Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0409974 (lupus)
 22,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The active vitamin D metabolite, 1,25-dihydroxyvitamin D3[1,25-(OH)2D3], exerts immunosuppressive activity. At a cellular and molecular level, the hormone preferentially targets helper T cell activity (Th1) by inhibiting the secretion of both IL-2 and IFN-gamma by Th1 and by suppressing the secretion pro-Th1 cytokine IL-12 by antigen-presenting cells. The active metabolite further inhibits class II antigen expression and enhances suppressor cell activity. In animal models of autoimmunity, 1,25-(OH)2D3 prevents the development of experimental autoimmune encephalomyelitis, reduces the incidence of diabetes, and attenuates murine lupus. The hormone also prolongs graft survival in animal models of transplantation. In humans, non-classical use of 1,25-(OH)2D3 has led to an anti-proliferative effect in psoriasis, antineoplastic effect in prostate cancer, and immunomodulatory effect in scleroderma. The development of less hypercalcemic analogs might open a new therapeutic area for vitamin D3.
 ...
PMID:1,25-Dihydroxyvitamin D3--a hormone with immunomodulatory properties. 1076 31

We previously showed that dietary fish oil (FO) and energy restriction (R) have beneficial anti-inflammatory properties in the peripheral blood and spleens of (NZB x NZW)F1 (B/W) lupus-prone mice. Furthermore, unsaturated fatty acids also were shown in the past to influence mesenteric lymph node (MLN) lymphocyte function in healthy young rats. The MLN play a pivotal role in mediating food allergy. To date, the effect of R on intestinal immunity is not well understood; therefore we determined the effect of diet on MLN lymphocyte function. Mice were given either free access to a 5 g/100 g corn oil (CO) or fish oil (FO) diet or the same corn oil (CR) or fish oil (FR) diets restricted to 60% of the intake of the control group. At the age of 4 (young) and 8 (old) mo, MLN lymphocytes were isolated and B- (CD19(+)) and T-lymphocyte subsets (CD4(+) and CD8(+)) were determined by flow cytometry. Additional MLN lymphocytes were placed in culture with or without concanavalin A and culture supernatants collected after 72 h for cytokine and immunoglobulin (Ig) quantitation by ELISA. Aging significantly (P < 0.05) decreased both CD4(+) and CD8(+) T-lymphocytes. Spontaneous and activation-induced interleukin-4 (IL-4), IL-10, and interferon-gamma secretion were greater while IL-2 was lower in CO-fed old mice compared to CO-fed young mice. In contrast, CR or FO alone partially blunted the age-dependent alterations in T-lymphocyte ratios including cytokine and Ig secretion, whereas the FR diet significantly (P < 0.005) normalized the accelerated aging effects on these immune variables. We show for the first time that FR is a far more potent anti-inflammatory therapy than either CR or FO alone in modulating MLN lymphocyte function.
 ...
PMID:Dietary (n-6) and (n-3) fatty acids and energy restriction modulate mesenteric lymph node lymphocyte function in autoimmune-prone (NZB x NZW)F1 mice. 1086 32

Autoreactive T cells responding to systemic autoantigens have been characterized in patients and mice with autoimmune diseases and in healthy individuals. Using peptides covering the whole sequence of histone H4, we characterized several epitopes recognized by lymph node Th cells from nonsystemic lupus erythematosus-prone mice immunized with the same peptides, the H4 protein, or nucleosomes. Multiple T epitopes were identified after immunizing H-2d BALB/c mice with H4 peptides. They spanned residues 28-42, 30-47, 66-83, 72-89, and 85-102. Within the region 85-102, a minimal CD4+ T epitope containing residues 88-99 was characterized. Although Abs to peptide 88-99 recognized H4, this peptide does not contain a dominant B cell epitope recognized by anti-H4 Abs raised in BALB/c mice or Abs from NZB/NZW H-2d/z lupus mice. Th cells primed in vivo with H4 responded to H4, but not to peptide 88-99. However, this peptide was able to stimulate the proliferation and IL-2 secretion of Th cells generated after immunization with nucleosomes. H488-99 thus represents a cryptic epitope with regard to H4 and a supradominant epitope presented by nucleosome, a supramolecular complex that plays a key role in lupus. This study shows that in the normal repertoire of naive BALB/c mice, autoreactive Th cells specific for histones are not deleted. The reactivity of these Th cells seems to be relatively restricted and resembles that of Th clones generated from SNF1 ((SWR x NZB)F1; I-Ad/q) lupus mice described earlier.
 ...
PMID:Identification of a minimal T cell epitope recognized by antinucleosome Th cells in the C-terminal region of histone H4. 1087 37

