The effect of infections on susceptibility to autoimmune and allergic diseases

The role of the early-life gut microbiome in childhood asthma

Asthma is a chronic disease affecting millions of children worldwide, and in severe cases requires hospitalization. The etiology of asthma is multifactorial, caused by both genetic and environmental factors. In recent years, the role of the early-life gut microbiome in relation to asthma has become apparent, supported by an increasing number of population studies, in vivo research, and intervention trials. Numerous early-life factors, which for decades have been associated with the risk of developing childhood asthma, are now being linked to the disease through alterations of the gut microbiome. These factors include cesarean birth, antibiotic use, breastfeeding, and having siblings or pets, among others. Association studies have highlighted several specific microbes that are altered in children developing asthma, but these can vary between studies and disease phenotype. This demonstrates the importance of the gut microbial ecosystem in asthma, and the necessity of well-designed studies to validate the underlying mechanisms and guide future clinical applications. In this review, we examine the current literature on the role of the gut microbiome in childhood asthma and identify research gaps to allow for future microbial-focused therapeutic applications in asthma.

Molecular mimicry in the pathogenesis of autoimmune rheumatic diseases

Autoimmune rheumatic diseases (ARDs) are a heterogeneous group of conditions characterized by excessive and misdirected immune responses against the body's own musculoskeletal tissues. Their exact aetiology remains unclear, with genetic, demographic, behavioural and environmental factors implicated in disease onset. One prominent hypothesis for the initial breach of immune tolerance (leading to autoimmunity) is molecular mimicry, which describes structural or sequence similarities between human and microbial proteins (mimotopes). This similarity can lead to cross-reactive antibodies and T-cell receptors, resulting in an immune response against autoantigens. Both commensal microbes in the human microbiome and pathogens can trigger molecular mimicry, thereby potentially contributing to the onset of ARDs. In this review, we focus on the role of molecular mimicry in the onset of rheumatoid arthritis and systemic lupus erythematosus. Moreover, implications of molecular mimicry are also briefly discussed for ankylosing spondylitis, systemic sclerosis and myositis.

IgE-Mediated Activation of Mast Cells and Basophils in Health and Disease

Type 2-mediated immune responses protect the body against environmental threats at barrier surfaces, such as large parasites and environmental toxins, and facilitate the repair of inflammatory tissue damage. However, maladaptive responses to typically nonpathogenic substances, commonly known as allergens, can lead to the development of allergic diseases. Type 2 immunity involves a series of prototype TH2 cytokines (IL-4, IL-5, IL-13) and alarmins (IL-33, TSLP) that promote the generation of adaptive CD4+ helper Type 2 cells and humoral products such as allergen-specific IgE. Mast cells and basophils are integral players in this network, serving as primary effectors of IgE-mediated responses. These cells bind IgE via high-affinity IgE receptors (FcεRI) expressed on their surface and, upon activation by allergens, release a variety of mediators that regulate tissue responses, attract and modulate other inflammatory cells, and contribute to tissue repair. Here, we review the biology and effector mechanisms of these cells, focusing primarily on their role in mediating IgE responses in both physiological and pathological contexts.

Research progress on pharmacokinetics, anti-inflammatory and immunomodulatory effects of kaempferol

Chronic inflammation (an abnormal state) and autoimmune disease (AD) can both cause multiple organ damage. AD is a heterogeneous group of diseases due to immune dysfunction. Chronic inflammation is closely related to AD and is an important part of AD. With the increasing prevalence of AD, researchers are constantly exploring new drugs with small side effects, considerable curative effects, and lower costs. Kaempferol, a flavonoid, possesses a range of biological functions, including antioxidant, anti-inflammatory, anti-neoplastic, and immunomodulatory capabilities. This compound is prevalent in a variety of plant sources, such as vegetables, fruits, and medicinal herbs traditionally used in Chinese medicine. A plethora of empirical evidence from animal-based research supports the assertion that this particular substance exhibits both anti-inflammatory and immunomodulatory effects, with the curative effect being significant and application prospects. This article mainly summarizes and discusses the pharmacokinetics, drug delivery system, and the mechanism of kaempferol on immune cells, cytokines, signaling pathways, and other aspects. This paper summarizes the existing kaempferol drug delivery system, analyzes the possibility and limitations of kaempferol as a new anti-inflammatory and immunomodulatory drug, and discusses how to apply it in clinical practice. Therefore, kaempferol can more effectively exert its anti-inflammatory and immune-modulating effects, thereby demonstrating therapeutic potential in clinical settings, while reducing patient burden.

Demography, sanitation and previous disease prevalence associate with COVID-19 deaths across Indian States

The severity of COVID-19 has varied across regions, with a disproportionately higher case-fatality ratio in developed nations. In India, states with higher income have reported more COVID-19 related deaths compared to lower-income states. Understanding the underlying factors such as demographics, disease burden, urbanization, and sanitation can help in designing better public health policies to mitigate future pandemics. The objective of this study is to identify key predictors of COVID-19 mortality across Indian states by examining the role of disease prevalence, demographics, urbanization, and sanitation. We analysed data from the Global Burden of Diseases India 2019 and the National Health Profile 2019, correlating them with COVID-19 mortality during two peak periods of the pandemic. Spearman correlation analysis and multivariate regression models were employed to determine significant associations and build predictive models for COVID-19 deaths. Our analysis showed a positive correlation between COVID-19 mortality and demographic factors such as the percentage of the elderly population (ρ = 0.44, p < 0.05 for the first peak; ρ = 0.46, p < 0.05 for the second peak). Urbanization was also significantly associated with higher mortality (ρ = 0.71, p < 0.05 for the first peak; ρ = 0.57, p < 0.05 for the second peak). Additionally, the prevalence of autoimmune diseases and cancer correlated positively with deaths. An unexpected finding was the positive correlation between improved sanitation (e.g., closed drainage systems and indoor toilets) and COVID-19 mortality. The best-fit multivariate regression model, combining demographics, sanitation, autoimmune diseases, and cancer, achieved an adjusted R2 of 0.71 for the first peak and 0.85 for the second peak. Our findings suggest that as states become wealthier, they undergo urbanization and infrastructural improvements, including better sanitation. However, these changes may also be associated with a rise in autoimmune diseases and cancer, potentially reducing immune resilience to emerging infections. This study provides novel insights into how improved living conditions and lifestyle changes may paradoxically contribute to increased COVID-19 mortality. By emphasizing the role of immune training in pandemic preparedness, our research offers a new perspective on public health strategies for mitigating future infectious disease outbreaks.

