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Bioconjugation is an important chemical biology research focus, especially in the development of methods to produce pharmaceutical bioconjugates and antibody-drug conjugates (ADCs). In this report, an enzyme-catalyzed conjugation method combined with a chemical reaction was used to modify a native antibody under mild reaction conditions. Our investigation revealed that lipoic-acid ligase (LplA) modifies native IgG1 with biased site-specificity. An intact mass analysis revealed that 98.3% of IgG1 was modified by LplA and possessed at least one molecule of octanocic acid. The average number of modifications per antibody was calculated to be 4.6. Peptide mapping analysis revealed that the modified residues were K225, K249 and K363 in the Fc region, and K30, K76 and K136 in the heavy chain and K39/K42, K169, K188 and K190 in the light chain of the Fab region. Careful evaluation including solvent exposed amino acid analysis suggested that these conjugate sites were not only solvent exposed but also biased by the site-specificity of LplA. Furthermore, antibody fragment conjugation may be able to take advantage of this enzymatic approach. This feasibility study serves as a demonstration for preparing enzymatically modified antibodies with conjugation site analysis., (Copyright © 2021. Published by Elsevier Ltd.)

The emergence of SARS-CoV-2 has resulted in the COVID-19 pandemic, leading to millions of infections and hundreds of thousands of human deaths. The efficient replication and population spread of SARS-CoV-2 indicates an effective evasion of human innate immune responses, although the viral proteins responsible for this immune evasion are not clear. In this study, we identified SARS-CoV-2 structural proteins, accessory proteins, and the main viral protease as potent inhibitors of host innate immune responses of distinct pathways. In particular, the main viral protease was a potent inhibitor of both the RLR and cGAS-STING pathways. Viral accessory protein ORF3a had the unique ability to inhibit STING, but not the RLR response. On the other hand, structural protein N was a unique RLR inhibitor. ORF3a bound STING in a unique fashion and blocked the nuclear accumulation of p65 to inhibit nuclear factor-κB signaling. 3CL of SARS-CoV-2 inhibited K63-ubiquitin modification of STING to disrupt the assembly of the STING functional complex and downstream signaling. Diverse vertebrate STINGs, including those from humans, mice, and chickens, could be inhibited by ORF3a and 3CL of SARS-CoV-2. The existence of more effective innate immune suppressors in pathogenic coronaviruses may allow them to replicate more efficiently in vivo. Since evasion of host innate immune responses is essential for the survival of all viruses, our study provides insights into the design of therapeutic agents against SARS-CoV-2.

The stringent response is an essential mechanism of metabolic reprogramming during environmental stress that is mediated by the nucleotide alarmones guanosine tetraphosphate and pentaphosphate [(p)ppGpp]. In addition to physiological adaptations, (p)ppGpp also regulates virulence programs in pathogenic bacteria, including Salmonella enterica serovar Typhimurium. S Typhimurium is a common cause of acute gastroenteritis, but it may also spread to systemic tissues, resulting in severe clinical outcomes. During infection, S Typhimurium encounters a broad repertoire of immune defenses that it must evade for successful host infection. Here, we examined the role of the stringent response in S Typhimurium resistance to complement-mediated killing and found that the (p)ppGpp synthetase-hydrolase, SpoT, is required for bacterial survival in human serum. We identified the nucleotide hydrolase, PpnN, as a target of the stringent response that is required to promote bacterial fitness in serum. Using chromatography and mass spectrometry, we show that PpnN hydrolyzes purine and pyrimidine monophosphates to generate free nucleobases and ribose 5'-phosphate, and that this metabolic activity is required for conferring resistance to complement killing. In addition to PpnN, we show that (p)ppGpp is required for the biosynthesis of the very long and long O-antigen in the outer membrane, known to be important for complement resistance. Our results provide new insights into the role of the stringent response in mediating evasion of the innate immune system by pathogenic bacteria., (Copyright © 2021 American Society for Microbiology.)

