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Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

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Claudin-11 regulates immunological barrier formation and spermatogonial proliferation through stem cell factor

Tight junctions (TJs) between adjacent Sertoli cells are believed to form immunological barriers that protect spermatogenic cells expressing autoantigens from autoimmune responses. However, there is no direct evidence that Sertoli cell TJs (SCTJs) do indeed form immunological barriers. Here, we analyzed male mice lacking claudin-11 (Cldn11), which encodes a SCTJ component, and found autoantibodies against antigens of spermatocytes/spermatids in their sera. Defective spermatogenesis was not restored in Cldn11-deficient mice on a genetic background mimicking a severely impaired adaptive immune system. This suggests that defective spermatogenesis is not caused by autoimmune responses against spermatogenic cells. Further analyses showed that Cldn11 knockout impaired Sertoli cell polarization, localization of stem cell factor (SCF) (a key molecule for maintaining differentiating spermatogonia) to the basal compartment of seminiferous tubules, and also proliferation of differentiating spermatogonia. We propose that CLDN11 creates a microenvironment for SCF-mediated spermatogonial proliferation at the basal compartment via Sertoli cell polarization.

developmental biology↗

Neuro-immunology in a mouse model of anti-NMDAR encephalitis and assessment of treatment approaches

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a disorder mediated by autoantibodies against the GluN1 subunit of NMDAR. It occurs with severe neuropsychiatric symptoms that often improve with immunotherapy. Clinical studies and animal models based on patients antibody transfer or NMDAR immunization suggest that the autoantibodies play a major pathogenic role. Yet, there is an important need of models offering an all-inclusive neuro-immunobiology of the disease together with a clinical course long enough to facilitate the assessment of potential new treatments. Toward this end, eight-week-old female mice (C57BL/6J) were immunized (days 1 and 28) with GluN1356-385 peptide or saline with AddaVax adjuvant and pertussis toxin. After symptom development ([~]day 35), subsets of mice were treated with an anti-CD20 (day 35), a positive allosteric modulator (PAM) of NMDAR (NMDAR-PAM, SGE-301) from days 45 to 71, or both. GluN1-antibody synthesis, epitope spreading, effects of antibodies on density and function of NMDAR, brain immunological infiltrates, microglial activation and NMDAR phagocytosis, and antibody synthesis in cultured inguinal and deep cervical lymph nodes (DCLN) were assessed with techniques including immunohistochemistry, calcium imaging, confocal and super-resolution microscopy, electrophysiology, or flow cytometry. Changes of memory and behaviour were assessed with a panel of behavioural tests, and clinical/subclinical seizures with brain-implanted electrodes. Immunized mice, but not controls, developed serum and CSF NMDAR-antibodies (IgG1 predominant) against the immunizing peptide and other GluN1 regions (epitope spreading) resulting in a decrease of synaptic and extrasynaptic NMDAR clusters and reduction of hippocampal plasticity. These findings were associated with brain inflammatory infiltrates, mainly B- and plasma cells, microglial activation, colocalization of NMDAR-IgG complexes with microglia, and presence of these complexes within microglial endosomes. Cultures of DCLC showed GluN1-antibody production. These findings were associated with psychotic-like behaviour (predominant at disease onset), memory deficit, depressive-like behaviour, abnormal movements (15% of mice), and lower threshold for developing pentylenetetrazole-induced seizures (hypoactivity, myoclonic jerks, continuous tonic-clonic) which correlated with regional cFOS expression. Most symptoms and neurobiological alterations were reversed by the anti-CD20 and PAM, alone or combined. Initial repopulation of B cells, by the end of the study, was associated with re-emergence of clinical-neurobiological alterations, which were abrogated by PAM. Overall, this model offers an all-inclusive neuro-immunobiology of the disease, allowing testing novel treatments, supporting the potential therapeutic role of NMDAR-PAM, and suggesting an immunological paradigm of systemic antigen presentation and brain NMDAR epitope spreading, which along the DCLN might contribute to fine-tune the polyclonal immune response.

neuroscience↗

Literature-scaled immunological gene set annotation using AI-powered immune cell knowledge graph (ICKG)

