A Subset of Type I Conventional Dendritic Cells Controls Cutaneous Bacterial Infections through VEGFα-Mediated Recruitment of Neutrophils.

Skin conventional dendritic cells (cDCs) exist as two distinct subsets, cDC1s and cDC2s, which maintain the balance of immunity to pathogens and tolerance to self and microbiota. Here, we examined the roles of dermal cDC1s and cDC2s during bacterial infection, notably Propionibacterium acnes (P. acnes). cDC1s, but not cDC2s, regulated the magnitude of the immune response to P. acnes in the murine dermis by controlling neutrophil recruitment to the inflamed site and survival and function therein. Single-cell mRNA sequencing revealed that this regulation relied on secretion of the cytokine vascular endothelial growth factor α (VEGF-α) by a minor subset of activated EpCAM+CD59+Ly-6D+ cDC1s. Neutrophil recruitment by dermal cDC1s was also observed during S. aureus, bacillus Calmette-Guérin (BCG), or E. coli infection, as well as in a model of bacterial insult in human skin. Thus, skin cDC1s are essential regulators of the innate response in cutaneous immunity and have roles beyond classical antigen presentation.

First-line rituximab combined with short-term prednisone versus prednisone alone for the treatment of pemphigus (Ritux 3): a prospective, multicentre, parallel-group, open-label randomised trial.

BACKGROUND: High doses of corticosteroids are considered the standard treatment for pemphigus. Because long-term corticosteroid treatment can cause severe and even life-threatening side-effects in patients with this disease, we assessed whether first-line use of rituximab as adjuvant therapy could improve the proportion of patients achieving complete remission off-therapy, compared with corticosteroid treatment alone, while decreasing treatment side-effects of corticosteroids. METHODS: We did a prospective, multicentre, parallel-group, open-label, randomised trial in 25 dermatology hospital departments in France (Ritux 3). Eligible participants were patients with newly diagnosed pemphigus aged 18-80 years being treated for the first time (not at the time of a relapse). We randomly assigned participants (1:1) to receive either oral prednisone alone, 1·0 or 1·5 mg/kg per day tapered over 12 or 18 months (prednisone alone group), or 1000 mg of intravenous rituximab on days 0 and 14, and 500 mg at months 12 and 18, combined with a short-term prednisone regimen, 0·5 or 1·0 mg/kg per day tapered over 3 or 6 months (rituximab plus short-term prednisone group). Follow-up was for 3 years (study visits were scheduled weekly during the first month of the study, then monthly until month 24, then an additional visit at month 36). Treatment was assigned through central computer-generated randomisation, with stratification according to disease-severity (severe or moderate, based on Harman's criteria). The primary endpoint was the proportion of patients who achieved complete remission off-therapy at month 24 (intention-to-treat analysis). This study is registered with ClinicalTrials.gov, number NCT00784589. FINDINGS: Between May 10, 2010, and Dec 7, 2012, we enrolled 91 patients and randomly assigned 90 to treatment (90 were analysed; 1 patient withdrew consent before the random assignment). At month 24, 41 (89%) of 46 patients assigned to rituximab plus short-term prednisone were in complete remission off-therapy versus 15 (34%) of 44 assigned to prednisone alone (absolute difference 55 percentage points, 95% CI 38·4-71·7; p<0·0001. This difference corresponded to a relative risk of success of 2·61 (95% CI 1·71-3·99, p<0·0001), corresponding to 1·82 patients (95% CI 1·39-2·60) who would need to be treated with rituximab plus prednisone (rather than prednisone alone) for one additional success. No patient died during the study. More severe adverse events of grade 3-4 were reported in the prednisone-alone group (53 events in 29 patients; mean 1·20 [SD 1·25]) than in the rituximab plus prednisone group (27 events in 16 patients; mean 0·59 [1·15]; p=0·0021). The most common of these events in both groups were diabetes and endocrine disorder (11 [21%] with prednisone alone vs six [22%] with rituximab plus prednisone), myopathy (ten [19%] vs three [11%]), and bone disorders (five [9%] vs five [19%]). INTERPRETATION: Data from our trial suggest that first-line use of rituximab plus short-term prednisone for patients with pemphigus is more effective than using prednisone alone, with fewer adverse events. FUNDING: French Ministry of Health, French Society of Dermatology, Roche.

New Approaches to Investigate Drug-Induced Hypersensitivity.

