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Obesity, and obesity-associated conditions such as hypertension, chronic kidney disease, type 2 diabetes, and cardiovascular disease, are important risk factors for severe Coronavirus disease-2019 (COVID-19). The common denominator is metaflammation, a portmanteau of metabolism and inflammation, which is characterized by chronically elevated levels of leptin and pro-inflammatory cytokines. These induce the "Suppressor Of Cytokine Signaling 1 and 3" (SOCS1/3), which deactivates the leptin receptor and also other SOCS1/3 sensitive cytokine receptors in immune cells, impairing the type I and III interferon early responses. By also upregulating SOCS1/3, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 adds a significant boost to this. The ensuing consequence is a delayed but over-reactive immune response, characterized by high-grade inflammation (e.g., cytokine storm), endothelial damage, and hypercoagulation, thus leading to severe COVID-19. Superimposing an acute disturbance, such as a SARS-CoV-2 infection, on metaflammation severely tests resilience. In the long run, metaflammation causes the "typical western" conditions associated with metabolic syndrome. Severe COVID-19 and other serious infectious diseases can be added to the list of its short-term consequences. Therefore, preventive measures should include not only vaccination and the well-established actions intended to avoid infection, but also dietary and lifestyle interventions aimed at improving body composition and preventing or reversing metaflammation.

Obesity, and obesity-associated conditions such as hypertension, chronic kidney disease, type 2 diabetes, and cardiovascular disease, are important risk factors for severe Coronavirus disease-2019 (COVID-19). The common denominator is metaflammation, a portmanteau of metabolism and inflammation, which is characterized by chronically elevated levels of leptin and pro-inflammatory cytokines. These induce the “Suppressor Of Cytokine Signaling 1 and 3” (SOCS1/3), which deactivates the leptin receptor and also other SOCS1/3 sensitive cytokine receptors in immune cells, impairing the type I and III interferon early responses. By also upregulating SOCS1/3, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 adds a significant boost to this. The ensuing consequence is a delayed but over-reactive immune response, characterized by high-grade inflammation (e.g., cytokine storm), endothelial damage, and hypercoagulation, thus leading to severe COVID-19. Superimposing an acute disturbance, such as a SARS-CoV-2 infection, on metaflammation severely tests resilience. In the long run, metaflammation causes the “typical western” conditions associated with metabolic syndrome. Severe COVID-19 and other serious infectious diseases can be added to the list of its short-term consequences. Therefore, preventive measures should include not only vaccination and the well-established actions intended to avoid infection, but also dietary and lifestyle interventions aimed at improving body composition and preventing or reversing metaflammation. Sin financiación 6.706 JCR (2021) Q1, 15/90 Nutrition & Dietetics 1.287 SJR (2021) Q1, 19/338 Food Science No data IDR 2021 UEM

Innate immune cells present a dual role during leishmaniasis: they constitute the first line of host defense but are also the main host cells for the parasite. Response against the infection that results in the control of parasite growth and lesion healing depends on activation of macrophages into a classical activated phenotype. We report an essential role for the microbiota in driving macrophage and monocyte-derived macrophage activation towards a resistance phenotype againstLeishmania majorinfection in mice. Both germ-free and dysbiotic mice showed a higher number of myeloid innate cells in lesions and increased number of infected cells, mainly dermal resident and inflammatory macrophages. Despite developing a Th1 immune response characterized by the same levels of IFN-γ production as the conventional mice, germ-free mice presented reduced numbers of iNOS+macrophages at the peak of infection. Absence or disturbance of host microbiota impaired the capacity of bone marrow-derived macrophage to be activated forLeishmaniakillingin vitro, even when stimulated by Th1 cytokines. These cells presented reduced expression ofinosmRNA, and diminished production of microbicidal molecules, such as ROS, while presenting a permissive activation status, characterized by increased expression ofarginase Iandil-10mRNA and higher arginase activity. Colonization of germ-free mice with complete microbiota from conventional mice rescued their ability to control the infection. This study demonstrates the essential role of host microbiota on innate immune response againstL. majorinfection, driving host macrophages to a resistance phenotype.