Autoantibodies directed against spliceosomal heterogeneous nuclear ribonucleoproteins (hnRNPs) are a typical feature of rheumatoid arthritis, systemic lupus erythematosus, and mixed-connective tissue disease. With the aim of investigating a potential pathogenic role of these Abs, we have studied the Ab response to A2/B1 hnRNPs in different murine models of lupus. The specificity of anti-A2/B1 Abs was tested with a series of 14 overlapping synthetic peptides covering the region 1-206 of A2 that contains most of the epitopes recognized by patients' Abs. A major epitope recognized very early during the course of the disease by Abs from most of MRL lpr/lpr mice but not from other lupus mice and from mice of different MHC haplotypes immunized against B1 was identified in residues 50-70. This peptide contains a highly conserved sequence RGFGFVTF also present in other hnRNPs and small nuclear ribonucleoproteins. Abs reacting with a second A2 epitope identified in residues 35-55 were detectable several weeks later, suggesting an intramolecular B cell epitope spreading during the course of the disease. We identified several T cell epitopes within the region 35-175 that generated an effective Th cell response with IL-2 and IFN-gamma secretion in nonautoimmune CBA/J mice sharing the same MHC haplotype H-2k as MRL/lpr mice. None of the peptides stimulated T cells primed in vivo with B1. Because Abs to peptide 50-70 were detected significantly earlier than Abs reacting with other A2 peptides and the protein itself, it is possible that within the protein, this segment contains residues playing an initiator role in the induction of the anti-A2/B1 and antispliceosome Ab response.
 ...
PMID:B and T cell responses to the spliceosomal heterogeneous nuclear ribonucleoproteins A2 and B1 in normal and lupus mice. 1092 19

Systemic lupus erythematosus is characterized by the presence of high titers of autoantibodies reacting with various components of the U1 small nuclear ribonucleoprotein particle (snRNP). It has been suggested that these antibodies are produced by an antigen-driven mechanism under the dependence of antigen-specific T cells. To investigate the role of T cell help in this process, we sought, with 20 overlapping peptides, the Th epitopes on the U1-70K snRNP in unprimed H-2(k) MRL / lpr lupus mice and immunized CBA normal mice. The peptide 131 - 151 was recognized by both IgG autoantibodies and CD4(+) T cells from 7 - 9-week-old MRL / lpr mice. In this test, antigen-presenting cells (APC) from MRL / lpr mice were required; APC from naive CBA mice failed to stimulate CD4(+) cells from MRL / lpr mice. The potential role of MRL / lpr B cells as APC, the expression of MHC class II molecules at their surface and their activation state (expression of CD69, CD80 / B7-1 and CD86 / B7-2 molecules) were studied. Peptide 131 - 151 bound both I-A(k) and I-E(k) class II molecules and favored an IL-2-positive T cell response but not IFN-gamma, IL-6 and IL-10 secretion. Segment 131 - 151 is localized within the RNP80 motif and contains residues that are highly conserved in many nuclear, nucleolar and cytoplasmic RNA binding proteins.
 ...
PMID:B and T cell immune response to small nuclear ribonucleoprotein particles in lupus mice: autoreactive CD4(+) T cells recognize a T cell epitope located within the RNP80 motif of the 70K protein. 1094 Sep 10