Large scale application of single-cell and spatial omics in models and patient samples has led to the discovery of many novel gene sets, particularly those from an immunotherapeutic context. However, the biological meaning of those gene sets has been interpreted anecdotally through over-representation analysis against canonical annotation databases of limited complexity, granularity, and accuracy. Rich functional descriptions of individual genes in an immunological context exist in the literature but are not semantically summarized to perform gene set analysis. To overcome this limitation, we constructed immune cell knowledge graphs (ICKGs) by integrating over 24,000 published abstracts from recent literature using large language models (LLMs). ICKGs effectively integrate knowledge across individual, peer-reviewed studies, enabling accurate, verifiable graph-based reasoning. We validated the quality of ICKGs using functional omics data obtained independently from cytokine stimulation, CRISPR gene knock-out, and protein-protein interaction experiments. Using ICKGs, we achieved rich, holistic, and accurate annotation of immunological gene sets, including those that were unannotated by existing approaches and those that are in use for clinical applications. We created an interactive website (https://kchen-lab.github.io/immune-knowledgegraph.github.io/) to perform ICKG-based gene set annotations and visualize the supporting rationale.

bioinformatics↗

Recapitulating physiologically relevant oxygen levels and extracellular matrix remodeling in patient-derived tumor-immune tunable models reveal targeting opportunities for immunologically cold high-grade serous tumors

High-grade serous tumors are immunologically cold, characterized by limited immune cell infiltration and reduced clinical outcome, primarily due to hypoxia and extensive extracellular matrix remodeling that disrupt tumor-stromal-immune interactions. However, current experimental models fail to fully capture oxygen and matrix microenvironmental features, limiting progress in understanding tumor-immune dynamics and developing effective treatments. Here, we demonstrate that patient-derived tumor-immune tunable models, mimicking physiologically relevant oxygen levels and extracellular matrix remodeling, recapitulate the hypoxia-induced stromal/matrix dysregulation, which causes impaired immune infiltration, and enable dissecting targeted opportunities via TGF-{beta} signaling. The models integrate cancer cells co-cultured with cancer-associated fibroblasts and exposed to immune cells as multi-culture or challenged them to infiltrate into a 3D model bioengineered with autologous plasma from the matching patient or onto decellularized human ovaries. By bioengineering physiologically relevant oxygen levels of hypoxic tumors and physoxic ovaries, we uncovered that intratumoral hypoxia acts as a friend and a foe, causing hypoxia-induced stromal-driven impaired immune infiltration but enhancing the activation and cytotoxicity of CD8+ T cells. We also showed that targeting TGF-{beta} signaling reversed the hypoxia-induced stromal-driven impaired immune infiltration. These human-relevant tunable models may aid the development of targeted therapies to turn immunologically cold tumors into hot ones.

bioengineering↗

Immunological and Biochemical Profiles in Rheumatoid Arthritis: Sex-Dependent Variations and Organ Function Implications

BackgroundRheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation, primarily affecting the joints, but it can also impact multiple organ systems. The disease disproportionately affects females and is associated with immunological, hematological, hepatic, and renal alterations. Monitoring these parameters can provide insights into disease severity, treatment compliance, and sex-specific responses. MethodologyThis case-control study included 50 RA patients (30 females [60%], 20 males [40%]) and 30 healthy controls. The disease duration ranged from 1 to 28 years, with the majority (28%) having a duration between 1-4 years. Eighty percent of patients were compliant with treatment. Blood and biochemical tests were performed to evaluate inflammatory markers (ESR, CRP, IL-6, TNF-, Anti-CCP)by Eliza technique, liver enzymes (ALT, AST, ALP, TSB, albumin), renal function tests (urea, creatinine) by Specterophotometer, and trace elements (copper by Atomic Absorption Spectrophotometry (AAS), ceruloplasmin by Immunoturbidimetric assay, transferrin by Immunoturbidimetry through Roche Cobas c501/c601 device). ResultsRA patients showed significantly elevated inflammatory markers compared to controls, including Anti-CCP (Females: 32.33 {+/-} 10.85 IU/mL; Males: 31.90 {+/-} 8.55 IU/mL), IL-6 (Females: 61.90 {+/-} 12.62 ng/L; Males: 66.55 {+/-} 10.32 ng/L), and TNF- (Females: 198.80 {+/-} 50.95 ng/L; Males: 234.95 {+/-} 83.43 ng/L) (P<0.01). ESR was significantly higher in RA patients (Females: 55.53 {+/-} 33.96 mm/h; Males: 38.00 {+/-} 18.12 mm/h) versus controls. Liver function was impaired in RA patients, with increased ALT, AST, and TSB levels, and decreased albumin and ALP. Kidney function markers (urea and creatinine) were elevated in females but comparatively reduced in males. Trace elements showed high copper and ceruloplasmin levels in RA patients of both sexes compared to controls, while transferrin was notably higher in males with RA (53.90 {+/-} 11.48 ng/mL vs. 28.08 {+/-} 4.33 ng/mL in controls). ConclusionRA significantly affects immunological, hepatic, renal, and haematological profiles, with marked differences between sexes. Female patients exhibited more profound renal and lymphocytic alterations, whereas male patients showed elevated transferrin levels. These findings highlight the importance of comprehensive, sex-specific monitoring of RA patients, particularly focusing on inflammatory and organ function biomarkers, to improve disease management and patient outcomes.

