UMLS:C0024141 - FACTA Search

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Query: UMLS:C0024141 (systemic lupus erythematosus)
44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The T-colony-forming capacity was examined in 13 normal subjects and 14 patients with biopsy-proven lipoid nephrosis (LN). Eighteen additional patients with other well-defined forms of glomerulonephritis were studied as a disease control. Significantly fewer T lymphocyte colonies were found in LN patients and the nephrotic syndrome (NS) than in normal controls. A similar change could be observed in the groups with other types of NS. LN patients with NS had the lowest values of T-colony-forming cells (TCFC), but there was no statistically significant difference between the groups of nephrotic subjects. It was also of interest that peripheral blood lymphocytes (PBL) from 3 patients with lupus nephritis (SLE) produced significantly low levels of TCFC. The lower levels of TCFC in LN could be enhanced when exogenous interleukin 2 (IL 2) was added to the system. We also examined the production of T-colony-stimulating factor (TCSF). The TCSF production by stimulated PBL from LN patients was lower than in normal subjects. To explain our observations, we presumed that the T colony dysfunction seen in LN patients with NS might in part be due to the decreased TCSF activity.
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PMID:Impaired T-lymphocyte colony formation in lipoid nephrosis. 387 48

Normal immunoregulation depends on a complex set of cellular interactions in which interleukin 2 (IL 2) appears to play an important role. We have examined the IL 2 activity in patients with systemic lupus erythematosus (SLE). IL 2 production by phytohemagglutinin (PHA)-stimulated T cells for 48 hr was measured by the ability of their culture fluid to induce proliferation of normal human T cells that had been activated for more than 20 days by PHA plus IL 2. To measure IL 2 responsiveness, T cells were blasted by preincubation with concanavalin A for 96 hr and stimulated for another 72 hr with lectin-free standard IL 2. SLE T cells failed to produce normal levels of IL 2 in vitro compared with normal control T cells. This failure resided in both OKT4+ and OKT8+ cells. Furthermore, the abnormality was due neither to soluble inhibitory factors produced by SLE T cells nor to active suppressor cells that might be induced by PHA-stimulation. Responsiveness to IL 2 of T cells from some, but not all, SLE patients was decreased significantly from that of normal controls. Absorption studies as well as studies with anti-Tac antibody demonstrated that the impaired responsiveness of T cells in the specific patients with SLE was due to inadequate expression of IL 2 receptors on the T cells upon activation. This defect was exclusively ascribed to the dysfunction of OKT4+, but not OKT8+, cells. The above defects in production of and responsiveness to IL 2 observed in patients with SLE were present at all times regardless of the disease activity or of corticosteroid therapy. Thus, the deficient IL 2 activity may be intrinsic to SLE lymphocytes and may contribute to impaired immunoregulation and to the development of SLE.
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PMID:Characterization of T lymphocyte subpopulations responsible for deficient interleukin 2 activity in patients with systemic lupus erythematosus. 391 75

The autosomal recessive lpr (lymphoproliferation) gene is responsible for a thymus-dependent massive lymphoproliferation associated with the development of lupus-like autoimmune disease. Phenotypic analysis of adult lpr/lpr lymph nodes has demonstrated accumulation of a dull Lyt-1+, Thy-1+ population that expresses neither Lyt-2 nor L3T4 antigens. With the use of a depletion method based on complement-mediated lysis with an anti-Lyt-2 monoclonal antibody (31 M) and a new anti-L3T4 monoclonal antibody (RL 172.4), we have purified the Lyt-2- L3T4- subset from lymph nodes or spleens of C57BL/6-lpr/lpr mice and determined whether they are immunologically functional in vitro. Production of neither interleukin 2 nor interferon-gamma was detected by the double-negative subset after stimulation with concanavalin A and/or phorbol myristate acetate. The frequencies of allospecific cytotoxic T lymphocyte (CTL) precursors and lectin-induced antigen-nonspecific CTL precursors were diminished to almost undetectable levels, whereas the Lyt-2+ population from lpr/lpr mice had CTL-precursor frequencies comparable with that of +/+ mice. These results show that the major cell subset of adult lpr/lpr lymph nodes or spleens is composed of lymphocytes with markedly limited potential for lymphokine production or antigenic stimulation.
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PMID:Functional analysis of T cell subsets from mice bearing the lpr gene. 392 47