An emerging paradigm suggests that gut glycosylation is a key force in maintaining the homeostatic relationship between the gut and its microbiota. Nevertheless, it is unclear how gut glycosylation contributes to the HIV-associated microbial translocation and inflammation that persist despite viral suppression and contribute to the development of several comorbidities. We examined terminal ileum, right colon, and sigmoid colon biopsies from HIV-infected virally-suppressed individuals and found that gut glycomic patterns are associated with distinct microbial compositions and differential levels of chronic inflammation and HIV persistence. In particular, high levels of the pro-inflammatory hypo-sialylated T-antigen glycans and low levels of the anti-inflammatory fucosylated glycans were associated with higher abundance of glycan-degrading microbial species (in particular, Bacteroides vulgatus), a less diverse microbiome, higher levels of inflammation, and higher levels of ileum-associated HIV DNA. These findings are linked to the activation of the inflammasome-mediating eIF2 signaling pathway. Our study thus provides the first proof-of-concept evidence that a previously unappreciated factor, gut glycosylation, is a force that may impact the vicious cycle between HIV infection, microbial translocation, and chronic inflammation.

PURPOSE OF REVIEW: Antiretroviral therapy (ART) is an essential, life-saving intervention for HIV infection. However, ART initiation is frequently complicated by the tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) in TB endemic settings. Here, we summarize the current understanding highlighting the recent evidence. RECENT FINDINGS: The incidence of paradoxical TB-IRIS is estimated at 18% (95% CI 16-21%), higher than previously reported and may be over 50% in high-risk groups. Early ART initiation in TB patients increases TB-IRIS risk by greater than two-fold, but is critical in TB patients with CD4 counts less than 50 cells/μl because it improves survival. There remains no validated diagnostic test for TB-IRIS, and biomarkers recently proposed are not routinely used. Prednisone initiated alongside ART in selected patients with CD4 less than 100 cells/μl reduced the risk of paradoxical TB-IRIS by 30% in a recent randomized-controlled trial (RCT) and was not associated with significant adverse effects. Effective also for treating paradoxical TB-IRIS, corticosteroids remain the only therapeutic intervention for TB-IRIS supported by RCT trial data. TB-IRIS pathogenesis studies implicate high antigen burden, innate immune cell cytotoxicity, inflammasome activation and dysregulated matrix metalloproteinases in the development of the condition. SUMMARY: Specific biomarkers would aid in identifying high-risk patients for interventions and a diagnostic test is needed. Clinicians should consider prednisone for TB-IRIS prevention in selected patients. Future research should focus on improving diagnosis and investigating novel therapeutic interventions, especially for patients in whom corticosteroid therapy is contraindicated.

Background. Anallergic contact reaction is accompanied by high oxidative stress in the skin. Pretreatment of the skin with antioxidative substances could reduce the elicitation reaction. Objectives. To investigate, in a proof-of-principle study, whether pretreatment of the skin with the antioxidant ascorbic acid reduces the elicitation reaction to a p-phenylenediamine (PPD)-containing hair dye in sensitized subjects. Methods. Twelve subjects with contact allergy to PPD, a documented skin reaction to a hair dye simulation exposure model and a history of hair dye-related skin complaints were included in this study. Skin areas on the forearms were, in a left versus right design, exposed to an emulsion with ascorbic acid and an emulsion without ascorbic acid, and then to a 2% PPD-containing hair dye testing formulation. In addition, control areas were exposed to the emulsions and to the PPD-containing hair dye formulation without pretreatment. Skin reactions were graded on day (D)2 and D3. Results. Pretreatment with ascorbic acid emulsion resulted in a reduction in the elicitation reaction in 7 of 12 subjects at D3 (p = 0.046). No statistically significant difference was observed at D2. Conclusions. Pretreatment of the skin with the antioxidant ascorbic acid had an attenuating effect on the elicitation reaction to PPD in sensitized individuals.