Exploring the role of breastfeeding, antibiotics, and indoor environments in preschool children atopic dermatitis through machine learning and hygiene hypothesis

The increasing global incidence of atopic dermatitis (AD) in children, especially in Western industrialized nations, has attracted considerable attention. The hygiene hypothesis, which posits that early pathogen exposure is crucial for immune system development, is central to understanding this trend. Furthermore, advanced machine learning algorithms have provided fresh insights into the interactions among various risk factors. This study investigates the relationship between early childhood antibiotic use, the duration of exclusive breastfeeding, indoor environmental factors, and child AD. By integrating machine learning techniques with the hygiene hypothesis, we aim to assess and interpret the significance of these risk factors. In this community-based case-control study with a 1:4 matching design, we evaluated the prevalence of AD in preschool-aged children. Data were collected via questionnaires completed by the parents of 771 children diagnosed with AD, matched with controls based on gender, age, and ethnicity. Univariate analyses identified relevant characteristics, which were further examined using multivariable logistic regression to calculate odds ratios (ORs). Stratified analyses assessed confounders and interactions, while the significance of variables was determined using a machine learning model. Renovating the dwelling during the mother's pregnancy (OR = 1.50; 95% CI 1.15-1.96) was identified as a risk factor for childhood AD. Additionally, antibiotic use three or more times during the child's first year (OR = 1.92; 95% CI 1.29-2.85) increased the risk of AD, independent of the parents' history of atopic disease and the child's mode of birth. Moreover, exclusive breastfeeding for four months or more (OR = 1.59; 95% CI 1.17-2.17) was identified as a risk factor for AD, particularly in the group without a maternal history of atopic disease. In contrast, having older siblings in the family (OR = 0.76; 95% CI 0.63-0.92) and low birth weight (OR = 0.62; 95% CI 0.47-0.81) were identified as protective factors against AD. Machine learning modeling indicated that the duration of exclusive breastfeeding, having older siblings, low birth weight, and parental history of AD or allergic rhinitis are key predictors of childhood AD. Our findings support the broader interpretation of the hygiene hypothesis. Machine learning analysis highlights the key role of the hygiene hypothesis and underscores the need for future AD prevention and healthcare initiatives focusing on children with a parental history of AD or allergic rhinitis. Moreover, minimizing antibiotic overuse may be essential for preventing AD in children. Further research is necessary to elucidate the impact and mechanisms of exclusive breastfeeding on AD to instruct maternal and child healthcare practices.

Pathogenic and Nonpathogenic Antibody Responses in Allergic Diseases

Allergen-specific antibodies, particularly of the IgE class, are a hallmark of many allergic diseases. Yet paradoxically, (1) a proportion of healthy individuals possess allergen-specific IgE without clinical signs of allergy; (2) some, but not all, allergic individuals develop a more severe disease over time or fail to respond to allergen-specific immunotherapy; and (3) allergen-specific IgG antibodies can inhibit IgE-mediated responses but they can also induce allergic reactions. In this review, we discuss the occurrence of and transition between nonpathogenic and pathogenic allergen-specific antibody responses in the light of a two-stage model. We recapitulate different factors and scenarios that may induce different inflammatory conditions and qualitatively distinct allergen-specific T- and B-cell responses, influencing IgE origins and affinities, IgE/IgG(4) ratios, IgG effector functions, antibody glycosylation patterns, Fc and glycan-binding receptor expression and involvement, and ultimately their propensity to elicit allergic responses. Differences in these antibody characteristics may determine the onset of symptomatic allergy and the severity or remission of the disease.

Protective effects of Mycobacterium vaccae ATCC 15483 against "Western"-style diet-induced weight gain and visceral adiposity in adolescent male mice

The prevalence of noncommunicable inflammatory disease is increasing in modern urban societies, posing significant challenges to public health. Novel prevention and therapeutic strategies are needed to effectively deal with this issue. One promising approach is leveraging microorganisms such as Mycobacterium vaccae ATCC 15483, known for its anti-inflammatory, immunoregulatory, and stress-resilience properties. This study aimed to assess whether weekly subcutaneous administrations of a whole-cell, heat-killed preparation of M. vaccae ATCC 15483 (eleven injections initiated one week before the onset of the diet intervention), relative to vehicle injections, in adolescent male C57BL/6N mice can mitigate inflammation associated with Western-style diet-induced obesity, which is considered a risk factor for a number of metabolic and inflammatory diseases. Our results show that treatment with M. vaccae ATCC 15483 prevented Western-style diet-induced excessive weight gain, visceral adipose tissue accumulation, and elevated plasma leptin concentrations. The Western-style diet, relative to a control diet condition, decreased alpha diversity and altered the community composition of the gut microbiome, increasing the Bacillota to Bacteroidota ratio (formerly referred to as the Firmicutes to Bacteroidetes ratio). Despite the finding that M. vaccae ATCC 15483 prevented Western-style diet-induced excessive weight gain, visceral adipose tissue accumulation, and elevated plasma leptin concentrations, it had no effect on the diversity or community composition of the gut microbiome, suggesting that it acts downstream of the gut microbiome to alter immunometabolic signaling. M. vaccae ATCC 15483 reduced baseline levels of biomarkers of hippocampal neuroinflammation and microglial priming, such as Nfkbia and Nlrp3, and notably decreased anxiety-like defensive behavioral responses. The current findings provide compelling evidence supporting the potential for M. vaccae ATCC 15483 as a promising intervention for prevention or treatment of adverse immunometabolic outcomes linked to the consumption of a Western-style diet and the associated dysbiosis of the gut microbiome.

Nicotine dependence is associated with an increased risk of developing chronic, non-communicable inflammatory disease: a large-scale retrospective cohort study

Introduction

Chronic, non-communicable inflammatory diseases (CIDs) affect a large portion of the population, imposing a significant morbidity, encompassing a substantial mortality. Thus, they are a major medical burden with a high unmet need. CIDs develop over the span of several years, and the risk of developing CIDs has been linked to genetic and environmental factors. Thus, modification of environmental factors is a promising approach for the prevention of CIDs. Among modifiable environmental factors that have been linked to the CID risk is nicotine dependence. However, for only few CIDs, compelling evidence suggests that nicotine dependence increases (e.g., rheumatoid arthritis and asthma) or decreases (e.g., pemphigus) the CID risk. For most CIDs, there are inconsistent, scant, or no reports on the risk of CID associated with nicotine dependence.

Methods

To address this gap, we leveraged TriNetX, analyzing data from over 120 million electronic health records (EHRs). Using propensity score matching (PSM) to control for age, sex, ethnicity, and other CID risk factors, we contrasted the risk of developing any or any of the 38 CIDs in 881,192 EHRs from individuals with nicotine dependence to PSM-matched unexposed counterparts.