The workshop on "New Approaches to Investigate Drug-Induced Hypersensitivity" was held on June 5, 2014 at the Foresight Center, University of Liverpool. The aims of the workshop were to (1) discuss our current understanding of the genetic, clinical, and chemical basis of small molecule drug hypersensitivity, (2) highlight the current status of assays that might be developed to predict potential drug immunogenicity, and (3) identify the limitations, knowledge gaps, and challenges that limit the use of these assays and utilize the knowledge gained from the workshop to develop a pathway to establish new and improved assays that better predict drug-induced hypersensitivity reactions during the early stages of drug development. This perspective reviews the clinical and immunological bases of drug hypersensitivity and summarizes various experts' views on the different topics covered during the meeting.

Human regulatory B cells combine phenotypic and genetic hallmarks with a distinct differentiation fate.

Regulatory B cells (B-reg) produce IL-10 and suppress inflammation in both mice and humans, but limited data on the phenotype and function of these cells have precluded detailed assessment of their contribution to host immunity. In this article, we report that human B-reg cannot be defined based on a phenotype composed of conventional B cell markers, and that IL-10 production can be elicited in both the CD27(+) memory population and naive B cell subset after only a brief stimulation in vitro. We therefore sought to obtain a better definition of IL-10-producing human B-regs using a multiparameter analysis of B cell phenotype, function, and gene expression profile. Exposure to CpG and anti-Ig are the most potent stimuli for IL-10 secretion in human B cells, but microarray analysis revealed that human B cells cotreated with these reagents resulted in only ∼0.7% of genes being differentially expressed between IL-10(+) and IL-10(-) cells. Instead, connectivity map analysis revealed that IL-10-secreting B cells are those undergoing specific differentiation toward a germinal center fate, and we identified a CD11c(+) B cell subset that was not capable of producing IL-10 even under optimal conditions. Our findings will assist in the identification of a broader range of human pro-B-reg populations that may represent novel targets for immunotherapy.

Lack of expression of an alternative CD20 transcript variant in circulating B cells from patients with pemphigus.

We have identified a spliced mRNA transcript of CD20 (named D393-CD20) which was associated with resistance to RTX in primary B cell from patients with lymphoma and leukaemia. In the present work, we wished to investigate whether D393-CD20 variant was expressed by B cells from patients with pemphigus. Ten patients with bullous pemphigoid and twenty-five patients with pemphigus were included. All patients were responder to conventional immunosuppressive agents or rituximab (n = 11). Efficacy of B-cell activation by pokeweed mitogen was assessed by CD86 expression using a FACS Canto II flow cytometer. mRNA CD20 expression study was then performed using RT-PCR assay allowing first to discriminate wild-type (wt)-CD20 and D393-CD20 transcript. Although wt-CD20 expression was always detected, we were unable to detect D393-CD20, even after B-cell activation or RTX treatment. Our results suggest that D393-CD20 transcript may be a molecular marker of B-cell malignancies rather than autoimmune disease like pemphigus. Further study of RTX non-responders or non-escaping PV patients is thus still required to appreciate whether D393-CD20 expression may be detected under the pressure of RTX therapy.

Sustained Remission Without Corticosteroids Among Patients With Pemphigus Who Had Rituximab as First-Line Therapy: Follow-Up of the Ritux 3 Trial.

Importance: The Ritux 3 trial demonstrated the short-term efficacy and safety of first-line treatment with rituximab compared with a standard corticosteroid regimen in pemphigus. No data on the long-term follow-up of patients who received rituximab as first line are available. Objective: To assess the long-term efficacy and safety of the Ritux 3 treatment regimen. Design, Setting, and Participants: This 7-year follow-up study of the Ritux 3 trial included patients with pemphigus from 25 dermatology departments in France from January 1, 2010, to December 31, 2015. Exposure: Patients were initially randomized in the rituximab plus prednisone group or prednisone-alone group. Main outcomes and measures: The primary outcome was the 5- and 7-year disease-free survival (DFS) without corticosteroids, assessed by Kaplan-Meier curves. Secondary outcomes were occurrence of relapse, occurrence of severe adverse events (SAEs), and evolution of antidesmoglein (Dsg) antibody enzyme-linked immunosorbent assay values to predict long-term relapse. Results: Of the 90 patients in the Ritux 3 trial, 83 were evaluated at the end of follow-up study visit (44 in the rituximab plus prednisone group; 39 in the prednisone-alone group) with a median (IQR) follow-up of 87.3 (79.1-97.5) months. Forty-three patients (93%) from the rituximab plus prednisone and 17 patients (39%) from the prednisone-alone group had achieved complete remission without corticosteroids at any time during the follow-up. Patients from the rituximab group had much longer 5- and 7-year DFS without corticosteroids than patients from the prednisone-alone group (76.7% and 72.1% vs 35.3% and 35.3%, respectively; P < .001), and had about half the relapses (42.2% vs 83.7%; P < .001). Patients who received rituximab as second-line treatment had shorter DFS than patients treated as first line (P = .007). Fewer SAEs were reported in the rituximab plus prednisone group compared with the prednisone-alone group, 31 vs 58 respectively, corresponding to 0.67 and 1.32 SAEs per patient, respectively (P = .003). The combination of anti-Dsg1 values of 20 or more IU/mL and/or anti-Dsg3 values of 48 or more IU/mL yielded 0.83 positive predictive value and 0.94 negative predictive value to predict long-term relapse. Conclusions and Relevance: In this secondary analysis of the Ritux 3 trail, first-line treatment of patients with pemphigus with the Ritux 3 regimen was associated with long-term sustained complete remission without corticosteroid therapy without any additional maintenance infusion of rituximab.

