Superficial cutaneous Staphylococcus aureus (S. aureus) infection in humans can lead to soft tissue infection, an important cause of morbidity and mortality. IL-17A production by skin TCRγδ+ cells in response to IL-1 and IL-23 produced by epithelial and immune cells is important for restraining S. aureus skin infection. How S. aureus evades this cutaneous innate immune response to establish infection is not clear. Here we show that mechanical injury of mouse skin by tape stripping predisposed mice to superficial skin infection with S. aureus. Topical application of S. aureus to tape-stripped skin caused cutaneous influx of basophils and increased Il4 expression. This basophil-derived IL-4 inhibited cutaneous IL-17A production by TCRγδ+ cells and promoted S. aureus infection of tape-stripped skin. We demonstrate that IL-4 acted on multiple checkpoints that suppress the cutaneous IL-17A response. It reduced Il1 and Il23 expression by keratinocytes, inhibited IL-1+IL-23-driven IL-17A production by TCRγδ+ cells, and impaired IL-17A-driven induction of neutrophil-attracting chemokines by keratinocytes. IL-4 receptor blockade is shown to promote Il17a expression and enhance bacterial clearance in tape-stripped mouse skin exposed to S. aureus, suggesting that it could serve as a therapeutic approach to prevent skin and soft tissue infection.

Keywords: Bacterial infections; Basophils; Immunology; Infectious disease; Innate immunity.

Background: Endometrial scratching (ES) has been proposed as a potential treatment for implantation improvement in unexplained repeated implantation failure (uRIF) patients, however, little is known about its exact molecular mechanisms.

Objective: This randomized controlled trial (RCT) was conducted on twenty uRIF patients to investigate the expression of innate and adaptive immune signaling genes after ES.

Methods: Ten uRIF patients in the intervention (twice endometrial sampling in follicular and luteal phases) and 10 uRIF patients in the control group (only luteal phase sampling) were randomly enrolled. Gene expression analysis with innate and adaptive immune response PCR-array kit between intervention and control groups were performed.

Results: Among innate immune-associated genes, a significant decrease was observed in the expression of APCS, CPR, CCL2, NLRP3, HLA-A, TLR3 and TLR4 in the intervention group. In adaptive immune-related genes, the expression level of CD80, CD86, CXCR3, IFNγ, IFNα1, IFNβ, MBL2, CCR6, CCR8 and IL17A were decreased and CSF2, GATA3, and IL4 increased significantly in the intervention group (P < 0.05). Of 14 uRIF patients, five live birth (35.71 %) was achieved.

Conclusion: ES in uRIF patients may exert positive effects on the endometrial preparation which increases its receptivity for embryo implantation by modulating the expression of an array of immune signaling pathway genes.

Keywords: Endometrial scratching; Inflammasome; Innate and adaptive immune response; Unexplained repeated implantation failure.

Introduction: We aimed to evaluate for any possible effects of treatment with rituximab (RTX) on the peripheral Th17 and Treg subpopulations in patients with rheumatoid arthritis (RA).

Patients and methods: We analyzed 16 patients with RA initiating RTX treatment, 11 patients with RA initiating abatacept treatment, 11 patients with RA treated with other medications, 8 patients with other autoimmune rheumatic diseases initiating RTX, and 14 healthy volunteers. Th17 cells (CD4⁺IL23R⁺IL17A⁺) and Treg cells (CD4⁺CD25^hiFoxP3⁺) were evaluated flow-cytometrically.

Results: Th17 cells from patients treated with RTX decreased significantly at weeks 8 and 16 (mean ± SEΜ: 3.01% ± 0.54℅ CD4⁺ cells at week 0 vs. 1.53% ± 0.24℅ at week 8 vs 1.10% ± 0.20℅ at week 16, p = 0.0004). Reductions of Th17 cells were evident in clinical responders (DAS28 score ≤ 3.2), ACPA (+) and RF (-) patients; circulating Tregs remained stable. Th17 and Tregs were not affected by ABA treatment or by changes in disease activity. Tregs, but not Th17 cells, decreased following treatment with RTX in patients with other autoimmune diseases (0.75% ± 0.16% at week 0 vs. 0.43% ± 0.16% at week 8, p = 0.033).

Conclusion: RTX-induced B cell depletion results in a significant reduction of circulating Th17 cell percentages, whereas it has no effect on Tregs of patients with RA. This reduction of Th17 cells was evident particularly in responders to RTX treatment, ACPA+ and RF (-) patients with RA.

Keywords: B cell depletion; Regulatory T cells; Rheumatoid arthritis; Rituximab; Thelper-17 cells.

Background: Neuromyelitis optica (NMO), multiple sclerosis (MS) and autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy are idiopathic inflammatory demyelinating diseases (IIDDs) that mainly present as encephalomyelitis. Heparan sulfate (HS) and hyaluronic acid (HA) are two components of glycocalyx, a carbohydrate-rich layer on the surface of blood vessels that mediates interaction with blood. Degradation of glycocalyx in NMO is poorly understood.