Results

The analytical pipeline was validated by demonstrating an increased risk of individuals exposed to nicotine dependence for subsequent diagnosis of myocardial infarction, malignant neoplasm of the lung, and chronic obstructive pulmonary disease. Overall, 16.8% of individuals with nicotine dependence developed CIDs, compared to 9.6% of individuals not exposed to nicotine dependence (hazard ratio 2.12, confidence interval 2.10-2.14, p < 0.0001). Investigating single CIDs, nicotine dependence imposed increased risks for 23 of the 38 investigated diseases, i.e., dermatomyositis, granulomatosis with polyangiitis, pyoderma gangrenosum, and immune thrombocytopenic purpura. The sex-stratified analysis revealed few sex-specific differences in CID risk.

Discussion

Our study emphasizes the importance of preventive measures targeting nicotine addiction to reduce the global burden of CIDs.

Toward curing neurological autoimmune disorders: Biomarkers, immunological mechanisms, and therapeutic targets

Autoimmune neurology is a rapidly expanding field driven by the discovery of neuroglial autoantibodies and encompassing a myriad of conditions affecting every level of the nervous system. Traditionally, autoantibodies targeting intracellular antigens are considered markers of T cell-mediated cytotoxicity, while those targeting extracellular antigens are viewed as pathogenic drivers of disease. However, recent advances highlight complex interactions between these immune mechanisms, suggesting a continuum of immunopathogenesis. The breakdown of immune tolerance, central to these conditions, is affected by modifiable and non-modifiable risk factors such as genetic predisposition, infections, and malignancy. While significant therapeutic advancements have revolutionized treatment of certain diseases, such as neuromyelitis optica, our understanding of many others, particularly T cell-mediated conditions, remains limited, with fewer treatment options available. Future research should focus on improving effector function modeling and deepening our understanding of the factors influencing immune tolerance, with the goal of providing novel treatment options and improving patient care.

New approach methodologies to assess wanted and unwanted drugs-induced immunostimulation

This review examines various classes of drugs, focusing on their therapeutic and adverse effects, particularly in relation to immunostimulation. We emphasize the potential of new approach methodologies (NAMs) to study both expected and unexpected immunostimulatory effects. By evaluating the modes of action of different immunostimulatory drugs, we aim to provide insights into effectively assessing unwanted immunostimulatory responses. The review begins by exploring drugs that stimulate the immune system-including immunostimulants, monoclonal antibodies, chemotherapeutics, and nucleic acid-based drugs-to outline NAMs that could be employed to evaluate immunostimulation.

The Role of the Gut Microbiota in Health, Diet, and Disease with a Focus on Obesity

The gut microbiota has been increasingly recognised as a critical determinant of human health, influencing a wide range of physiological processes. A healthy gut microbiota is essential for maintaining metabolic, immune, and gastrointestinal homeostasis, contributing to overall well-being. Alterations in its composition and functionality, often referred to as microbial dysbiosis, are strongly associated with the development of gut-related and systemic diseases. The gut microbiota synthesises several components and interacts with epithelial cell receptors, influencing processes that extend beyond nutritional status to the pathogenesis of diseases such as obesity, which extend beyond their known contribution to nutritional status. Therefore, this state-of-the-art review synthesises findings from recent studies on the composition, functions, and influencing factors of the gut microbiota, with a focus on its role in obesity. A systematic search of peer-reviewed literature was conducted to ensure comprehensive coverage, while expert insights are incorporated to discuss emerging research directions and future perspectives in the field.

Large-scale analysis highlights obesity as a risk factor for chronic, non-communicable inflammatory diseases

Background

Overweight and obesity are a global pandemic, contributing to death and disability-adjusted life-years. Obesity is a major factor in the onset of chronic inflammatory diseases (CIDs). Yet, several knowledge gaps remain: For several CIDs, inconsistent results have been reported, relating to their obesity-imposed risk, data on most rare CIDs remain unavailable, sex differences and racial disparities remain mostly unaddressed.

Methods

A large-scale cohort study compared the risk of developing 46 CIDs in individuals with overweight/obesity (n=3,101,824) to an equal number of non-overweight/obese individuals. Propensity score matching optimized between-group comparability, and sensitivity analyses assessed study robustness.

Results

The risk of developing any CID was 28.48% in overweight/obese individuals versus 17.55% in non-overweight/obese controls, with a hazard ratio (95%-confidence interval) of 1.52 (1.509-1.521, p<0.0001). This risk was consistent across all sensitivity, sex-, and race-stratified analyses. Overweight and obesity were associated with an increased risk for 24 of 46 CIDs in the primary analysis and all sensitivity analyses. For 12 diseases, increased risks were confirmed to one of the two sensitivity analyses, while for 10 diseases, results were discordant. No increased risk was observed for one disease. In sex-stratified analysis, overweight and obesity posed a more pronounced risk for four CIDs in female individuals. In race-stratified analysis, overweight and obesity were linked to a higher risk for seven CIDs in White individuals and to one CID in "Black or African American" individuals.

Conclusion

Overweight and obesity increase the risk for the majority of CIDs in a sex- and race-specific manner.

IL-10 is not required for the alleviation of collagen-induced arthritis by non-lethal malarial infection in mice

We previously reported that Plasmodium yoelii 17XNL (Py), a non-lethal rodent malarial parasite, could suppress collagen-induced arthritis (CIA) and increase the production of T cell-derived interleukin (IL)-10. However, it remained unclear whether IL-10 is essential for the Py-induced suppression of CIA. Male IL-10 knockout (KO) DBA/1 J mice were immunized with bovine type II collagen (CII) and subsequently infected with Py at one week post-immunization. The development of arthritis was evaluated by an arthritis score up to 6 weeks post-immunization. At 3 weeks post-immunization, cytokine production from splenocytes and serum anti-CII IgG/IgG1/IgG2a levels were compared between non-infected control mice and Py-infected mice. Py infection inhibited the development of CIA in IL-10KO mice until 4 weeks post-immunization, after which the arthritis score reached levels comparable with the control mice. Both pro-arthritic (IL-17 and TNF-α) and anti-arthritic (IFN-γ and IL-4) cytokines were down-regulated during the periods of parasitemia, while no significant differences were observed in levels of anti-CII IgG antibodies. Our findings indicate that Py alleviates CIA via IL-10-independent mechanisms.

Unusual Phospholipids from Morganella morganii Linked to Depression

A multifactorial association study detected a probable causal connection between the prevalence of Morganella morganii in the gut microbiome and the incidence of major depressive disorder (MDD) in the human host. A bioassay-guided fractionation approach identified bacterially produced metabolites that induced pro-inflammatory immune responses. The metabolites are unusual phospholipids that resemble conventional cardiolipins, in which diethanolamine (DEA) replaces the central glycerol. These molecular chimeras of endogenous metabolites from phospholipid biosynthetic pathways and the industrially produced micropollutant DEA activate TLR2/TLR1 receptors and induce the production of pro-inflammatory cytokines, especially IL-6. Their activity in conventional immunomodulatory assays largely parallels that of immunogenic cardiolipins with conventional structures. The molecular mechanism connecting these chimeric cardiolipins to MDD is supported by other studies and has implications for conditions other than MDD.