T cells play a critical role in both the immunological and clinical manifestations of systemic autoimmune diseases such as systemic lupus erythematosus (SLE). Although in normal mice multiple T cell epitopes have been characterized in several self-proteins, there is little information on the fine specificity of autoreactive T cells in lupus model mice and humans. In SLE-prone mice and humans, the only Th cell epitopes identified at the molecular level in self-antigens concern histones and nucleosomes, and the 70-kD U1-snRNP protein. T cell characterization in certain autoimmune mice such as MRL lpr/lpr and NZB/NZW mice has been largely impaired by their hyporesponsiveness in response to mitogen and minimal IL-2 secretion. In addition, MRL lpr/lpr mice also develop lymphadenopathy characterized by the progressive accumulation of functionally immature CD4(-) CD8(-) T cells. It is therefore important to optimize the methods used to measure T cell proliferation and cytokine production ex vivo in order to identify minimal activation in the presence of appropriate antigen. The protocol described in this article has been used for identifying in young MRL lpr/lpr and NZB/NZW mice a CD4(+) T cell epitope in the murine 70-kD U1-RNP protein.
 ...
PMID:Laboratory protocols for the identification of Th cell epitopes on self-antigens in mice with systemic autoimmune diseases. 1103 32

To identify intrinsic defects in lupus, we studied short-term, CD4(+) T cell lines that were established from 16 lupus patients (active or inactive) and 15 normal subjects by stimulating once with anti-CD3, anti-CD28, and IL-2. After resting, the pure CD4(+) T cells were exposed to anergy-inducing stimulation with plate-bound anti-CD3 mAb in the absence of APC. Lupus T cells showed prolonged high level expression of CD40 ligand (CD40L, CD154) even in the face of anergy protocol, which shut down CD40L expression in normal T cells. The sustained CD40L expression in lupus T cells did not correlate with memory status or Th deviation, and was relatively independent of IL-2 or other autocrine or paracrine signals via CD28 or CTLA-4. Cyclosporin A could block CD40L expression by lupus T cells when added early during the anti-CD3 stimulation period, but only partially when added later, indicating that another mechanism regulates the prolonged hyperexpression of CD40L besides the Ca(2+) --> calcineurin-dependent NF-AT pathway. When exposed to the anergy protocol, lupus T cells, in marked contrast to normal T cells, did not phosphorylate Cbl/Cbl-b but continued to express strongly phosphorylated extracellular signal-regulated kinase (ERK); U0126, a specific inhibitor of mitogen-activated protein kinase kinase --> ERK, could block both the early and the prolonged hyperexpression of CD40L. Thus, pathways regulating the activities of Cbl and one particular mitogen-activated protein kinase, ERK, are involved in the prolonged hyperexpression of CD40L in lupus T cells.
 ...
PMID:Regulatory defects in Cbl and mitogen-activated protein kinase (extracellular signal-related kinase) pathways cause persistent hyperexpression of CD40 ligand in human lupus T cells. 1108 8

Estrogen and prolactin have a reciprocal endocrinologic relationship and both hormones have pleiotropic effects on the immune system. Despite the presence of a number of confounding variables, these hormones modulate autoimmunity; however, mechanisms by which this modulation occurs remain obscure. Estrogen appears to suppress cell-mediated and augment humoral-based immunity. Prolactin appears to stimulate both cell and humoral-based immunity. Both hormones have been shown to modulate IFN gamma secretion. Similar evidence in experimental models, human autoimmune disease, and during pregnancy in autoimmune disease patients suggests disparate effects of estrogen and prolactin on autoimmune responses and disease pathogenesis. In the NZB x NZW F1 mouse model of lupus, prolactin accelerates disease expression, whereas estrogen, devoid of its prolactin stimulating properties, is immunosuppressive and inhibits IL-2 production. Estrogen, because of its endocrinologic and immune effects, may directly or indirectly stimulate or inhibit immune responses. These dichotomous effects have limited its successful pharmacologic manipulation in human autoimmune disease with estrogen compounds, tamoxifen, oral contraceptives, antigonadotropic agents, or ovulation induction regimens. In contrast, reduction of immunostimulatory concentrations of prolactin with bromocriptine has successfully suppressed development or expression of murine and human autoimmune disease. Further investigation into actions and interactions of estrogen and prolactin with autoimmunity will provide a better understanding of the female preponderance of autoimmunity and facilitate a more rational approach to hormonal immunotherapy.
 ...
PMID:Estrogen, prolactin, and autoimmunity: actions and interactions. 1140 18

