ICER is requisite for Th17 differentiation.

Inducible cAMP early repressor (ICER) has been described as a transcriptional repressor isoform of the cAMP response element modulator (CREM). Here we report that ICER is predominantly expressed in Th17 cells through the IL-6-STAT3 pathway and binds to the Il17a promoter, where it facilitates the accumulation of the canonical enhancer RORγt. In vitro differentiation from naive ICER/CREM-deficient CD4(+) T cells to Th17 cells is impaired but can be rescued by forced overexpression of ICER. Consistent with a role of Th17 cells in autoimmune and inflammatory diseases, ICER/CREM-deficient B6.lpr mice are protected from developing autoimmunity. Similarly, both anti-glomerular basement membrane-induced glomerulonephritis and experimental encephalomyelitis are attenuated in ICER/CREM-deficient mice compared with their ICER/CREM-sufficient littermates. Importantly, we find ICER overexpressed in CD4(+) T cells from patients with systemic lupus erythematosus. Collectively, our findings identify a unique role for ICER, which affects both organ-specific and systemic autoimmunity in a Th17-dependent manner

Gene therapy in systemic lupus erythematosus

Despite the fact that the etiopathogenesis of systemic lupus erythematosus is largely unknown, key steps in the pathophysiology of the disease have been recognized and targeted using gene therapy techniques. In animal models of lupus, gene transfer has been used to block the action of pro-inflammatory cytokines and co-stimulatory molecules leading to clinical improvement. In humans, ex vivo experiments have shown the feasibility of gene transfer in live T cells and its potential for restoring normal phenotype in T cells from patients with lupus. Still in experimental phase, gene therapy in lupus promises to correct the aberrant immunological response without the numerous side-effects of the currently used immunosuppressant medications. © 2005 Bentham Science Publishers Ltd

Review: Ocular side effects of anti-rheumatic medications: What a rheumatologist should know

Nearly every drug may cause changes to ocular tissues through a variety of mechanisms. Medication overdoses, drug-drug interactions but also chronic administration of medications at the recommended doses may lead to ocular toxicity. The ocular side effects, screening for eye toxicity and treatment guidelines for anti-inflammatory and immunosuppressive drugs commonly used by rheumatologists are reviewed herein. © The Author(s), 2010

Signaling Lymphocytic Activation Molecule Family Member 7 Engagement Restores Defective Effector CD8+ T Cell Function in Systemic Lupus Erythematosus.

Effector CD8+ T cell function is impaired in systemic lupus erythematosus (SLE) and is associated with a compromised ability to fight infections. Signaling lymphocytic activation molecule family member 7 (SLAMF7) engagement has been shown to enhance natural killer cell degranulation. This study was undertaken to characterize the expression and function of SLAMF7 on CD8+ T cell subsets isolated from the peripheral blood of SLE patients and healthy subjects. CD8+ T cell subset distribution, SLAMF7 expression, and expression of cytolytic enzymes (perforin, granzyme A [GzmA], and GzmB) on cells isolated from SLE patients and healthy controls were analyzed by flow cytometry. CD107a expression and interferon-γ (IFNγ) production in response to viral antigenic stimulation in the presence or absence of an anti-SLAMF7 antibody were assessed by flow cytometry. Antiviral cytotoxic activity in response to SLAMF7 engagement was determined using a flow cytometry-based assay. The distribution of CD8+ T cell subsets was altered in the peripheral blood of SLE patients, with a decreased effector cell subpopulation. Memory CD8+ T cells from SLE patients displayed decreased amounts of SLAMF7, a surface receptor that characterizes effector CD8+ T cells. Ligation of SLAMF7 increased CD8+ T cell degranulation capacity and the percentage of IFNγ-producing cells in response to antigen challenge in SLE patients and healthy controls. Moreover, SLAMF7 engagement promoted cytotoxic lysis of target cells in response to stimulation with viral antigens. CD8+ T cell activation in response to viral antigens is defective in SLE patients. Activation of SLAMF7 through a specific monoclonal antibody restores CD8+ T cell antiviral effector function to normal levels and thus represents a potential therapeutic option in SLE

Decreased SAP Expression in T Cells from Patients with Systemic Lupus Erythematosus Contributes to Early Signaling Abnormalities and Reduced IL-2 Production.

T cells from patients with systemic lupus erythematosus (SLE) display a number of abnormalities, including increased early signaling events following engagement of the TCR. Signaling lymphocytic activation molecule family cell surface receptors and the X-chromosome-defined signaling lymphocytic activation molecule-associated protein (SAP) adaptor are important in the development of several immunocyte lineages and modulating the immune response. We present evidence that SAP protein levels are decreased in T cells and in their main subsets isolated from 32 women and three men with SLE, independent of disease activity. In SLE T cells, SAP protein is also subject to increased degradation by caspase-3. Forced expression of SAP in SLE T cells normalized IL-2 production, calcium (Ca(2+)) responses, and tyrosine phosphorylation of a number of proteins. Exposure of normal T cells to SLE serum IgG, known to contain anti-CD3/TCR Abs, resulted in SAP downregulation. We conclude that SLE T cells display reduced levels of the adaptor protein SAP, probably as a result of continuous T cell activation and degradation by caspase-3. Restoration of SAP levels in SLE T cells corrects the overexcitable lupus T cell phenotype

Brief Report: CD4+ T Cells From Patients With Systemic Lupus Erythematosus Respond Poorly to Exogenous Interleukin-2.

