Anti-Inflammatory Effect of Muscle-Derived Interleukin-6 and Its Involvement in Lipid Metabolism.

Interleukin (IL)-6 has been studied since its discovery for its role in health and diseases. It is one of the most important pro-inflammatory cytokines. IL-6 was reported as an exacerbating factor in coronavirus disease. In recent years, it has become clear that the function of muscle-derived IL-6 is different from what has been reported so far. Exercise is accompanied by skeletal muscle contraction, during which, several bioactive substances, collectively named myokines, are secreted from the muscles. Many reports have shown that IL-6 is the most abundant myokine. Interestingly, it was indicated that IL-6 plays opposing roles as a myokine and as a pro-inflammatory cytokine. In this review, we discuss why IL-6 has different functions, the signaling mode of hyper-IL-6 via soluble IL-6 receptor (sIL-6R), and the involvement of soluble glycoprotein 130 in the suppressive effect of hyper-IL-6. Furthermore, the involvement of a disintegrin and metalloprotease family molecules in the secretion of sIL-6R is described. One of the functions of muscle-derived IL-6 is lipid metabolism in the liver. However, the differences between the functions of IL-6 as a pro-inflammatory cytokine and the functions of muscle-derived IL-6 are unclear. Although the involvement of myokines in lipid metabolism in adipocytes was previously discussed, little is known about the direct relationship between nonalcoholic fatty liver disease and muscle-derived IL-6. This review is the first to discuss the relationship between the function of IL-6 in diseases and the function of muscle-derived IL-6, focusing on IL-6 signaling and lipid metabolism in the liver.

Animal welfare and zoonosis risk: anti-Trichinella antibodies in breeding pigs farmed under controlled housing conditions.

BACKGROUND: Domesticated pigs are the main source of Trichinella sp. infections for humans, particularly when reared in backyards or free-ranging. In temperate areas of southern Europe, most pigs are farmed under controlled housing conditions, but sows and sometimes fattening pigs have access to outdoors to improve animal welfare. The aim of the present study was to investigate whether outdoor access of breeding pigs farmed under controlled housing conditions can represent a risk for Trichinella sp. transmission when the farm is located in an agricultural area interspersed with wooded areas and badlands, where Trichinella spp. could be present in wildlife. METHODS: Serum samples were collected from 63 breeding sows and one boar before and after their access to an open fenced area for 2 months and from 84 pigs that never had outdoor access. Samples were screened for anti-Trichinella antibodies by ELISA, and positive sera were confirmed using Western blot (Wb) excretory/secretory antigens. To detect Trichinella sp. larvae, muscle tissues from serologically positive and negative pigs were tested by artificial digestion. RESULTS: Thirteen (20.6%) sows and one boar tested positive with both ELISA and Wb. No larvae were detected in muscle samples of serologically positive and serologically negative pigs. Positive serum samples were then tested by Wb using crude worm extract as antigens. The Wb banding pattern displayed was that characteristic of encapsulated species (Trichinella spiralis or Trichinella britovi). CONCLUSIONS: The detection of anti-Trichinella antibodies without larvae in the pig muscles, supported by epidemiological data, suggests that pigs may have been exposed to T. britovi. This study stresses the importance of instigating monitoring systems at farm level to prevent Trichinella sp. transmission and to investigate, through a landscape parasitological study, the suitability of a site before the planting of a high containment level pig farm in which the sows can have outside access to improve their welfare during pregnancy.

Texture analysis of muscle MRI: machine learning-based classifications in idiopathic inflammatory myopathies.