Allergic and irritant skin reactions caused by topical exposure to permanent hair dyes are a common problem. For regulatory and ethnical purposes, it is required to perform chemical safety assessment following the replacement, reduction, and refinement of animal testing (312s). Permanent hair dyes are formed by a mixture of ingredients that vary from low to extreme skin sensitizing potency and that inter-react to form unknown by-products. Because of the complex reaction, this cytotoxic mechanism has not yet been elucidated and is the subject of this study. Here, we topically exposed p-phenylenediamine (PPD), Resorcinol (RES), Hydrogen Peroxide (H2O2) alone or as a mixture to RhE and evaluated parameters related to skin irritation such as epidermal' viability, keratinocytes damage, barrier loss and IL-1 alpha. Our data indicates that ingredients tested alone did not lead to an increase of cytotoxic parameters related to skin irritation. However, when the mixture of PPD/H2O2/RES and PPD/H2O2 was applied to the RhE, some of the parameters such as morphological changes including the presence of apoptotic cells, barrier loss and increased IL-1 alpha release were observed. The results indicate that the mixture of ingredients used in permanent hair dyes have an irritant effect in RhE while the ingredients alone not.

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system characterized by myelin loss and neuronal dysfunction. Although the majority of patients do not present familial aggregation, Mendelian forms have been described. We performed whole-exome sequencing analysis in 132 patients from 34 multi-incident families, which nominated likely pathogenic variants for MS in 12 genes of the innate immune system that regulate the transcription and activation of inflammatory mediators. Rare missense or nonsense variants were identified in genes of the fibrinolysis and complement pathways (PLAU, MASP1, C2), inflammasome assembly (NLRP12), Wnt signaling (UBR2, CTNNA3, NFATC2, RNF213), nuclear receptor complexes (NCOA3), and cation channels and exchangers (KCNG4, SLC24A6, SLC8B1). These genes suggest a disruption of interconnected immunological and pro-inflammatory pathways as the initial event in the pathophysiology of familial MS, and provide the molecular and biological rationale for the chronic inflammation, demyelination and neurodegeneration observed in MS patients., This research was undertaken thanks to funding from the Canada Research Chair program (950-228408), Michael Smith Foundation for Health Research (16827), the Canadian Institutes of Health Research (MOP-137051), the Vancouver Coastal Health Research Institute, the Milan & Maureen Ilich Foundation (11-32095000), and the Vancouver Foundation (ADV14-1597) to CVG. Additional funds were provided by >Red Española de Esclerosis Múltiple (REEM)> (grant to KV was RD12/0032/0013; RETICS, ISCIII), Project FIS PI13/ 0879 Grant RETICS-REEM RD07/0060/0019; Ministerio de Economía y Competitividad-FEDER SAF2016-80595-C2-1-P to AA and FM, Junta de Andalucia-FEDER to FM, and the Ricerca Finalizzata of the Italian Ministry of Health (RF-2011-02350347). EU, LL, LEP, and PUR are members of the Spanish Network of Multiple Sclerosis REEM RD16/0015/0010, supported by Institute of Health “Carlos III” of the Ministry of Economy and Competitiveness (grants cofunded by European Regional Development Fund). LL holds a Nicolas Monardes contract (C-0014-2015) from the Andalusian Health Ministry. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Background. Anallergic contact reaction is accompanied by high oxidative stress in the skin. Pretreatment of the skin with antioxidative substances could reduce the elicitation reaction. Objectives. To investigate, in a proof-of-principle study, whether pretreatment of the skin with the antioxidant ascorbic acid reduces the elicitation reaction to a p-phenylenediamine (PPD)-containing hair dye in sensitized subjects. Methods. Twelve subjects with contact allergy to PPD, a documented skin reaction to a hair dye simulation exposure model and a history of hair dye-related skin complaints were included in this study. Skin areas on the forearms were, in a left versus right design, exposed to an emulsion with ascorbic acid and an emulsion without ascorbic acid, and then to a 2% PPD-containing hair dye testing formulation. In addition, control areas were exposed to the emulsions and to the PPD-containing hair dye formulation without pretreatment. Skin reactions were graded on day (D)2 and D3. Results. Pretreatment with ascorbic acid emulsion resulted in a reduction in the elicitation reaction in 7 of 12 subjects at D3 (p = 0.046). No statistically significant difference was observed at D2. Conclusions. Pretreatment of the skin with the antioxidant ascorbic acid had an attenuating effect on the elicitation reaction to PPD in sensitized individuals.