Purpose: To detect the serum and cerebrospinal fluid (CSF) levels of shed HS and HA and to correlate these levels with disease severity to determine their diagnostic value.

Methods: We obtained serum and CSF samples from 24 NMO patients, 15 MS patients, 10 autoimmune GFAP astrocytopathy patients, and 18 controls without non-inflammatory neurological diseases. Soluble HS and HA, and IFNγ, IL17A, and matrix metalloproteinase (MMP) 1 were detected via ELISA.

Results: Serum and CSF levels of HS, HA and related cytokines but not of plasma MMP1 were significantly elevated in these diseases. Notably, HS and HA levels were positively correlated with Expanded Disability Status Scale scores.

Conclusions: Our results indicate glycocalyx degradation and inflammation in NMO, MS and autoimmune GFAP astrocytopathy. Moreover, increased shedding of HS or HA may indicate a worse clinical situation. Furthermore, therapeutic strategies that protect glycocalyx may be effective in these diseases.

Keywords: blood-brain barrier; glycocalyx; heparan sulfate; hyaluronic acid; neuromyelitis optica.

Background: Interleukin (IL)-17A has a dual role in tumor immunity, promotes anti-tumor responses and facilitates angiogenesis by interacting with IL-17 receptor A (IL-17RA). Although IL-17A has been associated with the pathogenesis of papillary thyroid carcinoma (PTC), the nucleotide variability at the IL17A and IL17RA genes is still poorly characterized.

Aim: To assess the contribution of the IL17A (-197 G >A, rs2275913) and IL17RA (-947 A >G, rs4819554) single nucleotide polymorphisms (SNP) on the development and progression of PTC and on IL-17 plasma levels.

Methods: We studied 188 PTC patients and 170 healthy controls. SNPs were identified using PCR-amplified DNA and restriction fragment length polymorphism (RFLP) techniques. Plasma levels of IL-17A was evaluated in 83 PTC patients using ELISA. Statistical analyses were performed to evaluate the associations between SNPs and clinicohistopathological features of PTC and IL-17A levels.

Results: No significant difference was observed regarding the allele and genotype distributions of both SNPs between PTC patients and controls. The IL17A GA was associated with poor biochemical and structural incomplete response to therapy, whereas no influence over the IL-17A expression was observed. The IL17RA AG was significantly associated with small-sized tumors, initial tumor stage at diagnosis and better response to therapy.

Conclusions: The IL17A SNP may predict an aggressive manifestation of PTC, whereas the IL17RA SNP was associated with a more favorable clinical outcome.

Keywords: IL-17A; IL-17RA; Papillary thyroid carcinoma; Response to therapy; Single nucleotide polymorphisms (SNP); Thyroid cancer.

Introduction: IL-17A and IL-17F cytokines have important roles in the pathogenesis of psoriasis.

Aim: To examine the associations of IL-17A rs2275913 and IL-17F rs763780 variants with the development of psoriasis and whether these polymorphisms affect the responsiveness of biological agents.

Material and methods: In our case-controlled study, which included 83 psoriatic patients who were treated with different biological agents and 69 healthy controls, we genotyped IL-17A rs2275913 and IL-17F rs763780 variants using TaqMan probes.

Results: We did not observe statistically significant changes in genotype frequencies of IL-17A rs2275913 (p = 0.922) and IL-17F rs763780 (p = 0.621) variants between patient and control groups. Although we did not find any association between these polymorphisms and the development of psoriasis, statistical analyses showed that individuals with the IL-17A AA genotype had shorter disease duration (9.09 ±6.82, p = 0.020) and AA genotype frequency was higher in patients who used single conventional treatment (34.6%; p = 0.025). IL17A/rs2275913 variant in terms of disease duration, it was observed that individuals with AA genotype had a shorter disease duration (less than 10 years) (p = 0.009). For patients with PASI90 and PASI100 response, the IL-17A AA genotype was significantly higher (p = 0.015). On the other hand, we did not detect any statistically significant correlation between variants and response to biological agents.

Conclusions: According to our results, we may suggest that rs2275913 variant seems to be associated with disease duration, use of single conventional treatment and responsiveness of PASI90 and PASI100 however both variants have no effect on the susceptibility to psoriasis in the population of Eastern Turkey.

Keywords: IL-17A; IL-17F; adalimumab; psoriasis; secukinumab; ustekinumab.