Rituximab Therapy for Mucous Membrane Pemphigoid: A Retrospective Monocentric Study With Long-Term Follow-Up in 109 Patients.

Mucous membrane pemphigoid (MMP) is a heterogeneous group of rare, chronic, subepithelial autoimmune blistering diseases (AIBDs) with predominant involvement of mucous membranes that can be sight-threatening and life-threatening. Rituximab (RTX) has demonstrated its efficacy in severe MMP refractory to conventional immunosuppressants in small series that differed in RTX scheme, concomitant therapies, and outcome definitions. In a meta-analysis involving 112 patients with MMP treated with RTX, complete remission (CR) was reported in 70.5% of cases. Herein, we report the largest retrospective monocentric study on RTX efficacy in a series of 109 severe and/or refractory patients with MMP treated with RTX with a median follow-up period of 51.4 months. RTX was administered in association with immunomodulatory drugs (dapsone, salazopyrine) without any other systemic immunosuppressant in 104 patients. The RTX schedule comprised two injections (1 g, 2 weeks apart), repeated every 6 months until CR or failure, with a unique consolidation injection (1 g) after CR. The median survival times to disease control and to CR were 7.1 months and 12.2 months, respectively. The median number of RTX cycles required to achieve CR in 85.3% of patients was two. The larynx was the lesional site that took the longest time to achieve disease control. One year after RTX weaning, CR off RTX was obtained in 68.7% of cases. CR off RTX with only minimum doses of immunomodulatory drugs was achieved in 22.0% of patients. Further, 10.1% of patients were partial responders and 4.6% were non-responders to RTX. Relapse occurred in 38.7% of cases, of whom 91.7% had achieved CR again at the last follow-up. In MMP, CR was achieved in a longer time and after more rituximab cycles than in pemphigus, especially for patients with MMP with anti-type VII collagen reactivity. RTX with concomitant immunomodulatory drugs was not responsible for an unusual proportion of adverse events. This large study confirms that RTX is an effective therapy in patients with severe and/or refractory MMP, corroborating previous findings regarding the effects of RTX on AIBDs such as pemphigus.

IL-10 produced by activated human B cells regulates CD4(+) T-cell activation in vitro.

IL-10-producing regulatory B cells have been identified in mice and shown to downregulate inflammation, making them potentially important for maintenance of tolerance. In this study, we isolated B cells from human blood and spleen, and showed that after a short period of ex vivo stimulation a number of these cells produced IL-10. The IL-10-producing B cells did not fall within a single clearly defined subpopulation, but were enriched in both the memory (CD27(+)) and the transitional (CD38(high)) B-cell compartments. Combined CpG-B+anti-Ig stimulation was the most potent IL-10 stimulus tested. B cells stimulated in this way inhibited CD4(+)CD25(-) T-cell proliferation in vitro by a partially IL-10-dependent mechanism. These findings imply that manipulating IL-10 production by human B cells could be a useful therapeutic strategy for modulating immune responses in humans.

