B Cell-activating Factor Research Articles

B-lymphocyte stimulator: can we consider it a marker for severity of hepatitis C virus-induced B-cell non-Hodgkin lymphoma?

ObjectiveB-lymphocyte stimulator (BLyS) is a member of tumor necrosis factor family. BLyS is essential for the survival of normal and malignant B lymphocyte. Hepatitis C virus (HCV) infection likely represents the early event leading to BLyS upregulation. The aim of this study was to determine the relation between serum BLyS levels and the severity of HCV-related B-cell non-Hodgkin lymphoma (B-NHL).Patients and methodsSeventy-eight B-NHL patients both HCV-positive and HCV-negative and 20 patients with HCV infection without lymphoproliferative disorders, in addition to 20 age-matched and sex-matched controls, were included in the study. PCR for HCV, evaluation of levels of soluble BLyS protein in blood, bone marrow aspirate and biopsy with flow cytometry, and lymph node biopsy with immunophenotyping for CD5, CD23, CD10, CD20, and cyclinD1 were performed.ResultsThe serum BLyS levels were significantly higher in B-NHL patients and HCV patients without lymphoproliferative disorders compared with the control group. The serum BLyS levels were statistically significantly higher in aggressive lymphoma patients with HCV-positive infection compared with aggressive lymphoma patients with HCV-negative infection, but there was no statistically significant difference between BLyS levels in indolent B-NHL patients with or without HCV infections. Moreover, there was no statistically significant difference between BLyS levels in aggressive and indolent lymphoma patients with HCV-positive infection.ConclusionBLyS levels are increased in HCV-induced B-NHL but it cannot be considered as a marker for severity of the disease (indolent or aggressive). More studies are needed.

B-cell activating factor BAFF reflects patients' immunological risk profile after kidney transplantation

The B-cell activating factor BAFF plays an important role in the development and maturation of B–lymphocytes, which can contribute to the generation of donor-specific antibodies and thus may influence graft function and graft survival. Inconsistent data on the role of BAFF levels after renal transplantation for the formation of donor-specific antibodies and the contribution for allograft rejection exist.The aim of the current study was to determine to what extent the degree of pre-immunization is reflected by each patient's BAFF levels before transplantation and in the follow-up. Furthermore, the impact of BAFF on allograft rejection frequency as well as severity and resulting allograft function over time was analyzed. Additionally, the impact of viral infections on BAFF levels after transplantation - as a potential confounder - was examined. For this purpose, a group of pre-sensitized patients (PRA>0%, (52±24% on average), n=40) was compared with non-sensitized patients (PRA=0%, n=62) and in a subsequent analysis stratification in accordance to the detected BAFF level was performed.Pre-sensitized patients had significantly higher BAFF levels before transplantation and suffered significantly more often from early steroid-resistant, mainly antibody-mediated rejections. A result which was confirmed also in highly sensitized patients with PRA levels >50%. Additionally, in the follow-up patients with either rising BAFF levels over time or BAFF levels above the median also had significantly more often antibody mediated rejections. Additionally, patients with BAFF levels above detected median even displayed impaired creatinine values as well as an induced eGFR slope up to month 48 after transplantation. The occurrence of viral infections (CMV, BKV) was only an additional influencing factor in the absence of concomitant allograft rejections. Therefore, the B-cell proliferation factor BAFF appears not only to reflect the immunological risk profile of patients in the context of kidney transplantation, it may possibly be further developed as a predictor of patients with an increased risk profile for subsequent allograft rejection and impaired allograft function.