Fibroblasts in rheumatoid arthritis: novel roles in joint inflammation and beyond

High-throughput technologies in human and animal studies have revealed novel molecular and cellular pathways involved in tissue inflammation of rheumatoid arthritis (RA). Fibroblasts have been in the forefront of research for several decades. Subpopulations with specific phenotypic and functional properties have been characterized both in mouse models and human disease. Data supporting the active involvement of fibroblasts in immune responses and tissue remodeling processes, as well as their central role in promoting clinical relapses and contributing to treatment resistance, have clearly reshaped their role in disease evolution. The lung is an important non-synovial component of RA both from a clinical and an immunopathogenic aspect. Interstitial lung disease (ILD) is a significant contributor to disease burden affecting morbidity and mortality. Although our knowledge of ILD has progressed, significant gaps in both basic and clinical science remain, posing hurdles to efficient diagnosis, prediction of disease course and its effective treatment. The specific role and contribution of fibroblasts to this process has not been clearly defined. The focus of this review is on fibroblasts and their contribution to RA and RA-ILD, presenting data on genetics and immune responses associated with RA-ILD in humans and animal models.

Impact of Early-Life Microbiota on Immune System Development and Allergic Disorders

Introduction: The shaping of the human intestinal microbiota starts during the intrauterine period and continues through the subsequent stages of extrauterine life. The microbiota plays a significant role in the predisposition and development of immune diseases, as well as various inflammatory processes. Importantly, the proper colonization of the fetal digestive system is influenced by maternal microbiota, the method of pregnancy completion and the further formation of the microbiota. In the subsequent stages of a child's life, breastfeeding, diet and the use of antibiotics influence the state of eubiosis, which determines proper growth and development from the neonatal period to adulthood. The literature data suggest that there is evidence to confirm that the intestinal microbiota of the infant plays an important role in regulating the immune response associated with the development of allergic diseases. However, the identification of specific bacterial species in relation to specific types of reactions in allergic diseases is the basic problem. Background: The main aim of the review was to demonstrate the influence of the microbiota of the mother, fetus and newborn on the functioning of the immune system in the context of allergies and asthma. Methods: We reviewed and thoroughly analyzed the content of over 1000 articles and abstracts between the beginning of June and the end of August 2024. Over 150 articles were selected for the detailed study. Results: The selection was based on the PubMed National Library of Medicine search engine, using selected keywords: "the impact of intestinal microbiota on the development of immune diseases and asthma", "intestinal microbiota and allergic diseases", "the impact of intrauterine microbiota on the development of asthma", "intrauterine microbiota and immune diseases", "intrauterine microbiota and atopic dermatitis", "intrauterine microbiota and food allergies", "maternal microbiota", "fetal microbiota" and "neonatal microbiota". The above relationships constituted the main criteria for including articles in the analysis. Conclusions: In the present review, we showed a relationship between the proper maternal microbiota and the normal functioning of the fetal and neonatal immune system. The state of eubiosis with an adequate amount and diversity of microbiota is essential in preventing the development of immune and allergic diseases. The way the microbiota is shaped, resulting from the health-promoting behavior of pregnant women, the rational conduct of the medical staff and the proper performance of the diagnostic and therapeutic process, is necessary to maintain the health of the mother and the child. Therefore, an appropriate lifestyle, rational antibiotic therapy as well as the way of completing the pregnancy are indispensable in the prevention of the above conditions. At the same time, considering the intestinal microbiota of the newborn in relation to the genera and phyla of bacteria that have a potentially protective effect, it is worth noting that the use of suitable probiotics and prebiotics seems to contribute to the protective effect.

Environment, Lifestyles, and Climate Change: The Many Nongenetic Contributors to The Long and Winding Road to Autoimmune Diseases

A critical unanswered question is what is causing the increase in the prevalence of autoimmunity and autoimmune diseases around the world. Given the rapidity of change, this is likely the result of major recent alterations in our exposures to environmental risk factors for these diseases. More evidence is becoming available that the evolution of autoimmune disease, years or even decades in the making, results from multiple exposures that alter susceptible genomes and immune systems over time. Exposures during sensitive phases in key developmental or hormonal periods may set the stage for the effects of later exposures. It is likely that synergistic and additive impacts of exposure mixtures result in chronic low-level inflammation. This inflammation may eventually pass thresholds that lead to immune system activation and autoimmunity, and with further molecular and pathologic changes, the complete clinical syndrome emerges. Much work remains to be done to define the mechanisms and risk and protective factors for autoimmune conditions. However, evidence points to a variety of pollutants, xenobiotics, infections, occupational exposures, medications, smoking, psychosocial stressors, changes in diet, obesity, exercise, and sleep patterns, as well as climate change impacts of increased heat, storms, floods, wildfires, droughts, UV radiation, malnutrition, and changing infections, as possible contributors. Substantial investments in defining the role of causal factors, in whom and when their effects are most important, the necessary and sufficient gene-environment interactions, improved diagnostics and therapies, and preventive strategies are needed now to limit the many negative personal, societal, and financial impacts that will otherwise occur.

Association of Helicobacter pylori Infection with Pediatric Asthma in Palestine

Purpose

Significant debate exists on the association between Helicobacter pylori infection and childhood asthma. We aimed to explore this association in a cohort of children in Palestine while estimating the prevalence of H. pylori in this population.

Methods

We conducted a prospective case-control study among children aged 6-15 years in Palestine, including 44 asthma cases diagnosed by pediatric pulmonologists and 99 age-matched healthy controls recruited through cluster sampling from schools. H. pylori status was determined using a stool antigen test. Asthma severity was assessed using the International Study of Asthma and Allergies in Childhood questionnaire. Data on recent antibiotic use, which could affect H. pylori status, were collected for both groups. Multiple logistic regression analyzed the association between H. pylori and asthma, adjusting for age and sex. The chi-square test assessed the impact of antibiotic use on H. pylori status.

Results

The prevalence of H. pylori infection in the study population was 45%. Children with asthma had a lower prevalence of H. pylori infection compared to healthy controls (32% vs. 51%, adjusted odds ratios, 0.46; 95% confidence interval, 0.22-0.99; p=0.04). Antibiotic use in the past month or year did not significantly impact H. pylori status. Among children with asthma, H. pylori infection rates did not vary by asthma severity (p=0.05).

Conclusion

H. pylori infection is associated with a reduced risk of asthma in children, suggesting a potential protective role. Further prospective cohort studies are warranted to clarify the mechanisms underlying this association.

The association between prenatal antibiotic exposure and adverse long-term health outcomes in children: A systematic review and meta-analysis

BACKGROUND

Antibiotics are the most commonly prescribed drugs during pregnancy. The long-term health risks to children associated with prenatal antibiotic exposure are uncertain.