Objectives: To evaluate the distribution of radiological characteristics stratified by different myositis-specific autoantibodies, identify prognostic value of high-resolution CT (HRCT) patterns in DM-associated interstitial lung disease (DM-ILD), and explore the possible mechanism associated with macrophage activation., Methods: We enrolled 165 patients with PM/DM-ILD. The distribution of HRCT radiological types with different myositis-specific autoantibodies and the relationship between radiological features and ILD course and prognosis were analysed. Additionally, the potential role of macrophage activation in rapidly progressive ILD (RP-ILD) with DM was studied., Results: The organizing pneumonia pattern was dominant in HRCT findings of patients with DM-ILD, especially those with anti-SAE (6/6, 100%) and anti-MDA5 (46/62, 74.2%) antibodies. The ratios of organizing pneumonia and nonspecific interstitial pneumonia patterns were almost equal in patients with aminoacyl tRNA synthetase antibodies, and nonspecific interstitial pneumonia pattern was associated with a mild clinical course. Lower lung zone consolidation in HRCT was related to RP-ILD in both anti-MDA5 and anti-aminoacyl tRNA synthetase antibody-positive groups. Ferritin levels of >1000 ng/ml (odds ratio (OR), 12.3; P=0.009), elevated carcinoembryonic antigen (OR, 5.8; P=0.046) and carbohydrate antigen 19-9 (OR, 7.8; P=0.018) were independent predictors of a lower lung zone consolidation pattern in anti-MDA5 antibody-positive DM. The infiltration of CD163-positive macrophages into alveolar spaces was significantly higher in the DM-RP-ILD group than in the chronic DM-ILD group., Conclusion: HRCT patterns are different among variable myositis-specific autoantibodies positive patients with ILD and lower zone consolidation in HRCT correlated with RP-ILD in DM. Activated macrophages may contribute to the pathogenesis of RP-ILD in DM., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Human tuberculosis (TB) is caused by a plethora of Mycobacterium tuberculosis complex (MTBC) strains belonging to seven phylogenetic branches. Lineages 2, 3 and 4 are considered "modern" branches of the MTBC responsible for the majority of worldwide TB. Since the current BCG vaccine confers variable protection against pulmonary TB, new candidates are investigated. MTBVAC is the unique live attenuated vaccine based on M. tuberculosis in human clinical trials., Methods: MTBVAC was originally constructed by unmarked phoP and fadD26 deletions in a clinical isolate belonging to L4. Here we construct new vaccines based on isogenic gene deletions in clinical isolates of the L2 and L3 modern lineages. These three vaccine candidates were characterized at molecular level and also in animal experiments of protection and safety., Findings: Safety studies in immunocompromised mice showed that MTBVAC-L2 was less attenuated than BCG Pasteur, while the original MTBVAC was found even more attenuated than BCG and MTBVAC-L3 showed an intermediate phenotype. The three MTBVAC candidates showed similar or superior protection compared to BCG in immunocompetent mice vaccinated with each MTBVAC candidate and challenged with three representative strains of the modern lineages., Interpretation: MTBVAC vaccines, based on double phoP and fadD26 deletions, protect against TB independently of the phylogenetic linage used as template strain for their construction. Nevertheless, lineage L4 confers the best safety profile., Funding: European Commission (TBVAC2020, H2020-PHC-643381), Spanish Ministry of Science (RTI2018-097625-B-I00), Instituto de Salud Carlos III (PI18/0336), Gobierno de Aragón/Fondo Social Europeo and the French National Research Council (ANR-10-LABX-62-IBEID, ANR-16-CE35-0009, ANR-16-CE15-0003)., Competing Interests: Declaration Competing of Interest C.M., A.A. and J.G.-A. are co-inventors on the patent “Tuberculosis vaccine”. N.A., C.M. and J. G-A. are co-inventors on the patent “Compositions for use as a prophylactic agent to those at risk of infection of tuberculosis, or as secondary agents for treating infected tuberculosis patients”. Both patents were filled by the University of Zaragoza, (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

The lengthy and complicated current regimen required to treat drug-susceptible tuberculosis (TB) reflects the ability of Mycobacterium tuberculosis (Mtb) to persist in host tissues. The stringent response pathway, governed by the dual (p)ppGpp synthetase/hydrolase, Rel Mtb , is a major mechanism underlying Mtb persistence and antibiotic tolerance. In the current study, we addressed the hypothesis that Rel Mtb is a "persistence antigen" presented during TB chemotherapy and that enhanced immunity to Rel Mtb can enhance the tuberculocidal activity of the first-line anti-TB drug, isoniazid, which has reduced efficacy against Mtb persisters. C57BL/6 mice and Hartley guinea pigs were aerosol-infected with M. tuberculosis (Mtb) and, 4 weeks later, received either human-equivalent daily doses of isoniazid alone, or isoniazid in combination with a DNA vaccine targeting rel Mtb . After isoniazid treatment, there was a significant reduction in dominant antigen ESAT6-reactive CD4 + or TB10.4-reactive CD8 + T cells in the lungs and spleens of mice. However, the total number of Rel Mtb -reactive CD4 + T cells remained stable in mouse lungs and spleens, as did the number of Rel Mtb -reactive CD8 + T cells. Therapeutic vaccination with rel Mtb DNA vaccine enhanced the activity of isoniazid in Mtb-infected C57BL/6 mice and guinea pigs. When treatment with isoniazid was discontinued, mice immunized with the rel Mtb DNA vaccine showed a lower mean lung bacterial burden at relapse compared to the control group. Our work shows that antitubercular treatment shapes the antigenic environment, and that therapeutic vaccination targeting the Mtb stringent response may represent a novel approach to enhance immunity against Mtb persisters, with the ultimate goal of shortening curative TB treatment., (Copyright © 2020 Chuang, Dutta, Gordy, Campodónico, Pinn, Markham, Hung and Karakousis.)