To develop a machine learning (ML) model that predicts disease groups or autoantibodies in patients with idiopathic inflammatory myopathies (IIMs) using muscle MRI radiomics features. Twenty-two patients with dermatomyositis (DM), 14 with amyopathic dermatomyositis (ADM), 19 with polymyositis (PM) and 19 with non-IIM were enrolled. Using 2D manual segmentation, 93 original features as well as 93 local binary pattern (LBP) features were extracted from MRI (short-tau inversion recovery [STIR] imaging) of proximal limb muscles. To construct and compare ML models that predict disease groups using each set of features, dimensional reductions were performed using a reproducibility analysis by inter-reader and intra-reader correlation coefficients, collinearity analysis, and the sequential feature selection (SFS) algorithm. Models were created using the linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), support vector machine (SVM), k-nearest neighbors (k-NN), random forest (RF) and multi-layer perceptron (MLP) classifiers, and validated using tenfold cross-validation repeated 100 times. We also investigated whether it was possible to construct models predicting autoantibody status. Our ML-based MRI radiomics models showed the potential to distinguish between PM, DM, and ADM. Models using LBP features provided better results, with macro-average AUC values of 0.767 and 0.714, accuracy of 61.2 and 61.4%, and macro-average recall of 61.9 and 59.8%, in the LDA and k-NN classifiers, respectively. In contrast, the accuracies of radiomics models distinguishing between non-IIM and IIM disease groups were low. A subgroup analysis showed that classification models for anti-Jo-1 and anti-ARS antibodies provided AUC values of 0.646-0.853 and 0.692-0.792, with accuracy of 71.5-81.0 and 65.8-78.3%, respectively. ML-based TA of muscle MRI may be used to predict disease groups or the autoantibody status in patients with IIM and is useful in non-invasive assessments of disease mechanisms.

Decreased Serum 25-(OH)-D Level Associated With Muscle Enzyme and Myositis Specific Autoantibodies in Patients With Idiopathic Inflammatory Myopathy.

Objectives: To determine whether there is serum vitamin D deficiency and the low levels of serum vitamin D are correlated with serological and immunological indexes in patients with idiopathic inflammatory myopathy (IIM). Methods: A total of 63 newly diagnosed patients with IIM, and 55 age- and sex- matched healthy controls were enrolled. Serum levels of 25-(OH)-D were measured by enzyme-linked immunosorbent assay. The correlations of 25-(OH)-D levels with disease indicators and T cell subsets were analyzed. Result: The levels of serum 25-(OH)-D in IIM were significantly lower than those in healthy controls (9.36 ± 5.56 vs 26.56 ± 5.37 ng/ml, p<0.001). The levels of serum liver enzyme ALT and AST and muscle enzyme CK, CKMB, LDH and HBDH were elevated as deficiency of vitamin D. In addition, the serum 25-(OH)-D levels were negatively correlated to ALT (r = -0.408, p = 0.001) and AST (r = -0.338, p = 0.007). The 25-(OH)-D levels in IIM patients in presence of anti-Jo-1 were significantly lower than those in patients without anti-Jo-1 (5.24 ± 3.17 vs 9.32 ± 5.60 ng/ml; p = 0.037). Similar results were found in patients with or without anti-Mi-2 antibody. The serum 25-(OH)-D levels were positively associated with total T (r = 0.203, p = 0.012) and Treg cells (r = 0.331, p = 0.013). The patients with deficient levels of vitamin D were more likely to have heliotrope, gastrointestinal and liver involvement. Conclusions: Vitamin D deficiency existed in IIM patients, which was significantly correlated with muscle enzyme, presence of anti-Jo-1 and anti-Mi-2 antibody, and the absolute numbers of total T and Treg cells in IIM. It is suggested that vitamin D may play an important role in the immunological pathogenesis of IIM.

Transcriptomic analysis of Procambarus clarkii affected by "Black May" disease.

Each year from April to May, high mortality rates are reported in red swamp crayfish (Procambarus clarkii) cultured in Jiangsu and other regions, in China, and this phenomenon has come to be known as "Black May" disease (BMD). Therefore, in order to investigate the possible causes of this disease, this study gathered BMD-affected P. clarkii samples and performed transcriptome analysis on hepatopancreas, gill, and muscle tissues. A total of 19,995,164, 149,212,804, and 222,053,848 clean reads were respectively obtained from the gills, muscle, and hepatopancreas of BMD-affected P. clarkii, and 114,024 unigenes were identified. The number of differentially expressed genes (DEGs) in gill, muscle, and hepatopancreas was 1703, 964, and 476, respectively. GO and KEGG enrichment analyses of the DEGs were then conducted. Based on KEGG pathway enrichment analysis, the most significantly differentially expressed pathways were mainly those involved with metabolism, human disease, and cellular processes. Further analysis of the significantly DEGs revealed that they were mainly related to the mitochondrial-mediated apoptosis pathway and that the expression of these DEGs was mostly down-regulated. Moreover, the expression of genes related to immune and metabolism-related pathways was also significantly down-regulated, and these significantly-inhibited pathways were the likely causes of P. clarkii death. Therefore, our results provide a basis for the identification of BMD causes.

