Altered function of suppressor T lymphocytes in patients with active systemic lupus erythematosus--in vitro immune response to autoantigen

The different immunomodulation of indirect moxibustion on normal subjects and patients with systemic lupus erythematosus

Moxibustion has been thought to enhance immunity in healthy condition, but suppress abnormal immune response in disease status. We collected 12 patients with systemic lupus erythematosus (SLE) and 12 healthy women who received indirect moxibustion on acupuncture points ST-36 (Zusanli) and SP-6 (Sanyinjiao) 20 minutes per day for 1 week. During the course, there were no changes of their regular medications or intercurrent infections in normal subjects and SLE patients. We found that indirect moxibustion for 1 week could elevate CD3+ and CD4+ T-lymphocytes in normal subjects, whereas decrease relative proportions of CD8+ T-lymphocytes in patients with SLE. This result confirms that indirect moxibustion has different immunomodulation in normal condition and autoimmune status. However, whether immunomodulatory effects of indirect moxibustion are beneficial for normal subjects and patients with SLE require further confirmation.

Brazilin augments cellular immunity in multiple low dose streptozotocin (MLD-STZ) induced type I diabetic mice

Brazilin, an active principle of Caesalprenia sappan, was examined for its immunopotentiating effects in multiple low dose streptozotocin (MLD-STZ) induced type diabetic mice. Brazilin was intraperitoneally administered for 5 consecutive days to MLD-STZ induced type I diabetic mice. Delayed type hypersensitivity, Con A-induced proliferation of splenocytes and mixed lymphocyte reaction, which had been decreased in diabetic mice, were significantly recovered by the administration of brazilin. Brazilin increased IL-2 production without affecting suppressor cell activity. Con A-induced and IL-2-induced expression of high affinity IL-2 receptors were also enhanced by brazilin. These results indicate that brazilin augments cellular immune responses, which are suppressed in the MLD-STZ induced type I diabetic mice, by increasing IL-2 production and responsiveness of immune cells to IL-2.

Characterization of inflammatory infiltrates in male pattern alopecia: implications for pathogenesis

Hair-bearing, transitional, and alopecic scalp from three males and one female with progressive pattern alopecia were examined. Ultrastructural studies disclosed measurable thickening of the follicular adventitial sheaths of transitional and alopecic zones compared with those in the non-alopecic zones. This finding was associated with mast cell degranulation and fibroblast activation within the fibrous sheaths. Immunohistochemically, control biopsies were devoid of follicular inflammation (n = 3), while transitional regions consistently showed the presence of activated T-cell infiltrates about the lower portions of follicular infundibula. These infiltrates were associated with the induction of class II antigens on the endothelial linings of venules within follicular adventitia and with apparent hyperplasia of follicular dendritic cells displaying the CD1 epitope. Inflammatory cells infiltrated the region of the follicular bulge, the putative source of stem cells in cycling follicles. The data suggest that progressive fibrosis of the perifollicular sheath occurs in lesions of pattern alopecia, and may begin with T-cell infiltration of follicular stem cell epithelium. Injury to follicular stem cell epithelium and/or thickening of adventitial sheaths may impair normal pilar cycling and result in hair loss.

Defective CD2 pathway T cell activation in systemic lupus erythematosus

CD2 (T11; sheep erythrocyte receptor) is the surface component of an alternative, antigen-independent pathway of human T cell activation. The response to certain anti-CD2 antibodies is relatively independent of accessory cell signals and therefore provides a direct measurement of T cell function. The CD2 pathway may be important in the differentiation of thymocytes, on which the expression of CD2 precedes the appearance of the CD3-T cell receptor complex. In view of the impaired T cell regulation of immune responses in patients with systemic lupus erythematosus (SLE), we examined the activation of peripheral blood lymphocytes by anti-CD2 antibodies in 57 SLE patients and 32 normal control subjects. The CD2 pathway response was lower in the SLE patients (P less than 0.0001); 18 of the 57 SLE patients had a lower response than any of the control subjects. The SLE low-responder patients did not differ from the normal-responder patients in terms of disease activity or use of antiinflammatory and immunosuppressive medications. Low responses to anti-CD2 were corrected to normal by the coaddition of a submitogenic amount of phorbol myristate acetate (1 ng/ml). In some low-responder patients, the responses were normalized by the removal of non-T cells. The data indicate that some SLE patients have impaired responses to CD2 pathway activation and that this may reflect intrinsic T cell defects and/or regulatory influences of non-T cells.