Objective: Post-hoc analyses of the Rituximab in Myositis trial indicate that specific autoantibodies profiles may influence treatment response. We compared the efficacy and safety of rituximab in anti-synthetase antibody (ARS-ab) positive and negative patients., Methods: Adult idiopathic inflammatory myopathy (IIM) subjects in the Swedish Rheumatology Quality Register who received ⩾ 1 cycle of rituximab were enrolled. Efficacy assessment was based on the International Myositis Assessment and Clinical Studies (IMACS) core set measures and the 2016 ACR/EULAR definition of improvement for PM and DM. Safety assessment included drug-related adverse event and death during study period. Comparisons were done within and between the ARS-ab defined groups before and after first and last cycles. Associations between selected clinical features and improvement after one rituximab cycle were assessed using logistic regression., Results: Sixty-five subjects were included and 43 had a follow-up visit within 5-10 months. Seventy-eight percent of ARS-ab positive subjects had moderate/major ACR/EULAR improvement after one cycle compared with 50% in the ARS-ab negative group. After several cycles, 79% of the ARS-ab positive and 67% of the ARS-ab negative patients achieved moderate/major improvement. A significant glucocorticoid-sparing effect was only observed in the ARS-ab positive group (P = 0.001). The most frequent adverse events were infections. One ARS-ab positive and two ARS-ab negative patients died during follow-up period., Conclusion: Irrespectively of their autoantibody status, a majority of subjects treated with several rituximab cycles had moderate/major improvement. In addition, ARS-ab positive subjects experienced a significant glucocorticoid-sparing effect., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: Autoantibodies targeting ubiquitously expressed nuclear antigens can be identified in most patients with SSc. Cytoplasmic autoantibodies (in otherwise ANA-negative sera) targeting eukaryotic initiation factor-2B (anti-eIF2B) have recently been identified in SSc with clinical associations to dcSSc disease and interstitial lung disease (ILD), although the majority of samples originated from a tertiary SSc-ILD centre. We investigated the prevalence and clinical associations of recently described SSc-specific (including anti-eIF2B) and other cytoplasmic autoantibodies in ANA-negative sera obtained from a large representative SSc cohort., Methods: ANA-negative sera from the Scleroderma Family Registry and DNA Repository underwent indirect immunofluorescence, radiolabelled protein immunoprecipitation (± immunodepletion) to identify anti-eIF2B and other CTD-related autoantibodies. The clinical phenotype of positive samples was evaluated., Results: Immunoprecipitation was performed on 128 ANA-negative samples (obtained from 3249 SSc patients). Anti-eIF2B antibodies were present in nine patients (7%), the majority of whom had dcSSc (8/9). SSc-ILD was present in all anti-eIF2B patients for whom chest imaging was available (7/9). Anti-synthetase autoantibodies (targeting PL12, PL7, OJ and Zo) were identified in seven patients (5.5%), all of whom fulfilled the 2013 ACR/EULAR classification criteria for SSc and had evidence of SSc-ILD where relevant outcomes were available for evaluation. Anti-RuvBL1/2 antibodies were identified in two patients with SSc-overlap syndromes., Conclusion: Anti-eIF2B antibodies are cytoplasmic SSc-specific autoantibodies with strong clinical associations with dcSSc and SSc-ILD found in ANA-negative sera. Anti-synthetase autoantibodies, and other recently discovered SSc-specific antibodies such as anti-RuvBL1/2, can also be identified in ANA-negative SSc.

Immunofluorescence on HEp2-cells is the standard diagnostic assay for the detection of anti-nuclear antibodies (ANA). Cytoplasmic speckled patterns are a common finding, and are associated with various antibodies, including anti-synthetase antibodies. However, classic ENA testing generally identifies only anti-Jo-1. Moreover, anti-synthetase syndrome is increasingly recognized as a pleomorphic entity, possibly presenting as isolated arthritis or interstitial lung disease. Sera referred for routine ANA testing were selected on the basis of the presence of a fine dense speckled cytoplasmic pattern (254 samples) and compared to control sera with negative cytoplasm (239 samples). All 493 samples were tested with a commercial synthetase profile dot-blot (D TEK - Alphadia-Alifax) including anti-Jo1, anti-PL7, anti-PL12, anti-EJ, anti-OJ, anti-KS, anti-ZO, anti-HA, anti-SRP, and anti-Ribosome P0. Retrospective clinical data was searched for positive patients. Dot-blot identified 18/254 (7.1%) positive sera in the samples with a cytoplasmic fluorescence pattern and 4/239 (1.7%) in the control group (χ2 = 8.4627; p = 0.003625). Blot intensity was more intense in samples with concordant cytoplasmic staining (cytoplasmic negative 27 ± 12.4; cytoplasmic positive 53.9 27 ± 27.7; p = 0.0027). In the positive samples, 8/18 had a highly compatible diagnosis (myositis, interstitial lung disease, arthritis), 7/18 an uncharacterized connective tissue disease, and 3 a diagnosis not associated with the presence of anti-synthetase antibodies. We evaluated the performance of a dot-blot assay for anti-cytoplasmic antibodies in a serologic cohort presenting a cytoplasmic speckled pattern found during routine ANA testing. This algorithm enabled the identification of a significant quota of patients with rare anti-synthetase antibodies and an incomplete or atypical clinical picture. Reflex testing strategies of speckled cytoplasmic patterns with multiplex assays containing cytoplasm-specific antigens, as opposed to standard ENA testing, may yield important data and for this reason should be implemented in routine ANA testing.

Staphylococcusaureus is a severe pathogen found in the community and in hospitals. Most notably, methicillin-resistant S. aureus (MRSA) is resistant to almost all antibiotics, which is a growing public health concern. The emergence of drug-resistant strains has prompted the search for alternative treatments such as immunotherapeutic approaches. Previous research showed that S. aureus exploit the immunomodulatory attributes of adenosine to escape host immunity. In this study, we investigated adenosine synthase A (AdsA), an S. aureus cell wall-anchored enzyme as possible targets for immunotherapy. Mice vaccinated with aluminum hydroxide-formulated recombinant AdsA (rAdsA) induced high-titer anti-AdsA antibodies, thereby providing consistent protection in 3 mouse infection models when challenged with 2 S. aureus strains. The importance of anti-AdsA antibody in protection was demonstrated by passive transfer experiments. Moreover, AdsA-specific antisera promote killing S. aureus by immune cells. Altogether, our data demonstrate that the AdsA is a promising target for vaccines and therapeutics development to alleviate severe S. aureus diseases., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.)