Comprehensive Multi-omics Analysis Reveals Mitochondrial Stress as a Central Biological Hub for Spaceflight Impact.

Spaceflight is known to impose changes on human physiology with unknown molecular etiologies. To reveal these causes, we used a multi-omics, systems biology analytical approach using biomedical profiles from fifty-nine astronauts and data from NASA's GeneLab derived from hundreds of samples flown in space to determine transcriptomic, proteomic, metabolomic, and epigenetic responses to spaceflight. Overall pathway analyses on the multi-omics datasets showed significant enrichment for mitochondrial processes, as well as innate immunity, chronic inflammation, cell cycle, circadian rhythm, and olfactory functions. Importantly, NASA's Twin Study provided a platform to confirm several of our principal findings. Evidence of altered mitochondrial function and DNA damage was also found in the urine and blood metabolic data compiled from the astronaut cohort and NASA Twin Study data, indicating mitochondrial stress as a consistent phenotype of spaceflight.

Shedding the Light on Litopenaeus vannamei Differential Muscle and Hepatopancreas Immune Responses in White Spot Syndrome Virus (WSSV) Exposure.

White Spot Syndrome Virus (WSSV) is one of the main threats to farming Litopenaeus vannamei, the most important crustacean commercialized in aquaculture worldwide. Here, we performed RNA-seq analyses in hepatopancreas and muscle from WSSV-negative (healthy) and WSSV-positive (unhealthy) L. vannamei, previously exposed to the virus, to obtain new insights about the molecular basis of resistance to WSSV. We detected 71% of our reads mapped against the recently described L. vannamei genome. This is the first report mapping RNA-seq transcripts from shrimps exposed to WSSV against the species reference genome. Differentially expressed gene (DEG) analyses were performed for four independent comparisons, and 13,338 DEGs were identified. When the redundancies and isoforms were disregarded, we observed 8351 and 6514 DEGs, respectively. Interestingly, after crossing the data, we detected a common set of DEGs for hepatopancreas and healthy shrimps, as well as another one for muscle and unhealthy shrimps. Our findings indicate that genes related to apoptosis, melanization, and the Imd pathway are likely to be involved in response to WSSV, offering knowledge about WSSV defense in shrimps exposed to the virus but not infected. These data present potential to be applied in further genetic studies in penaeids and other farmed shrimp species.

Identification of an immune-related long non-coding RNA signature and nomogram as prognostic target for muscle-invasive bladder cancer.

To identify an immune-related prognostic signature based on long non-coding RNAs (lncRNAs) and find immunotherapeutic targets for bladder urothelial carcinoma, we downloaded RNA-sequencing data from The Cancer Genome Atlas (TCGA) dataset. Functional enrichment analysis demonstrated bladder urothelial carcinoma was related to immune-related functions. We obtained 332 immune-related genes and 262 lncRNAs targeting immune-related genes. We constructed a signature based on eight lncRNAs in training cohort. Patients were classified as high-risk and low-risk according to signature risk score. High-risk patients had poor overall survival compared with low-risk patients (P < 0.001). Multivariate Cox regression suggested the signature was an independent prognostic indicator. The findings were further validated in testing, entire TCGA and external validation cohorts. Gene set enrichment analysis indicated significant enrichment of immune-related phenotype in high-risk group. Immunohistochemistry and online analyses validated the functions of 4 key immune-related genes (LIG1, TBX1, CTSG and CXCL12) in bladder urothelial carcinoma. Nomogram proved to be a good classifier for muscle-invasive bladder cancer through combining the signature. In conclusion, our immune-related prognostic signature and nomogram provided prognostic indicators and potential immunotherapeutic targets for muscle-invasive bladder cancer.

Tissue regulatory T cells.

Foxp3+  CD4+ regulatory T cells (Tregs) are an immune cell lineage endowed with immunosuppressive functionality in a wide array of contexts, including both anti-pathogenic and anti-self responses. In the past decades, our understanding of the functional diversity of circulating or lymphoid Tregs has grown exponentially. Only recently, the importance of Tregs residing within non-lymphoid tissues, such as visceral adipose tissue, muscle, skin and intestine, has been recognized. Not only are Tregs critical for influencing the kinetics and strength of immune responses, but the regulation of non-immune or parenchymal cells, also fall within the purview of tissue-resident or infiltrating Tregs. This review focuses on providing a systematic and comprehensive comparison of the molecular maintenance, local adaptation and functional specializations of Treg populations operating within different tissues.