Increased BAFF and APRIL levels in the cerebrospinal fluid of patients with anti-neutrophil cytoplasmic antibody-related hypertrophic pachymeningitis

Hypertrophic pachymeningitis (HP) is an inflammatory disorder involving intracranial or spinal thickened dura mater. It has been recognized that anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis may lead to HP; however, the immune-mediated pathogenesis of ANCA-related HP (ANCA-HP) remains elusive. In the present study, we analyzed B-cell activation factor of the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) expression in the cerebrospinal fluid (CSF) and serum of patients with ANCA-HP, multiple sclerosis (MS), and non-inflammatory neurological disorders (NIND). BAFF and APRIL levels in the CSF were significantly higher in patients with ANCA-HP than in those with MS and NIND. In addition, a positive correlation between BAFF levels in the CSF and IgG-index was found in patients with ANCA-HP. On the other hand, no correlation was detected between CSF and serum levels of BAFF or APRIL. The results suggest that increased levels of BAFF and APRIL produced in the central nervous system may influence the development of ANCA-HP.

SYK inhibition thwarts the BAFF - B-cell receptor crosstalk and thereby antagonizes Mcl-1 in chronic lymphocytic leukemia.

Although small molecule inhibitors of B-cell receptor-associated kinases have revolutionized therapy in chronic lymphocytic leukemia (CLL), responses are incomplete. Pro-survival signaling emanating from the microenvironment may foster therapeutic resistance of the malignant B cells resident in the protective lymphoid niches. B-cell activating factor (BAFF) is critical to the survival of both healthy and neoplastic B cells. However, the pro-survival pathways triggered by BAFF have not been fully characterized. Here we show that BAFF elicited resistance to spontaneous and drug-induced apoptosis in stromal co-cultures, induced activation of both canonical and non-canonical NFκB signaling pathways, and triggered B-cell receptor signaling in CLL cells, independently of IGHV mutational status. SYK, a proximal kinase in the B-cell receptor signaling cascade, acted via STAT3 to bolster transcription of the anti-apoptotic protein Mcl-1, thereby contributing to apoptosis resistance in BAFF-stimulated cells. SYK inhibitor entospletinib downregulated Mcl-1, abrogating BAFF-mediated cell survival. BAFF-B-cell receptor crosstalk in neoplastic B cells was mediated by SYK interaction with TRAF2/TRAF3 complex. Thus, SYK inhibition is a promising therapeutic strategy uniquely poised to antagonize crosstalk between BAFF and B-cell receptor, thereby disrupting the pro-survival microenvironment signaling in chronic lymphocytic leukemia.

Novel biomarkers for systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a complex and highly heterogeneous disease. By now, no novel drug has been approved by the US FDA in the past 50 years, except Belimumab, a monoclonal antibody to inhibit B-cell activating factor. The stagnating drug development of lupus may be due to our limited understanding of disease etiopathogenesis and the extreme heterogeneity of patient population. Thus, the individualized treatment for SLE becomes necessary. Recently, biomarkers have shown potential in individualized treatment. This review comprehensively summarizes novel potential biomarkers, discusses their current status in preclinical studies and clinical use, sensitivity to treatments and correlation with the disease activity, and provides an insight into the possibility of biomarkers in the utilization of individualized treatment for SLE.

Sputum autoantibodies in patients with severe eosinophilic asthma

The persistence of eosinophils in sputum despite high doses of corticosteroids indicates disease severity in asthmatic patients. Chronic inflamed airways can lose tolerance over time to immunogenic entities released on frequent eosinophil degranulation, which further contributes to disease severity and necessitates an increase in maintenance corticosteroids. We sought to investigate the possibility of a polyclonal autoimmune event in the airways of asthmatic patients and to identify associated clinical and molecular characteristics. The presence of autoantibodies against eosinophil peroxidase (EPX) and anti-nuclear antibodies was investigated in patients with eosinophilic asthma maintained on high-dose corticosteroids, prednisone, or both. The ability of sputum immunoglobulins to induce eosinophil degranulation invitro was assessed. In addition, the associated inflammatory microenvironment in patients with detectable autoantibodies was examined. We report a "polyclonal" autoimmune event occurring in the airways of prednisone-dependent asthmatic patients with increased eosinophil activity, recurrent pulmonary infections, or both, as evident by the concomitant presence of sputum anti-EPX and anti-nuclear antibodies of the IgG subtype. Extensive cytokine profiling of sputum revealed a TH2-dominated microenvironment (eotaxin-2, IL-5, IL-18, and IL-13) and increased signalling molecules that support the formation ofectopic lymphoid structures (B-cell activating factor and Bcell-attracting chemokine 1). Immunoprecipitated sputum immunoglobulins from patients with increased autoantibody levels triggered eosinophil degranulation invitro, with release of extensive histone-rich extracellular traps, an event unsuppressed by dexamethasone and possibly contributing to the steroid-unresponsive nature of these eosinophilic patients. This study identifies an autoimmune endotype of severe asthma that can be identified by the presence of sputum autoantibodies against EPX and autologous cellular components.