The idiopathic inflammatory myopathies are characterized by muscle weakness, skin disease and internal organ involvement. Autoimmunity is known to have a role in myositis pathogenesis, and myositis-specific autoantibodies, targeting important intracellular proteins, are regarded as key biomarkers aiding in the diagnosis of patients. In recent years, a number of novel myositis autoantibodies including anti-TIF1, anti-NXP2, anti-MDA5, anti-SAE, anti-HMGCR and anti-cN1A have been identified in both adult and juvenile patients. These autoantibodies correlate with distinct clinical manifestations and importantly are found in inclusion body, statin-induced, clinically amyopathic and juvenile groups of myositis patients, previously believed to be mainly autoantibody negative. In this review, we will describe the main myositis-specific and myositis-associated autoantibodies and their frequencies and clinical associations across different ages and ethnic groups. We will also discuss preliminary studies investigating correlations between specific myositis autoantibody titres and clinical markers of disease course, collectively demonstrating the utility of myositis autoantibodies as both diagnostic and prognostic markers of disease., (© 2015 The Association for the Publication of the Journal of Internal Medicine.)

Idiopathic inflammatory myopathies can be classified as polymyositis, dermatomyositis, immune-mediated necrotizing myopathy, sporadic inclusion body myositis or non-specific myositis. Anti-Jo-1 antibody-positive patients are assigned to either polymyositis or dermatomyositis suggesting overlapping pathological features. We aimed to determine if anti-Jo-1 antibody-positive myopathy has a specific morphological phenotype. In a series of 53 muscle biopsies of anti-Jo-1 antibody-positive patients, relevant descriptive criteria defining a characteristic morphological pattern were identified. They were tested in a second series of anti-Jo-1 antibody-positive patients and compared to 63 biopsies from patients suffering from other idiopathic inflammatory myopathies. In anti-Jo-1 antibody-positive patients, necrotic fibres, which strongly clustered in perifascicular regions, were frequently observed. Sarcolemmal complement deposition was detected specifically in perifascicular areas. Inflammation was mainly located in the perimysium and around vessels in 90.6%. Perimysial fragmentation was observed in 90% of cases. Major histocompatibility complex class I staining was diffusely positive, with a perifascicular reinforcement. Multivariate analysis showed that criteria defining perifascicular pathology: perifascicular necrosis, atrophy, and perimysial fragmentation allow the distinction of anti-Jo-1 antibody-positive patients, among patients suffering from other idiopathic inflammatory myopathies. Anti-Jo-1 antibody-positive patients displayed perifascicular necrosis, whereas dermatomyositis patients exhibited perifascicular atrophy., (© The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

We report a 37-year-old woman with a 2 month history of proximal muscle weakness and extremely high creatine kinase (21,808 U/L) due to necrotizing auto-immune myositis (NAM) in association with anti-synthetase syndrome. Myositis-specific auto-immune antibody panel was positive for anti-Signal recognition particle and anti-PL-12. CT scan of the chest confirmed interstitial lung disease. Prednisolone, intravenous immunoglobulin and cyclophosphamide therapy was given with gradual improvement. This patient is notable for the unusual combination of NAM and anti-synthetase syndrome with the rare finding of two myositis-specific autoantibodies, which directed testing for associated extramuscular features and management with more aggressive immunotherapy., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The stringent response is initiated by rapid (p)ppGpp synthesis, which leads to a profound reprogramming of gene expression in most bacteria. The stringent phenotype seems to be species specific and may be mediated by fundamentally different molecular mechanisms. In Staphylococcus aureus, (p)ppGpp synthesis upon amino acid deprivation is achieved through the synthase domain of the bifunctional enzyme RSH (RelA/SpoT homolog). In several firmicutes, a direct link between stringent response and the CodY regulon was proposed. Wild-type strain HG001, rsh(Syn), codY and rsh(Syn), codY double mutants were analyzed by transcriptome analysis to delineate different consequences of RSH-dependent (p)ppGpp synthesis after induction of the stringent response by amino-acid deprivation. Under these conditions genes coding for major components of the protein synthesis machinery and nucleotide metabolism were down-regulated only in rsh positive strains. Genes which became activated upon (p)ppGpp induction are mostly regulated indirectly via de-repression of the GTP-responsive repressor CodY. Only seven genes, including those coding for the cytotoxic phenol-soluble modulins (PSMs), were found to be up-regulated via RSH independently of CodY. qtRT-PCR analyses of hallmark genes of the stringent response indicate that an RSH activating stringent condition is induced after uptake of S. aureus in human polymorphonuclear neutrophils (PMNs). The RSH activity in turn is crucial for intracellular expression of psms. Accordingly, rsh(Syn) and rsh(Syn), codY mutants were less able to survive after phagocytosis similar to psm mutants. Intraphagosomal induction of psmα1-4 and/or psmβ1,2 could complement the survival of the rsh(Syn) mutant. Thus, an active RSH synthase is required for intracellular psm expression which contributes to survival after phagocytosis.

The different autoimmune myopathies-for example, dermatomyositis, polymyositis, and immune-mediated necrotizing myopathies (IMNM)-have unique muscle biopsy findings, but they also share specific clinical features, such as proximal muscle weakness and elevated serum levels of muscle enzymes. Furthermore, around 60% of patients with autoimmune myopathy have been shown to have a myositis-specific autoantibody, each of which is associated with a distinct clinical phenotype. The typical clinical presentations of the autoimmune myopathies are reviewed here, and the different myositis-specific autoantibodies, including the anti-synthetase antibodies, dermatomyositis-associated antibodies, and IMNM-associated antibodies, are discussed in detail. This Review also focuses on a newly recognized form of IMNM that is associated with statin use and the production of autoantibodies that recognize 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the pharmacological target of statins. The contribution of interferon signaling to the development of dermatomyositis and the potential link between malignancies and the initiation of autoimmune myopathies are also assessed.

