Loss of suppressor T-lymphocyte function in patients with systemic lupus erythematosus (SLE).

Immunological reactivity in patients with SLE was studied in vitro trinitrobenzene sulphonate (TNP) specific antibody formation by peripheral blood lymphocytes. Lymphocytes from patients with SLE could produce an increased number of TNP-specific plaque-forming cells (PFC), while no such response could be seen in normal controls. Co-culture of lymphocytes from active SLE patients and normal controls was performed with TNP-Horse red blood cells (TNP-HRBC). The number of PFC by B lymphocytes from active SLE patients was suppressed by T lymphocytes from normal controls. On the other hand, the number of PFC by B lymphocytes from normal controls was increased by T lymphocytes from active SLE patients. Co-culture of lymphocytes from identical twins discordant for SLE was also performed, and the same results were obtained. We further examined the effects of Con A on antibody formation. Con A-treated T lymphocytes from a normal control markedly suppressed TNP-specific PFC by peripheral lymphocytes from active SLE patients. However, Con A-treated T lymphocytes from an active SLE patient did not suppress TNP-specific PFC by lymphocytes from another active SLE patient. These results suggest that active SLE patients showed a loss of suppressor T-lymphocyte function.     

Frequency of anti-DNA antibody producing cells from normals and patients with systemic lupus erythematosus

The frequency of anti-DNA antibody producing cells from normals and patients with systemic lupus erythematosus (SLE) was determined. Peripheral blood lymphocytes (PBL) from normals and patients with SLE were cultured for 8 and 15 days with and without transformation by Epstein-Barr virus (EBV). Culture supernatants were examined for the presence of anti-DNA antibody using an enzyme-linked immunosorbent assay. We found that PBL from patients with SLE spontaneously produce anti-DNA antibodies whereas PBL from normals do not. After EBV transformation, anti-DNA antibody producing cells were detected in both cultures from patients with SLE as well as from normals. These data suggest that the high levels of anti-DNA antibody observed in patients with SLE represent activation of B cells committed to anti-DNA antibody production and that such cells are present but are not activated in normal individuals.     

Mitogenic Responses to Lipopolysaccharide by B Lymphocytes from Patients with Systemic Lupus Erythematosus

Peripheral blood lymphocytes from 43 patients with systemic lupus erythcmatosus (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 pathogenous of SLE.     

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.     

Antibody-dependent direct cytotoxicity of human lymphocytes. I. Studies on peripheral blood lymphocytes and sera of patients with systemic lupus erythematosus.

Antibody-dependent direct cytotoxicity (ADDC) is generally believed to be unrelated to T-cell function in experimental animals. The role of ADDC in humans and its clinical usefulesss was evaluated in patients with systemic lupus erythematosus (SLE) and normal controls. Peripheral blood lymphocytes from patients with active SLE were unable to lyse antibody-coated target cells in vitro to the same degree as lymphocytes from patients with inactive SLE and controls. Sera from patients with active SLE suppressed ADDC by lymphocytes derived from normal controls and this abnormality was not corrected by overnight incubation or by extensive washing of lymphocyte preparations. Although there was poor correlation between ADDC and the proportions of B cells and null cells in effector lymphocyte populations from SLE patients and controls, it is concluded that this assay provides another means of determining immune competence in man.     

Immunoglobulin production in vitro by peripheral blood lymphocytes in systemic lupus erythematosus: helper T cell defect and B cell hyperreactivity

Peripheral blood lymphocytes (PBL) from 16 patients with systemic lupus erythematosus (SLE) and 15 healthy control subjects were cultured and immunoglobulin (Ig) production in vitro was measured by immunofluorescent staining for intracytoplasmic Ig, a reverse haemolytic plaque assay to quantify cells secreting Ig and a solid-phase radioimmunoassay for Ig secreted into culture supernatants. Compared with normal PBL, lymphocytes from patients with SLE produced significantly fewer Ig-containing cells, Ig-secretion cells (ISC) and less Ig in supernatants in cultures stimulated by pokeweed mitogen (PWM). These differences were most pronounced during phases of disease activity. Culturing SLE PBL with a supernatant obtained from PWM-activated cultures of normal T lymphocytes partially restored their capacity to produce ISC. This observation suggests a helper T cell defect of SLE lymphocytes. In addition, PBL from patients with active SLE generated more ISC when cultured with Staphylococcus aureus bacteria (S aureus) than with PWM. S. aureus-stimulated cultures of SLE PBL also generated more ISC than PBL from normal individuals. The S. aureus response of SLE lymphocytes did not correlate with disease activity. As S. aureus is a T cell-independent mitogen, the latter observations suggest that in SLE an intrinsic B cell hyperreactivity may be a more persistent defect whereas T cell defects are transitory.     