T cell growth is principally regulated by the lymphokine interleukin 2 (IL 2). Following induction of IL 2 receptors, immunologically normal cells proliferate and will continue to do so until the level of IL2 becomes limiting. Spleen cells from autoimmune-prone mice and peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE), however, are severely deficient in their capacity to both produce and respond to IL 2 following a challenge with mitogenic lectins. These observations have suggested the possibility that IL 2 may not function as a T cell growth factor in the autoimmune milieu. In order to determine the requirements for T lymphocyte proliferation in autoimmunity, MRL-lpr/lpr mice were studied. Spleen cells from this murine model of lupus exhibit profound defects in IL 2 activity in vitro. Yet, paradoxically, massive expansion of the T cell pool occurs in vivo. While spleen cells from such mice were, indeed, unable to produce IL 2 or to proliferate when stimulated with concanavalin A (Con A), the combination of Con A plus the comitogen phorbol myristate acetate (PMA) engendered substantial IL 2 production and normal cellular proliferation. Since numerous lymphokines are produced when cells are cultured with Con A + PMA, it remained to be shown that IL 2 was, in fact, the responsible growth factor. We found that culturing lpr spleen cells with an anti-IL 2 receptor antibody abrogated the mitogenicity of Con A + PMA; that on stimulation with Con A + PMA, MRL-lpr/lpr T cells expressed IL 2 receptors, and that addition of recombinant IL 2 to the receptor positive population resulted in marked proliferation. Furthermore, by two-color flow cytometric analysis it was demonstrated that T cells which bear the phenotype of those which undergo clonal expansion in the lpr were capable of expressing IL 2 receptors. Thus, IL 2 can be utilized as a growth factor, in vitro, by autoimmune as well as normal T cells. The etiology of the Con A unresponsiveness of MRL-lpr/lpr cells remained to be clarified. We observed that, in contrast to the refractoriness of fresh cells, lymph node cells which had been cultured for several days in the absence of antigenic stimulation were capable of expressing IL 2 receptors and of proliferating on exposure to Con A. Using flow cytometry it was found that selective expansion of a subset of phenotypically "normal" lymphocytes had not occurred.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Signals required for activation and growth of autoimmune T lymphocytes. 608 44

One of the fundamental immunologic characteristics of systemic lupus erythematosus (SLE) is a depressed T cell proliferative response to various specific and nonspecific stimuli. Both intrinsic cellular defect(s) and inhibitory influences of humoral factors, e.g., antilymphocyte autoantibodies or immune complexes, have been postulated to underly this functional abnormality. Because patient serum can induce SLE-like T cell dysfunction in normal cells, an extrinsic mechanism is probably responsible, but the nature and site of action of this humoral activity has not been defined. This laboratory recently described a novel antibody specific for activated T cells in SLE, which raised the possibility that suppression of T cell proliferation by SLE serum involved antibodies directed to surface determinants expressed during the process of activation. In experiments to examine this concept further, relatively warm-reactive antibodies to T cell blasts were found to inhibit strongly the well-characterized T cell response to tetanus toxoid. These antibodies were distinct from conventional cold-reactive IgM antibodies to resting T cells, which exhibited little inhibitory activity. Inhibition involved noncytotoxic effects on early activation events at the level of the responding T cell, which markedly reduced the expression of receptors for interleukin 2. Inhibitory effects on antigen-pulsed macrophages or on T cells already committed to proliferate were not demonstrable. Anti-T blast antibodies were characteristic of active SLE and were detected only occasionally in patients with inactive disease or non-SLE rheumatic disorders. Although the exact antigenic specificity was not identified, considerable evidence was obtained against the presence of antibodies to Ia and certain other surface determinants of functional relevance. Our observations concerning the suppressive effects of anti-T blast antibodies in SLE serum on the T cell response to tetanus toxoid should provide new insight into mechanisms of in vivo T cell dysfunction in this and other immunologic disorders.
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PMID:Inhibition of soluble antigen-induced T cell proliferation by warm-reactive antibodies to activated T cells in systemic lupus erythematosus. 621 Mar 6