Post-translational modifications of target proteins by small ubiquitin-like modifier (SUMO) proteins modulate many cellular processes in yeast and animals. Here we present the development of monoclonal antibodies (MAb) and polyclonal antibodies (PAb) against Arabidopsis SIZ1 (AtSIZ1) protein with high specificity. Mice were immunized with recombinant AtSIZ1 protein for generating monoclonal antibodies via the classic hybridoma production technique. Anti-AtSIZ1 MAb and PAb were able to detect endogenous AtSIZ1 in Arabidopsis wild type and its complementary line formed by transforming C-siz1-2 mutant with construct containing the AtSIZ1 gene under the control of the native promoter, but not the siz1-2 deletion mutant. These results show that these anti-AtSIZ MAbs are highly sensitive to detect endogenous AtSIZ1 and can be used for immunoblotting and other experimental methods. The new anti-AtSIZ1 MAbs will be essential tools used to investigate the role of AtSIZ1 in plant developmental biology.

Cardiac involvement is a complication of end stage polymyositis with left heart insufficiency reported to be the most frequent manifestation. We here describe an unusual clinical presentation of antisynthetases syndrome, beginning with right-sided cardiomyopathy associated with right heart failure. A 26 year-old Caucasian male experienced a 6-month clinical course of polyarthritis, fever, sweats, and myalgia. Laboratory studies showed elevated C reactive protein, elevated sedimentation rate, and myolysis associated with anti SSA and anti JO1 antibodies. Electromyography showed a myopathic pattern. Muscle biopsy confirmed the diagnosis of polymyositis. Chest X ray, chest scan, and cardiac echography were normal. One week after hospital admission, the patient developed acute right heart insufficiency, and magnetic resonance imaging showed a right ventricular myocarditis with myocardial inflammatory thickening. Treatment with corticosteroids rapidly improved both symptoms and biological abnormalities.

Background: Mechanic's hand is a defined specific skin eruption associated with dermatomyositis; there are few reports concerning its histopathology. As mechanic's hand clinically resembles hand eczema, it is important to distinguish between these two conditions., Aim: To determine the characteristic clinical and histopathologic features of mechanic's hand, and to clarify whether these two conditions can be differentiated by histopathologic findings., Methods: We analyzed clinicopathologically five patients with mechanic's hands who visited our clinic between 2006 and 2007., Results: The clinical features of mechanic's hands were discrete hyperkeratotic erythema on the ulnar aspect of the thumbs and the radial aspect of the fingers. In all five cases, the histologic findings included marked hyperkeratosis, focal parakeratosis, psoriasiform acanthosis, and colloid bodies in the epidermis. There were mononuclear cell infiltrates around the blood vessels, and mucin deposition was observed in the dermis., Conclusions: The histopathologic findings of mechanic's hands are specific and different from those of eczema. A histopathologic examination is useful for the diagnosis of mechanic's hands associated with dermatomyositis and a high incidence of interstitial pneumonia.

Ubiquitin conjugating enzyme variants (Uev) Uev1 and Mms2 share >90% sequence identity but with distinct biological functions. Here, we report the monomeric and heterodimeric crystal structures of Uev1 and comparison with that of Mms2. Uev1 alone or in complex with Ubc13 is nearly identical with the corresponding Mms2 structures, except in one surface area containing 7/14 amino acid variations. To probe the biological significance of this unique region, we raised monoclonal antibodies specifically recognizing this region of Uev1, but not of Mms2. Epitope mapping and site-specific mutagenesis revealed at least two distinct epitopes within this region. These data collectively suggest the existence of cellular proteins capable of distinguishing Uev1 from Mms2 and directing the Ubc13-Uev complex to different pathways.

Rituximab has been documented to be an effective treatment for autoimmune diseases with contribution of B cells. We report a case of antisynthetase syndrome with a history of EBV-induced lymphoma which developed a pemphigus vulgaris. Rituximab was effective both on polymyositis and on pemphigus. Fifteen months later, the patient died from a septic shock after the first cyclophosphamide infusion for amyloidosis while the B cell population remained depleted. Rituximab may be a good alternative to immunosuppressive drugs in polymyositis and pemphigus especially in lymphoma-risk patients. However, it did not prevent progression to secondary amyloidosis and the fatal infection developed in this patient raises the question of whether a prolonged B cell depletion with rituximab contributes to a greater risk of infection.

Myositis autoantibodies continue to be the subject of substantial interest, with several significant recent developments. Recent studies have emphasized that anti-Jo-1 or other antisynthetases can be associated with interstitial lung disease, even in the absence of myositis. Anti-Jo-1 autoantibody levels were shown to correlate with disease activity over time. Immunization of mice with anti-Jo-1 led to muscle and lung inflammation, reminiscent of human disease. The complexity of the antibody picture in myositis continues to increase. Several new autoantibodies have been described or better characterized. Among these were a new antisynthetase reactive with phenylalanyl-transfer RNA synthetase (anti-Zo); an autoantibody that immunoprecipitates 155- and 140-kD proteins and was common in children but seemed to be associated with malignancy in adults; and an autoantibody to a small ubiquitin-like modifier--activating enzyme associated with dermatomyositis and interstitial lung disease. These findings have significant clinical implications and suggest promising areas of further research.