The amino acid arginine is fundamentally involved in the regulation of the immune response during infection, inflammatory diseases and tumor growth. Arginine deficiency (e.g. due to the myeloid cell enzyme arginase) inhibits proliferation and effector functions of activated T lymphocytes. Here, we studied intracellular mechanisms mediating this suppression of human T lymphocytes. Our proteomic analysis revealed an impaired dephosphorylation of the actin-binding protein cofilin upon T-cell activation in the absence of arginine. We show that this correlates with alteration of actin polymerization and impaired accumulation of CD2 and CD3 in the evolving immunological synapse in T cell-antigen presenting cells conjugates. In contrast, T-cell cytokine synthesis is differentially regulated in human T lymphocytes in the absence of arginine. While the production of certain cytokines (e.g. IFN-γ) is severely reduced, T lymphocytes produce other cytokines (e.g. IL-2) independent of extracellular arginine. MEK and PI3K activity are reciprocally regulated in association with impaired cofilin dephosphorylation. Finally, we show that impaired cofilin dephosphorylation is also detectable in human T cells activated in a granulocyte-dominated purulent micromilieu due to arginase-mediated arginine depletion. Our novel results identify cofilin as a potential regulator of human T-cell activation under conditions of inflammatory arginine deficiency.

Background: Cyclophosphamide and glucocorticoids have been the cornerstone of remission-induction therapy for severe antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis for 40 years. Uncontrolled studies suggest that rituximab is effective and may be safer than a cyclophosphamide-based regimen.Methods: We conducted a multicenter, randomized, double-blind, double-dummy, noninferiority trial of rituximab (375 mg per square meter of body-surface area per week for 4 weeks) as compared with cyclophosphamide (2 mg per kilogram of body weight per day) for remission induction. Glucocorticoids were tapered off; the primary end point was remission of disease without the use of prednisone at 6 months.Results: Nine centers enrolled 197 ANCA-positive patients with either Wegener's granulomatosis or microscopic polyangiitis. Baseline disease activity, organ involvement, and the proportion of patients with relapsing disease were similar in the two treatment groups. Sixty-three patients in the rituximab group (64%) reached the primary end point, as compared with 52 patients in the control group (53%), a result that met the criterion for noninferiority (PConclusions: Rituximab therapy was not inferior to daily cyclophosphamide treatment for induction of remission in severe ANCA-associated vasculitis and may be superior in relapsing disease. (Funded by the National Institutes of Allergy and Infectious Diseases, Genentech, and Biogen; ClinicalTrials.gov number, NCT00104299.)N Engl J Med 2010;363:221-32.