The objective of this study was to define some causes of the immunologic impairment characteristic of systemic lupus erythematosus. Blood mononuclear cells from 19 patients were stimulated to produce interleukin 1 and interleukin 2 and compared with controls. A severe defect in both IL 1 and IL 2 activity was observed. The low cytokine levels did not correlate with clinical or serologic activity of disease. These defects could not be explained by concurrent corticosteroid therapy. There was no correlation between a lower number of OKT4+ cells observed in these patients and the levels of IL 2 production, nor did removal of monocytes bring IL 2 to normal. Impaired IL 2 production could not be restored to normal by IL 1. The observed deficiency in these regulatory cytokines may therefore be a primary defect that is important in the pathogenesis of this disorder.
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PMID:Defective production of interleukin 1 and interleukin 2 in patients with systemic lupus erythematosus (SLE). 622 12

The aim of this study was to define as possible abnormality of interleukin 2 (IL2) production by PHA-stimulated peripheral blood lymphocytes (PBL) in systemic lupus erythematosus (SLE). Thirty-four SLE PBL samples were stimulated to produce IL2 and compared with PBL from healthy (age- and sex-matched) controls. A significant defect in IL2 production was observed in SLE patients. This defect was not restricted to corticosteroid-treated patients and was not correlated with the presence of lymphotoxic antibodies or with clinical disease activity. Although 5-day responsiveness to phytohaemagglutinin (PHA) decreased in SLE, the SLE PHA-blasts responded as well as control blasts to semipurified IL2, suggesting that the receptor for IL2 was normally expressed on SLE blasts. In 9 cases, the effect of addition of indomethacin (2 micrograms/ml) or of an optimal amount of IL1 on PHA-induced IL2 production was studied. Indomethacin increased (22%) the IL2 yield of healthy individual PBL. In SLE, indomethacin (but not IL1) was able to completely restore (41% increase) the IL2 production of lectin-stimulated PBL (P less than 0.01). These data suggest that, in SLE, the inhibition of IL2 production is mediated by prostaglandin, possibly produced by monocytes.
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PMID:Impaired IL2 production by lymphocytes of patients with systemic lupus erythematosus. 633 9

Disturbances in immune interferon (IFN gamma) activity have been implicated in the development of human systemic lupus erythematosus (SLE) and the spontaneous disease sustained by autoimmune-prone mice. We therefore investigated the cellular basis for IFN gamma production in MRL-Ipr/Ipr mice and examined the relationship between synthesis of interleukin 2 (IL 2) and IFN gamma. In vitro IL 2 and IFN gamma production in 3 to 6-mo-old, autoimmune MRL-Ipr/Ipr and MRL-+/+ mice was compared with that seen in age- and sex-matched, immunologically normal CBA/J mice. 5 X 10(6) spleen cells were pulsed with 5 micrograms of concanavalin A (Con A), and the cellfree supernatant was assayed for IL 2 and IFN gamma activity at various times up to 72 hr. We found that peak levels of IL 2 in MRL mice were less than 10% of those in the CBA/J. Yet, production of IFN gamma by cells from the autoimmune and normal strains was quite comparable. The addition of murine IL 2 to optimally Con A-stimulated cells from the MRL-Ipr/Ipr or normal mice did not affect the subsequent peak production of IFN gamma. Although the primary producers of IFN gamma in cultures of normal mice bear the Lyt-2+ phenotype, the Lyt-1+2- T-cell subset was found to be the principal source of IFN gamma in the aged MRL-Ipr/Ipr. These data suggest that Lyt-1+ cells from MRL-Ipr/Ipr mice may be differentially responsive to the signal delivered by the same mitogenic lectin with respect to lymphokine production and may indicate a distorted commitment of such cells toward production of IFN gamma and repression of IL 2 synthesis. The relationship between hypoproduction of IL 2, this usual source of IFN gamma, and the autoimmune disease sustained by MRL-Ipr/Ipr mice remains unclear.
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PMID:The cellular basis for immune interferon production in autoimmune MRL-Ipr/Ipr mice. 640 74