Critical role of TLR2 and TLR4 in autoantibody production and glomerulonephritis in lpr mutation-induced mouse lupus.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by pathogenic autoantibodies directed against nuclear Ags and immune complex deposits in damaged organs. Environmental factors have been thought to play a role in the onset of the disease. The recognition of these factors is mediated by TLRs, in particular TLR2 and TLR4 which bind pathogen-associated molecular patterns of Gram(+) and Gram(-) bacteria, respectively. We attempted to determine the role of these TLRs in SLE by creating TLR2- or TLR4-deficient C57BL/6(lpr/lpr) mice. These mice developed a less severe disease and fewer immunological alterations. Indeed, in C57BL/6(lpr/lpr)-TLR2 or -TLR4-deficient mice, glomerular IgG deposits and mesangial cell proliferation were dramatically decreased and antinuclear, anti-dsDNA, and anti-cardiolipin autoantibody titers were significantly reduced. However, the response against nucleosome remained unaffected, indicating a role of TLR2 and TLR4 in the production of Abs directed against only certain categories of SLE-related autoantigens. Analysis of B cell phenotype showed a significant reduction of marginal zone B cells, particularly in C57BL/6(lpr/lpr)-TLR4-deficient mice, suggesting an important role of TLR4 in the sustained activation of these cells likely involved in autoantibody production. Interestingly, the lack of TLR4 also affected the production of cytokines involved in the development of lupus disease.

Clinical and biological activity of rituximab in the treatment of pemphigus.

B-cells are major effector cells in autoimmunity since they differentiate into plasmocytes that produce pathogenic auto-antibody such as anti-desmoglein antibodies in pemphigus patients. Major advances were obtained using whole B-cell depleting therapies including anti-CD20 antibodies in refractory pemphigus patients that lead to rituximab approval in pemphigus patients in EU and USA. This review summarizes the data supporting the efficacy of rituximab in pemphigus and provides an overview of the reported immunological changes underlying its therapeutic action. Short and long-term remission in pemphigus is explained by the removal of autoreactive B-cells involved in the production of pathogenic IgG auto-antibodies and by enhancement of the appearance of regulatory B-cells that could maintain long term immune tolerance.

Autoimmune Pemphigus: Latest Advances and Emerging Therapies.

Pemphigus represents a group of rare and severe autoimmune intra-epidermal blistering diseases affecting the skin and mucous membranes. These painful and debilitating diseases are driven by the production of autoantibodies that are mainly directed against the desmosomal adhesion proteins, desmoglein 3 (Dsg3) and desmoglein 1 (Dsg1). The search to define underlying triggers for anti-Dsg-antibody production has revealed genetic, environmental, and possible vaccine-driven factors, but our knowledge of the processes underlying disease initiation and pathology remains incomplete. Recent studies point to an important role of T cells in supporting auto-antibody production; yet the involvement of the myeloid compartment remains unexplored. Clinical management of pemphigus is beginning to move away from broad-spectrum immunosuppression and towards B-cell-targeted therapies, which reduce many patients' symptoms but can have significant side effects. Here, we review the latest developments in our understanding of the predisposing factors/conditions of pemphigus, the underlying pathogenic mechanisms, and new and emerging therapies to treat these devastating diseases.

Modifications of the BAFF/BAFF-Receptor Axis in Patients With Pemphigus Treated With Rituximab Versus Standard Corticosteroid Regimen.

The efficacy of the B-cell-depleting agent rituximab has been reported in immune diseases but relapses are frequent, suggesting the need for repeated infusions. The B-cell activating factor (BAFF) is an important factor for B cell survival, class switch recombination and selection of autoreactive B cells, as well as maintaining long-lived plasma cells. It has been hypothesized that relapses after rituximab might be due to the increase of serum BAFF levels. From the Ritux3 trial, we showed that baseline serum BAFF levels were higher in pemphigus patients than in healthy donors (308 ± 13 pg/mL versus 252 ± 28 pg/mL, p=0.037) and in patients with early relapse compared who didn't (368 ± 92 vs 297 ± 118 pg/mL, p=0.036). Rituximab and high doses of CS alone have different effects on the BAFF/BAFF-R axis. Rituximab led to an increase of BAFF levels associated to a decreased mRNA (Day 0: 12.3 ± 7.6 AU vs Month 36: 3.3 ± 4.3 AU, p=0.01) and mean fluorescence intensity of BAFF-R in non-autoreactive (Day 0: 3232 vs Month 36: 1527, mean difference: 1705, 95%CI: 624 to 2786; p=0.002) as well as on reappearing autoreactive DSG-specific B cells (Day 0: 3873 vs Month 36: 2688, mean difference: 1185, 95%CI: -380 to 2750; p=0.20). Starting high doses of corticosteroids allowed a transitory decrease of serum BAFF levels that re-increased after doses tapering whereas it did not modify BAFF-R expression in autoreactive and non-autoreactive B cells. Our results suggest that the activation of autoreactive B cells at the onset of pemphigus is likely to be related to the presence of high BAFF serum levels and that the decreased BAFF-R expression after rituximab might be responsible for the delayed generation of memory B cells, resulting in a rather long period of mild pemphigus activity after rituximab therapy. Conversely, the incomplete B cell depletion and persistent BAFF-R expression associated with high BAFF serum levels might explain the high number of relapses in patients treated with CS alone.