Immunopathological characterization of red focal changes in Atlantic salmon (Salmo salar) white muscle.

Farmed Atlantic salmon (Salmo salar) are prone to various conditions affecting the quality of the fillet. A well-known but so far poorly understood condition is the focal red changes in muscle, often referred to as haemorrhages. Such changes are characterized by muscle necrosis, haemorrhages and acute inflammation. They can progress into focal melanised changes, a chronic inflammatory condition with melanin-producing leukocytes. The initial cause of intramuscular haemorrhages is unknown. In this study, we aimed to reveal some of their key immunological features. Samples of red focal changes were investigated by immunohistochemistry (IHC), in situ hybridization (ISH) and RT-qPCR for various immune markers. The results were compared with samples of melanised changes and control muscle, subjected to the same analyses. In all red changes, infiltrates with mononuclear cells were detected, consisting mostly of MHC class I/II+ cells, but also of CD3+ and CD8+ cells. ISH studies on IgM showed few to moderate amounts of B-cells in red focal changes. Trends in the RT-qPCR showed upregulation of genes related to innate immunity in the red changes, whereas genes related to adaptive immunity were upregulated in the melanised changes. An important result was the significant downregulation of the anti-inflammatory cytokine IL10 in all red changes. Our findings indicate that we can rule out an auto invasive nature of the changes. The downregulation of IL10 at an early phase is a trait for the condition.

Hypoosmotic stress induced tissue-specific immune responses of yellowfin seabream (Acanthopagrus latus) revealed by transcriptomic analysis.

Salinity is a limiting factor for many marine organisms, including fishes. The shift in the ambient salinity can cause osmotic stress and arouse immune responses in fish. In this study, yellowfin seabream (Acanthopagrus latus), a euryhaline marine teleost, was used to investigate immune responses of different tissues (gill, liver, and muscle) under hypoosmotic stress. Comparative transcriptomic and physiological analyses of three tissues were conducted after fish exposed to the fresh water (FW, salinity = 0 ppt), low-saline water (LW, salinity = 3 ppt), and brackish water (BW, salinity = 6 ppt) for 8 days. The results showed that hypoosmotic stress dramatically altered the gene expression of three tissues in yellowfin seabream; The investigation of differentially expressed genes (DEGs) related to osmoregulation and immune response indicated that T cell-mediate immunity pathways were essential to tackle such stress. In terms of tissues, gill was found to be the most sensitive tissue under hypoosmotic stress by enhancing of Na+K+-ATPase activity and preventing the loss of Na+ and K+; Liver, on the other hand, was under the most sever oxidative stress indicated by the fluctuation of SOD, CAT activities and the MDA content; In contrast, muscle had the least osmoregulation and immune related response. We also identified several potential candidate genes, which may serve as gene indicators to identify the stressor. Overall, this study provides preliminary mechanistic insights into hypoosmotic stress adaption of aquatic organism.

Systematic Evaluation of Kinetics and Distribution of Muscle and Lymph Node Activation Measured by 18F-FDG- and 11C-PBR28-PET/CT Imaging, and Whole Blood and Muscle Transcriptomics After Immunization of Healthy Humans With Adjuvanted and Unadjuvanted Vaccines.

Systems vaccinology has been applied to detect signatures of human vaccine induced immunity but its ability, together with high definition in vivo clinical imaging is not established to predict vaccine reactogenicity. Within two European Commission funded high impact programs, BIOVACSAFE and ADITEC, we applied high resolution positron emission tomography/computed tomography (PET/CT) scanning using tissue-specific and non-specific radioligands together with transcriptomic analysis of muscle biopsies in a clinical model systematically and prospectively comparing vaccine-induced immune/inflammatory responses. 109 male participants received a single immunization with licensed preparations of either AS04-adjuvanted hepatitis B virus vaccine (AHBVV); MF59C-adjuvanted (ATIV) or unadjuvanted seasonal trivalent influenza vaccine (STIV); or alum-OMV-meningococcal B protein vaccine (4CMenB), followed by a PET/CT scan (n = 54) or an injection site muscle biopsy (n = 45). Characteristic kinetics was observed with a localized intramuscular focus associated with increased tissue glycolysis at the site of immunization detected by 18F-fluorodeoxyglucose (FDG) PET/CT, peaking after 1-3 days and strongest and most prolonged after 4CMenB, which correlated with clinical experience. Draining lymph node activation peaked between days 3-5 and was most prominent after ATIV. Well defined uptake of the immune cell-binding radioligand 11C-PBR28 was observed in muscle lesions and draining lymph nodes. Kinetics of muscle gene expression module upregulation reflected those seen previously in preclinical models with a very early (~6hrs) upregulation of monocyte-, TLR- and cytokine/chemokine-associated modules after AHBVV, in contrast to a response on day 3 after ATIV, which was bracketed by whole blood responses on day 1 as antigen presenting, inflammatory and innate immune cells trafficked to the site of immunization, and on day 5 associated with activated CD4+ T cells. These observations confirm the use of PET/CT, including potentially tissue-, cell-, or cytokine/chemokine-specific radioligands, is a safe and ethical quantitative technique to compare candidate vaccine formulations and could be safely combined with biopsy to guide efficient collection of samples for integrated whole blood and tissue systems vaccinology in small-scale but intensive human clinical models of immunization and to accelerate clinical development and optimisation of vaccine candidates, adjuvants, and formulations.