microbiology↗

Inferring immunological control mechanisms from TKI dose alterations in CML patients

Recent clinical findings in chronic myeloid leukemia (CML) patients suggest that the risk of molecular recurrence after stopping tyrosine kinase inhibitors (TKI) treatment substantially depend on an individual, leukemia-specific immune response. However, it is still not possible to prospectively identify patients that will most likely remain in a long-term treatment free remission (TFR). Here, we use a mathematical model for CML, which explicitly includes an anti-leukemic (presumably immunological) effect and apply it to a set of patients (n=60) for whom BCR-ABL/ABL time courses had been quantified before and after TKI stop. We demonstrate that such a feedback control is conceptually necessary to explain long-term remission as observed in about half of the patients. Based on simulation results we classify the patient data sets into three different groups according to their predicted immune system configuration. While one class of patients requires a complete CML eradication to achieve TFR, other patients are able to control the leukemia after treatment cessation. Among them, we identified a third class of patients, which only maintains TFR if an optimal balance between leukemia abundance and immunological activation is achieved before treatment cessation. Further, we demonstrate that the immune response classification of the patients cannot be obtained solely from BCR-ABL measurements before treatment cessation. However, our results strongly suggest that changes in the BCR-ABL dynamics arising after system perturbations, such as TKI dose reduction, holds the information to predict the individual outcome after treatment cessation.

systems biology↗

Biochemical and Immunological Properties of Engineered Low-Immunogenic Staphylokinases for Next-Generation Thrombolytic Therapy

Staphylokinase (SAK) is a highly fibrin-specific plasminogen activator with significant potential as a safe and affordable thrombolytic. Yet, its clinical translation can be limited by potential immunogenicity. To accelerate the development of improved thrombolytics, a critical step is identifying the most suitable molecular template. Therefore, we performed a comparative analysis of biochemical and immunological properties of three engineered low-immunogenic variants (SAK SY155, SAK THR174, and SAK STAR FRIDA) and two wild-types (SAK STAR and SAK 42D), using a newly established panel of assays. All variants retained potent thrombolytic activity, with SAK SY155 displaying the highest catalytic efficiency and fibrin-clot permeability. However, this advantage did not fully translate into improved clot reduction under flow conditions. Comprehensive immunological profiling, including T lymphocyte proliferation, dendritic cell maturation, mouse immunization models, and human serum reactivity tests, confirmed decreased immunogenicity for two low-immunogenic variants. Overall, low-immunogenic SAK SY155 emerged as the most promising template for rational engineering of next-generation thrombolytics.

biochemistry↗

Immune Biomarkers of Islet Transplant Rejection Revealed by Synthetic Immunological Niche