We present a case of antisynthetase syndrome manifesting with interstitial lung disease, mechanic's hands, nailfold abnormalities, and subclinical myositis, in the presence of antibodies to the aminoacyl tRNA synthetase PL-12 and also to Ro52. Antibodies to Ro52 have been recently associated with idiopathic inflammatory myositis, but there have only been occasional reports of this antibody occurring in association with aminoacyl tRNA synthetases, including PL-12. Our case adds to the descriptions of the concurrence of antibodies to PL-12 and Ro52. The mechanism for the coupling of antibody response remains elusive but is likely to play a fundamental role in disease pathogenesis.

We describe 3 patients with inflammatory myositis in association with a neoplasm whose serum also contained anti-Jo1 antibodies, one of which presented characteristic features of the antisynthetase syndrome. No patient had a rash, and muscle biopsy was suggestive of polymyositis in all 3. Immunohistochemistry confirmed the diagnosis of polymyositis in the single patient with sufficient tissue available. Our patients remind us that the presence of antisynthetase antibodies (and even antisynthetase syndrome) in a patient with inflammatory myositis does not preclude the diagnosis of cancer-associated myositis.

Insects trigger a multifaceted innate immune response to fight microbial infections. We show that in the yellow mealworm, Tenebrio molitor, septic injuries induce the synthesis of N-beta-alanyldopamine (NBAD), which is known as the main sclerotization precursor of insect brown cuticles. We demonstrate that NBAD synthase is induced in the epidermis of the mealworm and of the Medfly, Ceratitis capitata, by infection with Escherichia coli. Our results indicate that synthesis of NBAD seems to be a novel component of the overall innate immune response in insects.

We report a case of idiopathic inflammatory myopathy accompanied with the presence of anti-Jo1 antibodies and complicated by diffuse parenchymal lung disease (antisynthetase syndrome). Efficacy of different therapeutic agents, including corticosteroids, cyclophosphamide and cyclosporin A, is described. We present beneficial effect of cyclosporin A and corticosteroids regimen, and confirm no benefits of plasmapheresis. An interesting association of the disease onset with toxoplasmosis infection is discussed and difficulties regarding diagnosis of cardiac involvement are addressed. We also review other case reports of this rare disorder of poor prognosis.

Objective: To determine the prevalence of myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs) and their clinical and immunogenetic correlations in Mediterranean patients with idiopathic inflammatory myopathies., Methods: Sera from 88 patients were studied for MSAs and MAAs by RNA and protein immunoprecipitation. HLA typing was performed by sequence-specific primer- and sequence-specific oligonucleotide-polymerase chain reaction and serology. Statistical analyses were performed with Student's t-test and Fisher's exact test. Cumulative survival probabilities were estimated by the Kaplan-Meier method and Cox regression analysis., Results: Twenty-eight patients (30%) had MSAs, most commonly antisynthetase antibodies (23.9%). Six patients (7.5%) had anti-Mi-2 antibodies. No anti-signal recognition particles were found. Arthritis, mechanic's hands, interstitial lung disease, and sicca syndrome were more prevalent in patients with antisynthetase antibodies. Dysphagia and the need for more treatment courses were more frequent in patients who were anti-Mi-2 positive. Forty-three patients (48%) had MAAs, 20 (22%) with anti-Ro 60 and 18 (20.4%) with anti-Ro 52. Ten patients (11.4%) were positive for anti-PM-Scl, 6 (6.8%) for anti-RNP, and 1 for anti-Ku antibodies. Patients with PM-Scl, RNP, or Ro antibodies were more often classified as having overlap syndrome. Immunogenetic studies found a significant association between HLA-DR3 and the presence of antisynthetase antibodies (P = 0.049), anti-PM-Scl antibodies (P = 0.017), and interstitial lung disease (P = 0.03). No statistically significant differences in mortality, survival, or clinical course were observed between patients positive for MSAs or MAAs and the remaining patients., Conclusion: These results are consistent with those from other published series, although some differences warrant consideration. Autoantibody studies may be useful for defining more homogeneous groups of patients with idiopathic inflammatory myopathies.

A 30-year-old man complained of polyarthralgia and fatigue. The clinical findings and laboratory data included myositis, polyarthritis, interstitial pneumonia, Raynaud's phenomenon, mechanic's hand, and anti PL-7 antibody (threonyl-tRNA synthetase antibody). All of these signs were consistent with antisynthetase syndrome. His chest radiograph revealed bilateral hilar lymphadenopathy. Biopsy specimens from his mediastinal lymph node and muscle showed noncaseating epithelioid cell granulomas. Lung histology revealed nonspecific interstitial pneumonia. Antisynthetase syndrome associated with sarcoidosis was diagnosed. Interstitial pneumonia in this patient responded well to high-dose corticosteroid therapy.

Introduction: Pneumomediastinum is a rare but classical complication of dermatomyositis. Its development is a serious matter and necessitates prompt recourse to aggressive treatment with corticosteroids combined with immuno-suppressants or intravenous human immunoglobulin., Case Report: We report the case of a 63 year old woman presenting with pulmonary infiltration, in the presence of dermatomyositis, as a clinical manifestation of the anti-synthetase syndrome. The progress was rapidly unfavourable with pneumomediastinum and acute respiratory distress despite initial treatment with corticosteroids followed by human immunoglobulin and immunosuppressants., Conclusion: The identification of cutaneous or muscular signs in the initial investigation of a pulmonary infiltrate should lead to a search for anti-synthetase antibodies in order to determine the optimal clinical management as quickly as possible.