Objective In patients with Wegener's granulomatosis (WG) or microscopic polyangiitis (MPA) autoantibodies to myeloid granule proteins (ANCA), particularly proteinase 3 (Pr3) and myeloperoxidase (MPO), and to endothelial cells (AECA) are frequently detected. The role of these autoantibodies in the development of vascular injury is incompletely understood. Since the expression of E-selectin and the production of interleukin 6 by endothelial cells is an early step in the sequence of events leading to vascular injury, we examined the capacity of IgG fractions from patients with WG and/or MPA to activate endothelial cells to the expression of E-selectin and the production of IL-6. we related those findings to the presence of ANCA and AECA in the IgG preparations.Methods Human umbilical vein endothelial cells (HUVEC) were incubated with immunoglobulin (IgG) preparations from 28 patients (17 positive for anti-Pr3, 10 for anti-MPO, and one for anti-Pr3/MPO) with active vasculitis andfrom 10 healthy volunteers. The final IgG concentration in the activation assay was 2 mg/ml TNF alpha (10 ng/ml) and LPS (10 ng/ml) were used as positive controls for HUVEC activation. The extent of HUVEC activation was assessed by the measurement of E-selectin expression by flow cytometry (after 4 hours of incubation) and the production of interleukin 6 by ELISA (after 24 hours).Results We found that II of the 28 ANCA positive IgG samples were capable of activating endothelial cells: six samples induced IL-6 production alone, one sample upregulated E-selectin expression alone, and four samples induced both IL-6 production and E-selectin upregulation. Five of 17 anti-Pr3 positive samples (one of which was also positive for AECA) and 6 of 10 anti-MPO positive samples (all simultaneously positive for AECA) induced endothelial cell activation. AECA positive samples that induced endothelial cell activation (n = 7) had higher AECA titres than samples that did not induce endothelial cell activation (n = 6)Conclusion Our data suggest that the activation of endothelial cells in patients with WG and MPA can be induced by circulating autoantibodies. Both ANCA and AECA can be responsible for this effect.

The 18-month efficacy of a single course of rituximab as compared with conventional immunosuppression with cyclophosphamide followed by azathioprine in patients with severe (organ-threatening) antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is unknown.In a multicenter, randomized, double-blind, double-dummy, noninferiority trial, we compared rituximab (375 mg per square meter of body-surface area administered once a week for 4 weeks) followed by placebo with cyclophosphamide administered for 3 to 6 months followed by azathioprine for 12 to 15 months. The primary outcome measure was complete remission of disease by 6 months, with the remission maintained through 18 months.A total of 197 patients were enrolled. As reported previously, 64% of the patients in the rituximab group, as compared with 53% of the patients in the cyclophosphamide-azathioprine group, had a complete remission by 6 months. At 12 and 18 months, 48% and 39%, respectively, of the patients in the rituximab group had maintained the complete remissions, as compared with 39% and 33%, respectively, in the comparison group. Rituximab met the prespecified criteria for noninferiority (P0.001, with a noninferiority margin of 20%). There was no significant difference between the groups in any efficacy measure, including the duration of complete remission and the frequency or severity of relapses. Among the 101 patients who had relapsing disease at baseline, rituximab was superior to conventional immunosuppression at 6 months (P=0.01) and at 12 months (P=0.009) but not at 18 months (P=0.06), at which time most patients in the rituximab group had reconstituted B cells. There was no significant between-group difference in adverse events.In patients with severe ANCA-associated vasculitis, a single course of rituximab was as effective as continuous conventional immunosuppressive therapy for the induction and maintenance of remissions over the course of 18 months. (Funded by the National Institute of Allergy and Infectious Diseases and others; RAVE ClinicalTrials.gov number, NCT00104299.)