Islet transplantation can restore glycemic control in type 1 diabetes, yet the heterogeneity of patient immune responses and transplant outcomes motivates the need for technologies to monitor the graft. Since transplanted islets are not readily accessible for biopsy due to their diffuse engraftment within the liver, clinical monitoring relies on measurements such as islet mass, blood glucose, and C-peptide levels, which are lagging indicators that change only after substantial graft injury. Here, we developed a minimally invasive synthetic immunological niche (IN) that captures graft-associated immune responses through serial subcutaneous biopsy. We evaluated the IN across murine syngeneic, allogeneic, and autoimmune islet transplant models, including CD40/CD154 costimulatory blockade with anti-CD40L. In syngeneic versus allogeneic recipients, IN identified immune populations and transcriptomic signatures that mirrored the graft and distinguished healthy from rejecting grafts. In anti-CD40L treated allografts, IN revealed innate macrophage- and dendritic cell-associated programs linked to graft acceptance versus rejection, whereas IN from untreated allografts showed stronger adaptive immune signatures. Longitudinal IN profiling further detected progressive inflammatory activation in accepted allografts, indicating persistent subclinical risk. Finally, in an autoimmune allograft model treated with anti-CD40L plus rapamycin, IN identified a 13-gene signature that separated early from late rejection trajectories and distinguished autoimmune-from alloimmune-associated rejection programs. Overall, these findings establish IN as a surrogate tissue for minimally invasive monitoring of islet graft and early detection of rejection-associated immune dysregulation. One Sentence SummaryAn engineered immunological niche captures distinct immune signatures of allo- and auto-mediated islet transplant rejection

bioengineering↗

Comprehensive Pan-Cancer Analysis Reveals the Prognostic, Molecular, and Immunological Significance of EPS8

Epidermal Growth Factor Receptor Pathway Substrate 8 (EPS8) is believed to function as a tumor driver; however, to understand its molecular characteristics across tumors, a comprehensive pan-cancer analysis of EPS8 is lacking. Objective: This study aimed to investigate the prognostic, molecular, and immunological significance of EPS8 across multiple human cancers. Methods: Comprehensive analyses were conducted using GEPIA2, UALCAN, TIMER2.0, cBioPortal, SMART, GSCA, Enrichr, and the TCGAplot R package to evaluate survival prognosis, gene expression, DNA methylation, immune infiltration, proteomic expression, tumor mutational burden (TMB), microsatellite instability (MSI), genetic alterations, drug sensitivity, and enriched pathways. Results: EPS8 overexpression in LGG (p=7.2x10-5) and PAAD (p=9.4x10-6) was significantly associated with poor overall survival and disease-free survival. Amplification was the most common genetic alteration, with alteration frequencies approaching 6% in TGCT and UCEC. In KIRC and PAAD, EPS8 expression correlated with tumor stage. Immune infiltration analysis revealed significant associations between EPS8 expression and immune cells. EPS8 expression also showed significant correlations with both TMB and MSI in STAD and ESCA. Enrichment analysis indicated an association between EPS8 and regulation of the actin cytoskeleton and similar pathways. Conclusion: These findings suggest that EPS8 has prognostic and immunological significance across multiple cancer types and may serve as a potential biomarker. The observed associations with immune-related features and drug response provide a basis for future experimental studies to evaluate its role in cancer biology and its potential relevance to immunotherapy.

cancer biology↗

IRNdb: The database of immunologically relevant non-coding RNAs.

MicroRNAs (miRNAs), long non-coding RNAs (lncRNAs) and other functional non-coding RNAs (ncRNAs) have emerged as pivotal regulators involved in multiple biological processes. Recently, ncRNA control of gene expression has been identified as a critical regulatory mechanism in the immune system. Despite the great efforts made to discover and characterize ncRNAs, the functional role for most remains unknown. To facilitate discoveries in ncRNA regulation of immune system-related processes we developed the database of immunologically relevant ncRNAs and target genes (IRNdb). We integrated mouse data on predicted and experimentally supported ncRNA-target interactions, ncRNA and gene annotations, biological pathways and processes, and experimental data in a uniform format with a user-friendly web interface. The current version of IRNdb documents 12,930 experimentally supported miRNA-target interactions between 724 miRNAs and 2,427 immune-related murine targets. In addition, we recorded 22,453 lncRNA-immune target and 377 PIWI-interacting RNA-immune target interactions. IRNdb is a comprehensive searchable data repository which will be of help in studying the role of ncRNAs in the immune system.\n\nDatabase URL: http://irndb.org

