Regulation of innate and adaptive immunity by the female sex hormones oestradiol and progesterone

Disturbed sex hormone milieu in males and females with major depressive disorder and low-grade inflammation

Sex hormones have biological effects on inflammation, and these might contribute to the sex-specific features of depression. C-reactive protein (CRP) is the most widely used inflammatory biomarker and consistent evidence shows a significant proportion (20-30 %) of patients with major depressive disorder (MDD) have CRP levels above 3 mg/L, a threshold indicating at least low-grade inflammation. Here, we investigate the interplay between sex hormones and CRP in the cross-sectional, observational Biomarkers in Depression Study. We measured serum high-sensitivity (hs-)CRP, in 64 healthy controls and 178 MDD patients, subdivided into those with hs-CRP below 3 mg/L (low-CRP; 53 males, 72 females) and with hs-CRP above 3 mg/L (high-CRP; 19 males, 34 females). We also measured interleukin-6, testosterone, 17-β-estradiol (E2), progesterone, sex-hormone binding globulin (SHBG), follicle-stimulating and luteinising hormones, and calculated testosterone-to-E2 ratio (T/E2), free androgen and estradiol indexes (FAI, FEI), and testosterone secretion index. In males, high-CRP patients had lower testosterone than controls (p = 0.001), and lower testosterone (p = 0.013), T/E2 (p < 0.001), and higher FEI (p = 0.015) than low-CRP patients. In females, high-CRP patients showed lower SHGB levels than controls (p = 0.033) and low-CRP patients (p = 0.034). The differences in testosterone, T/E2 ratio, and FEI levels in males survived the Benjamini-Hochberg FDR correction. In linear regression analyses, testosterone (β = -1.069 p = 0.033) predicted CRP concentrations (R2 = 0.252 p = 0.002) in male patients, and SHBG predicted CRP levels (β = -0.628 p = 0.009, R2 = 0.172 p = 0.003) in female patients. These findings may guide future research investigating interactions between gonadal and immune systems in depression, and the potential of hormonal therapies in MDD with inflammation.

Characterization and expression profiling of buffalo IFN-lambda family

Interferon lambda (IFN-λ) is an important type III interferon triggered mainly by viral infection. IFN-λ binds to their heterodimeric receptors and signals through JAK-STAT pathways similar to type I IFN. In this study, we deduced the buffalo IFN-λ sequences through the polymerase chain reaction, and then studied IFN-λ's expression patterns in different tissues, and post induction with poly I:C and live MRSA using RT-qPCR. The full-length sequences of buffalo IFN-λ3, IFN-λ receptors, and a transcript variant of IFN-λ4 were determined. IFN-λ1 is identified as a pseudogene. Virus response elements and a recombination hotspot factor was observed in the regulatory region of IFN-λ. The IFN-λ3 expressed highest in lungs and monocytes but IFN-λ4 did not. The expression of Interferon Lambda Receptor 1 was tissue specific, while Interleukin 10 Receptor subunit beta was ubiquitous. Following poly I:C induction, IFN-λ3 expression was primarily observed in epithelial cells as opposed to fibroblasts, displaying cell type-dependent expression. The cytosolic RNA sensors were expressed highest in endometrial epithelial cells, whereas the endosomal receptor was higher in fibroblasts. 2',5'-oligoadenylate synthetase expressed higher in fibroblasts, myxoma resistance protein 1 and IFN-stimulated gene 56 in epithelial cells, displaying cell-specific antiviral response of the interferon stimulated genes (ISGs). The endometrial epithelial cells expressed IFN-λ3 after live S. aureus infection indicating its importance in bacterial infection. The induction of IFN-λ3 was S. aureus isolate specific at the same multiplicity of infection (MOI). This study elucidates the IFN-λ sequences, diverse expression patterns revealing tissue specificity, and specificity in response to poly I:C and bacterial stimuli, emphasising its crucial role in innate immune response modulation.

Impact of the host immune response on the development of equine herpesvirus myeloencephalopathy in horses

Herpesviruses establish a well-adapted balance with their host's immune system. Despite this co-evolutionary balance, infections can lead to severe disease including neurological disorders in their natural host. In horses, equine herpesvirus 1 (EHV-1) causes respiratory disease, abortions, neonatal foal death and myeloencephalopathy (EHM) in ~10 % of acute infections worldwide. Many aspects of EHM pathogenesis and protection from EHM are still poorly understood. However, it has been shown that the incidence of EHM increases to >70 % in female horses >20 years of age. In this study we used old mares as an experimental equine EHV-1 model of EHM to identify host-specific factors contributing to EHM. Following experimental infection with the neuropathogenic strain EHV-1 Ab4, old mares and yearling horses were studied for 21 days post-infection. Nasal viral shedding and cell-associated viremia were assessed by quantitative PCR. Cytokine/chemokine responses were evaluated in nasal secretions and cerebrospinal fluid (CSF) by Luminex assay and in whole blood by quantitative real-time PCR. EHV-1-specific IgG sub-isotype responses were measured by ELISA. All young horses developed respiratory disease and a bi-phasic fever post-infection, but only 1/9 horses exhibited ataxia. In contrast, respiratory disease was absent in old mares, but all old mares developed EHM that resulted in euthanasia in 6/9 old mares. Old mares also presented significantly decreased nasal viral shedding but higher viremia coinciding with a single fever peak at the onset of viremia. According to clinical disease manifestation, horses were sorted into an EHM group (nine old horses and one young horse) and a non-EHM group (eight young horses) for assessment of host immune responses. Non-EHM horses showed an early upregulation of IFN-α (nasal secretions), IRF7/IRF9, IL-1β, CXCL10 and TBET (blood) in addition to an IFN-γ upregulation during viremia (blood). In contrast, IFN-α levels in nasal secretions of EHM horses were low and peak levels of IRF7, IRF9, CXCL10 and TGF-β (blood) coincided with viremia. Moreover, EHM horses showed significantly higher IL-10 levels in nasal secretions, peripheral blood mononuclear cells and CSF and higher serum IgG3/5 antibody titres compared to non-EHM horses. These results suggest that protection from EHM depends on timely induction of type 1 IFN and upregulation cytokines and chemokines that are representative of cellular immunity. In contrast, induction of regulatory or TH-2 type immunity appeared to correlate with an increased risk for EHM. It is likely that future vaccine development for protection from EHM must target shifting this 'at-risk' immunophenotype.

The foreign body response: emerging cell types and considerations for targeted therapeutics

The foreign body response (FBR) remains a clinical challenge in the field of biomaterials due to its ability to elicit a chronic and sustained immune response. Modulating the immune response to materials is a modern paradigm in tissue engineering to enhance repair while limiting fibrous encapsulation and implant isolation. Though the classical mediators of the FBR are well-characterized, recent studies highlight that our understanding of the cell types that shape the FBR may be incomplete. In this review, we discuss the emerging role of T cells, stromal-immune cell interactions, and senescent cells in the biomaterial response, particularly to synthetic materials. We emphasize future studies that will deepen the field's understanding of these cell types in the FBR, with the goal of identifying therapeutic targets that will improve implant integration. Finally, we briefly review several considerations that may influence our understanding of the FBR in humans, including rodent models, aging, gut microbiota, and sex differences. A better understanding of the heterogeneous host cell response during the FBR can enable the design and development of immunomodulatory materials that favor healing.

Incidence and Outcomes Associated with Menopausal Status in COVID-19 Patients: A Systematic Review and Meta-analysis

OBJECTIVE

 Menopause causes several changes in the body that may affect the response to COVID -19. We aimed to investigate the possible association between menopausal status and incidence and outcomes in COVID-19 patients.

METHODS

 Combinations of keywordsCOVID-19, menopause, and estrogen were used to search the PubMed, Embase, Web-of-Science, and Scopus databases for articles reporting the incidence and outcomes of COVID-19 (discharge, length-of-admission, intensive care, or mortality) in premenopausal women, available through December 29, 2022. Data from studies comparing the incidence of COVID-19 infection with the age-matched male population were pooled and meta-analyzed using a random-effects model.