Background: Cigarette smoke (CS) is a major risk factor for the development of COPD. CS exposure is associated with an increased risk of bacterial colonization and respiratory tract infection, because of suppressed antibacterial activities of the immune system and delayed clearance of microbial agents from the lungs. Colonization with Staphylococcus aureus results in release of virulent enterotoxins, with superantigen activity which causes T cell activation. Objective: To study the effect of Staphylococcus aureus enterotoxin B (SEB) on CS-induced inflammation, in a mouse model of COPD. Methods: C57/Bl6 mice were exposed to CS or air for 4 weeks (5 cigarettes/exposure, 4x/day, 5 days/week). Endonasal SEB (10 μg/ml) or saline was concomitantly applied starting from week 3, on alternate days. 24 h after the last CS and SEB exposure, mice were sacrificed and bronchoalveolar lavage (BAL) fluid and lung tissue were collected. Results: Combined exposure to CS and SEB resulted in a raised number of lymphocytes and neutrophils in BAL, as well as increased numbers of CD8 + T lymphocytes and granulocytes in lung tissue, compared to sole CS or SEB exposure. Moreover, concomitant CS/SEB exposure induced both IL-13 mRNA expression in lungs and goblet cell hyperplasia in the airway wall. In addition, combined CS/SEB exposure stimulated the formation of dense, organized aggregates of B- and T- lymphocytes in lungs, as well as significant higher CXCL-13 (protein, mRNA) and CCL19 (mRNA) levels in lungs. Conclusions: Combined CS and SEB exposure aggravates CS-induced inflammation in mice, suggesting that Staphylococcus aureus could influence the pathogenesis of COPD. Background Cigarette smoking is associated with an increased risk of bacterial colonization and respiratory tract infection, because of suppressed antibacterial activities of the immune system and delayed clearance of microbial agents from the lungs [1]. This is particularly relevant in COPD patients, where bacterial colonization in the lower respiratory tract has been shown [2]. These bacteria are implicated both in stable COPD and during exacerbations, where most commonly pneumococci, Haemophilus influenza, Moraxella catarrhalis and Staphylococcus aureus (S. aureus)are found [3]. Interestingly, colonization with S. aureus may embody a major source of superantigens as a set of toxins are being produced including S. aureus enterotoxins (SAEs) [4]. These toxins activate up to 20% of all T cells in the body by binding the human leukocyte antigen (HLA) class II molecules on antigen-presenting cells (APCs) and specific V beta regions of the T cell receptor [5]. Between 50 and 80% of S. aureus isolates are positive for at least one superantigen gene, and close to 50% of

Background Cyclophosphamide and glucocorticoids have been the cornerstone of remissioninduction therapy for severe antineutrophil cytoplasmic antibody (ANCA)−associated vasculitis for 40 years. Uncontrolled studies suggest that rituximab is effective and may be safer than a cyclophosphamide-based regimen. Methods We conducted a multicenter, randomized, double-blind, double-dummy, noninferiority trial of rituximab (375 mg per square meter of body-surface area per week for 4 weeks) as compared with cyclophosphamide (2 mg per kilogram of body weight per day) for remission induction. Glucocorticoids were tapered off; the primary end point was remission of disease without the use of prednisone at 6 months. Results Nine centers enrolled 197 ANCA-positive patients with either Wegener’s granulomatosis or microscopic polyangiitis. Baseline disease activity, organ involvement, and the proportion of patients with relapsing disease were similar in the two treatment groups. Sixty-three patients in the rituximab group (64%) reached the primary end point, as compared with 52 patients in the control group (53%), a result that met the criterion for noninferiority (P

After injury to the spinal cord, hemorrhages occur both near and far from the initial lesion. J. Marc Simard and his colleagues demonstrate that spinal cord injury induces expression of the channel Trpm4 on endothelial cells in the spinal cord, which leads to their fragmentation and the spread of the hemorrhage. The role of transient receptor potential M4 (Trpm4), an unusual member of the Trp family of ion channels, is poorly understood. Using rodent models of spinal cord injury, we studied involvement of Trpm4 in the progressive expansion of secondary hemorrhage associated with capillary fragmentation, the most destructive mechanism of secondary injury in the central nervous system. Trpm4 mRNA and protein were abundantly upregulated in capillaries preceding their fragmentation and formation of petechial hemorrhages. Trpm4 expression in vitro rendered COS-7 cells highly susceptible to oncotic swelling and oncotic death following ATP depletion. After spinal cord injury, in vivo gene suppression in rats treated with Trpm4 antisense or in Trpm4−/− mice preserved capillary structural integrity, eliminated secondary hemorrhage, yielded a threefold to fivefold reduction in lesion volume and produced a substantial improvement in neurological function. To our knowledge, this is the first example of a Trp channel that must undergo de novo expression for manifestation of central nervous system pathology.