In Vitro Immune Response of SLE Lymphocytes

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.     

Defective monocyte function in patients with systemic lupus erythematosus

Peripheral blood adherent cells from patients with systemic lupus erythematosus (SLE) were shown to have markedly reduced phagocytic activity as compared to normal adherent cells or those from non-SLE patients receiving corticosteroid therapy. Both resting and phagocytosing monocytes showed decreased hexose monophosphate shunt and glycolytic activity. Mononuclear cells from SLE patients showed grossly impaired proliferative activity after NaIO4 activation. Furthermore, addition of SLE adherent cells to normal adherent cell-depleted lymphocytes decreased [3H]thymidine incorporation of the latter cells following NaIO4 treatment. Addition of normal adherent cells to SLE lymphocytes corrected the previous defect, indicating that an adherent abnormality is responsible for the defect in SLE mononuclear cell proliferation to NaIO4 activation.     

Defective B cell function in systemic lupus erythematosus.

The in vitro synthesis of specific anti-influenza virus antibody was measured in cultures of peripheral blood lymphocytes from 25 patients with systemic lupus erythematosus (SLE) and 23 control subjects. Whilst all cultures derived from normal individuals synthesized specific antibody, cultures from patients with SLE were consistently unable to produce anti-influenza antibody. This defect could not be corrected by manipulating the culture conditions or by in vivo immunization. Co-cultivation of separated SLE-B or control B cells, with SLE-T or control T cells showed that the immunodeficiency exhibited by the SLE peripheral blood lymphocytes resides in the B cells.     

CD40在系统性红斑狼疮外周血淋巴细胞的表达

使用密度离心法分离SLE患者和正常人外周血单个核细胞 (PBMC ) ,采用流式细胞术检测B淋巴细胞白细胞分化抗原 4 0 (CD4 0 )的表达水平 ,进行SLE患者 (活动期和缓解期 )和正常人之间的比较 ;并进行B淋巴细胞CD4 0表达水平和血清抗dsDNA抗体水平及狼疮活动指数 (SLEDAI)的相关分析。结果表明 ,活动期SLE患者外周血B淋巴细胞比例 (% )和其表达CD4 0的比例 (% )均明显高于缓解期SLE患者和对照组 ,其表达CD4 0的平均荧光强度 (MFI)在活动期SLE患者最高 ,缓解期SLE患者稍低 ,对照组最低 ;相关分析结果表明 ,活动期SLE患者B淋巴细胞CD4 0的表达比例 (% )和强度 (MFI)均与血清抗dsDNA抗体及SLEDAI呈正相关 ,后两者呈高度相关 ;缓解期SLE患者B淋巴细胞表达CD4 0的强度 (MFI)和SLEDAI呈正相关。CD4 0在活动期SLE患者B淋巴细胞的表达增加 ,其水平与疾病活动度有关。     

In vitro activity of anti-DNA antibodies from SLE patients in antibody-dependent cell-mediated cytotoxicity.

Peripheral blood lymphoid cells from normal individuals were cytotoxic to target cells coated with DNA when incubated with serum from patients with systemic lupus erythematosus (SLE) but not when incubated with serum from normal subjects. Sera from SLE patients with clinically acitve disease were more active than sera obtained from those patients in remission. In the absence of normal lymphocytes, SLE sera were not cytotoxic to the DNA-coated cells. The active fraction in the serum appeared to be IgG anti-DNA antibodies. These studies indicate that anti-DNA can operate through the antibody-dependent cell-mediated cytotoxicity mechanisms in vitro.     

In vitro inhibition of anti-DNA producing cells from systemic lupus erythematosus patients by autologous anti-F(ab')2 antibodies

We have previously documented an inverse relationship between serum levels of anti-F(ab')2 antibodies and disease activity in systemic lupus erythematosus (SLE). The present study focused on the specific in vitro inhibition of anti-DNA producing cells from SLE patients by autologous anti-F(ab')2 antibodies. Peripheral blood lymphocytes (PBL) from eleven inactive SLE patients with no apparent disease activity were cultured in vitro to evaluate anti-DNA antibody secretion. Low levels of synthesis of anti-DNA antibody were detected in 3 of 11 SLE patients using unstimulated PBL; on the contrary, pokeweed mitogen stimulation of cultured cells increased production of anti-DNA in all SLE subjects. Parallel cultures were also performed in the presence of heterologous and autologous anti-F(ab')2 antibodies and results on production of anti-DNA evaluated. Lymphocytes from SLE patients in remission showed inhibition of synthesis of anti-DNA antibodies when autologous anti-F(ab')2 antibodies were added to the cultures, whereas production of anti-tetanus toxoid IgG by the same cells was not significantly altered under the same conditions. These data suggest that a functional anti-idiotypic role may be assigned to anti-F(ab')2 antibodies during clinical remission of SLE.     