Interactions of IgG from SLE patients with peripheral blood mononuclear cells and adherent cell populations

Peripheral blood mononuclear cells (PBMCs) from normal control subjects were studied for their interactions with IgG isolated from normal or active systemic lupus erythematosus (SLE) sera. Preincubation of PBMCs with SLE IgG at 0.5-1.0 mg for 24 h followed by washing and subsequent cell culture for 7 days resulted in marked relative increase in cell supernatant IgG. These findings were noted with and without inclusion of cyclosporin A or indomethacin in cultures. Experiments using isolated normal adherent cell populations showed that SLE IgG but not normal IgG, when preincubated with adherent cell macrophage/monocyte populations, was capable of inducing the latter to produce suppressor factors capable of down modulating IgG production or release from normal non-adherent cells cultured with pokeweed mitogen. These findings suggest that IgG from active SLE patients may interact with both IgG-producing PBMC populations as well as adherent-cell populations to influence IgG production or release from subsequently cultured cells.

Effects of immunoglobulin G from patients with systemic lupus erythematosus on human B cell function

We examined the effect of systemic lupus erythematous (SLE) sera and Ig fractions on IgG and IgM release by cultured normal peripheral blood mononuclear cells (PBMC) when these cells were preincubated with serum dilutions or Ig fractions. Increases in both IgM and IgG (P less than 0.001 and less than 0.01) in cultured cell supernatants were recorded when PBMC were preincubated with SLE serum dilutions. IgG but not IgM from SLE was found to stimulate PBMC to release IgG (P less than 0.01). Similar results were obtained when SLE IgG was preincubated with adherent cell depleted cells (ADC) or isolated normal B cell fractions. When normal PBMC were preincubated with SLE serum or IgG and subsequently stimulated with pokeweed mitogen (PWM), a relatively blunted IgG release was observed (P less than 0.05); however, IgM release was significantly increased (P less than 0.001). This effect was not observed when PBMC were preincubated with SLE IgM, normal serum dilutions, or normal Ig fractions. Relative blunting of PWM response after PBMC were preincubated with SLE IgG was not reversed in PBMC depleted of adherent cells, OKT8+, or OKT9+ cells. Depletion of PBMC of LeuM1 cells increased IgG release in response to PWM when cells had been preincubated with SLE IgG. SLE serum or Ig fractions did not induce B cell growth factor release by T cells. SLE IgG appeared to act directly on B cell enriched populations to release IgG; this was not associated with significant increase in thymidine uptake, or apparent lysis of cells.

In vitro production of autoantibodies to U1 ribonucleoproteins by peripheral blood mononuclear cells from patients with connective tissue diseases

Antibodies to U1 ribonucleoproteins produced by peripheral blood mononuclear cells from patients with connective tissue diseases were measured by a sensitive enzyme-linked immunosorbent assay and by immunoblotting. Mononuclear cells from patients with high-titer serum antibodies spontaneously started secreting IgG anti-U1 RNP antibodies on the second day after culture. The amount of anti-U1 RNP in the culture supernatants reached maximum level on day 8. The most effective production of anti-U1 RNP by B cells was observed when they were cultured in the presence of T cells and adherent cells. Mononuclear cells from patients without anti-U1 RNP antibodies or from normal subjects did not produce a measurable amount of anti-U1 RNP. Treatment of mononuclear cells by cycloheximide resulted in complete inhibition of anti-U1 RNP secretion, which indicates that antibody in the culture supernatants reflects the active biologic phenomenon in vitro. The methods described should be useful in the study of the cellular mechanisms involved in antinuclear antibody production of connective tissue diseases.