It is well known that chicken CD8⁺ T cell response is vital to clearing viral infections. However, the differences between T cell subsets expressing CD8 receptors in chicken peripheral blood mononuclear cells (PBMCs) have not been compared. Herein, we used Smart-Seq2 scRNA-seq technology to characterize the difference of chicken CD8^high+, CD8^high αα⁺, CD8^high αβ⁺, CD8^medium+, and CD4⁺CD8^low+ T cell subsets from PBMCs of avian leukosis virus subgroup J (ALV-J)-infected chickens. Weighted gene co-expression network analysis (WGCNA) and Trend analysis revealed that genes enriched in the "Cytokine-cytokine receptor interaction" pathway were most highly expressed in the CD8^high αα⁺ T cell population, especially T cell activation or response-related genes including CD40LG, IL2RA, IL2RB, IL17A, IL1R1, TNFRSF25, and TNFRSF11, suggesting that CD8^high αα⁺ T cells rather than other CD8 subpopulations were more responsive to ALV-J infections. On the other hand, genes involved in the "FoxO signaling pathway" and "TGF-beta signaling pathway" were most highly expressed in the CD4⁺CD8^low+ (CD8^low+) T cell population and the function of CD4⁺CD8^low+ T cells may play roles in negatively regulating the functions of T cells based on the high expression of CCND1, ROCK1, FOXO1, FOXO3, TNFRSF18, and TNFRSF21. The selected gene expressions in CD8⁺ T cells and CD4⁺CD8^low+ double-positive T cells confirmed by qRT-PCR matched the Smart-Seq2 data, indicating the reliability of the smart-seq results. The high expressions of Granzyme K, Granzyme A, and CCL5 indicated the positive response of CD8⁺ T cells. Conversely, CD4⁺CD8⁺ T cells may have the suppressor activity based on the low expression of activation molecules but high expression of T cell activity suppressor genes. These findings verified the heterogeneity and transcriptional differences of T cells expressing CD8 receptors in chicken PBMCs.

Keywords: CD4+CD8+ double-positive T cell; CD8+ T cell; CD8highαα+ T cell; PBMCs; Smart-seq2; chicken.

Background: Eczematous drug eruption (EDE) is a spongiotic skin reaction in response to systemic medications. Up to now, EDE has been described in patients treated with anti-IL17A monoclonal antibodies with a prevalence of 2.2-12.1%.

Objectives: To describe the clinical and histologic features, and the skin cytokines milieu in patients with EDE induced by anti-IL-17A, secukinumab and ixekizumab.

Methods: A prospective study, enrolling psoriasis patients who developed EDE during treatment with 2 anti-IL17, ixekizumab and secukinumab, from June 2019 to April 2021, was conducted. A 5 mm lesional(Les) and a 3 mm non-lesional(NLes) skin biopsy were taken from all the patients. Les sample was splitted in two parts, one for histological examination and the other for cytokines profile evaluation.

Results: 289 patients were treated with anti-IL17A mAb during the study period. Eight (2.8%) patients developed EDE during the treatment. Histopathological evaluation suggested a diagnosis of spongiotic dermatitis in all the patients. Cytokine-gene-expression showed predominance of Th2/Th22 cytokines in EDE-lesions with strong increase of IL-4, IL-22, and S100A7 levels in both Les and Nles skin compared to healthy skin. A significant enhancement of IL-4, IL-22, and S100A7 in Les compared to Nles skin was observed. IL-26 levels were significantly increased compared to healthy skin. Low levels of IL-23A were found both in Les and Nles skin.

Conclusion: EDE skin lesions have mainly Th2/Th22 features, with IL-22 playing a major role in the pathogenesis. EDE can be considered as the result of the imbalance towards Th2/Th22 response secondary to the blockade of IL-17A-activity.

Background: Platelets support tumour progression. However, their prognostic significance and relation to circulating tumour cells (CTCs) in operable breast cancer (BrCa) are still scarcely known and, thus, merit further investigation.

Methods: Preoperative platelet counts (PCs) were compared with clinical data, CTCs, 65 serum cytokines and 770 immune-related transcripts obtained using the NanoString technology.

Results: High normal PC (hPC; defined by the 75th centile cut-off) correlated with an increased number of lymph node metastases and mesenchymal CTCs in the 70 operable BrCa patients. Patients with hPC and CTC presence revealed the shortest overall survival compared to those with no CTC/any PC or even CTC/normal PC. Adverse prognostic impact of hPC was observed only in the luminal subtype, when 247 BrCa patients were analysed. hPC correlated with high content of intratumoural stroma, specifically its phenotype related to CD8+ T and resting mast cells, and an increased concentration of cytokines related to platelet activation or even production in bone marrow (i.e. APRIL, ENA78/CXCL5, HGF, IL16, IL17a, MDC/CCL22, MCP3, MMP1 and SCF).

Conclusions: Preoperative platelets evaluated alone and in combination with CTCs have prognostic potential in non-metastatic BrCa and define patients at the highest risk of disease progression, putatively benefiting from anti-platelet therapy.

Patients suffering from chronic inflammatory diseases such as psoriasis are prone to develop depressive symptoms. However, within the time constraints of dermatological clinics, depressive symptoms in psoriasis patients are often overlooked and thus underdiagnosed. The Two Questions Test may serve as a quick screening tool for an initial assessment of depressive burden in these patients. We evaluated its usefulness in the clinical context analyzing the records of patients starting systemic treatment for psoriasis with a selective interleukin (IL)23- or IL17A-inhibitor. In a total sample of N = 139 patients, baseline Two Questions Test scores were analyzed together with measures of psoriatic and psychiatric symptoms. In addition, the development of the Two Questions Test scores over the course of the first 28 weeks of treatment was assessed. No association was found between the Two Questions Test scores and skin symptoms measured by the Psoriasis Area and Severity Index and the visibility of skin lesions. However, skin related quality of life analyzed with the Dermatology Life Quality Index was associated with the Two Questions Test scores. In addition, the longitudinal analysis revealed improvement in Two Questions Test outcomes over the course of patients' treatment. These results indicate the Two Questions Test's usefulness both as an initial screening tool of depressive symptoms, as well as in its use as a sensitive tool for the repeated assessment of depressive symptoms in psoriasis patients.