Objective: To assess possible seasonal patterns in the onset of polymyositis (PM) and dermatomyositis (DM)., Methods: The study group comprised 503 patients who met the criteria for probable or definite PM or DM and for whom detailed data on the time of myositis onset were available. Statistical analyses were performed using a Poisson model that assessed associations of ethnicity, sex, autoantibody presence, and month of onset of muscle weakness., Results: There were no significant seasonal patterns of disease onset in myositis patients as a whole or in the total PM or DM populations. Significant seasonal associations were present, however, in the serologically defined groups. In the 131 patients with antisynthetase autoantibodies who were categorized as non-black, myositis onset peaked in March-April (P = 0.03). Among the antisynthetase-positive patients, the association was predominantly in those with PM (n = 85; P = 0.05) and in men (n = 51; P = 0.042). Patients with anti-signal recognition particle autoantibodies, however, did not have a significant seasonal onset, which is in contrast to previous findings. Patients without myositis-specific autoantibodies showed a significant peak in summer, with myositis onset in June-July (n = 252; P = 0.03); this seasonal association was significant in women (n = 182; P = 0.005), whereas there was no seasonal pattern in men (P = 0.9)., Conclusion: These findings, in conjunction with other data, suggest that diverse environmental agents, acting upon different immunogenetic backgrounds, result in distinct immune responses and clinical syndromes in the idiopathic inflammatory myopathies. Our results emphasize the importance of considering more homogeneous disease groups, based on clinicopathologic features, immune responses, ethnicity, and sex, when attempting to decipher the pathogeneses of autoimmune disorders.

Our objective was to improve the currently imperfect classifications of idiopathic inflammatory myopathies (IIM). In clinical practice, overlap features are common in IIM. This provided a rationale for positioning overlap clinical features at the core of a new classification system. We conducted a longitudinal study of 100 consecutive adult French Canadian patients with IIM. Clinical and laboratory data were obtained by retrospective chart review. Sera were analyzed for autoantibodies (aAbs) by protein A-assisted immunoprecipitation and double immunodiffusion. Overlap aAbs encompassed aAbs to synthetases, systemic sclerosis-associated aAbs, anti-signal recognition particle (SRP) and anti-nucleoporins. Patients were classified both at IIM diagnosis, based on data at presentation, and at the end of follow-up, based on cumulative findings. Three classifications were used: 1) the Bohan and Peter original classification, 2) a new version of that classification as modified by us, and 3) a novel clinicoserologic classification. As investigators were blinded to aAb results, the modified classification is strictly a clinical classification. Its core concept is the attribution of diagnostic significance to the presence of overlap features, that is, their presence resulted in a diagnosis of overlap myositis (OM). This approach allowed direct comparison with the original Bohan and Peter classification. By integrating aAb results to the modified classification, we also defined the clinicoserologic classification, which allowed to examine the added value of aAbs to diagnostic, therapeutic and prognostic stratification. Whereas polymyositis (PM) was the most common IIM according to the original classification, accounting for 45% of the cohort at diagnosis, its frequency fell to 14% with the modified classification. Conversely, while the frequency of myositis associated with connective tissue disease was 24% according to the original classification, the frequency of OM was 60% when using the modified classification. At last follow-up, the frequency of PM fell further to only 9%, while the frequency of OM rose to 67%. Systemic sclerosis was the most common connective tissue disease associated with IIM, accounting for 42.6% of OM patients and 29% of the cohort. The frequencies of overlap aAbs in the cohort and in OM patients were 48% and 70.5% (n =48/68), respectively. The presence of overlap aAbs at IIM diagnosis identified additional OM patients unrecognized by the modified classification. The sensitivity of the modified classification for OM at diagnosis was 87%, suggesting that clinicians may rely on the modified classification for identification of most OM patients, while awaiting results of aAb assays. The new classifications predicted the response to prednisone and IIM course. Using stringent definitions, IIM was classified as responsive or refractory after an adequate initial corticosteroid therapy, and the disease course as monophasic or chronic after a single adequate trial of prednisone. PM was always chronic and was associated with the highest rate (50%) of refractoriness to initial corticosteroid treatment. Dermatomyositis was almost always chronic (92% rate); however, its responsiveness to initial corticosteroid treatment was high (87%). OM was almost always responsive to corticosteroids (89%-100% rates). When OM patients were divided according to aAb subsets, anti-synthetase, SRP, or nucleoporin aAbs were markers for chronic myositis, whereas aAbs to U1RNP, Pm-Scl, or Ku were markers for monophasic myositis. We conclude that the original Bohan and Peter classification should be abandoned as it leads to misclassification of patients. Much of IIM is composed of OM. The proposed modified and clinicoserologic classifications have diagnostic, prognostic, and therapeutic value.

Antisynthetase syndrome is a rare disorder, included among the idiopathic inflammatory myopathies, characterized by the presence of antisynthetase antibodies. We present a case of a patient with a suggestive clinical stage of interstitial lung disease, skin and articular disease, but without muscle involvement, with the presence of anti Jol antibodies.