The ability of peripheral blood lymphocytes from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and Sjogren's syndrome (SS) to produce interleukin 2 (IL-2) and respond to it in-vitro was examined. Phytohemagglutinin-stimulated lymphocytes from over half of the SLE patients exhibited a decreased ability to produce IL-2 while their concanavalin A-generated blast cells responded normally to exogenous IL-2. Lymphocytes from RA patients not only produced less IL-2 than normals (P less than 0.001), but also responded poorly to exogenous IL-2 (P = 0.011). These abnormalities did not correlate with the patient's age, sex, duration of disease, or disease activity. Production of and response to IL-2 was widely varied among patients with SS and not different from controls. The decreased response of RA lymphocytes to IL-2 may result from a smaller number of cell surface IL-2 receptors since IL-2 adsorption to RA cells was lower than to either SLE or normal cells. These data suggest that IL-2-related abnormalities may play a role in the disordered immunoregulation characteristic of RA and perhaps of SLE.
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PMID:Interleukin 2 deficiencies in rheumatoid arthritis and systemic lupus erythematosus. 642 22

In the studies reported here, we have analyzed the production and consumption of T cell growth factor, more recently termed interleukin 2 (IL-2), as well as some cell-mediated immune functions, in murine strains [MRL, BXSB, NZB, and (NZB x NZWF1] manifesting systemic lupus erythematosus (SLE)-like syndromes. Young (4-6 wk) or old (4-8 mo) autoimmune or normal mice were studied and compared with regard to the following T cell functions in vitro after stimulation with concanavalin A (Con A): (a) mitogenic response; (b) IL-2 levels in culture supernates; and (c) the ability to respond to and adsorb IL-2. In addition, proliferative activity in the allogeneic mixed leukocyte culture and frequency of alloreactive cytotoxic T lymphocyte precursors (CTLp) were analyzed in some of these strains. Reduced Con A-induced mitogenic responses and IL-2 production appeared at 3-6 wk of age in the early, severe SLE developing strains MRL-Mp-lpr/lpr (MRL/l) and male BXSB and progressed thereafter. Similar defects appeared at a later stage in MRL/Mp-+/+ and (NZB x NZW)F1 hybrid mice, which develop late disease. Detailed analysis of cells from the enlarged lymph nodes and spleens of older MRL/l mice demonstrated that such cells: (a) responded poorly to Con A or allogeneic stimulator cells, even in the presence of exogenous IL-2; (b) did not suppress IL-2 production by normal spleen cells; (c) were relatively incapable of adsorbing or inactivating IL-2; and (d) had a markedly reduced anti-H-2b CTLp frequency in the mesenteric lymph nodes but a normal one in spleen. These results indicate that the proliferating Thy-1.2+, Lyt-1+ T cells in MRL/l mice are defective in their responses to mitogenic stimuli, in IL-2 production, and in expression of acceptor sites for IL-2. The relevance of these defects to the MRL/l disease as well as to the role of IL-2 in autoimmunity in general remains to be determined.
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PMID:Analysis of T cell function in autoimmune murine strains. Defects in production and responsiveness to interleukin 2. 645 21

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