AUTOIMMUNITY

Background/Purpose: Evidence supports the existence of different sub-phenotypes and the pivotal role of cytokines and autoantibodies in systemic lupus erythematosus (SLE). Cytokines interact in a highly complex network. Thus, understanding how these complex non-linear processes are connected and observed in real-life settings is a major challenge. Cluster approaches may assist in the identification of these …

A hallmark of systemic lupus erythematosus is high titers of circulating autoantibodies. Recently, a novel CD11c+ B-cell subset has been identified that is critical for the development of autoimmunity. However, the role of CD11c+ B cells in the development of lupus is unclear. Chronic graft-versus-host disease (cGVHD) is a lupus-like syndrome with high autoantibody production. The purpose of this study was to explore the role of CD11c+ B cells in the pathogenesis of lupus in cGVHD mice. cGVHD was induced by an intraperitoneal injection of 5 × 107 Bm12 splenocytes into B6 mice. Flow cytometry was used to analyze mice splenocytes and human samples. Magnetic beads were used to isolate mice B cells. Gene expression was determined by real-time quantitative polymerase chain reaction (RT-qPCR). Enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies in serum and supernatants. The percentage and absolute number of CD11c+ B cells was increased in cGVHD-induced lupus, with elevated levels of antichromatin immunoglobulin (Ig)G and IgG2a in sera. CD11c+ plasma cells from cGVHD mice produced large amounts of antichromatin IgG2a upon stimulation. Depletion of CD11c+ B cells reduced antichromatin IgG and IgG2a production. T-bet was upregulated in CD11c+ B cells. Knockout of T-bet in B cells alleviated cGVHD-induced lupus. Importantly, the percentage of T-bet+CD11c+ B cells increased in lupus patients and positively correlated with serum antichromatin levels. T-bet+CD11c+ B cells promoted high antichromatin IgG production in the lupus-like disease model cGVHD. In lupus patients, the percentage of T-bet+CD11c+ B cells was elevated and positively correlated with antichromatin antibodies. The findings provide potential therapeutic insight into lupus disease treatment.

BAFF is a B cell survival and maturation factor implicated in the pathogenesis of systemic lupus erythematosus (SLE). In this in vitro study, we describe that soluble BAFF in combination with IL-2 and IL-21 is a T cell contact-independent inducer of human B cell proliferation, plasmablast differentiation, and IgG secretion from circulating CD27+ memory and memory-like CD27−IgD− double-negative (DN) B cells, but not CD27−IgD+ naive B cells. In contrast, soluble CD40L in combination with IL-2 and IL-21 induces these activities in both memory and naive B cells. Blood from healthy donors and SLE patients have similar circulating levels of IL-2, whereas SLE patients exhibit elevated BAFF and DN B cells and reduced IL-21. B cell differentiation transcription factors in memory, DN, and naive B cells in SLE show elevated levels of Aiolos, whereas Ikaros levels are unchanged. Treatment with CC-220, a modulator of the cullin ring ligase 4-cereblon E3 ubiquitin ligase complex, reduces Aiolos and Ikaros protein levels and BAFF- and CD40L-induced proliferation, plasmablast differentiation, and IgG secretion. The observation that the soluble factors BAFF, IL-2, and IL-21 induce memory and DN B cell activation and differentiation has implications for extrafollicular plasmablast development within inflamed tissue. Inhibition of B cell plasmablast differentiation by reduction of Aiolos and Ikaros may have utility in the treatment of SLE, where elevated levels of BAFF and Aiolos may prime CD27+ memory and DN memory-like B cells to become Ab-producing plasmablasts in the presence of BAFF and proinflammatory cytokines.

Scientists from an international consortium have identified a large number of new genetic markers that predispose individuals to lupus

According to the latest market study released by Technavio, the global lupus therapeutic market is expected to reach USD 2,670.03 million by 2021.

A University of Birmingham academic has led the authorship of the UK's first guideline on the care of adults with systemic lupus erythematosus (lupus).

Ten percent of individuals worldwide are affected by autoimmune diseases, with systemic lupus erythematosus being one of the most common.

Premature, accelerated onset of atherothrombotic disease is prevalent in patients with systemic lupus erythematosus (SLE). Most, if not all, atherothrombotic diseases are likely to involve platelets and complement. Previously, we discovered that platelets bearing complement activation product C4d (P-C4d) are present in SLE patients, and are significantly associated with antiphospholipid (aPL) antibody positivity and stroke in SLE patients. The goal of the present study was to further elucidate the role of aPL and other platelet-reactive autoantibodies in the generation of P-C4d. To determine the association between P-C4d and aPL antibodies, the serum levels of aPL antibodies and P-C4d of 180 SLE patients were measured by enzyme-linked immunoassays and flow cytometry, respectively. To investigate the role of aPL antibodies, and possibly other autoantibodies as well, in mediating the generation of P-C4d, in vitro 2-step P-C4d induction experiments were performed. The results showed that the presence and levels of aPL antibodies in the serum were specifically elevated in SLE patients with positive P-C4d. The plasma and immunoglobulins purified from SLE patients who were positive for P-C4d and aPL were capable of inducing C4d deposition on normal platelets in vitro. The capacity of SLE plasma in inducing P-C4d appeared to correlate proportionately to the serum aPL levels. Collectively, the results demonstrate that both aPL and other platelet-reactive autoantibodies may participate in mediating the generation of P-C4d in SLE patients.