Myasthenia gravis is a chronic disease of neuromuscular transmission caused by loss of acetylcholine receptors. It can be found in association with other autoimmune disorders. We report the case of a 47-yr-old woman affected by Myasthenia gravis who complained of fever, progressive weakness of proximal limb muscle, arthritis and Raynauds phenomenon and dyspnea. Chest X-rays and CT scan showed an interstitial lung disease; laboratory data indicated an inflammatory picture and increased serum muscle enzymes. Evaluation for infectious, metabolic, iatrogenic and neoplastic aetiologies was unrevealing. The patients clinical condition together with positive results on antisynthetase antibody assay lead to the diagnosis of antisynthetase syndrome. To our knowledge, this is the first report on the association of Myasthenia gravis with antisynthetase syndrome.

Idiopathic inflammatory myopathies, mainly polymyositis (PM) may occur in the course of several autoimmune diseases. The overlapping forms of myositis, when the patient also meets the criteria for rheumatoid arthritis (RA), affect 3%-5% of myositis patients [1]. To the best of our knowledge this is the first report on the overlapping form of RA, antiphospholipid syndrome (APS) and the serological subgroup of PM, the antisynthetase syndrome (ASS).

Antisynthetase syndrome belongs to the idiopathic myositis group which includes pulmonary interstitial disease, arthritis, Raynaud's phenomenon, and mechanic's hands , associated with the anti-Jo1 antibody. We report three cases of antisynthetase syndrome, and review the clinical characteristics, and prognosis factors dominated by interstitial pneumonia.

Seven autoantibodies directed against synthetases have been identified to date, the best known being anti-Jo1. Synthetases play a vital role in protein synthesis by catalyzing the acetylation of transfer RNAs (tRNAs). The most common form of antisynthetase syndrome is characterized by anti-Jo1 production, interstitial lung disease (ILD), inflammatory muscle disease, and, in many cases, fever, polyarthritis, Raynaud's phenomenon, and thick cracked skin on the fingers (mechanic's hands). The interstitial lung disease is generally of the "usual interstitial pneumopathy" type and shares similarities with idiopathic pulmonary fibrosis or scleroderma-related pulmonary disease. It governs the prognosis of the disease, being associated with an excess mortality rate of about 40%. The pathogenic mechanisms underlying antisynthetase syndrome remain unknown but may involve cell-mediated immunity. The treatment is not standardized. The ILD responds to glucocorticoids in some patients but requires other immunosuppressant drugs in others.

Granulocytes and monocytes/macrophages of the myeloid lineage are the chief cellular agents of innate immunity. Here, we have examined the inflammatory response in mice with conditional knockouts of the hypoxia responsive transcription factor HIF-1alpha, its negative regulator VHL, and a known downstream target, VEGF. We find that activation of HIF-1alpha is essential for myeloid cell infiltration and activation in vivo through a mechanism independent of VEGF. Loss of VHL leads to a large increase in acute inflammatory responses. Our results show that HIF-1alpha is essential for the regulation of glycolytic capacity in myeloid cells: when HIF-1alpha is absent, the cellular ATP pool is drastically reduced. The metabolic defect results in profound impairment of myeloid cell aggregation, motility, invasiveness, and bacterial killing. This role for HIF-1alpha demonstrates its direct regulation of survival and function in the inflammatory microenvironment.

The cases of 6 patients (4 men, 2 women) with antisynthetase syndrome are reported. The mean age was 60 years and the most frequent symptom was increasing dyspnea (4 patients). One of the remaining 2 patients had hemoptysis and the last was asymptomatic. Systemic symptoms included Raynaud's phenomenon (2 patients), arthritis in hands (3) and muscle impairment (4). Chest films showed linear interstitial infiltrates of varying severity in 5 patients; the patient without such infiltrates also suffered silicosis. Functional assessment showed restrictive impairment in 4 patients; of the remaining 2 patients, 1 had chronic obstructive pulmonary disease and 1 had normal function. The antisynthetase antibody (ASAB) detected was anti-Jo-1 in 4 cases, anti-PL-12 in 1 case, and unidentified in 1 case. The course of disease was satisfactory for 5 patients. ASAB analysis is useful for studying idiopathic interstitial lung disease.

Mutations in alpha-synuclein (alpha S) and parkin cause heritable forms of Parkinson disease (PD). We hypothesized that neuronal parkin, a known E3 ubiquitin ligase, facilitates the formation of Lewy bodies (LBs), a pathological hallmark of PD. Here, we report that affinity-purified parkin antibodies labeled classical LBs in substantia nigra sections from four related human disorders: sporadic PD, inherited alphaS-linked PD, dementia with LBs (DLB), and LB-positive, parkin-linked PD. Anti-parkin antibodies also detected LBs in entorhinal and cingulate cortices from DLB brain and alphaS inclusions in sympathetic gangliocytes from sporadic PD. Double labeling with confocal microscopy of DLB midbrain sections revealed that approximately 90% of anti-alpha S-reactive LBs were also detected by a parkin antibody to amino acids 342 to 353. Accordingly, parkin proteins, including the 53-kd mature isoform, were present in affinity-isolated LBs from DLB cortex. Fluorescence resonance energy transfer and immunoelectron microscopy showed that alphaS and parkin co-localized within brainstem and cortical LBs. Biochemically, parkin appeared most enriched in cytosolic and postsynaptic fractions of adult rat brain, but also in purified, alpha S-rich presynaptic elements that additionally contained parkin's E2-binding partner, UbcH7. We conclude that parkin and UbcH7 are present with alphaS in subcellular compartments of normal brain and that parkin frequently co-localizes with alpha S aggregates in the characteristic LB inclusions of PD and DLB. These results suggest that functional parkin proteins may be required during LB formation.