Abnormal production of and response to B-cell growth factor and B-cell differentiation factor in patients with systemic lupus erythematosus

We examined the production of and the response to B-cell growth factor (BCGF) and B-cell differentiation factor (BCDF) in 21 patients with systemic lupus erythematosus (SLE) and 23 normal subjects. T cells, 2.5 X 10(6)/ml, were cultured for 24 or 72 h with 1% phytohaemagglutinin (PHA). After absorption of PHA by chicken erythrocytes (CRBC), they were used for BCGF and BCDF. In inactive SLE, BCGF activity was significantly lower than that in normal subjects. Active SLE contained two separate groups, one showing normal BCGF activity and the other showing lower activity than normal. In contrast, BCDF activity from initial culture in active SLE was elevated. The B-cell response both to BCGF and BCDF was elevated in active SLE without Staphylococcus aureus Cowan I antigen (SAC) preactivation. However, the B-cell response to SAC was markedly disturbed. Thus SLE B cells were shifted to the mature state in vivo. We also demonstrated pivotal abnormalities of monocytes in SLE B-cell growth and differentiation. These results may contribute to the understanding of the abnormalities of T-B interactions and the overproduction of antibody in SLE.

Deficient helper cell function as a cause of diminished pokeweed mitogen blastogenic responses in patients with non-Hodgkin's lymphomas

An investigation has been made of immunoregulatory T-cell function in the non-Hodgkin's lymphomas by comparing immunoregulation of healthy control and patient peripheral blood lymphocyte blastogenic responses to pokeweed mitogen. Normal mononuclear leukocytes (MNL) had significantly higher responses than patient MNL. MNL were subsequently separated into T- and non-T-cell fractions by differential E-rosette sedimentation for co-culture experiments. When normal non-T-cells and autologous irradiated T-cells were recombined, the mitogenic response again exceeded the response of patient non-T-cells recombined with their own irradiated T-cells. However, when normal non-T-cells were co-cultured with patient irradiated T-cells, the mitogenic response was diminished. Moreover, when patient non-T-cells were co-cultured with normal irradiated T-cells, a normal proliferative response occurred. These differences in non-T-cell response are not simply a result of allogeneic effects, since normal non-T-cell responses were the same regardless of whether autologous or normal allogeneic irradiated T-cells were used as helpers. Furthermore, co-culture of normal non-T-cells simultaneously with autologous irradiated T-cells and patient irradiated T-cells revealed no diminution of blastogenic response compared with co-cultures of normal non-T-plus autologous irradiated T only, suggesting no net suppression by patient irradiated T-cells. Studies with monoclonal antibodies revealed that patient T-cells had normal to increased ratios of OK-T4+:OK-T8+ cells. These results suggest that peripheral blood T-cells from patients with non-Hodgkin's lymphomas, despite the presence of a normal to increased ratio of OK-T4+:OK-T8+ cells, are functionally deficient in their helper capacity for non-T-cell blastogenic response to pokeweed mitogen. Abnormal helper T-cell function may explain some of the immune deficits in patients with non-Hodgkin's lymphoma and may be important in the pathogenesis of these diseases.

T cell subpopulations in alopecia areata

Alopecia areata remains a disease of unknown cause and unsatisfactory treatment. Histologically it is characterized by a lymphocytic infiltrate that surrounds the lower half of the hair follicle. Our findings show that 64% to 92% of this infiltrate is composed of T lymphocytes bearing the Leu 3a (helper-inducer) phenotype. The remaining lymphocytes demonstrate the Leu 2a (cytotoxic-suppressor) phenotype. This helper T cell predominance is present in all patients, irrespective of clinical activity or duration of disease. The Leu 3a/Leu 2a ratio ranged from 2.6 to 19.8, the higher ratios being seen in patients with clinically active disease. The cutaneous infiltrate also is Ia-positive, indicating the activated nature of these lymphocytes.

Cellular mechanism of DNA-specific antibody synthesis by lymphocytes from systemic lupus erythematosus patients

The cellular mechanism of anti-DNA antibody synthesis in patients with systemic lupus erythematosus (SLE) was studied by DNA-specific solid-phase radioimmunoassay. Anti-DNA antibody synthesis in response to DNA was T-dependent, and the experiments with reconstituted lymphocytes from identical twins discordant for SLE showed that B cells and T cells from SLE patients must cooperate to synthesize anti-DNA antibody. Anti-DNA antibody synthesis by lymphocytes from patients with inactive SLE was enhanced by T4 cells and suppressed by T8 cells in response to DNA. Although T4 cells from patients with active SLE could enhance anti-DNA antibody synthesis by autologous B cells, their T8 cells could not suppress anti-DNA antibody synthesis by autologous B cells. These results indicate that elevated anti-DNA antibody synthesis in response to DNA in patients with active SLE is due to abnormalities of both SLE B cells and SLE T cells. They further indicate that dysfunction of T8 cells from patients with active SLE may, in part, be responsible for deficient regulation of anti-DNA antibody synthesis.