Association of genetic polymorphisms of macrophage inhibitory factor (MIF) and B-cell activating factor (BAFF) with the detection of donor specific antibodies in kidney allograft recipients

The posttransplant development of donor specific antibodies (DSA) initiates the antibody mediated rejection (AMR), which is associated with the increased rate of graft loss. One of the characteristics of AMR is the infiltration of innate immune system including macrophages, monocytes, neutrophils or NK cells. Macrophage inhibitory factor (MIF) and B-cell activating factor (BAFF) are well known cytokines that are associated with the activation of the innate immune system which can damage kidney allograft. In this article, the association of the genetic polymorphisms of MIF and BAFF with the development of DSA including Class I and II in kidney transplant patients is investigated. A total of 231 renal transplant patients between 2008 and 2012 at St. Vincent Medical Center, CA were studied in a retrospective study design. DSA were determined by Luminex technology, and single nucleotide polymorphisms (SNP) of MIF and BAFF were determined by the real time PCR based on 5′ nuclease allelic discrimination assay. The genetic polymorphisms of MIF rs1007888 (C/T) was associated with increased risk of positive DSA detection (p=0.04) after transplantation, and consistently significant after 1year (p=0.016). Furthermore, the presence of C allele were associated with the increased risk of Class I DSA detection (OR 1.816, CI 1.141–2.889, p=0.011). Also, genetic polymorphisms of BAFF rs12583006 were associated with the increased risk of Class II DSA detection (p=0.033). In conclusion, the genetic polymorphisms of MIF and BAFF may increase the risk of posttransplant development of DSA. This result suggests the association between the development of posttransplant DSA and the activation of innate immune system.

Systemic lupus erythematosus: BAFF emerges from the genetic shadows.

A newly identified insertion–deletion variant of the B cell activating factor (BAFF)-encoding TNFSF13B gene leads to increased levels of soluble BAFF and is associated with the development of systemic lupus erythematosus. The discovery raises a number of compelling questions for further investigation.

Glucocorticoid-induced leucine zipper expression is associated with response to treatment and immunoregulation in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disorder in which cytokine balance is disturbed. Glucocorticoids (GCs) are shown to balance immune response by transcriptional regulation of glucocorticoid receptor target genes such as Glucocorticoid-induced leucine zipper (GILZ) which has been introduced as an endogenous anti-inflammatory mediator. In the present study, we assessed the expression of GILZ in association with interferon-γ (IFN-γ), interleukine-10 (IL-10), and B lymphocyte stimulator (BLyS) plasma levels in SLE patients. A total of 40 female patients (18 under treatment and 22 newly diagnosed) were recruited in this study. Real-time RT PCR was conducted to quantify the mRNA expression of GILZ. The plasma levels of IFN-γ, IL-10, and BLyS were evaluated using ELISA method. GILZ was overexpressed among under treatment SLE patients. The mRNA expression of GILZ was significantly correlated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score. IFN-γ and BLyS were downregulated in response to therapies with negative correlations to GILZ. Moreover, IL-10 was upregulated among treated patients. The levels of IFN-γ and BLyS were correlated with the severity of disease, while IL-10 was negatively correlated with SLEDAI score. GILZ could be introduced as one of the acting molecules in mediating the regulatory effects of GCs on producing pro- and anti-inflammatory cytokines in SLE.