RESULTS

 Overall, 1,564 studies were retrieved, of which 12 were finally included in the systematic review to compare disease outcomes, and 6 were meta-analyzed for the incidence of COVID-19 in premenopausal and postmenopausal women. All studies reported better COVID-19-associated outcomes in premenopausal women compared with postmenopausal women. After adjusting for confounding factors, three studies found better outcomes in postmenopausal women, and two found no association between menopausal status and COVID-19 outcomes. Our meta-analysis found a higher incidence of COVID-19 infection among premenopausal women than postmenopausal women, when compared with age-matched men (odds ratio = 1.270; 95% confidence interval: 1.086-1.486; p = 0.003).

CONCLUSION

 The incidence of COVID-19 was significantly higher in premenopausal women than in postmenopausal women when compared with age-matched men. Although premenopausal women may have more favorable COVID-19-associated outcomes, the presumed preventive effect of estrogens on the incidence and related outcomes of COVID-19 in premenopausal women cannot be proven at present. Further longitudinal studies comparing pre- and post-menopausal women are required to provide further insight into this matter.

New insights on the potential effect of progesterone in Covid-19: Anti-inflammatory and immunosuppressive effects

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a pandemic disease caused by severe acute respiratory syndrome CoV type 2 (SARS-CoV-2). COVID-19 is higher in men than women and sex hormones have immune-modulator effects during different viral infections, including SARS-CoV-2 infection. One of the essential sex hormones is progesterone (P4).

AIMS

This review aimed to reveal the association between P4 and Covid-19.

RESULTS AND DISCUSSION

The possible role of P4 in COVID-19 could be beneficial through the modulation of inflammatory signaling pathways, induction of the release of anti-inflammatory cytokines, and inhibition release of pro-inflammatory cytokines. P4 stimulates skew of naïve T cells from inflammatory Th1 toward anti-inflammatory Th2 with activation release of anti-inflammatory cytokines, and activation of regulatory T cells (Treg) with decreased interferon-gamma production that increased during SARS-CoV-2 infection. In addition, P4 is regarded as a potent antagonist of mineralocorticoid receptor (MR), it could reduce MRs that were activated by stimulated aldosterone from high AngII during SARS-CoV-2. P4 active metabolite allopregnanolone is regarded as a neurosteroid that acts as a positive modulator of γ-aminobutyric acid (GABAA ) so it may reduce neuropsychiatric manifestations and dysautonomia in COVID-19 patients.

CONCLUSION

Taken together, the anti-inflammatory and immunomodulatory properties of P4 may improve central and peripheral complications in COVID-19.

Maternal immunization with distinct influenza vaccine platforms elicits unique antibody profiles that impact the protection of offspring

Pregnant women and infants are considered high-risk groups for increased influenza disease severity. While influenza virus vaccines are recommended during pregnancy, infants cannot be vaccinated until at least six months of age. Passive transfer of maternal antibodies (matAbs) becomes vital for the infant's protection. Here, we employed an ultrasound-based timed-pregnancy murine model and examined matAb responses to distinct influenza vaccine platforms and influenza A virus (IAV) infection in dams and their offspring. We demonstrate vaccinating dams with a live-attenuated influenza virus (LAIV) vaccine or recombinant hemagglutinin (rHA) proteins administered with adjuvant resulted in enhanced and long-lasting immunity and protection from influenza in offspring. In contrast, a trivalent split-inactivated vaccine (TIV) afforded limited protection in our model. By cross-fostering pups, we show the timing of antibody transfer from vaccinated dams to their offspring (prenatal versus postnatal) can shape the antibody profile depending on the vaccine platform. Our studies provide information on how distinct influenza vaccines lead to immunogenicity and efficacy during pregnancy, impact the protection of their offspring, and detail roles for IgG1 and IgG2c in the development of vaccine administration during pregnancy that stimulate and measure expression of both antibody subclasses.

Lupus and recurrent pregnancy loss: the role of female sex hormones and B cells

Systemic lupus erythematosus is a debilitating autoimmune disease characterized by uncontrolled activation of adaptive immunity, particularly B cells, which predominantly affects women in a 9 to 1 ratio compared to men. This stark sex disparity strongly suggests a role for female sex hormones in the disease's onset and progression. Indeed, it is widely recognized that estradiol not only enhances the survival of autoreactive B cells but also stimulates the production of autoantibodies associated with systemic lupus erythematosus, such as anti-nuclear antibodies and anti-dsDNA antibodies. Clinical manifestations of systemic lupus erythematosus typically emerge after puberty and persist throughout reproductive life. Furthermore, symptoms often exacerbate during the premenstrual period and pregnancy, as increased levels of estradiol can contribute to disease flares. Despite being fertile, women with lupus face a heightened risk of pregnancy-related complications, including pregnancy loss and stillbirth, which significantly surpass the rates observed in the healthy population. Therefore, this review aims to summarize and discuss the existing literature on the influence of female sex hormones on B-cell activation in patients with systemic lupus erythematosus, with a particular emphasis on their impact on pregnancy loss.

The best of both worlds: no apparent trade-off between immunity and reproduction in two group-living African mole-rat species

Co-operatively breeding mammals often exhibit a female reproductive skew and suppression of the subordinate non-breeding group members. According to evolutionary theory and the immunity-fertility axis, an inverse relationship between reproductive investment and survival (through immunocompetence) is expected. As such, this study investigated if a trade-off between immunocompetence and reproduction arises in two co-operatively breeding African mole-rat species, namely the Damaraland mole-rat (Fukomys damarensis) and common mole-rat (Cryptomys hottentotus hottentotus), which possess female reproductive division of labour. This study also attempted to investigate the relationship between the immune and endocrine systems in Damaraland mole-rats. There was no trade-off between reproduction and immunocompetence in co-operatively breeding African mole-rat species, and in the case of the Damaraland mole-rats, breeding females (BFs) possessed increased immunocompetence compared with non-breeding females (NBFs). Furthermore, the increased levels of progesterone possessed by Damaraland mole-rat BFs compared with NBFs appear to be correlated to increased immunocompetence. In comparison, BF and NBF common mole-rats possess similar immunocompetence. The species-specific differences in the immunity-fertility axis may be due to variations in the strengths of reproductive suppression in each species. This article is part of the theme issue 'Evolutionary ecology of inequality'.

Use of intravaginal lactic acid bacteria prepartum as an approach for preventing uterine disease and its association with fertility of lactating dairy cows

The objective of this study was to evaluate the effects of the use of intravaginal probiotics prepartum on the incidence risk of metritis postpartum and conception risk after first artificial insemination (AI). A total of 606 Holstein cows were enrolled 3 wk before their expected calving date from 2 farms. Cows were randomly assigned to either receive a 2-mL dose of a combination of 3 lactic acid bacteria (probiotic treatment) washed with approximately 2 mL of a sterile saline solution, into the vaginal canal twice weekly until parturition, or no intervention (control). Metritis diagnoses were carried out on 6 and 12 d postpartum. Vaginal discharge and rectal temperature were assessed, and vaginal discharge was scored on a scale from 1 to 4, where 1 = clear and 4 = fetid, purulent discharge. Metritis was defined as cows having a vaginal discharge score of 4 with or without fever (rectal temperature ≥39.5°C) on either 6 or 12 d postpartum, or both. Cows were bred after a 60-d voluntary waiting period primarily via the detection of estrus using automated activity monitors; cows not found in estrus were enrolled onto timed AI protocols to receive first breeding before 100 DIM. Pregnancy diagnosis was carried out at d 35 ± 7 post-AI on both farms. Data were analyzed via ANOVA using linear mixed regression models and survival analysis using a Cox proportional hazard model. Total incidence risk of metritis was 23.7% and 34.4% on farm A and farm B, respectively. Overall, the incidence of metritis was not different between treatment groups (control: 41.6 ± 3.8%; probiotic: 38.6 ± 4.0%); however, an interaction by farm was detected, where the probiotic treatment reduced metritis on one farm but not on the other. Conception risk after first AI was not affected by treatment. However, we detected an interaction between parity and treatment, where multiparous cows receiving the probiotic treatment were more likely to become pregnant compared with multiparous cows within the control group (hazard ratio: 1.33; 95% confidence interval: 1.10-1.60); no effect of probiotic treatment was found on the hazard of pregnancy for primiparous cows. In addition, the probiotic treatment was associated with an increased proportion of cows being detected in estrus for the first AI postpartum. In conclusion, vaginal probiotic treatment applied during the 3 wk prepartum was associated with a decreased incidence of metritis on one farm but not the other, suggesting that farm management may be a key player influencing treatment efficacy. Overall, probiotic treatment was found to have only limited effects on fertility in the current study.