Keywords: Two Questions Test; depression; mental well-being; psoriasis; screening.

Rationale: Premature infants exposed to oxygen are at risk for bronchopulmonary dysplasia (BPD), which is characterised by lung growth arrest. Inflammation is important, but the mechanisms remain elusive. Here, we investigated inflammatory pathways and therapeutic targets in severe clinical and experimental BPD.

Methods and results: First, transcriptomic analysis with in-silico cellular deconvolution identified a lung-intrinsic M1-like-driven cytokine pattern in newborn mice after hyperoxia. These findings were confirmed by gene expression of macrophage-regulating chemokines (Ccl2, Ccl7, Cxcl5) and markers (Il6, Il17A, Mmp12). Second, hyperoxia-activated IL-6/STAT3 signaling was measured in vivo and related to loss of alveolar epithelial type II cells (ATII) as well as increased mesenchymal marker. Il6 null mice exhibited preserved ATII survival, reduced myofibroblasts and improved elastic fiber assembly, thus enabling lung growth and protecting lung function. Pharmacological inhibition of global IL-6 signaling and IL-6 trans-signaling promoted alveolarisation and ATII survival after hyperoxia. Third, hyperoxia triggered M1-like polarisation, possibly via Klf4; hyperoxia-conditioned medium of macrophages and IL-6 impaired ATII proliferation. Finally, clinical data demonstrate elevated macrophage-related plasma cytokines as potential biomarkers that identify infants receiving oxygen at increased risk of developing BPD. Moreover, macrophage-derived IL6 and active STAT3 were related to loss of epithelial cells in BPD lungs.

Conclusion: We present a novel IL-6-mediated mechanism by which hyperoxia activates macrophages in immature lungs, impairs ATII homeostasis, and disrupts elastic fiber formation, thereby inhibiting lung growth. The data provide evidence that IL-6 trans-signaling could offer an innovative pharmacological target to enable lung growth in severe neonatal chronic lung disease.

Streptococcus suis (S. suis), an emerging zoonotic pathogen, can cause streptococcal toxic shock-like syndrome (STSLS) in humans with high mortality. STSLS is characterized by high bacterial burden, an inflammatory cytokine storm, multi-organ dysfunction, and ultimately acute host death. Although it has been found that a significantly high level of IL-17A was induced in an NLRP3-dependent manner during STSLS development, the role of IL-17A on S. suis STSLS remains to be elucidated. In this study, we found that the epidemic strain SC 19 caused a significantly higher level of IL-17A than the non-epidemic strain P1/7. In addition, higher bacterial burden was observed from SC 19-infected il17a-/- mice than il17a+/+ mice, although acute death, tissue injury and inflammatory cytokines storm were observed in both types of mice. Furthermore, compared with il17a+/+ mice, the level of neutrophils recruitment was lower in il17a-/- mice, and the levels of induced antimicrobial proteins, such as CRAMP, S100A8 and lipocalin-2, were also decreased in il17a-/- mice. In conclusion, this study demonstrated that IL-17A does not contribute to the severe inflammation, although it may play a minor role for bacterial clearance by inducing antimicrobial proteins and promoting neutrophil recruitment during STSLS.

Keywords: Interleukin-17A; Streptococcus suis; antimicrobial proteins; bacterial clearance; neutrophils; streptococcal toxic shock-like syndrome.

Background and aims: Primary Biliary Cholangitis (PBC) is an organ-specific autoimmune liver disease. Mononuclear phagocytes (MNPs), comprise of monocyte, dendritic cells and monocyte-derived macrophages, constitute major arm of the innate immune system known to be involved in the pathogenesis of autoimmune disorders. MNPs were shown to accumulate around intra-hepatic bile ducts in livers of PBC patients. Interleukin 23 (IL-23) is a pro-inflammatory cytokine. IL-23-positive cells were detected in livers of patients with advanced stage PBC and IL-23 serum levels found to be in correlation with PBC disease severity. Our overall goal was to assess the importance of IL-23 derived from MNPs in PBC pathogenesis.

Methods: We utilized an inducible murine model of PBC and took advantage of transgenic mice targeting expression of IL-23 by specific MNP populations. Analysis included liver histology assessment, flow cytometry of hepatic immune cells and hepatic cytokine profile evaluation. Specific MNPs sub-populations were sorted and assessed for IL-23 expression levels.