Multiple B cell stimulation by individual antigen-specific T lymphocytes

Recently, an experimental system has been described which allows for the isolation and antigenic stimulation of individual antigen-specific helper T lymphocytes in collaboration with a nonlimiting number of primary B lymphocytes. In the studies presented in this report, this system has been employed to determine whether an individual T lymphocyte has the potential to interact with more than a single B lymphocyte, when the B cells are of different antigenic specificities. The results of these studies indicate that an individual influenza virus PR 8-specific T lymphocyte has the ability to promote antibody responses of both trinitrophenyl (TNP)- and PR8-specific B lymphocytes in response to the in vitro antigen TNP-PR8. Similar results were obtained when T cells specific for the hapten TNP were used in collaboration with TNP- and PR8-specific B cells. These results demonstrate that an individual T lymphocyte has the potential to collaborate with more than one B lymphocyte, and that these B cells may differ in their antibody receptor for antigen. These results do not rule out a role for idiotype or allotype-specific T cells in antibody responses but, rather, strongly argue that antigen-specific T cells are able to independently initiate primary B cell responses of B cells with distinct antibody receptors. In addition, under these conditions, hapten-specific helper T cells can be readily demonstrated and may facilitate the response of B cells specific for the same or different determinants.     

Specific allogeneic help by T lymphocytes from patients with systemic lupus erythematosus.

Unfractionated mononuclear cells from patients with systemic lupus erythematosus (SLE) immunized with influenza vaccines do not produce a secondary in vitro anti-influenza antibody response when challenged with virus antigen. Irradiated T lymphocytes from normal, disease control and from SLE donors whether vaccinated or not, help allogeneic normal non-T cells to produce specific anti-influenza antibody in vitro. Irradiated normal T cells, however, do not help allogeneic non-T cells from SLE donors. Non-irradiated T cells from 40% of the SLE patients, irrespective of whether or not they had been vaccinated, also provide specific help for MLC incompatible normal non-T cells in the influenza antibody response. This non-restricted interaction was not seen using non-irradiated T cells from any normal or disease control donor. No anti-DNA antibodies were produced in virus stimulated cultures of non-irradiated or irradiated SLE T cells with allogeneic normal non-T cells.     

Impaired responsiveness of lymphocytes in patients with systemic lupus erythematosus

Cellular immune responsiveness, as measured by lymphocyte transformation in one-way mixed leucocyte cultures (MLC) and in phytohaemagglutinin (PHA) stimulated cultures was evaluated in forty patients with systemic lupus erythematosus (SLE) and in seventy-four normal controls. The effect produced by sera from these subjects on in vitro lymphocyte reactivity was tested on autologous cells and on homologous responding cells from a constant panel of ten healthy volunteers.

The reactivity of lymphocytes from SLE patients to PHA and to a battery of allogeneic cells was significantly lower than that of normal controls.

Sera from some SLE patients inhibited the MLC reactions, while in other cases a distinct stimulatory effect was found.

It is suggested that virus-induced modifications of normal histocompatibility antigens cause the appearance of blocking antibody that might bind to the surface of T lymphocytes, impairing their function.

     

Mononuclear phagocytes from patients with active systemic lupus erythematosus down-regulate the specific in vitro reactivity of autologous lymphocytes to double-stranded DNA.

Peripheral mononuclear cells (MNC) from patients with systemic lupus erythematosus (SLE) are hyporesponsive in vitro. In order to study the role of mononuclear phagocytes (m phag) in regulating the in vitro responses of autologous lymphocytes, the MNC from 16 SLE patients (eight active, eight inactive) and 14 healthy controls were stimulated in vitro with PHA or dsDNA. The proliferative response to PHA was tested by 3H-thymidine incorporation on day 4 and the response to dsDNA using a specific haemolytic plaque assay. Indomethacin, an inhibitor of prostaglandin (PG) synthesis by m phag, was added into the cultures to test the presence of suppressive m phag acting through a PG-mediated pathway. Indomethacin augmented the proliferative response to PHA in active SLE cultures and not in inactive SLE or controls. In six of 13 SLE cultures, dsDNA totally or partly suppressed anti-dsDNA plaque-forming cell (PFC) generation. Indomethacin restored or enhanced the PFC response to dsDNA in active SLE and not in inactive SLE or controls. M phag depletion by plastic adherence prevented the effects of indomethacin. These results show that m phage exerting a suppressive activity on PHA-induced lymphocyte proliferation and on anti-dsDNA antibody production are found in cultures from active SLE and generally not in inactive SLE or healthy individuals. PHA being primarily a T-cell stimulator, the m phag suppressive activity observed in PHA-stimulated cultures is exerted on T cells. On the other hand, in two active SLE cultures depleted of T cells by OKT3 antibody, indomethacin still could enhance the PFC response to dsDNA, showing that in vitro suppressive m phag can act directly on B cells from patients with active SLE.     