OBJECTIVE

To identify the association between prenatal antibiotics and adverse long-term health outcomes in children.

METHODS

A systematic search was done to identify original studies investigating the association between prenatal antibiotic exposure and adverse long-term health outcomes in children. Studies were excluded if: (i) antibiotics were only given during delivery or (ii) the outcome was present before antibiotic exposure.

RESULTS

We included 158 studies, reporting 23 outcomes in 21,943,763 children, in our analysis. For the following adverse health outcomes, there was a significant association with antibiotic exposure found in two or more studies: atopic dermatitis (OR 1.27, 95% CI 1.06-1.52, p=0.01), food allergies (OR 1.25, 95% CI 1.09-1.44, p<0.01), allergic rhinoconjunctivitis (OR 1.16, 95% CI 1.15-1.17, p<0.01), wheezing (OR 1.39, 95% CI 1.14-1.69, p<0.01), asthma (OR 1.36, 95% CI 1.24-1.50, p<0.01), obesity (OR 1.36, 95% CI 1.12-1.64, p<0.01), cerebral palsy (OR 1.25, 95% CI 1.10-1.43, p<0.01), epilepsy or febrile seizure (OR 1.16, 95% CI 1.08-1.24, p<0.01), and cancer (OR 1.13, 95% CI 1.01-1.26, p=0.04).

CONCLUSION

Although causality cannot be implied, these findings support antibiotic stewardship efforts to ensure judicious use of antibiotics during pregnancy to avoid potential long-term health risks.

After the Infection: A Survey of Pathogens and Non-communicable Human Disease

There are many well-established relationships between pathogens and human disease, but far fewer when focusing on non-communicable diseases (NCDs). We leverage data from The UK Biobank and TriNetX to perform a systematic survey across 20 pathogens and 426 diseases, primarily NCDs. To this end, we assess the association between disease status and infection history proxies. We identify 206 pathogen-disease pairs that replicate in both cohorts. We replicate many established relationships, including Helicobacter pylori with several gastroenterological diseases and connections between Epstein-Barr virus with multiple sclerosis and lupus. Overall, our approach identified evidence of association for 15 pathogens and 96 distinct diseases, including a currently controversial link between human cytomegalovirus (CMV) and ulcerative colitis (UC). We validate this connection through two orthogonal analyses, revealing increased CMV gene expression in UC patients and enrichment for UC genetic risk signal near human genes that have altered expression upon CMV infection. Collectively, these results form a foundation for future investigations into mechanistic roles played by pathogens in NCDs. All results are easily accessible on our website, https://tf.cchmc.org/pathogen-disease.

Celiac in the twenty-first century-the change in BMI of children at diagnosis over the last two decades

This study examined the prevalence of different BMI categories among newly diagnosed pediatric celiac disease (CD) patients in Israel from 2002 to 2018. A retrospective cross-sectional study using the database of Clalit Health Services in Israel included 5520 newly diagnosed CD children aged 2-18 between 2002 and 2018. Data on BMI, gender, ethnicity, and socioeconomic status (SES) were collected and analyzed Of the 5520 CD patients, 57.5% were female, 39.7% had low SES, and 77.1% were Jewish. At diagnosis, 13.1% were underweight, 73% had normal BMI, 9.1% overweight, and 4.8% were obese. Underweight and obese patients tended to be older at diagnosis (9 years) compared with normal and overweight patients (8 years) (P < 0.001). A higher proportion of Arab patients were underweight, while more Jewish patients were obese. Lower SES was significantly associated with increased underweight risk (P < 0.001). Over time, diagnosed patients had improved SES and were less underweight (P < 0.001). Male gender increased obesity risk (OR 1.36 [95% CI 1.06-1.74], P = 0.017), while Arab ethnicity was protective for obesity (OR 0.67 [95% CI, (0.45-0.99)], P = 0.047)Conclusion: Underweight prevalence significantly decreased in the second decade, but no significant change in overweight and obesity was noted. Underweight was associated with older age at diagnosis, poverty, and Arab ethnicity. Obesity was associated with older age and was more frequent in Jewish and male patients. Physicians should have a low threshold for CD screening regardless of BMI status to enable timely diagnosis and treatment to prevent long-term health consequences. What Is Known: • Celiac disease is traditionally associated with underweight due to malabsorption, but recent reports suggest an increasing prevalence of overweight and obesity in pediatric patients at diagnosis What Is New: • This study found that underweight prevalence decreased significantly over time, while overweight and obesity prevalence remained unchanged. Underweight was associated with older age, poverty, and Arab ethnicity, while obesity was more common in Jewish and male patients.

EBV-specific T-cell immunity: relevance for multiple sclerosis

Genetic and environmental factors jointly determine the susceptibility to develop multiple sclerosis (MS). Improvements in the design of epidemiological studies have helped to identify consistent environmental risk associations such as the increased susceptibility for MS following Epstein-Barr virus (EBV) infection, while biological mechanisms that drive the association between EBV and MS remain incompletely understood. An increased and broadened repertoire of antibody and T-cell immune responses to EBV-encoded antigens, especially to the dominant CD4+ T-cell EBV nuclear antigen 1 (EBNA1), is consistently observed in patients with MS, indicating that protective EBV-specific immune responses are deregulated in MS and potentially contribute to disease development. Exploitation of B-cell trajectories by EBV infection might promote survival of autoreactive B-cell species and proinflammatory B:T-cell interactions. In this review article, we illustrate evidence for a causal role of EBV infection in MS, discuss how EBV-targeting adaptive immune responses potentially modulate disease susceptibility and progression, and provide future perspectives on how novel model systems could be utilized to better define the role of EBV and viral pathogens in MS. Insights gained from these studies might facilitate the development of prevention strategies and more effective treatments for MS.

Infants born during COVID-19 pandemic experience increased susceptibility to airway hyperresponsiveness

Background

Asthma, allergic rhinitis, atopic dermatitis, and food allergy are type 2 inflammation diseases. Since the 1960s, the prevalence of those diseases has steadily increased, presumably due to the "Hygiene hypothesis" which suggests that early exposure of infants to pathogens, siblings, and environmental dust, has a protective effect against the development of allergic diseases. The COVID-19 pandemic increased environmental hygiene due to lockdowns, masks, and social distancing.

Objective

To compare the prevalence of allergic diseases among children born before and during the pandemic.

Methods

The Cow's Milk Early Exposure Trial prospectively followed newborns until 12-months of age using monthly survey and examined milk allergy development. Some were born before the first COVID-19 lockdown in Israel (April 2018-March 2020), and some were born during the pandemic (March 2020-May 2021). The monthly surveys included questions regarding atopic comorbidities.

Results

A total of 1,989 infants completed 12-months of follow-up. Among them, 1,086(54.5%) were diagnosed with at least one atopic disease. Among 235 infants born after the last lockdown, 162 were diagnosed with airway hyperresponsiveness (AHR)(68.9%), significantly more than in any other group. No other significant differences were found between the study groups.