Immune checkpoint inhibitor-induced hepatitis injury: risk factors, outcomes, and impact on survival

PURPOSE

Immune checkpoint inhibitors (ICIs) are associated with a unique set of immune-related adverse events (irAEs). Few studies have evaluated the risk factors and outcomes of patients who develop ICI-induced hepatitis (ICIH).

METHODS

We utilized an institutional database of patients with advanced cancers treated with ICI to identify patients with ICIH. irAEs were graded using the Common Terminology Criteria for Adverse Events v4. Overall survival (OS) was calculated from the date of ICI to death from any cause or the date of the last follow-up. OS with 95% confidence intervals were estimated using the Kaplan-Meier method and stratified by the occurrence of ICIH.

RESULTS

We identified 1096 patients treated with ICI. The most common ICIs were PD1/L1 (n = 774) and CTLA-4 inhibitors (n = 195). ICIH occurred among 64 (6%) patients: severity was < grade 3 in 30 and ≥ grade 3 in 24 patients (3.1% overall). Median time to ICIH was 63 days. ICIH was more frequent in women (p = 0.038), in patients treated with combination ICIs (p < 0.001), and when given as first-line therapy (p = 0.018). Occurrence of ICIH was associated with significantly longer OS, median 37.0 months (95% CI 21.4, NR) compared to 11.3 months (95% CI 10, 13, p < 0.001); there was no difference in OS between patients with ≥ grade 3 ICIH vs grade 1-2.

CONCLUSIONS

Female sex, combination immunotherapy, and the first line of immunotherapy were associated with ICIH. Patients with ICIH had improved clinical survival compared to those that did not develop ICIH. There is a need for prospective further studies to confirm our findings.

The effect of chronic stress on behaviors, inflammation and lymphocyte subtypes in male and female rats

Excessively released proinflammatory mediators from activated macrophages and lymphocytes may contribute to the etiology of depression. However, the relationship between lymphocytes and depression is not fully understood. Although women have higher depression risk than men, sex/gender differences in psychoneuroimmunological mechanisms are still unclear. To explore these two questions, chronic unpredictable mild stress (CUMS) was used to evaluate the changes in behaviors, inflammation and lymphocyte subtypes in adult male and female Wistar rats. Results show that CUMS increased anhedonia and anxiety-like behaviors, along with increased serum corticosterone, hippocampal pro-inflammatory factors, CD11b, IFN-γ, IL-6 and IL-17, but decreased CD4, CD25, CD4/CD8 ratio, GFAP, 5-hydroxytryptamine (5-HT) and NE concentrations, regardless of sex. There was no positive correlation between sucrose preference and blood CD4/CD8 ratio, but a positive correlation between sucrose preference and spleen CD25, sucrose preference and neurotransmitters (NE and 5-HT), spleen CD25 and serum TGF-β1/IL-6 ratio were found, regardless of sex. Females presented higher basal locomotion, blood CD4, CD4/CD8 ratio, serum corticosteroid and IL-6 concentrations, but lower hippocampal norepinephrine (NE) than males. Although CUMS didn't induce significant sex differences, females presented more changes in CD4 and CD8 lymphocytes than male rats. CUMS caused abnormalities in corticosteroid, lymphocytes, cytokines and neurotransmitters, which might be the precursors for inducing depression-like behaviors in both sexes.

The Role of NF-κB in Endometrial Diseases in Humans and Animals: A Review

The expression of genes of various proinflammatory chemokines and cytokines is controlled, among others, by the signaling pathway of the nuclear factor kappaB (NF-κB) superfamily of proteins, providing an impact on immune system functioning. The present review addresses the influence and role of the NF-κB pathway in the development and progression of most vital endometrial diseases in human and animal species. Immune modulation by NF-κB in endometritis, endometrosis, endometriosis, and carcinoma results in changes in cell migration, proliferation, and inflammation intensity in both the stroma and epithelium. In endometrial cells, the NF-κB signaling pathway may be activated by multiple stimuli, such as bacterial parts, cytokines, or hormones binding to specific receptors. The dysregulation of the immune system in response to NF-κB involves aberrant production of chemokines and cytokines, which plays a role in endometritis, endometriosis, endometrosis, and endometrial carcinoma. However, estrogen and progesterone influence on the reproductive tract always plays a major role in its regulation. Thus, sex hormones cannot be overlooked in endometrial disease physiopathology. While immune system dysregulation seems to be NF-κB-dependent, the hormone-independent and hormone-dependent regulation of NF-κB signaling in the endometrium should be considered in future studies. Future goals in this research should be a step up into clinical trials with compounds affecting NF-κB as treatment for endometrial diseases.

Potential Therapeutic Effects of Human Amniotic Epithelial Cells on Gynecological Disorders Leading to Infertility or Abortion

The induction of feto-maternal tolerance, fetal non-immunogenicity, and the regulation of mother's immune system are essential variables in a successful pregnancy. Fetal membranes have been used as a source of stem cells and biological components in recent decades. Human amniotic epithelial cells (hAEC) have stem/progenitor characteristics like those found in the amniotic membrane. Based on their immunomodulatory capabilities, recent studies have focused on the experimental and therapeutic applications of hAECs in allograft transplantation, autoimmune disorders, and gynecological problems such as recurrent spontaneous abortion (RSA), recurrent implantation failure (RIF), and premature ovarian failure (POF). This review discusses some of the immunomodulatory features and therapeutic potential of hAECs in preventing infertility, miscarriage, and implantation failure by controlling the maternal immune system.

Polycystic Ovary Syndrome, Subclinical Hypothyroidism, the Cut-Off Value of Thyroid Stimulating Hormone; Is There a Link? Findings of a Population-Based Study

Despite solid evidence regarding the association of over-hypothyroidism with polycystic ovary syndrome (PCOS), the relationship between PCOS and subclinical hypothyroidism (SCH) is still a topic of debate. In the present population-based study, we aimed to assess if there is a difference between PCOS and the control group regarding the upper reference limit of thyroid stimulating hormone (TSH). We also aimed to identify the prevalence of SCH in women with PCOS compared to controls. This study was conducted on data collected in the Iranian PCOS prevalence study and the Khuzestan PCOS prevalence study. Participants that met our eligibility criteria were categorized into two groups: PCOS (n = 207) and control (n = 644). Quantile and logistic regression models were used to explore the effect of PCOS status on TSH cut-off values and SCH, respectively. The 95 percentiles of TSH were not significantly different in the PCOS group compared to control ones (6.12 and 6.56 microU/mL, respectively). There was no statistically significant association between PCOS status and SCH (OR adjusted: 1.40; 95%CI: 0.79, 2.50; p = 0.2). The prevalence of SCH and the upper reference limit of TSH were not significantly different in PCOS and controls. Investigation of SCH in women with PCOS might be questionable.

Immune regulation based on sex differences in ischemic stroke pathology

Ischemic stroke is one of the world's leading causes of death and disability. It has been established that gender differences in stroke outcomes prevail, and the immune response after stroke is an important factor affecting patient outcomes. However, gender disparities lead to different immune metabolic tendencies closely related to immune regulation after stroke. The present review provides a comprehensive overview of the role and mechanism of immune regulation based on sex differences in ischemic stroke pathology.

Steroid hormone catabolites activate the pyrin inflammasome through a non-canonical mechanism

The pyrin inflammasome acts as a guard of RhoA GTPases and is central to immune defenses against RhoA-manipulating pathogens. Pyrin activation proceeds in two steps. Yet, the second step is still poorly understood. Using cells constitutively activated for the pyrin step 1, a chemical screen identifies etiocholanolone and pregnanolone, two catabolites of testosterone and progesterone, acting at low concentrations as specific step 2 activators. High concentrations of these metabolites fully and rapidly activate pyrin, in a human specific, B30.2 domain-dependent manner and without inhibiting RhoA. Mutations in MEFV, encoding pyrin, cause two distinct autoinflammatory diseases pyrin-associated autoinflammation with neutrophilic dermatosis (PAAND) and familial Mediterranean fever (FMF). Monocytes from PAAND patients, and to a lower extent from FMF patients, display increased responses to these metabolites. This study identifies an unconventional pyrin activation mechanism, indicates that endogenous steroid catabolites can drive autoinflammation, through the pyrin inflammasome, and explains the “steroid fever” described in the late 1950s upon steroid injection in humans.