Imbalanced cytokine production by T cells characterizes both patients with systemic lupus erythematosus (SLE) and lupus-prone mice and contributes to immune dysregulation. This study was undertaken to further investigate in detail the production of interleukin-2 (IL-2), interferon-γ (IFNγ), IL-4, and IL-17A by CD4+ cell subsets in healthy subjects and patients with SLE, and the signaling response of CD4+ T cells in response to exogenous IL-2. Cytokine production by differentiated subsets of CD4+ T cells was assessed by intracellular staining following stimulation with phorbol myristate acetate and ionomycin and by enzyme-linked immunosorbent assay after anti-CD3/anti-CD28 stimulation. The IL-2 signaling pathway was examined by assessing JAK-3/STAT-5 phosphorylation. Cell proliferation in response to IL-2 was examined by carboxyfluorescein succinimidyl ester dilution. Production of IL-2 was defective primarily among naive CD4+ T cells, whereas the production of IFNγ, IL-4, and IL-17A was not significantly different between patients with SLE and healthy subjects. JAK-3/STAT-5 phosphorylation and proliferation of CD4+ T cells from SLE patients in response to exogenous IL-2 were impaired compared to cells from healthy subjects. These data suggest that altered IL-2 production, as well as impaired IL-2-mediated signaling and proliferative responses, characterize SLE CD4+ T cells. Our data demonstrate the need for caution in designing IL-2 treatment trials for patients with SLE. Approaches to restore CD4+ T cell sensitivity to IL-2 should be considered

Signaling Lymphocytic Activation Molecule Family Member 1 Engagement Inhibits T Cell-B Cell Interaction and Diminishes Interleukin-6 Production and Plasmablast Differentiation in Systemic Lupus Erythematosus.

Signaling lymphocytic activation molecule family member 1 (SLAMF1) homophilic interactions promote immunoglobulin production and T cell-B cell cross-talk. SLAMF1 is overexpressed on T and B cells in patients with systemic lupus erythematosus (SLE). This study was undertaken to determine the role of SLAMF1 monoclonal antibody (mAb) in modulating T cell-B cell interaction and B cell activation. Anti-IgM-prestimulated naive or total B cells from either healthy donors or patients with SLE were cocultured with autologous T cells under CD3/CD28 stimulation, in the presence or absence of the SLAMF1 mAb. Naive B cells were stimulated with anti-IgM and CD40L in the presence of the SLAMF1 antibody. Cytokine production by CD4+ T cells and B cells was examined by flow cytometry and/or quantitative polymerase chain reaction. Plasmablast formation and T cell and B cell conjugates were assessed by flow cytometry. IgG and antinuclear antibody production was determined by enzyme-linked immunosorbent assay. SLAMF1 ligation in a human peripheral blood T cell-B cell culture system reduced the following in both healthy controls and patients with SLE: conjugate formation, interleukin-6 (IL-6) production by B cells, IL-21 and IL-17A production by T cells, and Ig and autoantibody production. Whereas the SLAMF1 mAb directly affected the function of isolated peripheral B cells by decreasing IL-6 and Ig production in vitro, it did not affect cytokine production by isolated T cells stimulated in vitro. The SLAMF1 antibody inhibits T cell-B cell interaction and suppresses B cell cytokine production and differentiation, thereby acting as a potential therapeutic tool in the treatment of patients with SLE

Engagement of SLAMF3 enhances CD4+ T-cell sensitivity to IL-2 and favors regulatory T-cell polarization in systemic lupus erythematosus.

Signaling lymphocytic activation molecule family 3 (SLAMF3/Ly9) is a coregulatory molecule implicated in T-cell activation and differentiation. Systemic lupus erythematosus (SLE) is characterized by aberrant T-cell activation and compromised IL-2 production, leading to abnormal regulatory T-cell (Treg) development/function. Here we show that SLAMF3 functions as a costimulator on CD4(+) T cells and influences IL-2 response and T helper cell differentiation. SLAMF3 ligation promotes T-cell responses to IL-2 via up-regulation of CD25 in a small mothers against decapentaplegic homolog 3 (Smad3)-dependent mechanism. This augments the activation of the IL-2/IL-2R/STAT5 pathway and enhances cell proliferation in response to exogenous IL-2. SLAMF3 costimulation promotes Treg differentiation from naïve CD4(+) T cells. Ligation of SLAMF3 receptors on SLE CD4(+) T cells restores IL-2 responses to levels comparable to those seen in healthy controls and promotes functional Treg generation. Taken together, our results suggest that SLAMF3 acts as potential therapeutic target in SLE patients by augmenting sensitivity to IL-2

Human Lupus Serum Induces Neutrophil-Mediated Organ Damage in Mice That Is Enabled by Mac-1 Deficiency

Systemic lupus erythematosus (SLE) is a chronic, multi-organ inflammatory autoimmune disorder associated with high levels of circulating autoantibodies and immune complexes. We report that passive transfer of human SLE sera into mice expressing the uniquely human FcγRIIA and FcγRIIIB on neutrophils induces lupus nephritis and in some cases arthritis only when the mice additionally lack the CD18 integrin, Mac-1. The prevailing view is that Mac-1 on macrophages is responsible for immune complex clearance. However, disease permitted by the absence of Mac-1 is not related to enhanced renal immune-complex deposition or in situ C1q/C3 complement activation and proceeds even in the absence of macrophages. Instead, disease is associated with increased FcγRIIA-induced neutrophil accumulation that is enabled by Mac-1 deficiency. Intravital microscopy in the cremasteric vasculature reveals that Mac-1 mitigates FcγRIIA dependent neutrophil recruitment in response to deposited immune complexes. Our results provide direct evidence that human SLE immune-complexes are pathogenic, demonstrate that neutrophils are primary mediators of end organ damage in a novel humanized lupus mouse model, and identify Mac-1 regulation of FcγRIIA-mediated neutrophil recruitment as a key step in development of target organ damage