Suppressor T-cell abnormality in idiopathic systemic lupus erythematosus

Tgamma cells in systemic lupus erythematosus. Variation with disease activity

Circulating T cells bearing receptors for the Fc portion of IgG (T gamma) were identified by sensitive immunofluorescent techniques with rabbit IgG b4 allotype/anti-b4 complexes. A twofold decrease in both proportion and absolute number of T gamma cells was found in patients with active systemic lupus erythematosus (SLE) relative to values obtained during disease remission. The reduction in T gamma cells was most evident in patients with severe hypocomplementemia. A deficit of T gamma cells in active patients was not demonstrated. The percentage of total T cells rosetting with sheep erythrocytes was reduced in peripheral blood of most patients regardless of disease activity status, but particularly during SLE exacerbation. Cells lacking intrinsic surface immunoglobulin, IgG Fc receptors, and receptors for sheep erythrocytes were increased. These cells, operationally termed null, exhibited an inverse linear relationship with T cells that was not apparent in regression analyses performed against other lymphocyte subpopulations. Such differences were not found for B cells and IgG receptor-bearing non-B/non-T cells which were present in normal proportions in virtually all patients. The origin and functional significance of these unusual lymphocyte subpopulation abnormalities are discussed.

PHA-induced cellular cytotoxicity. Inhibition by a nonimmunoglobulin factor present in sera from patients with active systemic lupus erythematosus

Phytohemagglutinin-induced cellular cytotoxicity by normal mononuclear cells (MNC) is inhibited by serum of patients with active untreated systemic lupus erythematosus (SLE) but not by that of patients with untreated inactive SLE or rheumatoid arthritis. Three-hour preincubation of normal MNC with SLE sera suffices to inhibit throughout the assay. Preincubation with phytohemagglutinin (PHA) before addition of sera does not prevent the inhibition. DEAE-cellulose chromatography, Sephadex G-200 fractionation and immunoelectrophoretic analysis have shown the nonimmunoglobulin nature of this factor. It is thermostable and not affected by deoxyribonuclease or ribonuclease treatment. The mitogen-induced cellular cytotoxicity-inhibiting factor seems to be independent of other serum factors capable of blocking PHA-induced blastogenic transformation.

Some observations on the immunological status in scleroderma (progressive systemic sclerosis)

A variety of tests were performed to determine the immune status of a group of patients with scleroderma (progressive systemic sclerosis). Sera of 11 of 35 patients showed autoantibodies by an immunofluorescent technique. There was no significant difference between the C3 and C4 components of complement in 12 patients tested and laboratory controls. IgM levels were raised in 24 of 34 sera. Four of ten patients showed some deficiency of phagocytic function in the leucocyte iodination test. B cell and T cell numbers were normal in the eight patients tested. Reactivity to mitogens was usually normal in ten patients tested with a deficient response to one of the three mitogens in two patients. In skin reactivity tests in 23 patients, only one was anergic to all of the four antigens tested. It is concluded that although some immune abnormalities are common in scleroderma there is no consistent abnormality in any of the tests used. This does not exclude the possibility that immune factors may be involved in systemic manifestations of the disease, or that there may be some subtle specific abnormality not revealed by the tests performed.

Studies of immune functions of patients with systemic lupus erythematosus. I. Dysfunction of suppressor T-cell activity related to impaired generation of, rather than response to, suppressor cells

T cell suppressor function in patients with systemic lupus erythematosus (SLE) was evaluated by studying the ability of concanavalin A- (Con A) activated T cells to suppress proliferative responses by responder cells autologous with the Con A-activated T cells. Impaired suppressor T-cell activity in patients with SLE was observed with regard to three effector functions: 1) the allogeneic response of T cells, 2) the Con A response of T cells, and 3) the B cell response to pokeweed mitogen (PWM). No defect was found with regard to suppression of the T-cell response to phytohemagglutinin (PHA). Mixing experiments between SLE and normal cells were carried out to further define the nature of the SLE suppressor defect. When responder cells from SLE patients were cultured with Con A-activated T cells from normal controls, the normal suppressor T cells caused suppression of SLE responder cells. In contrast, Con A-activated T cells from SLE patients were incapable of exerting suppressor effects on normal responder cells. These observations indicate that the impaired suppressor activity in SLE patients resides in the generation of suppressor T cells, rather than in the response to suppressor T cell signals.