Suppressor T cell function in patients with rheumatoid arthritis complicated by vasculitis

Concanavalin A (Con A)-induced suppressor T cell activity was determined in 10 rheumatoid arthritis (RA) patients with vasculitis, 34 RA patients without vasculitis, and 10 healthy individuals. The percent Con A-induced suppression in RA patients with vasculitis was 24.6. In contrast, it was 68.4% in those RA patients without vascular lesions. Further, the proportion of T cells reactive with OKT8 monoclonal antibody was also decreased in RA patients with vasculitis. Accordingly, the reduced Con A-induced suppressor T cell activity in these RA patients resulted, in part, from the reduction in the number of cells of the suppressor T cell subset. Those patients with vascular lesions also had a higher percentage of positive antilymphocytotoxic antibodies than RA patients without vasculitis. Since the differences in Con A-induced suppressor T cell activity and frequency of positive antilymphocytotoxic antibodies were so great, we believe RA patients with vasculitis could be recognized as a disease group distinct from RA patients without vasculitis.

Potentiation of the canine lymphocyte blastogenic response by indomethacin

Cultivation of normal canine peripheral blood lymphocytes in the presence of indomethacin, a potent prostaglandin synthetase inhibitor, produced a consistent potentiation of their in vitro response to mitogenic stimulation as compared to cultures without indomethacin. The enhancing effect of indomethacin increased with decreasing concentrations of mitogens. Indomethacin had to be added to the cultures during the first four hours for the potentiating effect to be observed. These data suggest that prostaglandins may play an important role in the regulation of the dog's immune response.

[Pathogenesis and immunotherapy of insulin-dependent (type I) diabetes mellitus]

The association of insulin-dependent (type I) diabetes mellitus with HLA-DR3 and DR4 and with several epidemiological, virological, immunological, and clinical data suggests a heterogenous pathogenesis. the initial lesion in most cases is a virologically induced autoimmune process. It is only rarely that insulin-dependent diabetes results from a pure viral infection or as part of polyendocrine autoimmune deficiencies. The knowledge of the genetical risk factors and of disease-specific humoral and cellular immune deviations exhibits possibilities of successful intervention by means of immunotherapy.

A selective effect upon IgG synthesis by T gamma lymphocytes and their products in man

Depletion of T lymphocytes possessing receptors for IgG (T gamma cells) from peripheral blood lymphocytes (PBL) results in enhanced pokeweed mitogen (PWM)-induced IgG synthesis and secretion as compared to IgM. Concanavalin A (Con A) stimulation of T gamma cells causes release of soluble mediators able to suppress immunoglobulin synthesis by PWM-activated PBL. Such factors cause concentration-dependent selective suppression of IgG synthesis. The mediators act upon T gamma cell-depleted lymphocyte populations, also preferentially suppressing the IgG PFC response while leaving the IgM response relatively intact. Thus T gamma cells and their products selectively affect IgG synthesis in vitro.

Nucleoside-specific suppression in MRL/MP +/+ mice

The induction of nucleoside-specific nonresponsiveness was further studied in the autoimmune strain MRL/MP +/+ (MRL/n). Experiments were undertaken to determine (i) whether nucleoside-conjugated spleen cells are able to induce specific nonresponsiveness to T-dependent nucleoside antigens in MRL/n mice, and (ii) whether periodic treatment with nucleoside-conjugated spleen cells would retard the development of spontaneous anti-DNA antibodies and associated indicators of autoimmunity. The results show that nonresponsiveness to nucleoside antigens is inducable in male, but not in female, MRL/n mice. Nonresponsiveness in male MRL/n was transferable and mediated by T cells. Treatment of male MRL/n mice with nucleoside-conjugated spleen cells (NSC) appeared to attenuate the progress of autoimmune symptoms in experimental animals. These results are discussed in the context of recent studies exploring the etiology of autoantibody production and the loss of self-tolerance in murine models of autoimmunity.