Circumventing cellular immunity by miR142-mediated regulation sufficiently supports rAAV-delivered OVA expression without activating humoral immunity.

Recombinant adeno-associated virus (rAAV)-mediated gene delivery can efficiently target muscle tissues to serve as "biofactories" for secreted proteins in prophylactic and therapeutic scenarios. Nevertheless, efficient rAAV-mediated gene delivery is often limited by host immune responses against the transgene product. The development of strategies to prevent anti-transgene immunity is therefore crucial. The employment of endogenous microRNA (miRNA)-mediated regulation to detarget transgene expression from antigen presenting cells (APCs) has shown promise for reducing immunogenicity. However, the mechanisms underlying miRNA-mediated modulation of anti-transgene immunity by APC detargeting are not fully understood. Using the highly immunogenic ovalbumin (OVA) protein as a proxy for foreign antigens, we show that rAAV vectors containing miR142 binding sites efficiently repress co-stimulatory signals in dendritic cells, significantly blunt the cytotoxic T cell response, allow for sustained transgene expression in skeletal myoblasts, and attenuate clearance of transduced muscle cells in mice. Furthermore, the blunting of humoral immunity against circulating OVA correlates with detargeting of OVA expression from APCs. This demonstrates that incorporating APC-specific miRNA binding sites into rAAV vectors provides an effective strategy for reducing transgene-specific immune response. This approach holds promise for clinical applications where the safe and efficient delivery of a prophylactic or therapeutic protein is desired.

A tissue communication network coordinating innate immune response during muscle stress.

Complex tissue communication networks function throughout an organism's lifespan to maintain tissue homeostasis. Using the genetic model Drosophila melanogaster, we have defined a network of immune responses that are activated following the induction of muscle stresses, including hypercontraction, detachment and oxidative stress. Of these stressors, loss of the genes that cause muscle detachment produced the strongest levels of JAK-STAT activation. In one of these mutants, fondue (fon), we also observe hemocyte recruitment and the accumulation of melanin at muscle attachment sites (MASs), indicating a broad involvement of innate immune responses upon muscle detachment. Loss of fon results in pathogen-independent Toll signaling in the fat body and increased expression of the Toll-dependent antimicrobial peptide Drosomycin. Interestingly, genetic interactions between fon and various Toll pathway components enhance muscle detachment. Finally, we show that JAK-STAT and Toll signaling are capable of reciprocal activation in larval tissues. We propose a model of tissue communication for the integration of immune responses at the local and systemic level in response to altered muscle physiology.

Dynamics of expression of antibacterial and antioxidant defence genes in Indian major carp, Labeo rohita in response to Aeromonas hydrophila infection.