A single cycle of rituximab for the treatment of severe pemphigus.

BACKGROUND: The combination of multiple cycles of rituximab and intravenous immune globulins has been reported to be effective in patients with severe pemphigus. The aim of this study was to assess the efficacy of a single cycle of rituximab in severe types of pemphigus. METHODS: We studied 21 patients with pemphigus whose disease had not responded to an 8-week course of 1.5 mg of prednisone per kilogram of body weight per day (corticosteroid-refractory disease), who had had at least two relapses despite doses of prednisone higher than 20 mg per day (corticosteroid-dependent disease), or who had severe contraindications to corticosteroids. The patients were treated with four weekly infusions of 375 mg of rituximab per square meter of body-surface area. The primary end point was complete remission 3 months after the end of rituximab treatment; complete remission was defined as epithelialization of all skin and mucosal lesions. RESULTS: Eighteen of 21 patients (86%; 95% confidence interval, 64 to 97%) had a complete remission at 3 months. The disease relapsed in nine patients after a mean of 18.9+/-7.9 months. After a median follow-up of 34 months, 18 patients (86%) were free of disease, including 8 who were not receiving corticosteroids; the mean prednisone dose decreased from 94.0+/-10.2 to 12.0+/-7.5 mg per day (P=0.04) in patients with corticosteroid-refractory disease and from 29.1+/-12.4 to 10.9+/-16.5 mg per day (P=0.007) in patients with corticosteroid-dependent disease. Pyelonephritis developed in one patient 12 months after rituximab treatment, and one patient died of septicemia 18 months after rituximab treatment. These patients had a profound decrease in the number of circulating B lymphocytes but normal serum levels of IgG. CONCLUSIONS: A single cycle of rituximab is an effective treatment for pemphigus. Because of its potentially severe side effects, its use should be limited to the most severe types of the disease. (ClinicalTrials.gov number, NCT00213512 [ClinicalTrials.gov].).

Toll-like receptors 4 contribute to endothelial injury and inflammation in hemorrhagic shock in mice.

OBJECTIVE: Hemorrhagic shock followed by resuscitation (HS/R) promotes organ injury by priming cells of the innate immune system for inflammatory response. Toll-like receptors (TLRs) play an important role in signal transduction in shock/resuscitation conditions. Because proinflammatory mediators are a critical event in mesenteric endothelial injury induced by HS/R, we assessed the role of TLR4 or TLR2 in this setting. DESIGN: Laboratory investigation. SETTING: Research laboratory at Rouen University Medical School. SUBJECTS: Male wild-type, TLR4(-/-) and TLR2(-/-) mice with the same C57BL/6 background. INTERVENTIONS: Mice were submitted to 30 minutes hemorrhagic shock followed by 1 hour resuscitation, after which mesenteric endothelial dysfunction, microvascular injury, and TNF[alpha] production were assessed. MEASUREMENTS AND MAIN RESULTS: HS/R markedly decreased nitric oxide-mediated mesenteric relaxations induced by acetylcholine, assessed ex vivo on a myograph. By contrast, in TLR4-deficient mice, HS/R did not impair the nitric oxide-mediated responses to acetylcholine. No protection was observed in TLR2-deficient mice. TLR4-deficient mice also displayed a significant reduction in fluid resuscitation and TNF[alpha] systemic production. CONCLUSIONS: TLR4 contributes to mesenteric endothelial dysfunction after hemorrhagic shock. This early TLR4-induced vascular injury may be an important trigger of the systemic inflammatory response occurring in this disease.

Author Correction: B-cell depletion induces a shift in self antigen specific B-cell repertoire and cytokine pattern in patients with bullous pemphigoid.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

B-cell depletion induces a shift in self antigen specific B-cell repertoire and cytokine pattern in patients with bullous pemphigoid.