In vitro immune response of SLE lymphocytes. The mechanism involved in B-cell activation

Peripheral blood lymphocytes from 26 patients with systemic lupus erythematosus (SLE) and six normal individuals were tested for IgG synthesis in the presence or absence of PWM. Lymphocytes from patients with active SLE synthesized increased amounts of IgG in the absence of PWM and reduced amounts of IgG in the presence of PWM. Serum from patients with active SLE had an enhancing effect on the in vitro IgG synthesis of normal lymphocytes. The IgG or F(ab')2 fractions of SLE serum retained the enhancing effect on in vitro IgG synthesis, and the enhancing activity was absorbed by human spleen cells. As little as 4 h of incubation with SLE serum was needed for the enhancing activity of normal lymphocytes. Treatment of B lymphocytes appeared to be of main importance for an increase in the in vitro IgG synthesis of SLE serum-treated lymphocytes. These results suggest that anti-B-lymphocyte antibodies from patients with active SLE are responsible in part for the hyperactive response of SLE B lymphocytes.

Effect of indomethacin on phytohemagglutinin-stimulated peripheral blood lymphocytes in thyroid autoimmune diseases

Suppressor lymphocyte function was evaluated in control subjects and in patients with autoimmune thyroid disease, utilizing an assay in which indomethacin was added to lymphocyte cultures to inhibit prostaglandin-producing suppressor cells. This assay is based on the observation that the addition of indomethacin, a potent prostaglandin synthesis inhibitor, to phytohemagglutinin-stimulated peripheral blood lymphocytes should cause an increase in the incorporation of iododeoxyuridine in control subjects and a smaller increase in diseases with reduced prostaglandin-producing suppressor cells. The addition of indomethacin, 1 microgram/ml, stimulated iododeoxyuridine incorporation in phytohemagglutinin-stimulated cultures in control subjects to an index value of 1.43 (i.e., the increment in iododeoxyuridine incorporation with both indomethacin and phytohemagglutinin was 43% greater than the incorporation with phytohemagglutinin alone). The stimulation index was significantly lower in patients with Graves' disease who were toxic and untreated (1.18 +/- 0.25, mean +/- SD; P less than 0.003). Patients who were toxic while receiving antithyroid drugs or after radioiodine therapy or patients euthyroid after treatment had a mean stimulation index in the normal range, although the spread of data was very large in these groups. Responses in patients with Hashimoto's thyroiditis were also quite variable. The average response was 1.74 +/- 0.72, with 40% of the patients showing a high stimulation index. This study supports our previous investigations in which we used different assay systems for measuring suppressor-cell function in patients with thyroid autoimmune diseases and indicates that a defect in suppressor lymphocyte function is measureable by another technique. The abnormality persists in some cases after metabolic control has been achieved, but usually returns toward normal over months or years.

Enumeration of T-lymphocytes and T-lymphocyte subsets in rheumatoid arthritis using monoclonal antibodies

The number of T-lymphocytes and T-lymphocyte subsets was measured in peripheral blood of 51 patients with rheumatoid arthritis. T-lymphocytes were counted by E-rosette tests and by the immunogold staining method with OKT3.PAN monoclonal antibody. Helper and suppressor T-lymphocytes were determined by the immunogold staining method with OKT4.IND and OKT8.SUP monoclonal antibody. The relative and absolute numbers of T-lymphocytes and helper T-lymphocytes in peripheral blood of patients with RA did not differ significantly from those in the blood of healthy subjects. However, the relative and absolute numbers of suppressor T-cells were significantly lower in patients with RA than in healthy subjects. The decrease of suppressor T-cells in the blood of patients with RA dit not correlate with the activity of the disease nor the presence of the rheumatoid factor.