Cells produce large number of antioxidant molecules to prevent reactive oxygen species-induced self-damage during microbial assault while generating simultaneously number of antimicrobial molecules to target the pathogen. The present study was aimed at looking into molecules involved in antibacterial and self-protection mechanism of a host Labeo rohita when challenged with a pathogenic bacterium Aeromonas hydrophila. Expression profiles of few of the important host antibacterial genes viz., inducible nitric oxide synthase (iNOS), lysozyme G (LysoG), apolipoprotein A-I (ApoA-I) and hepcidin, and self-defence anti-oxidant genes viz., manganese superoxide dismutase (MnSOD), catalase and glutathione peroxidases (GPx3) were examined in skin and muscle tissues of bacteria challenged fish. Transcription levels of iNOS, LysoG, ApoA-I, hepcidin, catalase, GPx3 and MnSOD were significantly upregulated (P < 0.05) in both tissues at different time points post-bacterial challenge. Increased expression of antibacterial genes in the muscle and skin clearly explains strong defensive mechanism activated in fish tissues in terms of both oxygen-dependent (iNOS) and independent (lysozyme) ways of microbe reduction, and bacterial lysis via production of antimicrobial molecules (ApoA-I and hepcidin) in the host. Simultaneous upregulation of MnSOD, GPx3 and catalase genes explains their involvement in patrolling the cells with regulated production of reactive oxygen species and keeping at a safe level to protect the host's own cells from oxidative damage.

DNA immunization site determines the level of gene expression and the magnitude, but not the type of the induced immune response.

Optimization of DNA vaccine delivery improves the potency of the immune response and is crucial to clinical success. Here, we inquired how such optimization impacts the magnitude of the response, its specificity and type. BALB/c mice were DNA-immunized with two model immunogens, HIV-1 protease and reverse transcriptase by intramuscular or intradermal injections with electroporation. DNA immunogens were co-delivered with DNA encoding luciferase. Delivery and expression were monitored by in vivo bioluminescence imaging (BLI). The endpoint immune responses were assessed by IFN-γ/IL-2 FluoroSpot, multiparametric flow cytometry and antibody ELISA. Expression and immunogenicity were compared in relation to the delivery route. Regardless of the route, protease generated mainly IFN-γ, and reverse transcriptase, IL-2 and antibody response. BLI of mice immunized with protease- or reverse transcriptase/reporter plasmid mixtures, demonstrated significant loss of luminescence over time. The rate of decline of luminescence strongly correlated with the magnitude of immunogen-specific response, and depended on the immunogenicity profile and the immunization route. In vitro and in vivo BLI-based assays demonstrated that intradermal delivery strongly improved the immunogenicity of protease, and to a lesser extent, of reverse transcriptase. Immune response polarization and epitope hierarchy were not affected. Thus, by changing delivery/immunogen expression sites, it is possible to modulate the magnitude, but not the type or fine specificity of the induced immune response.

Plasmid pcDNA3.1-s11 constructed based on the S11 segment of grass carp reovirus as DNA vaccine provides immune protection.

Although some commercial vaccines against grass carp reovirus (GCRV) are available, given the many varieties of GCRV and limited types of vaccines, the disease caused by GCRV remains a major problem, which leads to economic losses in grass carp aquaculture. A reovirus strain (GCRV-HN14) was recently isolated from local diseased fish in our laboratory. The S11 segment of GCRV-HN14 was speculated to encode the virus capsid protein VP35. In our study, the S11 segment was cloned into the eukaryotic expression vector pcDNA3.1(+) to construct the recombinant plasmid pcDNA3.1-s11, which was then transfected into CIK cells, and the VP35 protein was successfully expressed. Grass carp was immunized with pcDNA3.1-s11, and the in vivo distribution and expression of the pcDNA3.1-s11 plasmids were analyzed by PCR and Western blot. Recombinant plasmids were detected in the blood, liver, spleen, kidney, and muscle. However, protein expression could only be detected in the muscle. The immune protection of the pcDNA3.1-s11 plasmid in grass carp was evaluated using a series of experiments. Results showed that the population of white blood cells significantly increased at 1, 7, and 14 days post-immunization (dpi) and reached a peak with (9.58 ±â€¯0.72) × 107/ml at 7 dpi (P < 0.01 or P < 0.05). The percentage of neutrophils reached a peak with (24.13 ±â€¯2.38)% at 7 dpi (P < 0.01), whereas the lymphocytes peaked with (93.30 ±â€¯4.71)% at 14 dpi (P < 0.05). Serum antibody levels were significantly enhanced in immunized fish at 14, 21, and 28 dpi (P < 0.01). The mRNA expression levels of type I interferon, immunoglobulin M, Toll-like receptor 22, and major histocompatibility complex class I were significantly up-regulated in the head kidney and spleen of immunized fish (P < 0.05). Grass carp immunized with pcDNA3.1-s11 exhibited a higher survival percentage (70.4%-73.3%) than the controls (5%-13%). Overall, as a DNA vaccine, the pcDNA3.1-s11 plasmid could induce immune protection against GCRV.