Results: Flow cytometry analysis of non-parenchymal liver cells in autoimmune cholangitis revealed massive infiltration of the liver by MNPs and neutrophils and a decrease in Kupffer cells numbers. In addition, a 4-fold increase in the incidence of hepatic IL-17A producing CD4⁺ T cells was found to be associated with an increase in hepatic IL23-p19 and IL17A expression levels. Disease severity was significantly ameliorated in both CD11c^creP19^flox/flox and CX₃CR1^creP19 ^flox/flox mice as assessed by reduced portal inflammation and decreased hepatic expression of various inflammatory cytokines. Amelioration of disease severity was associated with reduction in IL-17A producing CD4⁺ T cells percentages and decreased hepatic IL23-p19 and IL17A expression levels. qRT-PCR analysis of sorted hepatic MNPs demonstrated high expression levels of IL-23 mRNA specifically by CX₃CR1^hiCD11c⁺ monocyte-derived macrophages.

Conclusion: Our results indicate a major role for IL-23 produced by hepatic monocyte-derived macrophages in the pathogenesis of PBC. These results may pave the road for the development of new immune-based and cell specific therapeutic modalities for PBC patients not responding to current therapies.

Keywords: cytokines; interleukin-23; macrophages; monocytes; primary biliary cholangitis.

Inflammatory bowel disease (IBD) is a complex, chronic, and dysregulated inflammatory condition which etiology is still largely unknown. Its prognosis and disease progression are highly variable and unpredictable. IBD comprises several heterogeneous inflammatory conditions ranging from Ulcerative Colitis (UC) to Crohn's Disease (CD). Importantly, a definite, well-established, and effective clinical treatment for these pathologies is still lacking. The urgent need for treatment is further supported by the notion that patients affected by UC or CD are also at risk of developing cancer. Therefore, a deeper understanding of the molecular mechanisms at the basis of IBD development and progression is strictly required to design new and efficient therapeutic regimens. Although the development of animal models has undoubtedly facilitated the study of IBD, such in vivo approaches are often expensive and time-consuming. Here we propose an organ ex vivo culture (Gut-Ex-Vivo system, GEVS) based on colon from Balb/c mice cultivated in a dynamic condition, able to model the biochemical and morphological features of the mouse models exposed to DNBS (5-12 days), in 5 h. Indeed, upon DNBS exposure, we observed a dose-dependent: (i) up-regulation of the stress-related protein transglutaminase 2 (TG2); (ii) increased intestinal permeability associated with deregulated tight junction protein expression; (iii) increased expression of pro-inflammatory cytokines, such as TNFα, IFNγ, IL1β, IL6, IL17A, and IL15; (iv) down-regulation of the anti-inflammatory IL10; and (v) induction of Endoplasmic Reticulum stress (ER stress), all markers of IBD. Altogether, these data indicate that the proposed model can be efficiently used to study the pathogenesis of IBD, in a time- and cost-effective manner.

Keywords: DNBS; IBD; UPR; ex vivo organ; tissue culture.

Background: Bovine viral diarrhea virus (BVDV) is a major pathogen that causes bovine viral diarrhea/mucosal disease (BVD-MD), which has become a global infectious disease due to its wide spread and the lack of effective treatment. The process of BVDV infection is complex. Once infected, host immune cells are activated and modulated. As a major immune cell, peripheral blood lymphocyte cells (PBLCs) are the primary target of BVDV. In order to further understand the mechanism of BVDV- host interaction, the expression profiles of host lymphocytes mRNAs associated with BVDV infection were investigated by transcriptomic sequencing analysis.

Results: The transcriptomic sequencing analysis was performed on bovine PBLCs infected with CP BVDV-2 GS2018 after 12 h of infection. Gene expression profiling demonstrated that 1052 genes were differentially expressed in GS2018 infected PBLCs compared with the control group. Of these genes, 485 genes were up-regulated and 567 were down-regulated. The 19 differential expressed genes (DEGs) were selected for validation using quantitative real-time PCR and the results were consistent with the results of RNA-Seq. Gene ontology enrichment and KEGG pathway analysis showed that 1052 DEGs were significantly enriched in 16 pathways, including cytokine-cytokine receptor interaction, IL17, PI3K-Akt, MAPK and TNF signaling pathway. PPI network analysis showed that IL17A, IFN-γ and TNF-α interacted with various proteins and may play crucial roles in BVDV-2 infection. Of note, we confirmed that GS2018 induced Th17 cell differentiation in PBLCs and persistently increased the expression levels of IL17A. In turn, the replication of GS2018 was inhibited by IL17A.

Conclusion: In this study, the transcription changes of DEGs related to host immune responses in bovine PBLCs were caused by CP BVDV-2 infection. In particular, the effector molecules IL17A of Th17 cells were significantly up-regulated, which inhibited viral replication. These results will contribute to exploration and further understanding of the host immune response mechanism and interaction between host and BVDV-2.

Keywords: BVDV-2; Immune response; RNA-Seq; Th17 cell differentiation; Viral replication.