Conclusions

There was no significant difference in the development of atopic comorbidities between infants born before and during the pandemic. Significantly more infants who were born after restrictions were eased were diagnosed AHR. A longer follow-up period is needed to obtain a better understanding of the influence of the COVID-19 restrictions on the development of atopic comorbidities.

Clinical Trial Registry

NIH Clinical Trials Registry: NCT02785679.

The influence of lifestyle and environmental factors on host resilience through a homeostatic skin microbiota: An EAACI Task Force Report

Human skin is colonized with skin microbiota that includes commensal bacteria, fungi, arthropods, archaea and viruses. The composition of the microbiota varies at different anatomical locations according to changes in body temperature, pH, humidity/hydration or sebum content. A homeostatic skin microbiota is crucial to maintain epithelial barrier functions, to protect from invading pathogens and to interact with the immune system. Therefore, maintaining homeostasis holds promise to be an achievable goal for microbiome-directed treatment strategies as well as a prophylactic strategy to prevent the development of skin diseases, as dysbiosis or disruption of homeostatic skin microbiota is associated with skin inflammation. A healthy skin microbiome is likely modulated by genetic as well as environmental and lifestyle factors. In this review, we aim to provide a complete overview of the lifestyle and environmental factors that can contribute to maintaining the skin microbiome healthy. Awareness of these factors could be the basis for a prophylactic strategy to prevent the development of skin diseases or to be used as a therapeutic approach.

Preceding hepatitis B virus infection is highly prevalent in patients with neuromyelitis optica spectrum disorder in Taiwan

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system, characterized by pathogenic anti-Aquaporin-4 antibodies (AQP4-Ab). Given that infections can trigger autoimmune responses, we investigated the association between Hepatitis B virus (HBV) infection and NMOSD.

METHODS

HBV and hepatitis C virus serologies were analyzed in 105 NMOSD patients, 85 multiple sclerosis (MS) patients, and 1,661 healthy Taiwanese controls. Participants were classified into four HBV infection statuses (acute, chronic, resolved, and never infected), and further grouped by vaccination status. Logistic regression was used to estimate odds ratios (OR) for NMOSD development in individuals with chronic or resolved HBV infection.

RESULTS

Among those born before the Taiwan's universal vaccination program, 63.4 % of NMOSD patients had resolved HBV infection, compared to 30.6 % of MS patients and 16.4 % of controls. Resolved HBV infection was associated with a 2.3-fold increased risk for NMOSD development (95 % CI, 1.4-3.8), but not with MS risk. In the post-vaccination cohort, resolved HBV infection remained more frequent in NMOSD patients (8.7 %) than in MS (0 %) and controls (1.8 %). NMOSD patients with resolved HBV infection had later disease onset by 14.6 years and higher Expanded Disability Status Scale (EDSS) scores compared to those without HBV infection, even after adjusting for age and sex (3.5 ± 1.9 vs. 2.2 ± 1.8, p < 0.001).

CONCLUSION

Preceding HBV infection is prevalent among Taiwanese NMOSD patients and is associated with increased disease risk, older age at onset, and greater disability. Screening for HBV is essential for NMOSD patients, particularly in endemic regions.

Human Papillomavirus Infection and Autoimmune Diseases: A Two-Sample Bidirectional Mendelian Randomization Study

BACKGROUND

Although earlier observational studies have revealed a connection between human papillomavirus (HPV) infection and several autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), the exact causative mechanism underlying this association is still unknown.

METHODS

This two-sample bidirectional MR study was conducted based on publicly released data from genome-wide association studies (GWAS). Our results were mainly derived from the inverse variance weighted (IVW) model, with the remaining three models also being calculated. The MR Steiger test was used to examine the correctness of our causal direction. Sensitivity analysis was performed using Mendelian randomized pleiotropy residual sum and outlier (MR-PRESSO), MR-Egger regression.

RESULTS

The IVW results showed that there was a positive causal association between HPV16 E7 protein and SLE (odds ratio (OR) = 1.075, 95% confidence interval (CI), 1.003-1.151, FDR-p = 0.04), however, there was a negative causal association between HPV18 E7 protein and SLE (OR = 0.884, 95% CI, 0.804-0.972, FDR-p = 0.02). No causal associations of HPV16 E7 protein and HPV18 E7 protein with RA, IBD was observed including its subtypes Ulcerative colitis (UC) and Crohn's disease (CD). Sensitivity analysis showed that there was no significant heterogeneity (p > 0.05) or genetic pleiotropy (p > 0.05).

CONCLUSION

Our two-sample bidirectional Mendelian randomization study identifies a causal association between HPV infection and SLE, but no causal association between HPV infection and RA and IBD.

Epithelial barrier dysfunction and associated diseases in companion animals: Differences and similarities between humans and animals and research needs

Since the 1960s, more than 350,000 new chemicals have been introduced into the lives of humans and domestic animals. Many of them have become part of modern life and some are affecting nature as pollutants. Yet, our comprehension of their potential health risks for both humans and animals remains partial. The "epithelial barrier theory" suggests that genetic predisposition and exposure to diverse factors damaging the epithelial barriers contribute to the emergence of allergic and autoimmune conditions. Impaired epithelial barriers, microbial dysbiosis, and tissue inflammation have been observed in a high number of mucosal inflammatory, autoimmune and neuropsychiatric diseases, many of which showed increased prevalence in the last decades. Pets, especially cats and dogs, share living spaces with humans and are exposed to household cleaners, personal care products, air pollutants, and microplastics. The utilisation of cosmetic products and food additives for pets is on the rise, unfortunately, accompanied by less rigorous safety regulations than those governing human products. In this review, we explore the implications of disruptions in epithelial barriers on the well-being of companion animals, drawing comparisons with humans, and endeavour to elucidate the spectrum of diseases that afflict them. In addition, future research areas with the interconnectedness of human, animal, and environmental well-being are highlighted in line with the "One Health" concept.

Diverse roles of dendritic cell and regulatory T cell crosstalk in controlling health and disease

Dendritic cells (DCs) are specialized antigen-presenting cells for lymphocytes, including regulatory T (Treg) cells, a subset of CD4+ T cells expressing CD25 and Foxp3, a transcription factor. Treg cells maintain immunological self-tolerance in mice and humans, and suppress autoimmunity and other various immune responses such as tumor immunity, transplant rejection, allergy, responses to microbes, and inflammation. Treg-cell proliferation is controlled by antigen-presenting DCs. On the other hand, Treg cells suppress the function of DCs by restraining DC maturation. Therefore, the interaction between DCs and Treg cells, DC-Treg crosstalk, could contribute to controlling health and disease. We recently found that unique DC-Treg crosstalk plays a role in several conditions. First, Treg cells are expanded in ultraviolet B (UVB)-exposed skin by interacting with DCs, and the UVB-expanded Treg cells have a healing function. Second, manipulating DC-Treg crosstalk can induce effective acquired immune responses against severe acute respiratory syndrome coronavirus 2 antigens without adjuvants. Third, Treg cells with a special feature interact with DCs in the tumor microenvironment of human head and neck cancer, which may contribute to the prognosis. Understanding the underlying mechanisms of DC-Treg crosstalk may provide a novel strategy to control health and disease.