Immunology↗

Analysis of the immunological biomarker profile during acute Zika virus infection reveals the overexpression of CXCL10, a chemokine already linked to neuronal damage

Infection with Zika virus (ZIKV) manifests in a broad spectrum of disease ranging from mild illness to severe neurological complications. To define immunologic correlates of ZIKV infection, we characterized the levels of circulating cytokines, chemokines and growth factors in 54 infected patients of both genders, at five different time-points after symptoms onset using microbeads multiplex immunoassay; statistical analysis and data mining compared to 100 age-matched controls. ZIKV-infected patients present a striking systemic inflammatory response with high levels of pro-inflammatory mediators. Despite the strong inflammatory pattern, IL-1Ra and IL-4 are also induced during acute infection. Interestingly, the inflammatory cytokines, IL-1{beta}, IL-13, IL-17, TNF-, IFN-{gamma}; chemokines, CXCL8, CCL2, CCL5; and the growth factor G-CSF display a bimodal distribution accompanying viremia. While this is the first manuscript to document bimodal distributions of viremia in ZIKV infection, bimodal viremia has been documented in other viral infections with primary viremia peaks during mild systemic disease and a secondary viremia with distribution of the virus to organs and tissues. Moreover, biomarker network analysis demonstrated distinct dynamics in consonance with the bimodal viremia profiles at different time-points during ZIKV infection. Such robust cytokine and chemokine response has been associated with blood-brain barrier permeability and neuroinvasiveness in other flaviviral infections. High-dimensional data analysis further established CXCL10, a chemokine involved in fetal neuron apoptosis and Guillain-Barre syndrome, as the most promising biomarker of acute ZIKV infection for a potential clinical application.\n\nAuthor SummaryInfection with Zika virus manifests in a broad spectrum of disease ranging from mild illness to severe neurological complications. This study characterized the levels of circulating cytokines, chemokines and growth factors in Zika-infected patients showing an inflammatory immune response. Specifically, this study identified a chemokine, CXCL10, known to be involved in fetal neuron apoptosis and Guillain-Barre syndrome, as the most promising biomarker to characterize acute Zika virus infection.

immunology↗

Immunologic perturbations in severe COVID-19/SARS-CoV-2 infection

Although critical illness has been associated with SARS-CoV-2-induced hyperinflammation, the immune correlates of severe COVID-19 remain unclear. Here, we comprehensively analyzed peripheral blood immune perturbations in 42 SARS-CoV-2 infected and recovered individuals. We identified broad changes in neutrophils, NK cells, and monocytes during severe COVID-19, suggesting excessive mobilization of innate lineages. We found marked activation within T and B cells, highly oligoclonal B cell populations, profound plasmablast expansion, and SARS-CoV-2-specific antibodies in many, but not all, severe COVID-19 cases. Despite this heterogeneity, we found selective clustering of severe COVID-19 cases through unbiased analysis of the aggregated immunological phenotypes. Our findings demonstrate broad immune perturbations spanning both innate and adaptive leukocytes that distinguish dysregulated host responses in severe SARS-CoV-2 infection and warrant therapeutic investigation. One Sentence SummaryBroad immune perturbations in severe COVID-19