Chagas disease has a complex pathogenesis wherein the host immune response is essential for controlling its development. Suppressor of cytokine signaling(SOCS)2 is a crucial protein that regulates cytokine production. In this study, SOCS2 deficiency resulted in an initial imbalance of IL12- and IL-10-producing neutrophils and dendritic cells (DCs), which caused a long-lasting impact reducing inflammatory neutrophils and DCs, and tolerogenic DCs at the peak of acute disease. A reduced number of inflammatory and pro-resolving macrophages, and IL17A-producing CD4⁺ T cells, and increased lymphocyte apoptosis was found in SOCS2-deficient mice. Electrocardiogram analysis of chimeric mice showed that WT mice that received SOCS2 KO bone marrow transplantation presented increased heart dysfunction. Taken together, the results demonstrated that SOCS2 is a crucial regulator of the immune response during Trypanosoma cruzi infection, and suggest that a SOCS2 genetic polymorphism, or failure of its expression, may increase the susceptibility of cardiomyopathy development in Chagasic patients.

Keywords: Cardiac function; Chagas disease; Immunorregulation; SOCS2; Trypanosoma cruzi.

Background: Gastroinestinal nematodes (GIN) are one of the major health problem in grazing sheep. Although genetic variability of the resistance to GIN has been documented, traditional selection is hampered by the difficulty of recording phenotypes, usually fecal egg count (FEC). To identify causative mutations or markers in linkage disequilibrium (LD) to be used for selection, the detection of quantitative trait loci (QTL) for FEC based on linkage disequilibrium-linkage analysis (LDLA) was performed on 4097 ewes (from 181 sires) all genotyped with the OvineSNP50 Beadchip. Identified QTL regions (QTLR) were imputed from whole-genome sequences of 56 target animals of the population. An association analysis and a functional annotation of imputed polymorphisms in the identified QTLR were performed to pinpoint functional variants with potential impact on candidate genes identified from ontological classification or differentially expressed in previous studies.

Results: After clustering close significant locations, ten QTLR were defined on nine Ovis aries chromosomes (OAR) by LDLA. The ratio between the ANOVA estimators of the QTL variance and the total phenotypic variance ranged from 0.0087 to 0.0176. QTL on OAR4, 12, 19, and 20 were the most significant. The combination of association analysis and functional annotation of sequence data did not highlight any putative causative mutations. None of the most significant SNPs showed a functional effect on genes' transcript. However, in the most significant QTLR, we identified genes that contained polymorphisms with a high or moderate impact, were differentially expressed in previous studies, contributed to enrich the most represented GO process (regulation of immune system process, defense response). Among these, the most likely candidate genes were: TNFRSF1B and SELE on OAR12, IL5RA on OAR19, IL17A, IL17F, TRIM26, TRIM38, TNFRSF21, LOC101118999, VEGFA, and TNF on OAR20.

Conclusions: This study performed on a large experimental population provides a list of candidate genes and polymorphisms which could be used in further validation studies. The expected advancements in the quality of the annotation of the ovine genome and the use of experimental designs based on sequence data and phenotypes from multiple breeds that show different LD extents and gametic phases may help to identify causative mutations.

Objective: The goal of this investigation was to evaluate circulating and skeletal muscle inflammatory biomarkers between MHD and demographic-matched control subjects (CON) before and after ingestion of a protein rich meal.

Design and methods: CON (n=8; 50±2 y; 31±1 kg/m²) and MHD patients (n=8; 56±5 y; 32±2 kg/m²) underwent a basal blood draw and muscle biopsy and serial blood draws after the ingestion of a mixed meal on a non-dialysis day. Plasma advanced glycation end products (AGEs) and markers of oxidation (OX) were assessed via LC-MS/MS before and after the meal (+240 min). Circulating inflammatory cytokines, soluble receptor for AGEs (sRAGE) isoforms (endogenous secretory RAGE, esRAGE; cleaved RAGE, cRAGE) were determined before and after the meal (+240 min). Basal muscle was probed for inflammatory cytokines and protein expression of related signaling components (RAGE, TLR4, OST48, TRIF, total and pIκBα).

Results: Basal circulating AGEs were 7-343 fold higher (P<0.001) in MHD than CON but only MG-H1 increased in CON following the meal (P<0.001). There was a group effect (MHD>CON) for total sRAGE (P=0.02) and esRAGE (P<0.001) and a trend for cRAGE (P=0.09), with no meal effect. Additionally, there was a group effect (MHD<CON; P<0.05) for circulating Fractalkine, IL10, IL17A, and IL1β and a trend (P<0.10) for IL6 and MIP1α, whereas TNFα was higher in MHD (P<0.001). In muscle, TLR4 (P=0.03), TRIF (P=0.002), and OST48 (P=0.02) expression was lower in MHD than CON, while IL6 was higher (P=0.01) and IL8 (P=0.08) tended to be higher in MHD.

Conclusion: Overall, MHD exhibited an exaggerated circulating and skeletal muscle inflammatory biomarker environment and the meal did not appreciably affect inflammatory status.

Keywords: AGEs; Diet; Inflammation; Maintenance Hemodialysis.

Objectives: The importance of IL-17A in the pathogenesis of Axial Spondyloarthritis (AxSpA) has been demonstrated by the success of IL-17A blockade. However, the nature of the cell populations producing this important pro-inflammatory cytokine remains poorly defined. Accordingly, we characterized major IL-17A-producing blood cell populations in AxSpA, with reference to entheseal biology, with a focus on mucosal associated invariant T-cells, (MAITs) a population known to be capable of producing IL-17.