(NZB x NZW)F(1) and MRL/Fas(lpr) lupus mice present a similar phenotype with a spectrum of autoantibodies associated with very severe nephritis. It is thought, however, that in contrast to other lupus-prone mice such as MRL/Fas(lpr) mice, (NZB x NZW)F(1) mice do not generate autoantibodies to ribonucleoproteins (RNP) Sm/RNP. In this study, we demonstrate that contrary to previous reports, the autoimmune response directed against Sm/RNP antigens also occurs in NZB x NZW mice. CD4(+) T cells from unprimed 10-week-old NZB x NZW mice proliferate and secrete IL-2 in response to peptide 131-151 of the U1-70K protein, which is known to contain a T(h) epitope recognized by CD4(+) T cells from MRL/Fas(lpr) mice. Peptide 131-151, which was found to bind I-A(k) and I-E(k) class II MHC molecules, also bound both I-A(d) and I-E(d) molecules. This result led us to also re-evaluate longitudinally the anti-Sm/RNP antibody response in NZB x NZW mice. We found that 25-week-old mice do produce antibodies reacting with several small nuclear and heterogeneous nuclear (hn) RNP proteins, such as SmD1, U1-70K and hnRNP A2/B1 proteins. The fine specificity of these antibodies was studied with overlapping synthetic peptides. The same antigenically positive and negative peptides were characterized in MRL/Fas(lpr) and NZB x NZW mice in the three proteins. This new finding can help to understand the mechanisms involved in the development of the anti-Sm/RNP antibody response and, particularly, the role played by non-MHC genes in this autoimmune response.
 ...
PMID:Murine models of systemic lupus erythematosus: B and T cell responses to spliceosomal ribonucleoproteins in MRL/Fas(lpr) and (NZB x NZW)F(1) lupus mice. 1152 96

DAB(389)IL-2 (denileukin diftitox, ONTAK) is an interleukin-2 receptor (IL-2R)-specific ligand fusion protein that may potentially be selective for IL-2R-expressing malignancies. The activity of DAB(389)IL-2 in the treatment of cutaneous T-cell lymphoma has established the feasibility of utilizing such a targeted therapeutic in disseminated disease with acceptable toxicity. Data from the phase I trial suggest that the definition of activity in other cancer types, including other non-Hodgkin's lymphomas (NHL), is warranted. Three NHL patients in this study responded, two of whom had follicular lymphomas, with the third having a primary intermediate-grade B-cell NHL that was refractory to chemotherapy and stem cell transplant. This patient has remained in complete remission over 3 years after treatment with DAB(389)IL-2. Patients treated to date have had IL-2R-positive tumors, but this remains a very complex clinical issue. The need for a threshold level of receptor expression, the difficulty in obtaining representative tissue, the lack of an assay that accurately reflects high-affinity receptor, and the potential difficulty of observer variability in evaluating the assays should point us toward examining response rates in cancer patients where IL-2R cannot be detected or is unknown. The potential to target the high-affinity IL-2R supports the development of this agent in transplantation and in autoimmune diseases. Targeting IL-2R-expressing lymphocytes may be an effective strategy for the prevention of graft rejection and to treat or prevent graft-versus-host disease. DAB(389)IL-2 has been examined in clinical trials of psoriasis and rheumatoid arthritis and has shown promising results. The potential utility in other autoimmune disorders is unknown, but diseases such as systemic lupus, scleroderma, and vasculitis also may be effective candidates for such ligand fusion therapy.
 ...
PMID:DAB(389)IL-2 (denileukin diftitox, ONTAK): other potential applications. 1170 62


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>