Magnotti et al. use a chemical screen to identify pyrin inflammasome activators acting primarily on pyrin step 2. Pregnanolone and etiocholanolone, two catabolites of progesterone and testosterone, activate human pyrin in a B30.2-dependent manner. Pyrin-mutated PAAND patients are highly responsive to pregnanolone. These endogenous catabolites could contribute to sterile (auto)inflammation.

On maternity and the stronger immune response in women

Medical research reports that women often exhibit stronger immune responses than men, while pathogens tend to be more virulent in men. Current explanations cannot account for this pattern, creating an obstacle for our understanding of infectious-disease outcomes and the incidence of autoimmune diseases. We offer an alternative explanation that relies on a fundamental difference between the sexes: maternity and the opportunities it creates for transmission of pathogens from mother to child (vertical transmission). Our explanation relies on a mathematical model of the co-evolution of host immunocompetence and pathogen virulence. Here, we show that when there is sufficient vertical transmission co-evolution leads women to defend strongly against temperate pathogens and men to defend weakly against aggressive pathogens, in keeping with medical observations. From a more applied perspective, we argue that limiting vertical transmission of infections would alleviate the disproportionate incidence of autoimmune diseases in women over evolutionary time.

Women generally mount a stronger immune response to infections than men do, resulting in a higher impact of autoimmune diseases. Here, the authors show that pathogen transmission from mother-to-child during pregnancy drives the co-evolution of a stout defence against harmless pathogens in women.

Sex hormones and immune system: Menopausal hormone therapy in the context of COVID-19 pandemic

The fatal outcomes of COVID-19 are related to the high reactivity of the innate wing of immunity. Estrogens could exert anti-inflammatory effects during SARS-CoV-2 infection at different stages: from increasing the antiviral resistance of individual cells to counteracting the pro-inflammatory cytokine production. A complex relationship between sex hormones and immune system implies that menopausal hormone therapy (MHT) has pleiotropic effects on immunity in peri- and postmenopausal patients. The definite immunological benefits of perimenopausal MHT confirm the important role of estrogens in regulation of immune functionalities. In this review, we attempt to explore how sex hormones and MHT affect immunological parameters of the organism at different level (in vitro, in vivo) and what mechanisms are involved in their protective response to the new coronavirus infection. The correlation of sex steroid levels with severity and lethality of the disease indicates the potential of using hormone therapy to modulate the immune response and increase the resilience to adverse outcomes. The overall success of MHT is based on decades of experience in clinical trials. According to the current standards, MHT should not be discontinued in COVID-19 with the exception of critical cases.

Pathological Response and Immune Biomarker Assessment in Non-Small-Cell Lung Carcinoma Receiving Neoadjuvant Immune Checkpoint Inhibitors

Simple Summary

Recently, the U.S. Food and Drug Administration (FDA) approved neoadjuvant immunotherapy plus chemotherapy for the treatment of resectable non-small-cell lung carcinoma (NSCLC) due to the clinical benefits reported in several clinical trials. In these settings, the pathological assessment of the tumor bed to quantify a pathological response has been used as a surrogate method of clinical benefit to neoadjuvant therapy. In addition, several clinical trials are including the assessment of tissue-, blood-, or host-based biomarkers to predict therapy response and to monitor the response to neoadjuvant treatment. In this manuscript, we provide an overview of current recommendations for the evaluation of pathological response and describe potential biomarkers used in clinical trials of neoadjuvant immunotherapy in resectable NSCLC.

Abstract

Lung cancer is the leading cause of cancer incidence and mortality worldwide. Adjuvant and neoadjuvant chemotherapy have been used in the perioperative setting of non-small-cell carcinoma (NSCLC); however, the five-year survival rate only improves by about 5%. Neoadjuvant treatment with immune checkpoint inhibitors (ICIs) has become significant due to improved survival in advanced NSCLC patients treated with immunotherapy agents. The assessment of pathology response has been proposed as a surrogate indicator of the benefits of neaodjuvant therapy. An outline of recommendations has been published by the International Association for the Study of Lung Cancer (IASLC) for the evaluation of pathologic response (PR). However, recent studies indicate that evaluations of immune-related changes are distinct in surgical resected samples from patients treated with immunotherapy. Several clinical trials of neoadjuvant immunotherapy in resectable NSCLC have included the study of biomarkers that can predict the response of therapy and monitor the response to treatment. In this review, we provide relevant information on the current recommendations of the assessment of pathological responses in surgical resected NSCLC tumors treated with neoadjuvant immunotherapy, and we describe current and potential biomarkers to predict the benefits of neoadjuvant immunotherapy in patients with resectable NSCLC.

Shrimp peptide hydrolysate modulates the immune response in cyclophosphamide immunosuppressed mice model

Bioactive peptides are naturally found in various foods and were shown to have various distinct physiological as well as medicinal benefits. In this study shrimp peptide hydrolysate (SPH) was prepared to investigate its immunomodulatory effect against cyclophosphamide (CTX) induced immunosuppressed mice. The SPH effect was also analyzed on murine macrophage (RAW264.7 cells). The findings show that SPH stimulates macrophages to form multiple pseudopodia, has no cytotoxic effect, and increases phagocytic activity in RAW264.7 cells. Furthermore, the immunosuppressed in-vivo model illustrates the improvement in various aspects, that is body weight, escalation in immune organ index, and ameliorates histopathological transformation of thymus along with the spleen. SPH enhances cell-mediated immunity by facilitating splenocyte proliferation and inhibit excessive apoptosis. Moreover, the significant outcome had been observed with the upregulation of cytokines interferon-gamma (IFN-ϒ), interleukin-2 (IL-2) level and simultaneously downregulate certain genes include interleukin-4 (IL-4) and interleukin-10 (IL-10). Additionally, SPH expedites cellular immunity by enhancing the regulation of immunoglobulin A (IgA) and immunoglobulin M (IgM). However, these findings support the hypothesis that SPH is an effective immunomodulatory agent capable of preventing immune system hypofunction. It is necessary to investigate the detailed mechanism to rule out any unforeseen effects of SPH in future research. PRACTICAL APPLICATIONS: Chemotherapy medications, despite their dominating detrimental effects of damaging immunological organs such as the spleen and thymus, extend the treatment process as well as the destruction of the self-immune system. This study found that SPH is an effective immunomodulatory agent capable of avoiding immune organ hypofunction and improving cell mediate immunity by enhancing macrophage activation, phagocytosis, spleenocyte proliferation, suppressing apoptosis, and elevating cytokines and antibodies. As a result, SPH can be utilized as a nutritional and functional dietary supplement to boost immunological modulation in combination with chemotherapy medications in order to lessen their adverse effects.

Sex Differences Distinctly Impact High-Fat Diet-Induced Immune Dysfunction in Wistar Rats

BACKGROUND

Immune function is altered during obesity. Moreover, males and females across different species demonstrate distinct susceptibility to several diseases. However, less is known regarding the interplay between high-fat diet (HFD) and sex in the context of immune function.

OBJECTIVES

The objective was to determine sex differences on immune function in response to an HFD compared with a control low-fat diet (LFD) in Wistar rats.

METHODS

At 5 wk of age, male and female Wistar rats were randomly assigned to 1 of 2 diets for 9 wk: ad libitum control LFD (20 kcal% fat, 53 kcal% carbohydrate, and 27 kcal% protein) or HFD (50 kcal% fat, 23 kcal% carbohydrate, and 27 kcal% protein). At 13 wk of age, rats were killed and splenocytes were isolated. Immune cell subsets were determined by flow cytometry. Immune cell function was determined by measuring the ex vivo cytokine production following stimulation with mitogens. Two-factor ANOVA was used to assess the main effect of sex, diet, and their interaction.