Methods: IL-17A production from 5 sorted peripheral blood cell populations, namely MAITs, γδ T-cells, CD4+T-cells, CD8+T-cells and neutrophils was evaluated pre- and post-stimulation with PMA, the calcium ionophore A23187 and β1,3 glucan. IL-17A transcript and protein expression were determined using nCounter Technology and ultra-sensitive SimoA technology, respectively. MAITs from control human axial entheses (n=5) were further characterized by flow cytometric immunophenotyping, qPCR and IL-17 production assessed following stimulation.

Results: In blood, on a per cell basis, MAIT cells produced the highest amount of IL-17A compared to CD4+ (p <0.01), CD8+ (p <0.0001) and γδ T-cells (p <0.0001). IL-17A was not produced by neutrophils. Gene expression analysis also showed significantly higher IL17A and IL23R expression in MAIT cells. Stimulation of blood MAIT cells with αCD3/CD28 and IL-7 and/or IL-18 induced strong expression of IL17F. MAITs were present in the normal enthesis and showed elevated AHR, JAK1, STAT4 and TGFB1 transcript expression with inducible IL-17A protein. IL-18 protein expression was evident in spinal enthesis digests.

Conclusion: Both blood MAITs and resident MAITs in axial entheses contribute to IL-17 production and may play important roles in AxSpA pathogenesis.

Psoriasis is a chronic inflammatory skin disease involving several cell types, including T cells, via the IL-23/IL-17 axis. IL-17A acts on the surrounding epithelial cells thus resulting in an inflammatory feedback loop. The development of immunocompetent models that correctly recapitulate the complex phenotype of psoriasis remains challenging, which also includes both the T cells isolation and activation methods. The purpose of this work was to develop an advanced in vitro 3D psoriatic skin model that enables the study of the T cells impact on psoriatic epithelial cells. To reach that aim, healthy and psoriatic fibroblasts and keratinocytes were used to reproduce this tissue-engineered skin model in which activated T cells, isolated beforehand from human whole blood, have been incorporated. Our study showed that isolation of T cells with the EasySep procedure, followed by activation with PMA/ionomycin, mimicked the psoriatic characteristics in an optimal manner with the production of inflammatory cytokines important in the pathogenesis of psoriasis, as well as increased expression of Ki67, S100A7, elafin and involucrin. This psoriatic model enriched in activated T cells displayed enhanced production of IL-17A, IFN-ƴ, CCL2, CXCL10, IL-1ra, IL-6 and CXCL8 compared with the healthy model and whose increased secretion was maintained over time. In addition, anti-IL17A treatment restored some psoriatic features, including epidermal thickness and basal keratinocytes proliferation, as well as a downregulation of S100A7, elafin and involucrin expression. Altogether, our study demonstrated that this model reflects a proper psoriatic inflammatory environment and is effective for the investigation of epidermal and T cell interaction over time. STATEMENT OF SIGNIFICANCE: : The aim of this study was to provide an innovative 3D immunocompetent human psoriatic skin model. To our knowledge, this is the first immunocompetent model that uses skin cells from psoriatic patients to study the impact of IL-17A on pathological cells. Through the use of this model, we demonstrated that the T-cell enriched psoriatic model differs from T-cell enriched healthy model, highlighting efficient crosstalk between pathologic epithelial cells and T cells. This advanced preclinical model further mimics the original psoriatic skin and will prove relevant in predicting clinical outcomes, thereby decreasing inaccurate predictions of compound effects.

Keywords: 3D psoriatic skin model; IL-17A; T cells; psoriasis; tissue-engineering.

The euglycemic hyperinsulinemic clamp model (EHC) of equine endocrinopathic laminitis induces rapid loss of lamellar tissue integrity, disrupts keratinocyte functions, and induces inflammation similar to natural disease. Continuous digital hypothermia (CDH) blocks tissue damage in this experimental model, allowing identification of specific genes or molecular pathways contributing to disease initiation or early progression. Archived lamellar tissues (8 horses, 48 h EHC treatment, including CDH-treated front limbs) were used to measure relative expression levels of genes encoding keratin 17 (KRT17), a stress-induced intermediate filament protein, and genes upregulated downstream of keratin 17 and/or interleukin 17A (IL-17A), as mediators of inflammation. Compared to front or hind limbs at ambient temperature, CDH resulted in significantly lower expression of KRT17, CCL2, CxCL8, PTGS2 (encoding COX2), IL6, TNFα, S100A8 and MMP1. By immunofluorescence, COX2 was robustly expressed in lamellar keratinocytes from ambient limbs, but not in CDH-treated limbs. Genes not significantly reduced by CDH were IL17A, DEFB4B, S100A9 and MMP9. Overall, 8 of 12 genes were expressed at lower levels in the CDH-treated limb. These 8 genes are expressed by wounded or stress-activated keratinocytes in human disease or mouse models, highlighting the role of keratinocytes in equine laminitis.