Suppressor cell activity and beta-cell function in insulin-dependent diabetics

Immunological mechanisms may play a role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM), and suppressor cell activity (SCA) has been found depressed at diagnosis. The aim of the present study was to elucidate whether patients with preserved beta-cell function display a different SCA than other patients. Sixteen patients without and 12 patients with beta-cell function after averagely 9 years' duration of IDDM were examined. The suppressive effect of lymphocytes was investigated after incubation with concanavalin A followed by inactivation. Suppression was measured as the ability of the lymphocytes to inhibit 3H-thymidine incorporation in concanavalin A stimulated normal donor lymphocytes. The main findings were: (1) No significant differences in SCA between patients with and without beta-cell function, and one of these patient groups had SCA significantly different from normal controls. (2) A correlation between SCA and administered dose of insulin among patients without beta-cell function. It is concluded that the actual SCA several years after diagnosis is not connected with the beta-cell function in patients with IDDM.

Immunological aspects of psoriasis: V. T. cell subsets and suppressor cell functions regulating immune responses in peripheral blood

T cell subsets bearing Fc-receptors for either IgG (TG) or IgM (TM), and suppressor cell activity of peripheral blood mononuclear cells on in vitro lymphoproliferative responses were studied in patients with untreated psoriasis. The proportions of TG and TM cells were unmodified in 15 patients compared to 15 control subjects studied in parallel experiments. The concanavalin A-induced suppressor cell activity, as well as the spontaneous suppressor cell function of in vitro short-lived adherent cells, were in the normal range for 7 out of 8 psoriatic patients investigated. The data argue against the possibility that a generalized suppressor cell defect occurs in psoriasis.

Association between endogenously activated T cells and immunoglobulin-secreting B cells in patients with active systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is characterized by increased numbers of circulating B cells activated polyclonally to secrete immunoglobulin. Because T cells secrete, or shed, various factors that are functionally important in regulating immunoglobulin production by B cells, a reverse hemolytic plaque assay was developed to quantitate such activated T cells. In this technique, we used a rabbit antiserum raised to supernatants of concanavalin-A--stimulated human lymphocytes. The relevant antigenic specificity of this antiserum is directed toward the shed surface membrane determinant(s) preferentially expressed on activated T cells. Freshly isolated peripheral blood mononuclear cells from 14 SLE patients contained more than 10 times the number of endogenously activated T cells than cells from normal subjects. Within the SLE group, plaque-forming T cells were particularly increased in patients with active disease. By linear regression analysis, a significant positive correlation was revealed between such activated T cells and immunoglobulin-secreting B cells, also measured by a reverse plaque assay (r = 0.83). It appears that both activated B cells and T cells circulate in increased numbers in SLE. Additional investigation will be required to define the molecular nature of the T cell product(s) being measured and to clarify the relationship of these findings to the immunoregulatory abnormalities in this disorder.

Mitogenic responses to lipopolysaccharide by B lymphocytes from patients with systemic lupus erythematosus

Peripheral blood lymphocytes from 43 patients with systemic lupus erythematosus (SLE) and from age- and sex-matched normal controls were cultured with lipopolysaccharide (LPS) to examine the response to the polyclonal B-cell activator. Lymphocytes from active SLE patients incorporated 4840 +/- 471 (mean +/- SE) cpm in response to LPS, whereas lymphocytes from inactive SLE patients incorporated 6906 +/- 897 cpm. In contrast, lymphocytes from normal individuals incorporated 7452 +/- 1126 cpm. Ig synthesis of lymphocytes from active SLE in response to LPS stimulation was also less than that of normal individuals. The helper T-cell function of active SLE, as examined by co-culturing irradiated SLE lymphocytes with unirradiated normal lymphocytes, was normal. These results thus suggested that a defect of B lymphocytes exists in active SLE patients. This B-cell defect and T suppressor cells apparently play an important role in the pathogenesis of SLE.