Epithelial barrier theory in the context of nutrition and environmental exposure in athletes

Exposure to toxic substances, introduced into our daily lives during industrialization and modernization, can disrupt the epithelial barriers in the skin, respiratory, and gastrointestinal systems, leading to microbial dysbiosis and inflammation. Athletes and physically active individuals are at increased risk of exposure to agents that damage the epithelial barriers and microbiome, and their extreme physical exercise exerts stress on many organs, resulting in tissue damage and inflammation. Epithelial barrier-damaging substances include surfactants and enzymes in cleaning products, laundry and dishwasher detergents, chlorine in swimming pools, microplastics, air pollutants such as ozone, particulate matter, and diesel exhaust. Athletes' high-calorie diet often relies on processed foods that may contain food emulsifiers and other additives that may cause epithelial barrier dysfunction and microbial dysbiosis. The type of the material used in the sport equipment and clothing and their extensive exposure may increase the inflammatory effects. Excessive travel-related stress, sleep disturbances and different food and microbe exposure may represent additional factors. Here, we review the detrimental impact of toxic agents on epithelial barriers and microbiome; bring a new perspective on the factors affecting the health and performance of athletes and physically active individuals.

Lupus and other autoimmune diseases: Epidemiology in the population of African ancestry and diagnostic and management challenges in Africa

Autoimmune diseases are prevalent among people of African ancestry living outside Africa. However, the burden of autoimmune diseases in Africa is not well understood. This article provides a global overview of the current burden of autoimmune diseases in individuals of African descent. It also discusses the major factors contributing to autoimmune diseases in this population group, as well as the challenges involved in diagnosing and managing autoimmune diseases in Africa.

Asthma development is associated with low mucosal IL-10 during viral infections in early life

BACKGROUND

Viral infection is a common trigger of severe respiratory illnesses in early life and a risk factor for later asthma development. The mechanism leading to asthma could involve an aberrant airway immune response to viral infections, but this has rarely been studied in a human setting.

OBJECTIVES

To investigate in situ virus-specific differences in upper airway immune mediator levels during viral episodes of respiratory illnesses and the association with later asthma.

METHODS

We included 493 episodes of acute respiratory illnesses in 277 children aged 0-3 years from the COPSAC2010 mother-child cohort. Levels of 18 different immune mediators were assessed in nasal epithelial lining fluid using high-sensitivity MesoScale Discovery kits and compared between children with and without viral PCR-identification in nasopharyngeal samples. Finally, we investigated whether the virus-specific immune response was associated with asthma by age 6 years.

RESULTS

Viral detection were associated with upregulation of several Type 1 and regulatory immune mediators, including IFN-ɣ, TNF-α, CCL4, CXCL10 and IL-10 and downregulation of Type 2 and Type 17 immune mediators, including CCL13, and CXCL8 (FDR <0.05). Children developing asthma had decreased levels of IL-10 (FDR <0.05) during viral episodes compared to children not developing asthma.

CONCLUSION

We described the airway immune mediator profile during viral respiratory illnesses in early life and showed that children developing asthma by age 6 years have a reduced regulatory (IL-10) immune mediator level. This provides insight into the interplay between early-life viral infections, airway immunity and asthma development.

Lifestyle score is associated with cellular immune profiles in healthy Tanzanian adults

Immune system and vaccine responses vary across geographical locations worldwide, not only between high and low-middle income countries (LMICs), but also between rural and urban populations within the same country. Lifestyle factors such as housing conditions, exposure to microorganisms and parasites and diet are associated with rural-and urban-living. However, the relationships between these lifestyle factors and immune profiles have not been mapped in detail. Here, we profiled the immune system of 100 healthy Tanzanians living across four rural/urban areas using mass cytometry. We developed a lifestyle score based on an individual's household assets, housing condition and recent dietary history and studied the association with cellular immune profiles. Seventeen out of 80 immune cell clusters were associated with living location or lifestyle score, with eight identifiable only using lifestyle score. Individuals with low lifestyle score, most of whom live in rural settings, showed higher frequencies of NK cells, plasmablasts, atypical memory B cells, T helper 2 cells, regulatory T cells and activated CD4+ T effector memory cells expressing CD38, HLA-DR and CTLA-4. In contrast, those with high lifestyle score, most of whom live in urban areas, showed a less activated state of the immune system illustrated by higher frequencies of naïve CD8+ T cells. Using an elastic net machine learning model, we identified cellular immune signatures most associated with lifestyle score. Assuming a link between these immune profiles and vaccine responses, these signatures may inform us on the cellular mechanisms underlying poor responses to vaccines, but also reduced autoimmunity and allergies in low- and middle-income countries.

The function of antibodies

Antibodies have multiple biological activities. They can both recognize and act on specific antigens. They can protect against and cause serious diseases, enhance and inhibit antibody responses, enable survival, and threaten life. Which among their many, often antagonistic properties explains that antibodies were selected half a billion years ago and transmitted to mammals across millions of generations? In other words, what is the function of antibodies? Here I examine how their structure endows antibodies with unique cognitive and effector properties that contribute to their multiple biological activities. I show that rather than specific properties, antibodies have large functional repertoires. They have a cognitive repertoire and an effector repertoire that are selected from larger available repertoires, themselves drawn at random from even larger virtual repertoires. These virtual repertoires provide the adaptive immune system with immense, constantly renewed, reservoirs of cognitive and effector functions that can be actualized at any time according to the context. I propose that such a flexibility, which enables living individuals to adapt to a rapidly changing environment, and even deal with an unknown future, may provide a better selective advantage than any particular function.

[The human microbiome proofed by the Anthropocene: from correlation to causality and intervention]

The deleterious effects of human activities on biodiversity in the vegetal and animal world, and on climate changes are now well-established facts. However, little is yet known on the impact of human activities on microbial diversity on the planet and more specifically on the human microbiota Large implementation of metagenomics allows exaustive microbial cataloguing with broad spatio-temporal resolution of human microbiota. A reduction in bacterial richness and diversity in the human microbiota, particularly in the intestinal tract, is now established and particularly obvious in the most industrialized regions of the planet. Massive, uncontrolled use of antibiotics, drastic changes in traditional food habits and some elements of the "global exposome" that remain to identify are usually considered as stressors accounting for this situation of "missing microbes". As a consequence, a dysbiotic situation develops, a "dysbiosis" being characterized by the erosion of the central core of shared bacterial species across individuals and the development of opportunistic "pathobionts" in response to a weaker barrier capacity of these impoverished microbiota. The current challenge is to establish a causality link between the extension of these dysbiotic situations and the steady emergence of epidemic, non-communicable diseases such as asthma, allergy, obesity, diabetes, autoimmune diseases and some cancers. Experimental animal models combined with controlled, prospective clinical interventions are in demand to consolidate causality links, with the understanding that in the deciphering of the mechanisms of alteration of the human-microbiome symbiosis resides a novel exciting chapter of medicine: "microbial medicine".