Spontaneous production of antibodies to deoxyribonucleic acids in patients with systemic lupus erythematosus

In vitro spontaneous anti-DNA antibody production in patients with systemic lupus erythematosus (SLE) was examined. SLE lymphocytes produced IgG and IgM anti-DNA antibody from the third culture day, and reached a plateau on the seventh culture day. This anti-DNA antibody activity in 7-day culture supernatant was abolished by pretreatment of the lymphocytes with cycloheximide, suggesting de novo immunoglobulin synthesis was required for this spontaneous anti-DNA antibody production. Lymphocytes from patients with rheumatoid arthritis (RA) and other collagen diseases including progressive systemic sclerosis, polymyositis/dermatomyositis, and polyarteritis nodosa did not produce IgG and IgM anti-DNA antibody spontaneously, but SLE lymphocytes produced substantial amounts of IgG and IgM anti-DNA antibody spontaneously. Furthermore, active SLE produced a larger amount of IgG anti-DNA antibody than inactive SLE. We observed a significant negative correlation between the number of Ia+ T cells and IgG, but not IgM, anti-DNA antibody production. Furthermore, spontaneous IgG anti-DNA antibody production was elevated after pretreatment of SLE T cells with anti-Ia and complement, suggesting that Ia+ T cells in SLE bring about suppression of autologous B cells producing IgG anti-DNA antibody.     

Effects of dexamethasone on the expression of Fas molecules and apoptosis of lymphocytes in patients with systemic lupus erythematosus

Previous studies have shown that the autoimmune phenomenon could be caused by defective apoptosis of autoreactive lymphocytes. Corticosteroids used for treatment of systemic lupus erythematosus (SLE) are potent apoptosis inducers. We examined dexamethasone (DEX)-induced apoptosis and Fas expression in peripheral blood lymphocytes of SLE patients and normal subjects. Peripheral blood lymphocytes were obtained from 40 SLE patients and 18 sex- and age-matched control subjects. Percentages of apoptosis and expression of Fas molecule in lymphocytes were assessed by flow cytometry. Fas expression in lymphocytes treated with or without DEX was significantly higher in SLE patients than normal controls [median (interquartile range) of mean fluorescence intensity without DEX: 74.9 (50.7-98.0) vs 20.0 (17.7-25.0), p < 0.001; with DEX: 77.9 (56.0-130.5) vs 20.5 (18.6-24.7), p<0.001]. DEX (0.1-5 microM) could also induce apoptosis of lymphocytes from SLE and control subjects in a dose-dependent manner. Elevation of apoptotic susceptibility was more prominent in DEX-treated SLE lymphocytes [33.9% (24.7-37.5%) vs 19.6% (13.6-26.1 %), p = 0.003]. The higher apoptotic susceptibility of SLE lymphocytes upon DEX treatment in vitro may be related, at least partly, to the pharmacological action of corticosteroids.     

Studies of Anti-lymphocyte Antibody of Patients with Active SLE

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.     

Studies on human blood lymphocytes with iC3b (type 3) complement receptors: III. Abnormalities in patients with active systemic lupus erythematosus.

Lymphocytes displaying iC3b (Type 3) complement receptors (CR3) were quantified by flow cytometry in patients with systemic lupus erythematosus. The percentages and absolute numbers were compared to age and sex matched controls. Total CR3+ lymphocytes identified by the monoclonal antibodies OKM1 or Leu 15 were significantly decreased in patients with symptomatic arthritis, serositis or vasculitis and those with lupus nephritis, whereas values for CR3+ lymphocytes in patients with inactive disease were similar to normal donors. The phenotype of CR3+ lymphocytes was markedly different in patients with active SLE. In normals granular lymphocytes bearing Fc receptors for IgG (L cells) comprised two-thirds of CR3+ lymphocytes. However, in SLE this subset was reduced to 20% and there was a corresponding increase in CR3+ lymphocytes co-expressing the T3 marker. Percentages of CR3 T4+ but not CR3+ T8+ lymphocytes were significantly increased in SLE. Although patients with active disease were lymphopenic, absolute numbers of CR3+ lymphocytes co-expressing T cell markers were similar to normal controls. Since L cells are non-specific suppressors of Ig production, the reduction of this subset along with the increase in CR3 T4+ cells could contribute to unregulated antibody production characteristic of SLE.