RESULTS

Males gained more weight than females (410 ± 46 vs. 219 ± 45 g), independently of diet (P-sex < 0.01). The HFD led to a lower production of IL-2 while increasing the production of IL-10 (both P-diet ≤ 0.05), independently of sex. HFD-fed females had increased production of cytokines (IL-2 and IL-6) after stimulation with phorbol 12-myristate 13-acetate plus ionomycin (PMA+I), as well as a higher T-helper (Th) 1:Th2 balance compared with HFD-fed males (all P < 0.05). Males fed the HFD had significantly lower production of IL-2 upon stimulation compared with all other groups.

CONCLUSIONS

Female Wistar rats developed a milder obesity phenotype and maintained enhanced cytokine production compared with males fed the HFD. Sex differences modulate immune function in the context of high-fat feeding and it should be considered in research design to establish personalized health-related recommendations.

Ovarian activation delays in peripubertal ewe lambs infected with Haemonchus contortus can be avoided by supplementing protein in their diets

BACKGROUND

The ewe lamb nutritional and physiological state interfere with the ovarian environment and fertility. The lack or excess of circulating nutrients reaching the ovary can change its gene expression. A protein deficiency in the blood caused by an Haemonchus contortus abomasal infection is detrimental to the organism's development during puberty. The peripubertal period is a time of intensive growth that requires a high level of nutrients. An essential feature controlling pubertal arousal and female reproductive potential is ovarian follicle growth activation. Protein supplementation improves the sheep's immune response to helminthic infections. We aimed to determine if supplementing protein in infected ewe lambs' diet would impact the ovarian environment leading to earlier ovarian follicle activation than in infected not supplemented animals.

METHODS

We fed 18 Santa Ines ewe lambs (Ovis aries) - bred by the same ram - with either 12% protein (Control groups) or 19% protein (Supplemented groups) in their diets. After 35 days of the diet, they were each artificially infected or not with 10,000 Haemonchus contortus L3 larvae. Following 77 days of the diet and 42 days of infection, we surgically collected their left ovaries and examined their genes expression through RNA sequencing.

RESULTS

We found that protein supplementation in infected animals led to an up-regulation of genes (FDR p-values < 0.05) and biological processes (p-value cut-off = 0.01) linked to meiotic activation in pre-ovulatory follicles and primordial follicle activation, among others. The supplemented not infected animals also up-regulated genes and processes linked to meiosis and others, such as circadian behaviour. The not supplemented animals had these same processes down-regulated while up-regulated processes related to tissue morphogenesis, inflammation and immune response.

CONCLUSION

Diet's protein supplementation of peripubertal infected animals allowed them to express genes related to a more mature ovarian follicle stage than their half-sisters that were not supplemented. These results could be modelling potential effects of the interaction between environmental factors, nutrition and infection on reproductive health. When ovarian activation is achieved in a timely fashion, the ewe may generate more lambs during its reproductive life, increasing sheep breeders' productivity.

Recipient sex and estradiol levels affect transplant outcomes in an age-specific fashion

Sex-specific influences have been shown for a variety of diseases. Whether donor or recipient sex and sex hormone levels impact alloimmune responses remains unclear. In unifactorial and multifactorial analyses of more than 400 000 SRTR listed kidney transplant patients, we found that younger female recipients had an inferior death-censored graft survival that was independent of donor sex. In contrast, graft survival was superior in older female recipients, suggesting the impact of recipient sex hormones over chromosomal sex mismatches. Those clinical changes were delineated in experimental skin and heart transplant models showing a prolongation of graft survival in ovariectomized young female recipients. In contrast, graft survival was comparable in ovariectomized and naïve old female recipients. Young ovariectomized mice showed reduced amounts and a compromised T cell proliferation. Deprivation of female hormones dampened the production of interferon (IFN)-γ and interleukin (IL)-17+ by CD4+ T cells while augmenting systemic counts of Tregs. Increasing estradiol concentrations in vitro promoted the switch of naïve CD4+ T cells into Th1 cells; high physiological estradiol concentrations dampening Th1 responses, promoted Tregs, and prolonged graft survival. Thus, clinical observations demonstrate age-specific graft survival patterns in female recipients. Estrogen levels, in turn, impact the fate of T cell subsets, providing relevant and novel information on age- and sex-specific alloimmunity.

The Role of Regulatory T Cells in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a chronic, incurable condition characterized by pulmonary vascular remodeling, perivascular inflammation, and right heart failure. Regulatory T cells (Tregs) stave off autoimmunity, and there is increasing evidence for their compromised activity in the inflammatory milieu of PAH. Abnormal Treg function is strongly correlated with a predisposition to PAH in animals and patients. Athymic Treg-depleted rats treated with SU5416, an agent causing pulmonary vascular injury, develop PAH, which is prevented by infusing missing CD4⁺CD25^highFOXP3⁺ Tregs. Abnormal Treg activity may also explain why PAH disproportionately affects women more than men. This mini review focuses on the role of Tregs in PAH with a special view to sexual dimorphism and the future promise of Treg therapy.

An overview of sex hormones in relation to SARS-CoV-2 infection

Aim: Sex differences in COVID-19 outcomes might be explained from a sex hormones (SexHs) perspective. Materials & methods: PubMed, Scopus, Web of Science, EMBASE and Google Scholar were searched up to March 2021. Results: Based on the literature review, the crosstalk between SexHs (estrogens, progesterone and testosterone), their receptors (estrogen α and β, androgen, and progesterone) and the immune system shaped the sex-related differences in immune responses against COVID-19. Differential production of SexHs over the lifespan (during pregnancy, reproductive years, menopause and andropause) and over different seasons may result in disparities in body response toward COVID-19. Moreover, SexHs-specific differences might affect vaccine efficacy and response to treatment. Conclusion: The roles of SexHs need to be considered in vaccine development and even treatment of COVID-19.

The role of sexual dimorphism in susceptibility to SARS-CoV-2 infection, disease severity, and mortality: facts, controversies and future perspectives

Former studies have revealed intersex variability in immune response to infectious diseases, including Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological surveillance of the ongoing pandemic has demonstrated a male vulnerability to morbidity and mortality, despite similar infection rates between the two sexes. Divergence in the frequency of comorbidities between males and females, differences in hormonal profile, chromosomal composition and gender behavior have all been proposed as potential causative factors. Data deriving from the immunization process indirectly support the existence of a sex-specific response to SARS-CoV-2, since females apparently produce higher numbers of antibodies while simultaneously exhibiting higher rates of side effects, indicating a stronger immune reactivity to the vaccine's elements. Interpreting intersex differences in immune response to SARS-CoV-2 could lead to a deeper understanding of the COVID-19 pathophysiology and enable healthcare professionals to conduct a more accurate patient risk assessment and better predict the clinical outcome of the disease. This narrative review aims to discuss the pathophysiological and behavioral basis of the disproportionate male morbidity and mortality observed in COVID-19, in the context of most research findings in the field.

Cholinergic System and Its Therapeutic Importance in Inflammation and Autoimmunity

Neurological and immunological signals constitute an extensive regulatory network in our body that maintains physiology and homeostasis. The cholinergic system plays a significant role in neuroimmune communication, transmitting information regarding the peripheral immune status to the central nervous system (CNS) and vice versa. The cholinergic system includes the neurotransmitter\ molecule, acetylcholine (ACh), cholinergic receptors (AChRs), choline acetyltransferase (ChAT) enzyme, and acetylcholinesterase (AChE) enzyme. These molecules are involved in regulating immune response and playing a crucial role in maintaining homeostasis. Most innate and adaptive immune cells respond to neuronal inputs by releasing or expressing these molecules on their surfaces. Dysregulation of this neuroimmune communication may lead to several inflammatory and autoimmune diseases. Several agonists, antagonists, and inhibitors have been developed to target the cholinergic system to control inflammation in different tissues. This review discusses how various molecules of the neuronal and non-neuronal cholinergic system (NNCS) interact with the immune cells. What are the agonists and antagonists that alter the cholinergic system, and how are these molecules modulate inflammation and immunity. Understanding the various functions of pharmacological molecules could help in designing better strategies to control inflammation and autoimmunity.