Therapeutic studies in NZB/NZW mice. VI. Age-dependent effects of concanavalin A stimulated spleen cell supernate

Spleen cells from normal mice were cultured with Concanavalin A to produce an immunosuppressive supernate. This supernate was used to treat the lupus-like autoimmune disease of NZB/NZW mice. Such treated mice lived significantly longer than did controls, but only if treatment was initiated early in the course of the illness.

Reactivity of lupus erythematosus antibodies with leukemic helper T cells

Immunoabsorbent columns, containing membrane fragments of either leukemic "helper" T cells or B cell lymphoblasts, were used to isolate and study antilymphocyte antibodies from plasmas of 2 patients with systemic lupus erythematosus (SLE). Both plasmas contained IgG which bound to and could be eluted from the "helper" T cell column. These antibodies significantly inhibited normal lymphocyte proliferative responses to microbial and histocompatibility antigens. The findings indicate that these SLE plasmas contain immunoglobulins of the IgG class which react with leukemic "helper" T cells and inhibit normal effector T cell function.

Aplastic anemia associated with bone marrow suppressor T-cell hyperactivity: successful treatment with antithymocyte globulin

In five patients with idiopathic aplastic anemia, the colony-forming unit (CFU-c) assay was used to quantitate stem cells and test the possible presence of suppressor cells inhibiting bone marrow differentiation. All five marrows failed to form CFU-c. In one out of the five cases tested, coculture of the patient's marrow with normal marrow suppressed the latter to form CFU-c. Removal of T-cells from the patient's bone marrow freed the aplastic marrow to produce more colonies and, in the coculture study, abrogated its inhibitory activity on the normal bone marrow. Treatment of the patient with horse antihuman thymocyte globulin (ATG), improved the peripheral blood count and myelopoiesis. Furthermore, the aplastic marrow increased its colony forming capacity from less than 1% pre-ATG to 46% post-ATG of the normal control, and its inhibitory activity on the normal marrow was ablated. In selected cases of aplastic anemia, with evidence of T-suppressor cell hyperactivity, treatment with ATG may offer an alternative approach to bone-marrow transplantation.

Malakoplakia: evidence for monocyte lysosomal abnormality correctable by cholinergic agonist in vitro and in vivo

We studied monocyte function in a case of malakoplakia in an attempt to characterize the immune defect in this condition. Our patient's intracellular cyclic-GMP levels were abnormally low (mean +/- S.D. of 0.17 +/- 0.05 pmol per 10(7) malakoplakia cells, versus 0.79 +/- 0.12 in normals) p less than 0.001). After phagocytosis, his monocytes failed to release beta-glucuronidase. In the bactericidal assay, incubation of the patient's monocytes with Escherichia coli allowed growth of 542 +/- 46 colonies, normal monocytes allowed 95 +/- 22 (p less than 0.001). The percentage of monocytes with large lysosomal granules was 23 +/- 4 in the patient and 4 +/- 2 in normal controls. After in vitro incubation of the patient's cells or in vivo treatment with bethanechol chloride, the cyclic-GMP levels, bactericidal ability and lysosomal granules of the cells returned to normal levels. Low levels of cyclic-GMP could impair lysosomal function and bacterial killing in this condition. Cholinergic agonists correct the in vitro abnormalities and are beneficial in vivo.

Induction of suppressor T cells in systemic lupus erythematosus by thymosin and cultured thymic epithelium

Patients with systemic lupus erythematosus lacked suppressor T cell function. Suppressor cell activity was induced in cells from many of these patients by incubation with thymosin or cultured thymic epithelium. These results suggest that thymic manipulation may be a useful therapeutic modality in this disease.