A CCR4 antagonist enhances DC activation and homing to the regional lymph node and shows potent vaccine adjuvant activity through the inhibition of regulatory T-cell recruitment.

CCR4 is a major chemokine receptor expressed by Treg cells that downregulate immune responses. Here, we investigated the role of CCR4-mediated Treg cell recruitment in antigen-specific immune responses. CCR4-deficient mice immunized intramuscularly with ovalbumin (OVA) showed enhanced OVA-specific IgG responses. Furthermore, intramuscular administration of OVA induced the expression of MDC/CCL22, a ligand for CCR4, in macrophages of the muscle tissues, and enhanced the recruitment of CCR4+ Treg cells in wild-type mice, whereas this recruitment of Treg cells was severely impaired in CCR4-deficient mice. Furthermore, OVA-loaded dendritic cells (DCs) derived from the muscle injection site of CCR4-deficient mice had an upregulated expression of the DC activation marker CD40 and 86, and the lymphoid organ homing receptor CCR7 resulting in an increased number of migratory DCs in the regional lymph node. Compound 22, a CCR4 antagonist, also inhibited the recruitment of Treg cells to the muscle tissue, and further enhanced DC activation and homing to the regional lymph node. Consequently, Compound 22 enhanced OVA-specific IgG responses, and the expression levels of IL-4 and IFN-γ in CD4+ T cells and the levels of IFN-γ in CD8+ T cells. Finally, intramuscular administration of OVA and Compound 22 significantly inhibited the growth of OVA-expressing tumors. Collectively, CCR4 plays a pivotal role in Treg cell recruitment to the muscle tissue, and intramuscular administration of CCR4 antagonists may be a promising approach for enhancing vaccine efficacy.

Triggers of inflammatory myopathy: insights into pathogenesis.

The inflammatory myopathies, which include dermatomyositis, polymyositis, and the immune-mediated necrotizing myopathies, are a heterogeneous group of autoimmune diseases that manifest with muscle, skin, or lung damage. Collectively, these autoimmune diseases result from loss of tolerance to a select group of self-antigens, although the precise mechanism through which this occurs is not known. Infection, malignancy, and certain medications including statins and the immune checkpoint inhibitors used in cancer therapy have been identified as potential immunologic triggers of the inflammatory myopathies. Some of these triggers are classically associated with specific myositis-specific autoantibodies (MSAs). The strong association between certain triggers and MSAs provides insights into how an immunologic event can lead to loss of tolerance to specific self-antigens, resulting in autoimmune disease. In this review, we discuss the proposed triggers of the inflammatory myopathies and their associations with MSAs, and provide insights into how these triggers may result in the inflammatory myopathies.

Long-term regulation of local cytokine production following immunization in mice.

Vaccines based on pathogen components require adjuvants to enhance the antigen-specific adaptive immune response. Intramuscular injection of adjuvanted-vaccines induces inflammatory cytokines and inflammatory nodules at the injection site within 48 hr after injection (Vaccine 2014; 32: 3393-401). In the present study, long-term regulation of cytokine production was investigated at 3, 6, 24, and 48 hr, 5 and 7 days, and 2 and 4 weeks after immunization with human papilloma virus (HPV), diphtheria and tetanus toxoids combined with acellular pertussis (DTaP), Haemophilus influenza type B (Hib), and pneumococcal conjugated (PCV) vaccines in mouse models. The second dose was given 4 weeks later, and cytokine profiles were investigated 2, 5, and 7 days after re-immunization. IL-1ß, IL-6, granulocyte-colony stimulating factor (G-CSF), and MCP-1 were produced from 3 hr and peaked at 48 hr after immunization with Cervarix in mice. IL-4, MCP-1, and TNF-α peaked at 5 or 7 days after immunization with Gardasil. These cytokines decreased 7 days after immunization with Cervarix and Gardasil. After the second dose, similar responses were observed. Both vaccines induced neutrophil extracellular traps (NET) in inflammatory nodules. The peak amount of IL-1ß, IL-6, G-CSF, and MCP-1 was observed on day 5 of immunization and that of IL-4 on days 5-7 of immunization with DTaP, but no increase in IL-6 and G-CSF was observed after re-immunization. A similar response was noted after immunization with PCV13. An inflammatory response is essential for the development of adaptive immunity through the production of inflammatory cytokines.