Bullous Pemphigoid is the most common auto-immune bullous skin disease. It is characterized by the production of auto-antibodies directed against 2 proteins of the hemi-desmosome (BP180 and BP230). We assessed the efficacy and mechanisms of action of rituximab, an anti-CD20 monoclonal antibody, in 17 patients with severe and relapsing type of bullous pemphigoid. The phenotype, cytokine gene expression, and rearrangement of BP180-specific B-cell receptor genes were performed over 2 years following treatment. At the end of the study, 5 patients had died, 3 had withdrawn from the study, and 9 patients were in complete remission. The one- and two-year relapse rates were 44.1% (95% Confidence Interval (CI): 21.0-76.0%) and 66.5%, (95% CI: 38.4-91.4%), respectively. Phenotypic analyses confirmed dramatic B-cell depletion, which lasted for 9 to 12 months. The ELISA values of serum anti-BP180 antibodies and the frequency of BP180-specific circulating B cells decreased dramatically following treatment, which paralleled the improvement of skin lesions. During B-cell reconstitution, a polyclonal IgM repertoire appeared and a shift in the rearrangement of the B-cell receptor genes of BP180-specific circulating B cells was observed. Concurrently, we observed a decrease of IL-15, IL-6 and TNFα expressing BP180-specific B cells, and the emergence of IL-10 and IL-1RA-expressing BP180-specific IgM+ B cells in patients in complete remission off therapy, suggesting the functional plasticity of BP180-specific auto-immune B cells after rituximab treatment.

Toll-like receptor 9 in murine lupus: more friend than foe!

The immune response induced by the pathogen-associated-pattern recognition receptor toll-like receptor 9 (TLR9) upon binding of CpG motif-containing DNA has been widely accepted as an important pathway in the immune defense against microbial pathogens. In contrast, the role of TLR9 in anti-DNA antibody generation and the pathogenesis of systemic lupus erythematosus (SLE) remains controversial. Indeed, the in vivo situation might consist of a delicate balance between B-cell receptor and DNA receptor signaling. Most surprisingly, TLR9 deletion does not ameliorate but rather exacerbates pathology in murine models. Such observations warrant caution with therapeutic efforts to treat autoimmune diseases, especially SLE, via TLR modulation.

Toll-like receptors 2-deficient mice are protected against postischemic coronary endothelial dysfunction.

OBJECTIVES: Toll-like receptors (TLR) 2 are expressed in cardiac and inflammatory cells, and regulate leukocyte function. Because leukocyte adhesion is a critical event in endothelial injury induced by ischemia/reperfusion (I/R), we assessed whether TLR2 were involved in I/R-induced coronary endothelial injury. METHODS AND RESULTS: Ischemia-reperfusion markedly decreased NO-mediated coronary relaxations to acetylcholine assessed ex vivo. In contrast, in TLR2 deficient mice, I/R paradoxically improved the NO-mediated responses to acetylcholine. To precise the cellular compartment expressing TLR2 which is involved in endothelial injury, we developed bone-marrow chimeric mice by transplanting TLR2-/- bone marrow to WT mice or WT bone marrow to TLR2-/- mice and submitted them to I/R 5 weeks after transplant. Both chimeric mice displayed similar protection as TLR2-/- mice against I/R-induced endothelial dysfunction, suggesting a role of TLR2 expressed on both non-bone marrow cells (in our case presumably endothelial cells and/or cardiomyocytes) and cells of bone marrow origin (presumably neutrophils). TLR2 deficiency was also associated with a smaller infarct size, and reduced reperfusion-induced production of reactive oxygen species and leukocyte infiltration. CONCLUSIONS: TLR2 contribute to coronary endothelial dysfunction after I/R, possibly through stimulation of neutrophil- (and free radical-) mediated endothelial injury.

B Cell Modulation Strategies in Autoimmune Diseases: New Concepts.

B cells are major effector cells in autoimmunity through antibody production, T cell help and pro-inflammatory cytokine production. Major advances have been made in human B cell biology knowledge using rituximab and type II new anti-CD20 antibodies, anti-CD19 antibodies, anti-CD22 antibodies, autoantigen specific B cell depleting therapy (chimeric antigen receptor T cells), and B cell receptor signaling inhibition (Bruton's tyrosine kinase inhibitors). However, in certain circumstances B cell depleting therapy may lead to the worsening of the autoimmune disease which is in accordance with the existence of a regulatory B cell population. Current concepts and future directions for B cell modulating therapies in autoimmune diseases with a special focus on pemphigus are discussed.