The gene fragment encoding bovine complement component C3d (boC3d) was isolated, cloned, sequenced and expressed in preparation for investigation of its potential as an adjuvant in cattle. Studies in mice attribute the adjuvant activity of C3d to a lowered B-cell activation threshold, resulting from the cross-linking of membrane-Ig and the B-cell co-receptor complex CD21(CR2)/CD19/CD81. To evaluate binding of recombinant boC3d to native bovine CD21, a recombinant boC3d protein was generated that included a biotinylation signal sequence at the N-terminal end of the boC3d sequence, for endogenous biotinylation by 'E. coli' via the BirA holoenzyme synthetase. Three additional constructs containing a portion of the gene encoding the leukotoxin produced by 'Mannheimia haemolytica' A1 linked to one, two or three boC3d units were created for expression in 'E. coli' as recombinant fusion proteins, as potential vaccines. All recombinant proteins incorporated polyhistidine tags and were purified by Ni-NTA agarose chromatography, then identified by SDS-PAGE and western blot. These proteins will provide the basis for future studies of receptor binding and cell-activation, and for immunization trials in cattle.

Objective In patients with Wegener's granulomatosis (WG) or microscopic polyangiitis (MPA) autoantibodies to myeloid granule proteins (ANCA), particularly proteinase 3 (Pr3) and myeloperoxidase (MPO), and to endothelial cells (AECA) are frequently detected. The role of these autoantibodies in the development of vascular injury is incompletely understood. Since the expression of E-selectin and the production of interleukin 6 by endothelial cells is an early step in the sequence of events leading to vascular injury, we examined the capacity of IgG fractions from patients with WG and/or MPA to activate endothelial cells to the expression of E-selectin and the production of IL-6. we related those findings to the presence of ANCA and AECA in the IgG preparations. Methods Human umbilical vein endothelial cells (HUVEC) were incubated with immunoglobulin (IgG) preparations from 28 patients (17 positive for anti-Pr3, 10 for anti-MPO, and one for anti-Pr3/MPO) with active vasculitis andfrom 10 healthy volunteers. The final IgG concentration in the activation assay was 2 mg/ml TNF alpha (10 ng/ml) and LPS (10 ng/ml) were used as positive controls for HUVEC activation. The extent of HUVEC activation was assessed by the measurement of E-selectin expression by flow cytometry (after 4 hours of incubation) and the production of interleukin 6 by ELISA (after 24 hours). Results We found that II of the 28 ANCA positive IgG samples were capable of activating endothelial cells: six samples induced IL-6 production alone, one sample upregulated E-selectin expression alone, and four samples induced both IL-6 production and E-selectin upregulation. Five of 17 anti-Pr3 positive samples (one of which was also positive for AECA) and 6 of 10 anti-MPO positive samples (all simultaneously positive for AECA) induced endothelial cell activation. AECA positive samples that induced endothelial cell activation (n = 7) had higher AECA titres than samples that did not induce endothelial cell activation (n = 6) Conclusion Our data suggest that the activation of endothelial cells in patients with WG and MPA can be induced by circulating autoantibodies. Both ANCA and AECA can be responsible for this effect.

The activation of memory T cells is a very rapid and concerted cellular response that requires coordination between cellular processes in different compartments and on different time scales. In this study, we use ribosome profiling and deep RNA sequencing to define the acute mRNA translation changes in CD8 memory T cells following initial activation events. We find that initial translation enables subsequent events of human and mouse T cell activation and expansion. Briefly, early events in the activation of Ag-experienced CD8 T cells are insensitive to transcriptional blockade with actinomycin D, and instead depend on the translation of pre-existing mRNAs and are blocked by cycloheximide. Ribosome profiling identifies ∼92 mRNAs that are recruited into ribosomes following CD8 T cell stimulation. These mRNAs typically have structured GC and pyrimidine-rich 5′ untranslated regions and they encode key regulators of T cell activation and proliferation such as Notch1, Ifngr1, Il2rb, and serine metabolism enzymes Psat1 and Shmt2 (serine hydroxymethyltransferase 2), as well as translation factors eEF1a1 (eukaryotic elongation factor α1) and eEF2 (eukaryotic elongation factor 2). The increased production of receptors of IL-2 and IFN-γ precedes the activation of gene expression and augments cellular signals and T cell activation. Taken together, we identify an early RNA translation program that acts in a feed-forward manner to enable the rapid and dramatic process of CD8 memory T cell expansion and activation.