Depressed primary in vitro antibody response in untreated systemic lupus erythematosus. T helper cell defect and lack of defective suppressor cell function

The in vitro antibody response of peripheral blood lymphocytes (PBL) from 19 patients with untreated systemic lupus erythematosus (SLE) was compared with that of 20 control patients and 44 normal subjects. Trinitrophenyl polyacrylamide beads (TNP-PAA) were used to induce IgM anti-TNP plaque-forming cells. SLE patients displayed a markedly depressed, and in most instances virtually absent, response. This was not due to an unusual kinetics of the response; nor could it be induced by preincubation of SLE patients' PBL. In co-cultures of SLE patients and normal PBL, the former, with few exceptions, did not exert a suppressive effect. In four patients the anti-TNP response of either unfractionated or T-depleted SLE PBL could be restored by T cells from a normal individual. Conversely in three of these patients, SLE T cells could not support the response of normal B cells, suggesting a T helper cell defect in SLE PBL. Concanavalin A (Con A)-induced suppressor cells of the antibody response could be assayed by two approaches: (a) in responder SLE patients, by the direct addition of Con A to TNP-PAA-stimulated cultures; (b) in seven patients by transfer of Con A-activated cells to the responding culture of a normal allogeneic donor. In both cases SLE PBL were able to exert a suppressive effect to the same extent as normal PBL.

The cellular basis of impaired T lymphocyte functions in the elderly

Immunologic changes associated with aging were studied by various immunologic tests in 24 aged persons (age range, 76-83) and 25 young persons (age range, 20-40). The responses to phytohemagglutinin (PHA) and concanavalin A (Con A) were depressed in the aged subjects compared to the young ones (p less than 0.05), whereas the responses to pokeweed mitogen (PWM) were similar. The activity of adhereent and non-adherent cells was assessed in various combinations. The adherent cells of aged persons were indistinguishable from those of young persons in their ability to response to Con A. Lymphocytes from the aged synthesized larger in vitro amounts of immunoglobulin than did lymphocytes from the young, when stimulated with PWM. Con A-stimulated T lymphocytes derived from aged subjects showed a variable loss of suppressor activity. The mixed lymphocyte culture reaction with mitomycin-treated allogeneic and autologous cells was also impaired in aged subjects. Such an impaired response in the aged is related to higher incidences of malignant lesions and auto-antibodies.

Studies of anti-lymphocyte antibody in patients with active SLE. II. Effect of anti-lymphocyte antibody on autoreactive cell clones

The effect of anti-lymphocyte antibodies of active systemic lupus erythematosus (SLE) on the immune regulation of autoantibody production was studied. The present study demonstrated that there were native DNA (nDNA)-sensitized T lymphocytes even in inactive SLE and no or few nDNA-sensitized T lymphocytes in normal individuals, and that in the inactive stages of SLE suppressor T lymphocytes might inhibit the activation of nDNA-sensitized T lymphocytes eliciting the production of anti-DNA antibodies by B lymphocytes. In the active stage of SLE, the anti-lymphocyte antibodies could eliminate the suppressor function of T lymphocytes or a subset of cells capable of either regulating their appearance or differentiating into them, which inhibited such responses. The different suppression of DNA and extractable nuclear antigen (ENA)-stimulated blastogenic response is further discussed.

Studies of anti-lymphocyte antibody of patients with active SLE. I. Cause of loss of suppressor T-lymphocyte function

Effect of anti-lymphocyte antibody of active systemic lupus erythematosus (SLE) on lymphocyte function was examined. Lymphocytes from normal individuals treated with anti-lymphocyte antibody and complement exhibited marked inhibition of response to concanavalin A (Con A), while the response of lymphocytes to phytohaemagglutinin M (PHA-M) and pokeweed mitogen (PWM) was slightly affected. In mixed lymphocyte culture response, both stimulator and responder cells were insensitive to anti-lymphocyte antibody. Treatment of sensitized lymphocytes with anti-lymphocyte antibody and complement caused a dose-dependent suppression of blastogenic response to purified protein derivatives (PPD). No effect, however, was noted on migration-inhibitory factor (MIF)-producing cells. In PWM-driven Ig synthesis, T lymphocytes lacking the anti-lymphocyte antibody-reactive T-cell subset enhanced PWM-driven Ig synthesis of autologous B lymphocytes. Con-A-induced suppressor function of lymphocytes was abolished by the treatment with anti-lymphocyte antibody and complement. The present study demonstrated that lymphocytes from normal individuals after treatment with anti-lymphocyte antibody and complement showed similar immunological reactivities with lymphocytes from active SLE, indicating that those anti-lymphocyte antibodies could play an important role in defective suppressor cell function.