Fetomaternal Immune Tolerance: Crucial Mechanisms of Tolerance for Successful Pregnancy in Humans

For many years, the question of how the maternal immune system tolerates the foreign fetus has remained unanswered, and numerous studies have considerably attempted to elucidate underlying mechanisms for fetomaternal tolerance. This review aimed at discussing various significant mechanisms in fetomaternal compatibility. At the fetomaternal interface, in addition to having efficient control against infections, innate and adaptive maternal immune systems selectively prevent fetal rejection. In general, understanding the complex mechanisms of fetomaternal tolerance is critical for immunologic tolerance induction and spontaneous abortion prevention in high-risk populations. Different cells and molecules, such as regulatory T-cells, dendritic cells, decidua cells, IDO, Class I HLA molecules, TGF-β, and IL-10, induce maternal immune tolerance in the fetus in numerous ways. The findings on fetomaternal immune tolerance have remained controversial and require further research.

Characterization of the CDAA Diet-Induced Non-alcoholic Steatohepatitis Model: Sex-Specific Differences in Inflammation, Fibrosis, and Cholesterol Metabolism in Middle-Aged Mice

Background

The prevalence of non-alcoholic steatohepatitis (NASH) rapidly increases with associated metabolic disorders such as dyslipidemia; therefore, NASH is now considered an independent risk factor of cardiovascular diseases. NASH displays sex-linked epidemiological, phenotypical, and molecular differences; however, little is known about the background of these sex-specific differences on the molecular level.

Objectives

We aimed to assess sex-specific differences in the expression of inflammatory and fibrotic genes, as well as in cholesterol metabolism, focusing on the expression of Pcsk9 in several tissues in a mouse model of NASH that shows the typical features of the human condition.

Methods and Results

We fed 10-months-old male and female C57Bl/6J mice with a NASH-inducing CDAA or corresponding control diet for 8 weeks. We found that, compared to the control male mice baseline, hepatic Pcsk9 expression as well as serum PCSK9 level was significantly higher in females, and both circulating PCSK9 level and the hepatic Pcsk9 gene were markedly decreased in female mice during NASH development. Histological analysis revealed that male and female mice develop a similar degree of steatosis; however, fibrosis was more pronounced in males upon CDAA diet feeding. Strikingly, female mice have higher hepatic expression of the pro-inflammatory cytokines (Il1b, Ifng), and increased IL-1β cleavage by the NLRP3 inflammasome, and a decrease in Clec4f⁺ resident Kupffer cell population in comparison to males in the CDAA-fed groups.

Conclusion

This is the first demonstration that there are critical sex-specific differences during NASH development in middle-aged mice regarding inflammation, fibrosis, and cholesterol metabolism and that changes in PCSK9 and IL-1β are likely important contributors to sex-specific changes during the transition to NASH.

Chronic Drug-Induced Liver Injury: Updates and Future Challenges

Chronic drug-induced liver injury (DILI), defined as DILI with persistent liver injury more than one year after the first onset by the latest European guidelines, is a notable challenge globally with big issues of defining causality and establishing effective treatment. About 20% of patients with DILI develop into chronic DILI. Chronic DILI manifests as persistent or repeated inflammatory or diminishing bile ducts, even progresses to cirrhosis and needs liver transplantation eventually. However, research on chronic DILI over the last decades is still lacking, and the incidence, phenotypes, mechanisms, risk factors, and treatment have not been fully understood. In this paper, we reviewed the definition of chronic DILI, updated clinical studies in terms of incidence, special manifestations, and promising risk factors of chronic DILI, along with the recent progress and challenges in glucocorticoid therapy.

Antisclerothic effect of tibolone by reducing proinflammatory cytokines expression, ROS production and LDL-ox uptake in THP-1 macrophages

BACKGROUND

Cardiovascular disease is more frequent in menopausal women, which has been related to factor such as weight gain, altered fat distribution, and increased inflammation markers including adipokines (MCP-1, TNF-α, IL-6) and cytokines (IL-1, IL-6, TNF-α) produced by macrophages. In addition to their phagocytic activity, macrophages secrete cytokines and chemokines that induces cell recruitment, which is a process related to vascular damage that favors the formation of atheromatous plaques. Tibolone (Tb) therapy is used to reduce the symptoms of menopause as well as osteoporosis and it has been shown to decreases the risk of fractures.

METHODS

To investigate the effect of tibolone in macrophage enzymatic activity, gene expression of cytokines, and its effect on foam cells formation. We use phorbol-12-myristate-13-acetate (PMA)-differentiated THP-1 cells. The cells were incubated 24 h and 48 h using pre and post-treatment schemes. We evaluated total ROS determination by NBT assay, expression of cytokines (IL-1β, IL-6, TNF-α, NOS2, ARG1, TGFβ) by RT-qPCR and foam cell formation in THP-1 differentiated macrophages stimulated with PMA.

RESULTS

It was observed that the minor levels of total ROS determination were obtained with tibolone at 48 h in post-treatment scheme. Also, in a long term we found decrease the proinflammatory cytokines (IL-1β, IL-6 and TNF-α). Finally, with treatment for 24 h with P4 y Tb we observed fewer LDL vesicles into macrophages cytoplasm.

CONCLUSIONS

These results suggest that tibolone reduces the inflammatory process, also inhibits the foam cells formation; suggesting a possible role in reducing cardiovascular risk.

Association of menopausal status with COVID-19 outcomes: a propensity score matching analysis

Background

Despite the growing number of studies on the coronavirus disease-19 (COVID-19), little is known about the association of menopausal status with COVID-19 outcomes.

Materials and methods

In this retrospective study, we included 336 COVID-19 inpatients between February 15, 2020 and April 30, 2020 at the Taikang Tongji Hospital (Wuhan), China. Electronic medical records including patient demographics, laboratory results, and chest computed tomography (CT) images were reviewed.

Results

In total, 300 patients with complete clinical outcomes were included for analysis. The mean age was 65.3 years, and most patients were women (n = 167, 55.7%). Over 50% of patients presented with comorbidities, with hypertension (63.5%) being the most common comorbidity. After propensity score matching, results showed that men had significantly higher odds than premenopausal women for developing severe disease type (23.7% vs. 0%, OR 17.12, 95% CI 1.00–293.60; p = 0.003) and bilateral lung infiltration (86.1% vs. 64.7%, OR 3.39, 95% CI 1.08–10.64; p = 0.04), but not for mortality (2.0% vs. 0%, OR 0.88, 95% CI 0.04–19.12, p = 1.00). However, non-significant difference was observed among men and postmenopausal women in the percentage of severe disease type (32.7% vs. 41.7%, OR 0.68, 95% CI 0.37–1.24, p = 0.21), bilateral lung infiltration (86.1% vs. 91.7%, OR 0.56, 95% CI 0.22–1.47, p = 0.24), and mortality (2.0% vs. 6.0%, OR 0.32, 95% CI 0.06–1.69, p = 0.25).

Conclusions

Men had higher disease severity than premenopausal women, while the differences disappeared between postmenopausal women and men. These findings support aggressive treatment for the poor prognosis of postmenopausal women in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-021-00363-6.

High Serum Estradiol Reduces Acute Hepatotoxicity Risk Induced by Epirubicin Plus Cyclophosphamide Chemotherapy in Premenopausal Women with Breast Cancer

Aim: We evaluated whether acute drug-induced liver injury (DILI) caused by adjuvant chemotherapy with epirubicin plus cyclophosphamide for early breast cancer was associated with estradiol (E2), luteinizing hormone (LH), and follicle-stimulating hormone (FSH).

Methods: Reproductive hormone test results of breast cancer patients were collected in the first chemotherapy cycle. E2, LH, and FSH levels were log_e-transformed to normally distributed variables and were assessed using Student’s t-test to determine significant differences between the case and control groups. Hormone levels were classified according to the interquartile range and analyzed by logistic regression to determine their association with DILI caused by chemotherapy.

