal individuals seropositive for herpes simplex type 1 virus (HSV) were studied for their capacity to regulate in vitro polyclonal immunoglobulin (Ig) production induced by inactivated HSV. Polyclonal Ig production induced by HSV has been demonstrated to be T-cell dependent. T cells, OKT4 cells and OKT8 cells were co-cultured with autologous non-T cells in the presence of HSV or pokeweed mitogen (PWM) and the number of plaque-forming cells (PFC) was measured with an hemolytic plaque assay after 6 days of culture. The results in the HSV system show that the OKT4 cells provided significantly more helper activity than OKT8 cells (p = 0.002); and the OKT8 cells exhibited more suppressor activity than OKT4 cells for Ig production (p = 0.02). The helper activity of OKT4 cells after HSV stimulation was significantly less than that obtained after pokeweed mitogen stimulation (p = 0.01). The in vitro polyclonal immunoglobulin response to HSV antigen is regulated by the balance of helper/suppressor activity exerted by OKT4 and OKT8 cell subsets.

The regulatory roles of T4 and T8 subsets in tetanus toxoid-induced in vitro immunoglobulin production.

A new mitogenic system for in vitro immunoglobulin production induced by tetanus toxoid is presented and the role of T4 and T8 subsets in tetanus toxoid-induced in vitro immunoglobulin production is investigated. Purified T, T4, T8, and B cells from normal individuals previously immunized but not boosted with tetanus toxoid were cultured in helper and suppressor assays and the number of immunoglobulin-secreting cells were enumerated after culture using a hemolytic plaque assay. The regulatory roles of T4 and T8 cells in this tetanus toxoid system were compared with the role of these subsets after pokeweed mitogen stimulation. Although most of the immunoglobulin produced in the tetanus toxoid system was polyclonal, there were differences in the time course, the magnitude of the responses, the radiosensitivity of the subsets, and optimal T- to B-cell ratios for immunoglobulin production which distinguish the tetanus toxoid and pokeweed mitogen systems.

Functional diversity in OKT4 and OKT8 subsets from long-term survivors after HLA-identical marrow grafting.

T and B cells from one short-term and nine long-term patients who had received HLA-identical bone marrow transplants for aplastic anemia or hematologic malignancy were studied for their ability to synthesize immunoglobulin after in vitro stimulation with pokeweed mitogen, Herpes simplex type 1 antigen, tetanus toxoid, or Epstein-Barr virus. Purified T, OKT4, OKT8, or B cells from patients were cocultured with normal T and/or B cells in the presence of the various stimulants. Multiple regulatory defects were observed in long-term patients with and without chronic graft-versus-host disease. The lymphocytes from the long-term healthy chimeras exhibited fewer defects in their ability to regulate in vitro immunoglobulin synthesis than those of patients with chronic graft-versus-host disease. These findings suggest that the presence of chronic graft-versus-host disease delays or impairs the "rematuration" of the immune system after bone marrow grafting and that the rematurational process occurs at the clonal level.

The regulation of Ig synthesis after marrow transplantation. IV. T4 and T8 subset function in patients with chronic graft-vs-host disease.

This study compares pokeweed mitogen-activated immunoglobulin synthesis functions of T, T4 T8, and B cells from 13 marrow graft recipients with chronic graft-vs-host disease (GVHD), 10 long-term healthy marrow graft recipients, and 20 normal individuals. T cells expressed helper function (greater than 20% of the control) in eight of 10 long-term healthy patients and in only four of 13 patients with chronic GVHD. T4 cells expressed helper activity in all 10 long-term healthy patients, whereas T4 cells in four of 13 chronic GVHD patients did not express helper activity. Chronic GVHD patients had T cells (eight of 13), T4 cells (four of 13), and T8 cells (11 of 13) that suppressed immunoglobulin synthesis by normal T and B cells greater than 50%; radiosensitive and radioresistant suppressors were detected. Three of 10 patients with chronic GVHD and one of the long-term healthy patients had T4 cells that exhibited suppression. T cells from all 20 normal individuals expressed help and none suppressed immunoglobulin production. Altered T, T4, T8, and B cell functions were more frequent in patients with chronic GVHD than in long-term healthy patients or normals. Variable function within a T cell phenotype, variable radiosensitivity of suppressor cells, and higher frequencies of altered function in patients with chronic GVHD suggest there are different maturational stages expressed in each T cell phenotype.

Immunoglobulin production after marrow transplantation. III. The functional heterogeneity of FC-IgG receptor positive and negative T cell subpopulations.

Ten patients with chronic graft-versus-host disease (GVHD) after HLA-identical marrow transplantation were studied between 372 and 1649 days post-transplant for their T cell subset functions in pokeweed mitogen-stimulated immunoglobulin (Ig) synthesis. In vitro Ig synthesis was assessed using an indirect haemolytic plaque assay after 6 days of culture. T cells, TG+ cells (Fc-IgG receptor positive), TG- cells (Fc-IgG receptor negative), and B cell-enriched populations from the patients were co-cultured with normal T and/or B cells. Such cultures in patients with chronic GVHD showed deficient B cell activity (eight of 10); and deficient helper activity in T cells (six of 10), TG+ cells (five of nine), and TG- cells (three of nine). Greater than 50% suppression of Ig synthesis was detected with T cells (four of 10), TG+ cells (three of 10), and TG- cells (three of 10). This study provides evidence for variable regulatory function of Fc receptor T cell subsets in patients with chronic GVHD. The unexpected finding was that TG+ and TG- subpopulations can lack helper activity or actively suppress Ig synthesis.