B-cell activating factor deficiency suppresses splenomegaly during Leishmania donovani infection

B-cell activating factor (BAFF) is a critical regulator for B-cell development and differentiation. We previously reported elevation of serum BAFF levels in patients with visceral leishmaniasis (VL). In this study, we examined if BAFF is involved in pathologies during infection of Leishmania donovani. BALB/cA mice infected with L. donovani showed significant elevation in serum BAFF and IgG levels as seen in VL patients. In contrast, elevation of serum IgG by L. donovani infection was significantly suppressed in BAFF-deficient mice. The spleen weight of the BAFF-deficient mice after infection was significantly lower than that of the infected wild-type mice, whereas comparable degree of hepatomegaly and anemia were observed in those mice. In the enlarged spleen of L. donovani-infected wild-type mice, increase of CD19+ lymphocytes was more prominent than that of CD3+ cells, suggesting the contribution of B cell increase to splenomegaly during VL. Besides, increase of CD19+ lymphocytes was not found in BAFF-deficient mice after L. donovani infection. Taken together, these results suggest that BAFF is involved in strong B cell activation, which has a pathological role in splenomegaly but not in hepatomegaly or anemia, during VL.

Blockade of chondroitin sulfate proteoglycans-induced axonal growth inhibition by LOTUS

Chondroitin sulfate proteoglycans (CSPGs) are axon growth inhibitors in the glial scar, and restrict axon regeneration following damage to the adult mammalian central nervous system. CSPGs have recently been identified as functional ligands for Nogo receptor-1 (NgR1), which is the common receptor for Nogo proteins, myelin-associated glycoprotein (MAG), oligodendrocyte myelin glycoprotein (OMgp) and B lymphocyte stimulator (BLyS). We have previously reported that through its binding to NgR1, lateral olfactory tract usher substance (LOTUS) suppresses Nogo, MAG, OMgp, and BLyS-induced axon growth inhibition. However, it remains unknown whether LOTUS also exerts this suppressive action on CSPG-induced axon growth inhibition. LOTUS overexpression rescued CSPG-induced growth cone collapse and neurite outgrowth inhibition in cultured dorsal root ganglion neurons, which only weakly express endogenous LOTUS. In cultured olfactory bulb neurons, which endogenously express LOTUS, the growth cone was insensitive to CSPG-induced collapse, but was sensitive to collapse induced by CSPGs in lotus-deficient mice. Our data demonstrate that LOTUS suppresses CSPG-induced axon growth inhibition, suggesting that LOTUS may represent a promising therapeutic agent for promoting axon regeneration.

Belimumab in the management of systemic lupus erythematosus – an update

ABSTRACTIntroduction: Belimumab is a fully humanised mAb against B lymphocyte stimulator (B-LyS). It is the first biological drug licensed and approved by the US FDA and the European Medicines Agency (EMA) for use in combination with standard immunosuppressants in autoantibody-positive systemic lupus erythematosus (SLE).Areas covered: This manuscript evalues the recent data concerning belimumab’s safety and clinical effectiveness and its current place in the treatment of SLE. This includes an overview of the recent data coming from the post-hoc analyses of the BLISS trials, real-life experience with belimumab and the accumulating data on its safety. Attention is also paid to the progress made in the identification of predictors of response to belimumab, recent phase I/II/III studies with subcutaneous belimumab, and experience with B cell modulation coming from recent trials with other B cell modulating drugs.Expert opinion: Belimumab currently has its established role in the treatment of patients with SLE with serologic activity and clinical activity namely in mucocutaneous and musculoskeletal domains despite standard of care treatment. Better identification of patients who can benefit from treatment with belimumab is warranted. Data from ongoing studies in lupus nephritis and other data from observational studies are eagerly awaited.