Results: Among the 915 enrolled patients (DILI group: 204; control group: 711), menopausal status, along with serum E2, LH, and FSH levels, did not substantially differ between case and control groups. However, in the premenopause subgroup (n = 483), we found a significant difference in the E2 level between the case and control groups (p = 0.001). After adjusting for age and body mass index, premenopausal patients with 152–2,813 pg/mL E2 showed a lower risk of chemotherapy-induced DILI than patients with ≤20 pg/mL E2 (odds ratio: 0.394; 95% confidence interval: 0.207–0.748). The linear trend χ2 test revealed that E2 levels in premenopausal patients with breast cancer were inversely associated with the development of DILI.

Conclusion: High serum E2 levels are associated with a reduced DILI risk in premenopausal patients with breast cancer undergoing epirubicin plus cyclophosphamide adjuvant chemotherapy.

Alu retrotransposons and COVID-19 susceptibility and morbidity

SARS-CoV-2 has spread rapidly across the world and is negatively impacting the global human population. COVID-19 patients display a wide variety of symptoms and clinical outcomes, including those attributed to genetic ancestry. Alu retrotransposons have played an important role in human evolution, and their variants influence host response to viral infection. Intronic Alus regulate gene expression through several mechanisms, including both genetic and epigenetic pathways. With respect to SARS-CoV-2, an intronic Alu within the ACE gene is hypothesized to be associated with COVID-19 susceptibility and morbidity. Here, we review specific Alu polymorphisms that are of particular interest when considering host response to SARS-CoV-2 infection, especially polymorphic Alu insertions in genes associated with immune response and coagulation/fibrinolysis cascade. We posit that additional research focused on Alu-related pathways could yield novel biomarkers capable of predicting clinical outcomes as well as patient-specific treatment strategies for COVID-19 and related infectious diseases.

Increased estrogen to androgen ratio enhances immunoglobulin levels and impairs B cell function in male mice

Sex steroids, such as estrogens and androgens, are important regulators of the humoral immune response. Studies in female mice have demonstrated that alteration of circulating estrogen concentration regulates antibody-mediated immunity. As males have normally little endogenous estrogen, we hypothesized that in males high estrogens and low androgens affect the immune system and enhance the allergic inflammatory response. Here, we studied transgenic male mice expressing human aromatase (AROM+). These animals have a high circulating estrogen to androgen ratio (E/A), causing female traits such as gynecomastia. We found that AROM+ male mice had significantly higher plasma immunoglobulin levels, particularly IgE. Flow cytometry analyses of splenocytes revealed changes in mature/immature B cell ratio together with a transcriptional upregulation of the Igh locus. Furthermore, higher proliferation rate and increased IgE synthesis after IgE class-switching was found. Subsequently, we utilized an ovalbumin airway challenge model to test the allergic response in AROM+ male mice. In line with above observations, an increase in IgE levels was measured, albeit no impact on immune cell infiltration into the lungs was detected. Together, our findings suggest that high circulating E/A in males significantly alters B cell function without any significant enhancement in allergic inflammation.

Vaccination with the recombinant major outer membrane protein elicits long-term protection in mice against vaginal shedding and infertility following a Chlamydia muridarum genital challenge

Implementation of a vaccine is likely the best approach to curtail Chlamydia trachomatis infections. The aim of this study was to determine the ability of a vaccine formulated with the recombinant major outer membrane protein (MOMP) and Th1 and Th2 adjuvants, delivered by combinations of systemic and mucosal routes, to elicit long-term protection in mice against a genital challenge with Chlamydia muridarum. As a negative control, mice were vaccinated with the recombinant Neisseria gonorrhoeae porinB, and the positive control group was immunized with C. muridarum live elementary bodies (EB). The four vaccines formulated with MOMP, as determined by the titers of IgG and neutralizing antibodies in serum, proliferative responses of T-cells stimulated with EB and levels of IFN-γ in the supernatants, elicited robust humoral and cellular immune responses over a 6-month period. Groups of mice were challenged genitally at 60, 120, or 180 days postimmunization. Based on the number of mice with positive vaginal cultures, number of positive cultures, length of time of shedding, and number of inclusion forming units recovered, MOMP vaccinated groups were significantly protected. To assess fertility, when the vaginal cultures became negative, female mice were caged with male mice and the outcome of the pregnancy evaluated. As determined by the number of pregnant mice and the number of embryos, two of the vaccine formulations protected mice up to 180 days postimmunization. To our knowledge this is the first subunit of Chlamydia vaccine that has elicited in mice significant long-term protection against a genital challenge.

Long-term exposure to low 17α-ethinylestradiol (EE2) concentrations disrupts both the reproductive and the immune system of juvenile rainbow trout, Oncorhynchus mykiss

Estrogenic endocrine disrupting compounds (EEDCs), such as ethinylestradiol (EE2), are well studied for their impact on the reproductive system of fish. EEDCs may also impact the immune system and, as a consequence, the disease susceptibility of fish. It is currently not yet known whether the low concentrations of EEDCs that are able to disrupt the reproductive system of trout are effective in disrupting the immune system and the fish host resistance towards pathogens, too, or whether such immunodisruptive effects would occur only at higher EEDC concentrations. Therefore, in the present study we compare the effect thresholds of low 17α-ethinylestradiol concentrations (1.5 and 5.5 EE2 ng/L) on the reproductive system, the immune system, the energy expenditures and the resistance of juvenile rainbow trout (Oncorhynchus mykiss) against the parasite Tetracapsuloides bryosalmonae - the etiological agent of proliferative kidney disease (PKD) of salmonids. The parasite infection was conducted without injection and under low pathogen exposure concentrations. The disease development was followed over 130 days post infection - in the presence or absence of EE2 exposure. The results show that the long-term EE2 exposure affected, at both concentrations, reproductive parameters like the mRNA levels of hepatic vitellogenin and estrogen receptors. At the same concentrations, EE2 exposure modulated the immune parameters: mRNA levels of several immune genes were altered and the parasite intensity as well as the disease severity (histopathology) were significantly reduced in EE2-exposed fish compared to infected control fish. The combination of EE2 exposure and parasite infection was energetically costly, as indicated by the decreased values of the swim tunnel respirometry. Although further substantiation is needed, our findings suggest that EE2 exerts endocrine disruptive and immunomodulating activities at comparable effect thresholds, since reproductive and immune parameters were affected by the same, low EE2 concentrations.

Considerations for Studying Sex as a Biological Variable in Spinal Cord Injury

In response to NIH initiatives to investigate sex as a biological variable in preclinical animal studies, researchers have increased their focus on male and female differences in neurotrauma. Inclusion of both sexes when modeling neurotrauma is leading to the identification of novel areas for therapeutic and scientific exploitation. Here, we review the organizational and activational effects of sex hormones on recovery from injury and how these changes impact the long-term health of spinal cord injury (SCI) patients. When determining how sex affects SCI it remains imperative to expand outcomes beyond locomotor recovery and consider other complications plaguing the quality of life of patients with SCI. Interestingly, the SCI field predominately utilizes female rodents for basic science research which contrasts most other male-biased research fields. We discuss the unique caveats this creates to the translatability of preclinical research in the SCI field. We also review current clinical and preclinical data examining sex as biological variable in SCI. Further, we report how technical considerations such as housing, size, care management, and age, confound the interpretation of sex-specific effects in animal studies of SCI. We have uncovered novel findings regarding how age differentially affects mortality and injury-induced anemia in males and females after SCI, and further identified estrus cycle dysfunction in mice after injury. Emerging concepts underlying sexually dimorphic responses to therapy are also discussed. Through a combination of literature review and primary research observations we present a practical guide for considering and incorporating sex as biological variable in preclinical neurotrauma studies.

IL-27 regulation of innate immunity and control of microbial growth

IL-27 is a pleiotropic cytokine capable of influencing both innate and adaptive immune responses. With anti- and pro-inflammatory activity, IL-27 exerts its opposing effects in a cell-dependent and infectious context-specific manner. Upon pathogenic stimuli, IL-27 regulates innate immune cells, such as monocytes, dendritic cells, macrophages and neutrophils. Immune responses involving these innate cells that are negatively regulated by IL-27 signaling include inflammatory cytokine production, phagolysosomal acidification following phagocytosis, oxidative burst and autophagy. IL-27 signaling is crucial in maintaining the subtle balance between Th1 and Th2 immunity, in which protective inflammation is upregulated within the early stages of infection and subsequently downregulated once microbial growth is controlled. The immunomodulatory effects of IL-27 provide promising therapeutic targets for multiple disease types.