Keywords: Horse; Inflammation; Insulin; Keratin; Laminitis.

Background: Conversion disorder/functional neurological disorder (CD/FND) occurs often in neurological settings and can lead to long-term distress, disability and demand on health care services. Systemic low-grade inflammation might play a role, however, the pathogenic mechanism is still unknown.

Aim: 1) To explore the feasibility to establish and assess a cohort of CD/FND with motor symptoms, involving persons with lived experience (PPI). 2) To generate proof of concept regarding a possible role for cytokines, microRNA, cortisol levels and neurocognitive symptoms in patients with motor CD/FND.

Method: Feasibility study.

Results: The study showed active involvement of patients despite high clinical illness burden and disability, neurocognitive symptoms, childhood adverse experiences (ACE) and current life events. The study provided valuable knowledge regarding the feasibility of conducting a study in these patients that will inform future study phases. In the sample there were elevated levels of IL6, IL12, IL17A, IFNg, TNFa and VEGF-a, suggesting systemic low-grade inflammation. Also, microRNAs involved in inflammation and vascular inflammation were correlated with TNFa and VEGFa respectively, suggesting proof of concept for an epigenetic mechanism. Owing to the COVID-19 outbreak, the patient sample was limited to 15 patients.

Conclusion: It is a novelty that this study is conducted in the clinical setting. This innovative, translational study explores stress-related SLI in CD/FND patients and the feasibility of a larger project aiming to develop new treatments for this vulnerable population. Given the positive findings, there is scope to conduct further research into the mechanism of disease in CD/FND.

Keywords: Childhood adverse experiences (ACE); Conversion disorder/functional neurological disorder; Cytokines; Epigenetic mechanism; Feasibility study; Functional movement disorder; Neurocognitive symptoms; Systemic low-grade inflammation; microRNA.

The IL-17 family is structurally distinct from other cytokine subclasses. IL-17A and IL-17F, the most closely related of this family, form homodimers and an IL-17AF heterodimer. While IL-17A and IL-17F exhibit similar activities in many settings, in others their functions are divergent. To better understand the function of IL-17F in vivo, we created mice harboring a mutation in Il17f originally described in humans with unexplained chronic mucosal candidiasis (Ser-65-Leu). We evaluated Il17f^S65L/S65L mice in DSS-colitis, as this is one of the few settings where IL-17A and IL-17F exhibit opposing activities. Specifically, IL-17A is protective of the gut epithelium, a finding that was revealed when trials of anti-IL-17A biologics in Crohn's disease failed and recapitulated in many mouse models of colitis. In contrast, mice lacking IL-17F are resistant to DSS-colitis, partly attributable to alterations in intestinal microbiota that mobilize Tregs. Here we report that Il17f^S65L/S65L mice do not phenocopy Il17f^-/- mice in DSS colitis, but rather exhibited a worsening disease phenotype much like Il17a^-/- mice. Gut inflammation in Il17f^S65L/S65L mice correlated with reduced Treg accumulation and lowered intestinal levels of Clostridium cluster XIV. Unexpectedly, the protective DSS-colitis phenotype in Il17f^-/- mice could be reversed upon co-housing with Il17f^S65L/S65L mice, also correlating with Clostridium cluster XIV levels in gut. Thus, the Il17f^S65L/S65L phenotype resembles an IL-17A deficiency more closely than IL-17F deficiency in the setting of DSS colitis.

Q-VAX®, a whole cell, formalin-inactivated vaccine, is the only vaccine licensed for human use to protect against Coxiella burnetii, the cause of Q fever. Although this vaccine provides long-term protection, local and systemic reactogenic responses are common in previously sensitized individuals which prevents its use outside of Australia. Despite the importance of preventing these adverse reactions to develop widely accepted, novel vaccines against C. burnetii, little is understood about the underlying cellular mechanisms. This is mostly attributed to the use of a guinea pig reactogenicity model where complex cellular analysis is limited. To address this, we compared three different mouse strains develop a model of C. burnetii whole cell vaccine reactogenic responses. SKH1 and C57Bl/6, but not BALBc mice, develop local granulomatous reactions after either infection- or vaccine-induced sensitization. We evaluated local and systemic responses by measuring T cell populations from the vaccination site and spleen during elicitation using flow cytometry. Local reaction sites showed influx of IFNγ+ and IL17a+ CD4 T cells in sensitized mice compared with controls and a reduction in IL4+ CD4 T cells. Additionally, sensitized mice showed a systemic response to elicitation by an increase in IFNγ+ and IL17a+ CD4 T cells in the spleen. These results indicate that local and systemic C. burnetii reactogenic responses are consistent with a Th1 delayed-type hypersensitivity. Our experiments provide insights into the pathophysiology of C. burnetii whole cell vaccine reactogenicity and demonstrate that C57Bl/6 and SKH1 mice can provide a valuable model for evaluating the reactogenicity of novel C. burnetii vaccine candidates.

Keywords: Coxiella burnetii; Q fever; Th1; delayed-type hypersensitivity; mouse model; vaccine.