Modulation of autophagy via lentivirus-derived shAtg5 ameliorates lupus-like disease in mice

Abstract Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of anti-nuclear antibodies. Traditionally, immunosuppressive and cytotoxic agents were widely used to treat lupus. However, the side effect and toxicities are inevitable. Autophagy is a process which can degrade the aged organelles and unfolded proteins to maintain the cell homeostasis. Previous studies have shown that autophagy levels were positively correlated with disease severity and elevated in B and T cells of lupus-prone mice and lupus patients. Furthermore, autophagy is essential for plasma cell differentiation, survival and antibody production. These results implicate that autophagy may promote lupus progression through regulating the survival of autoreactive immune cells. Therefore, we aim to modulate the autophagy of lupus-prone mice by lentivirus-derived shRNA targeting Atg5, an essential protein for autophagy. First, we found that levels of autophagy in splenocytes and lymphocytes of peripheral blood (PB) were elevated and positively correlated with disease severity in lupus-prone mice. The shAtg5-lentivirus, which can effectively inhibit autophagy in vitro, were then i.p. injected into TREM-1−/−. lpr mice. Mice treated with shAtg5-lentivirus exhibited lower levels of proteinuria, serum anti-dsDNA antibody and B-cell activating factor (BAFF). Lymphadenopathy as well as autophagy levels in lymph node cells and PB lymphocytes were decreased following Atg5 suppression. We also found numbers of plasma cells, CD4−CD8−, and CD4+T cells were decreased in mice treated with shAtg5-lentivirus. Thus, inhibition of autophagy may suppress immune cell expansion in lupus-prone mice and provide a novel target therapy for SLE.

A TLR9-dependent checkpoint governs B cell responses to DNA-containing antigens.

Mature B cell pools retain a substantial proportion of polyreactive and self-reactive clonotypes, suggesting that activation checkpoints exist to reduce the initiation of autoreactive B cell responses. Here, we have described a relationship among the B cell receptor (BCR), TLR9, and cytokine signals that regulate B cell responses to DNA-containing antigens. In both mouse and human B cells, BCR ligands that deliver a TLR9 agonist induce an initial proliferative burst that is followed by apoptotic death. The latter mechanism involves p38-dependent G1 cell-cycle arrest and subsequent intrinsic mitochondrial apoptosis and is shared by all preimmune murine B cell subsets and CD27- human B cells. Survival or costimulatory signals rescue B cells from this fate, but the outcome varies depending on the signals involved. B lymphocyte stimulator (BLyS) engenders survival and antibody secretion, whereas CD40 costimulation with IL-21 or IFN-γ promotes a T-bet+ B cell phenotype. Finally, in vivo immunization studies revealed that when protein antigens are conjugated with DNA, the humoral immune response is blunted and acquires features associated with T-bet+ B cell differentiation. We propose that this mechanism integrating BCR, TLR9, and cytokine signals provides a peripheral checkpoint for DNA-containing antigens that, if circumvented by survival and differentiative cues, yields B cells with the autoimmune-associated T-bet+ phenotype.

Novel Treatments in Lupus.

The treatment of systemic lupus erythematosus (SLE) still depends on non-specific immunosuppression. Herein, we review promising targeted therapies that have the potential to change this therapeutic paradigm. Besides the FDA-approved B lymphocyte stimulator (BLyS) inhibitor, belimumab, interferon-α represents a promising treatment target, albeit with modest effectiveness primarily in non-renal SLE. Preclinical and early-phase clinical trials using biologics and small molecules targeting B and T cell activation as well as the cross-talk between these cells also show promise. BLyS and interferon targeting show the most promising results in challenging the current treatment status in non-renal SLE.

Smoking and pre-existing organ damage reduce the efficacy of belimumab in systemic lupus erythematosus.