A primary role of IL-27 is to communicate between various immune cells to initiate different immune responses. Among these responses are those involved with destroying and eliminating microbial pathogens and then turning off inflammatory responses when the infectious threat has been resolved. IL-27 possesses both anti- and pro-inflammatory activity that varies with context, immune cell and pathogen stimulus. Depending on the precise formula of these details, there are important implications for IL-27 in disease outcomes. As such, harnessing or opposing IL-27 activity may have the potential to treat a variety of infectious diseases.

Modification of Fecal Bacteria Counts and Blood Immune Cells in the Offspring of BALB/c and C57BL/6 Mice Obtained through Interstrain Mouse Embryo Transfer

The reproducibility of results obtained with rodent models depends on the genetic purity of the strain and the stability of the environment. However, another potential factor is changes in the gut microbiota due to the transmission of mother's bacteria during embryo transfer. In this study, we demonstrate the transmission of the microbiota and immune cell blood phenotype to the offspring of 2 strains, C57BL/6JNskrc and BALB/cJNskrc, from surrogate dams of different genotypes. Interstrain embryo transfer resulted in a change in the number of Enterococcus spp. organisms, as shown by quantitative PCR analysis. The number of blood leukocytes was also affected, as estimated by flow cytometry. The number of blood leukocytes, including B cells and helper T cells, and the number of Enterococcus spp. organisms in male C57BL/6JNskrc offspring bornto BALB/cJNskrc surrogate dams became similar to those of male BALB/cJNskrc mice born to BALB/cJNskrc dams. Likewise, the same parameters of male BALB/cJNskrc mice born to C57BL/6JNskrc dams became similar to those of male C57BL/6JNskrc offspring. Researchers should be aware of the possible transmission of the dam's microbiota and immune cell phenotypes to the experimental strains when planning embryo transfer experiments, because these factors could affect the experimental outcomes or the reproducibility of experimental results.

Perceived Immune Fitness, Individual Strength and Hangover Severity

Various factors may contribute to alcohol hangover severity. The purpose of the current investigation was to evaluate the possible impact of alcohol consumption patterns, perceived immune status, and baseline fatigue on hangover severity. A survey was completed by a convenience sample of N = 199 Dutch students who reported on their latest past month's heavy drinking occasion, including subjective intoxication (perceived drunkenness) and next-day hangover severity, which were rated on single-item scales ranging from 0 (absent) to 10 (extreme). In addition, perceived (momentary) immune fitness was assessed, and the Checklist Individual Strength (CIS) was completed to assess baseline fatigue. The analysis revealed that instead of the amount of alcohol consumed or estimated blood alcohol concentration, it appeared that subjective intoxication (i.e., level of drunkenness) was the most important determinant of alcohol hangover severity. Especially in men, albeit modest, it was perceived that immune fitness also significantly contributed to the level of hangover severity experienced.

Stress and immunity: Field comparisons among populations of invasive cane toads in Florida

Cane toads (Rhinella marina) were introduced worldwide and have become invasive in multiple locations, representing a major driver of biodiversity loss through competition (food, shelter, territory), predation, and the poisoning of native species. These toads have been used in Australia as a model for studies concerning invasion biology and ecoimmunology, as longer-established (core) and invasion front (edge) populations show altered stress and immune response profiles. Although cane toads were also introduced into the United States in the 1950s, these patterns have yet to be evaluated for the populations spanning Florida. Toads introduced into Florida have dispersed primarily northward along a latitudinal gradient, where they encounter cooler temperatures that may further impact stress and immune differences between core and edge populations. In this study, we sampled cane toads from nine different locations spanning their invasion in Florida. Cane toads from southern populations showed higher plasma bacterial killing ability and natural antibody titers than the toads from the northern populations, indicating they have a better immune surveillance system. Also, southern toads were more responsive to a novel stressor (1 hr restraint), showing a higher increase in corticosterone levels. These results indicate that possible trade-offs have occurred between immune and stress responses as these toads have become established in northern cooler areas in Florida.

Sex-Specific Effects of the Nlrp3 Inflammasome on Atherogenesis in LDL Receptor-Deficient Mice

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In this study we observed sex-specific effects of the NLRP3 inflammasome on atherogenesis in LDLR-deficient mice, with NLRP3 inflammasome playing a more prominent role in atherosclerosis in female mice than in males.

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Sex hormones may be involved in NLRP3 inflammasome–mediated atherogenesis and may underlie differential responses to anti-NLRP3 therapy between males and females.

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Testosterone may play an inhibitory role by blocking NLRP3 inflammasome and inflammation in atherogenesis, whereas female sex hormones may promote NLRP3 inflammasome–mediated atherosclerosis.

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The results of the present study may help design future clinical trials, with the objective to personalize cardiovascular care for men and women.

In the Ldlr^-/- mouse model of atherosclerosis, female Nlrp3^-/- bone marrow chimera and Nlrp3^-/- mice developed significantly smaller lesions in the aortic sinus and decreased lipid content in aorta en face, but a similar protection was not observed in males. Ovariectomized female mice lost protection from atherosclerosis in the setting of NLRP3 deficiency, whereas atherosclerosis showed a greater dependency on NLRP3 in castrated males. Thus, castration increased the dependency of atherosclerosis on the NLRP3 inflammasome, suggesting that testosterone may block inflammation in atherogenesis. Conversely, ovariectomy reduced the dependency on NLRP3 inflammasome components for atherogenesis, suggesting that estrogen may promote inflammasome-mediated atherosclerosis.

Weighted Gene Correlation Network Meta-Analysis Reveals Functional Candidate Genes Associated with High- and Sub-Fertile Reproductive Performance in Beef Cattle

Improved reproductive efficiency could lead to economic benefits for the beef industry, once the intensive selection pressure has led to a decreased fertility. However, several factors limit our understanding of fertility traits, including genetic differences between populations and statistical limitations. In the present study, the RNA-sequencing data from uterine samples of high-fertile (HF) and sub-fertile (SF) animals was integrated using co-expression network meta-analysis, weighted gene correlation network analysis, identification of upstream regulators, variant calling, and network topology approaches. Using this pipeline, top hub-genes harboring fixed variants (HF × SF) were identified in differentially co-expressed gene modules (DcoExp). The functional prioritization analysis identified the genes with highest potential to be key-regulators of the DcoExp modules between HF and SF animals. Consequently, 32 functional candidate genes (10 upstream regulators and 22 top hub-genes of DcoExp modules) were identified. These genes were associated with the regulation of relevant biological processes for fertility, such as embryonic development, germ cell proliferation, and ovarian hormone regulation. Additionally, 100 candidate variants (single nucleotide polymorphisms (SNPs) and insertions and deletions (INDELs)) were identified within those genes. In the long-term, the results obtained here may help to reduce the frequency of subfertility in beef herds, reducing the associated economic losses caused by this condition.

Dehydration enhances cellular and humoral immunity in a mesic snake community

The immunocompetence of a community of free-living animals can be affected by seasonality, sex, and parasite burden. However, each of these factors is often examined independently. Recent studies have also found that dehydration can enhance aspects of immunocompetence in drought-adapted species. To explore how all of these factors interact, and their effect on the immune system in mesic-adapted species, we collected blood samples from a community of free-ranging snakes in coastal South Carolina, United States, across 2 years. We specifically examined (a) how sex and seasonality influence humoral and cellular immunocompetence and parasite burden, (b) the dynamics among hydration state, parasite burden, and immunocompetence, and (c) whether mesic-adapted species also show enhanced innate immunity with dehydration. Consistent with previous work on drought-adapted species, we found that dehydration enhances multiple aspects of humoral immunity in mesic species, and we are the first to report that dehydration also enhances aspects of cellular immunocompetence. Contrary to previous results in other squamates, sex and season did not impact immunocompetence or parasite prevalence. Our results also reveal complex interactions among parasite prevalence, immunocompetence, and hydration state demonstrating that hydration state and parasitism are two ubiquitous factors that should continue to be considered in future studies examining ecoimmunological variation.