immunology↗

IMMUNOLOGICAL INVESTIGATIONS OF HHV-6 U12 AND U51 ENCODED PROTEINS INVOLVEMENT IN AUTOIMMUNE THYROIDITIS DEVELOPMENT

Human herpesvirus 6 (HHV-6) is a human pathogen with a wide cell tropism and many immunomodulating properties. HHV-6 has been linked to the development of multiple diseases, among them - autoimmune. Conflicting evidence implicates HHV-6 in autoimmune thyroiditis (AIT). HHV-6 contains two genes (U12 and U51) that encode putative homologues of human G-protein-coupled receptors (GPCR) like CCR1, CCR3 and CCR5. It has been shown that proteins encoded by HHV-6 U12 and U51 genes can be expressed on the surface of epithelial and some peripheral blood mononuclear cells populations, which makes them a potential cause for evoking autoimmunity. The aim of this study was to identify potentially immunogenic synthetic peptides derived from HHV-6 U12 and U51 amino acid sequences and to find evidences of the possible involvement of these proteins in AIT development. 62 AIT patients positive for HHV-6 infection were enrolled in this study. 30 different synthetic peptides designed from HHV-6 U12 and U51 proteins amino acid sequences, as well as, recombinant human CCR1, CCR3 and CCR5 proteins were used for suspension multiplex immunological assay (SMIA) to detect specific IgG, and IgM antibodies. HHV-6 peptide specific IgG and IgM antibodies were found in patients samples, with higher signals for IgM antibodies, which is indicative of reactivation and active HHV-6 infection. As well recombinant CCR1 and CCR5 showed high signals on IgM antibodies which is indicating on the presence of potential auto-antibodies against human G protein-coupled receptors. No cross reactivity between HHV-6 peptide specific antibodies and human recombinant CCR1, CCR3 and CCR5 was found, however, the possibility of cross-reactive autoantibodies specific for structural epitopes cannot be excluded.

immunology↗

Immunologically distinct responses occur in the CNS of COVID-19 patients

One third of COVID-19 patients develop significant neurological symptoms, yet SARS-CoV-2 is rarely detected in central nervous system (CNS) tissue, suggesting a potential role for parainfectious processes, including neuroimmune responses. We therefore examined immune parameters in cerebrospinal fluid (CSF) and blood samples from a cohort of patients with COVID-19 and significant neurological complications. We found divergent immunological responses in the CNS compartment, including increased levels of IL-12 and IL-12-associated innate and adaptive immune cell activation. Moreover, we found increased proportions of B cells in the CSF relative to the periphery and evidence of clonal expansion of CSF B cells, suggesting a divergent intrathecal humoral response to SARS-CoV-2. Indeed, all COVID-19 cases examined had anti-SARS-CoV-2 IgG antibodies in the CSF whose target epitopes diverged from serum antibodies. We directly examined whether CSF resident antibodies target self-antigens and found a significant burden of CNS autoimmunity, with the CSF from most patients recognizing neural self-antigens. Finally, we produced a panel of monoclonal antibodies from patients CSF and show that these target both anti-viral and anti-neural antigens--including one mAb specific for the spike protein that also recognizes neural tissue. This exploratory immune survey reveals evidence of a compartmentalized and self-reactive immune response in the CNS meriting a more systematic evaluation of neurologically impaired COVID-19 patients. One Sentence SummaryA subset of COVID-19 patients with neurologic impairment show cerebrospinal fluid-specific immune alterations that point to both neuroinvasion and anti-neural autoimmunity as potential causes of impairment.

immunology↗

Effects of relocation on Immunological and physiological measures in squirrel monkeys ( Saimiri boliviensis boliviensis)

In the present study, we have quantified the effects of transport, relocation and acclimate/adapt to their new surroundings on squirrel monkey. These responses are measured in blood samples obtained from squirrel monkeys, at different time points relative to their relocation from their old home to their new home. A variety of immunological assays are performed on the phenotype and function of peripheral blood mononuclear cells (PBMCs) in a group of squirrel monkeys that were transported by road for approximately 10 hours from one facility to another. Using a panel of human antibodies and a set of standardized human immune assays, we evaluated the phenotype of lymphocyte subsets by flow, mitogen-specific immune responses of PBMCs in vitro, and levels of cytokines at various time points including immediately before transport, immediately upon arrival, and after approximately 150 days of acclimation. We observed significant changes in T cells and subsets, NK and B cells (CD4+, CD8+, CD4+/CD8+, CD16+, and CD20+). Mitogen specific (e.g. PHA, PWM and LPS) proliferation responses, IFN-g by ELISPOT assay, and cytokines (IL-2, IL-4 and VEGF) significant changes were observed. Changes seen in the serum chemistry measurements mostly complement those seen in the hematology data. The specific goal was to empirically assess the effects of relocation stress in squirrel monkeys in terms of changes in the numbers and functions of various leukocyte subsets in the blood and the amount of time require for acclimating to their new environment. Such data will help to determine when newly arrived animals become available for use in research studies.