Belimumab is the first biologic drug approved for Systemic Lupus Erythematosus (SLE). Here, we aimed to investigate the effects of belimumab on clinical and serologic outcomes, and sought to identify predictors of treatment response in three Swedish real-life settings. Fifty-eight patients were enrolled at initiation of belimumab and followed longitudinally for up to 53months. Surveillance outcomes included the SLE Disease Activity Index 2000 (SLEDAI-2K), 100mm Visual Analogue Scales for Physician's Global Assessment (PGA), fatigue, pain and general health, and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). Assessment of treatment response included the SLE responder index (SRI). B lymphocyte stimulator (BLyS) levels were determined using ELISA. SLEDAI-2K (median baseline score: 8.0; IQR: 4.0-13.8), PGA and corticosteroid use decreased during therapy, and patients reported improvements on fatigue, pain, and general health (p<0.0001 for all). SDI scores remained stable (p=0.08). Patients with baseline SDI scores >1 showed decreased probability and prolonged time to attain SRI response (HR: 0.449; 95% CI: 0.208-0.967), as did current smokers compared with non-smokers (HR: 0.103; 95% CI: 0.025-0.427). In contrast, baseline BLyS levels ≥1.2ng/mL predicted increased probability and shorter time to attain SRI response (HR: 2.566; 95% CI: 1.222-5.387). Disease activity and corticosteroid usage decreased, patient-reported outcomes improved, and no significant organ damage was accrued during follow-up. Smoking and organ damage predicted reduced treatment efficacy. These findings might contribute to a better selection of patients who are likely to benefit from belimumab.

Efficacy of belimumab on renal outcomes in patients with systemic lupus erythematosus: A systematic review.

Both BLISS-52 and BLISS-76 international phase III trials in Systemic Lupus Erythematosus (SLE) met their primary outcomes; however, they were not designed to assess the efficacy of belimumab for the treatment of lupus nephritis (LN). LN is a frequent cause of SLE-associated morbidity and mortality, and emerging evidence suggests a potential therapeutic role for agents that target B lymphocyte stimulator (BLyS). We conducted a systematic review to identify data on the effect of belimumab on LN. A total of 2004 patients with SLE were identified from 11 studies. Three hundred and twenty-six patients had LN at baseline and 234 (71.8%) of those received belimumab. Thirteen patients out of 234 (5.5%) received belimumab for active LN. Due to the heterogeneous definitions of treatment response, clinical presentation and renal involvement, it was not possible to compare results using a single outcome parameter. However, the majority of these studies defined clinical response in terms of rates of renal flare, renal remission, and/or renal organ disease improvement. One hundred twenty-nine (55.1%) of the 234 patients with LN at baseline showed an improvement in renal parameters after treatment with belimumab. In patients with baseline proteinuria>0.2g/24h, (n=687), those receiving belimumab had a median reduction in proteinuria during follow-up as high as 38%. When focusing on patients with proteinuria≥1g/24h (n=228), 70.7% of those treated with belimumab (n=157) achieved a renal response. In the pooled population of patients receiving belimumab, we found an overall annual renal flare rate of 1.7% [24/1448, mean observation time 1,1years (0,5-3)]. Despite the limitations of the studies included in this analysis, available data are promising and provide preliminary support for targeting BlyS to induce or maintain a renal response. Further trials should examine whether belimumab (alone or following rituximab) represents an additional therapeutic option in the treatment of LN.

Sjogren's syndrome: Review of the aetiology, Pathophysiology & Potential therapeutic interventions.

BackgroundSjogren’s syndrome (SS) is an autoimmune disorder characterised by lymphocytic infiltration of exocrine glands, resulting in glandular dysfunction. Objectives: This study aims to review the aetiology of Sjogren’s syndrome, highlight aspects that contribute to the pathophysiology of the disease and explore treatment options that target different mediators of pathogenesis.Material and MethodsThe MEDLINE/PubMed and Google Scholar databases were searched systematically with the terms “Sjogren’s syndrome”; “clinical”; “treatment”; “management”. Eligible studies had to meet a predefined inclusion criteria.Results912 identified studies were evaluated against the inclusion criteria. 25 eligible studies were included for review. Sjogren’s syndrome is a multifactorial condition with genetic, environmental and hormonal factors playing a role in establishing the condition. B-cell activating factor (BAFF) is an important mediator in the induction and perpetuation of this condition. Elevated BAFF levels, found in patients with SS, promote growth of B-cells and subsequent production of autoantibody; anti-SSA/Ro. BAFF inhibitors are important potential therapeutic drugs that may be effective in patients with Sjogren’s syndrome. Other potential targets include CD20 and CD22 that cause B-cell depletion.ConclusionsThe pathophysiology of this exocrinopathy has not fully been elucidated. Potential therapeutic interventions include BAFF inhibitors and anti-CD20 and anti-CD22 therapy. However, no clinical trials have been conducted on subjects with Sjogren’s syndrome to support existing research. Key words:Sjogren’s syndrome, autoimmune, rheumatology.

Belimumab for the treatment of recalcitrant cutaneous lupus.

Background Belimumab is a monoclonal antibody that reduces B lymphocyte survival by blocking the binding of soluble human B lymphocyte stimulator (BLyS) to its B cell receptors. The utility of belimumab for management of resistant systemic lupus erythematosus (SLE) skin manifestations has not been reported. We present our experience of using this novel molecule for the successful management of cutaneous lupus at our center. Methods We studied five patients with significant SLE skin manifestations. All patients met 1997 American College of Rheumatology (ACR) SLE criteria and had failed multiple medications to control their skin disease. SLE disease activity indexes (SLEDAI), Cutaneous LE disease Area and Severity Index (CLASI) and patient's global assessment (PGA) were recorded before and 16 weeks after belimumab treatment. Belimumab was added to concomitant standard therapy. Results All five patients demonstrated marked clinical improvement subsequent to belimumab treatment. The average time to clinical improvement after treatment initiation was 8-12 weeks. SLEDAI scores (median, range) improved in all the patients ((2, 2-6) to (0, 0-4); p = 0.025). PGA scores (median, range) were better in all patients ((3, 2-3) to (1, 0-1); p = 0.039). CLASI activity scores (median, range) improved dramatically in all patients ((17, 9-31) to (3, 2-14); p = 0.043). There was no worsening of the CLASI damage scores. The mean daily prednisone dose decreased significantly from 31 mg (±18.8) at baseline to 3 mg (± 2.7) ( p = 0.042). Conclusion In this case series, the addition of belimumab to standard therapy improved the signs and symptoms of refractory cutaneous lupus. This is one of the first reports highlighting the potential utility of this medication for the treatment of severe skin involvement in SLE refractory to conventional therapies. Additional studies need to be performed to assess the use of belimumab in the treatment of cutaneous lupus.

Apa2H1, the first head domain of Apa2 trimeric autotransporter adhesin, activates mouse bone marrow-derived dendritic cells and immunization with Apa2H1 protects against Actinobacillus pleuropneumoniae infection.

Actinobacillus pleuropneumoniae is the causative pathogen of porcine pleuropneumonia, which results in large economic losses in the pig industry worldwide. There are, however, no effective subunit vaccines are available in the market owing to the various serotypes and the absence of cross-protection against this pathogen. Therefore, the selection of protective components is of great significance for vaccine development. We previously showed that trimeric autotransporter adhesins are important virulence factors of A. pleuropneumoniae. To determine the potential role in vaccine development of the functional head domain (Apa2H1) of Apa2, a trimeric autotransporter adhesin found in A. pleuropneumoniae, we obtained nature-like trimeric Apa2H1 using a prokaryotic expression system and co-culture of Apa2H1 with bone marrow derived dendritic cells (BMDCs) in vitro resulted in maturation of BMDCs, characterised by the up-regulation of CD83, MHC-II, CCR7, ICAM-I and the increased expression of factors related to B lymphoid cells stimulation, such as proliferation-inducing ligand (APRIL), B lymphocyte stimulator (BLyS) and B cell activating factor (BAFF). The in vivo results showed that vaccination with Apa2H1 resulted in the robust production of antigen-specific antibodies, modestly induced mixed Th1 and Th2 immunity, impaired bacterial colonization and dissemination, and improved mouse survival rates. This study is the first to show that Apa2H1 is antigenic and can be used as a component of a subunit vaccine against A. pleuropneumoniae infection, providing valuable reference material for the development of an effective vaccine against A. pleuropneumoniae.