immunology↗

IL-27R signaling serves as immunological checkpoint for NK cells to promote hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common form of liver cancer with poor survival and limited therapeutic options. HCC has different etiologies, typically associated with viral or carcinogenic insults or fatty liver disease and underlying chronic inflammation presents as a major unifying mechanism for tumor promotion. On the other hand, mechanisms of how inflammatory response can regulate anti-cancer immunity in HCC remain incompletely understood. Interleukin (IL)-27 receptor signaling plays an anti-inflammatory role in a variety of infectious and chronic inflammatory diseases. Here, using genetic and pharmacological approaches we found that IL-27 receptor (IL-27R) signaling promotes HCC development in vivo. Genetic loss of IL-27R suppressed HCC development in both toxin/carcinogen-induced diethylnitrosamine (DEN) and non-alcoholic steatohepatitis (NASH)-driven models. Elevated expression of IL-27RA rendered poor prognosis to HCC patients. Mechanistically, the pro-tumorigenic effect was mediated by immunoregulatory role of IL-27R signaling within the tumor microenvironment, particularly the suppression of Natural killer (NK) cells. IL-27R ablation enhanced the accumulation and activation of cytotoxic NK cells during acute liver injury and in HCC tumors, while depletion of NK cells abrogated the effect of genetic IL-27R disruption. Taken together, our data suggest an unexpected role of IL-27R signaling as a novel immunological checkpoint regulating NK cell activity and promoting development of HCC of different etiologies.

immunology↗

The Immunological Factors Predisposing To Severe COVID-19 Are Already Present In Healthy Elderly And Men

BackgroundMale sex and old age are risk factors for COVID-19 severity, but the underlying causes are unknown. A possible explanation for this might be the differences in immunological profiles in males and the elderly before the infection. Given the seasonal profile of COVID-19, the seasonal response against SARS-CoV-2 could also be different in these groups. MethodsThe abundance of circulating proteins and immune populations associated with severe COVID-19 was analyzed in 2 healthy cohorts. PBMCs of female, male, young, and old subjects in different seasons of the year were stimulated with heat-inactivated SARS-CoV-2. ResultSeveral T cell subsets, which are known to be depleted in severe COVID-19 patients, were intrinsically less abundant in men and older individuals. Plasma proteins increasing with disease severity, including HGF, IL-8, and MCP-1, were more abundant in the elderly and males. The elderly produced significantly more IL-1RA and had a dysregulated IFN{gamma} response with lower production in the summer compared with young individuals. ConclusionsThe immune characteristics of severe COVID-19, described by a differential abundance of immune cells and circulating inflammatory proteins, are intrinsically present in healthy men and the elderly. This might explain the susceptibility of men and the elderly to SARS-CoV-2 infection. SummaryImmunological profile of severe COVID-19, characterized by altered immune cell populations and inflammatory plasma proteins is intrinsically present in healthy men and the elderly. Different age and sex groups show distinct seasonal responses to SARS-CoV-2.

immunology↗

The legacy of maternal SARS-CoV-2 infection on the immunology of the neonate

Despite extensive and ongoing studies of SARS-CoV-2 and evidence that pregnant women are at increased risk of severe COVID-19, the effect of maternal infection on the developing infant remains unclear. To determine the potential impact of exposure to SARS-CoV-2 in utero on the neonate, we have assessed the immunological status of infants born to mothers with confirmed SARS-CoV-2 infection during gestation. No evidence of vertical transmission of SARS-CoV-2 was observed, but transfer of maternal SARS-CoV-2 specific IgG to infants was apparent, although to a lesser extent in cases of active or recent maternal infection. Infants born to mothers with recent/ongoing infection had elevated circulating pro-inflammatory cytokines and enhanced percentages of innate immune cells compared to that seen in infants born to uninfected mothers. In tandem, higher frequencies of FOXP3+ regulatory T cells and circulating IL-10 demonstrated a further nuance to the neonatal effector response. Interestingly, cytokine functionality was enhanced in infants born to mothers exposed to SARS-CoV-2 at any time during pregnancy. This indicates that maternal SARS-CoV-2 infection influences in utero priming of the fetal immune system.

immunology↗