The protective effect of the intestinal microbiota in type-1 diabetes in NOD mice is limited to a time window in early life

Introduction

The incidence of type-1 diabetes is on the rise, particularly in developed nations, and predominantly affects the youth. While genetic predisposition plays a substantial role, environmental factors, including alterations in the gut microbiota, are increasingly recognized as significant contributors to the disease.

Methods

In this study, we utilized germ-free non-obese diabetic mice to explore the effects of microbiota colonization during early life on type-1 diabetes susceptibility.

Results

Our findings reveal that microbiota introduction at birth, rather than at weaning, significantly reduces the risk of type-1 diabetes, indicating a crucial window for microbiota-mediated modulation of immune responses. This protective effect was independent of alterations in intestinal barrier function but correlated with testosterone levels in male mice. Additionally, early life colonization modulated T cell subset frequencies, particularly T helper cells and regulatory T cells, in the intestine, potentially shaping type-1 diabetes predisposition.

Discussion

Our findings underscore the pivotal role of early-life microbial interactions in immune regulation and the development of autoimmune diseases.

A systematic framework for understanding the microbiome in human health and disease: from basic principles to clinical translation

The human microbiome is a complex and dynamic system that plays important roles in human health and disease. However, there remain limitations and theoretical gaps in our current understanding of the intricate relationship between microbes and humans. In this narrative review, we integrate the knowledge and insights from various fields, including anatomy, physiology, immunology, histology, genetics, and evolution, to propose a systematic framework. It introduces key concepts such as the 'innate and adaptive genomes', which enhance genetic and evolutionary comprehension of the human genome. The 'germ-free syndrome' challenges the traditional 'microbes as pathogens' view, advocating for the necessity of microbes for health. The 'slave tissue' concept underscores the symbiotic intricacies between human tissues and their microbial counterparts, highlighting the dynamic health implications of microbial interactions. 'Acquired microbial immunity' positions the microbiome as an adjunct to human immune systems, providing a rationale for probiotic therapies and prudent antibiotic use. The 'homeostatic reprogramming hypothesis' integrates the microbiome into the internal environment theory, potentially explaining the change in homeostatic indicators post-industrialization. The 'cell-microbe co-ecology model' elucidates the symbiotic regulation affecting cellular balance, while the 'meta-host model' broadens the host definition to include symbiotic microbes. The 'health-illness conversion model' encapsulates the innate and adaptive genomes' interplay and dysbiosis patterns. The aim here is to provide a more focused and coherent understanding of microbiome and highlight future research avenues that could lead to a more effective and efficient healthcare system.

Preclinical Development of SHR-1819, a Potent Humanized IL-4Rα Antibody for Treating Type 2 Inflammatory Diseases

Background

Interleukin (IL)-4 and IL-13 are critical pathogenic factors for type 2 inflammation-related allergic diseases, sharing the mutual receptor subunit IL-4Rα. However, it was ineffective for certain type 2 inflammation diseases by targeting IL-4, IL-13 ligand alone or both in clinical studies. The work presented herein aimed to evaluate the preclinical efficacy and pharmacokinetics profile of a novel monoclonal antibody against IL-4Rα, SHR-1819, as a promising therapy for type 2 inflammation diseases.

Methods

SHR-1819 was generated through immunization by C57BL/6 mice with recombinant hIL-4Rα protein, followed by humanization and affinity maturation. Then, its binding properties with IL-4Rα were determined using surface plasmon resonance (SPR) and ELISA. In vitro inhibitory effects of SHR-1819 were assessed on hIL-4-/hIL-13-induced cell proliferation and signal transducer and activator of transcription 6 (STAT6) signaling activation. In vivo efficacy of SHR-1819 was evaluated in several type 2 inflammatory diseases models, including asthma, atopic dermatitis (AD), and allergic rhinitis (AR) by using hIL-4/hIL-4Rα transgenic mice. Furthermore, the pharmacokinetic (PK) profiles of SHR-1819 were characterized.

Results

SHR-1819 showed high binding affinity to human IL-4Rα and effectively blocked IL-4Rα at sub-nanomolar concentration. In vitro assays indicated that SHR-1819 significantly inhibited TF-1 cell proliferation and STAT6 activation induced by hIL-4/hIL-13. In the asthma model, SHR-1819 could reduce airway hyperresponsiveness, decrease serum IgE levels, and alleviated inflammatory lung cell infiltration. In the AD model, SHR-1819 could significantly alleviate inflammatory and skin symptoms. In the AR model, it could remarkably decrease the frequencies of nasal rubbing and sneezing, and inflammatory cell infiltration in nasal tissues. These in vivo efficacy studies demonstrated the therapeutic potential of SHR-1819 in preclinical disease models. Moreover, subcutaneous administration of SHR-1819 exhibited favorable bioavailability in mice.

Conclusion

The results supported SHR-1819 as a promising preclinical candidate for the treatment of type 2 inflammatory diseases, including asthma, AD and AR.

Hydrogel-based approaches to target hypersensitivity mechanisms underlying autoimmune disease

A robust adaptive immune response is essential for combatting pathogens. In the wrong context such as due to genetic and environmental factors, however, the same mechanisms crucial for self-preservation can lead to a loss of self-tolerance. Resulting autoimmunity manifests in the development of a host of organ-specific or systemic autoimmune diseases, hallmarked by aberrant immune responses and tissue damage. The prevalence of autoimmune diseases is on the rise, medical management of which focuses primarily on pharmacological immunosuppression that places patients at a risk of side effects, including opportunistic infections and tumorigenesis. Biomaterial-based drug delivery systems confer many opportunities to address challenges associated with conventional disease management. Hydrogels, in particular, can protect encapsulated cargo (drug or cell therapeutics) from the host environment, afford their presentation in a controlled manner, and can be tailored to respond to disease conditions or support treatment via multiplexed functionality. Moreover, localized delivery to affected sites by these approaches has the potential to concentrate drug action at the site, reduce off-target exposure, and enhance patient compliance by reducing the need for frequent administration. Despite their many benefits for the management of autoimmune disease, such biomaterial-based approaches focus largely on the downstream effects of hypersensitivity mechanisms and have a limited capacity to eradicate the disease. In contrast, direct targeting of mechanisms of hypersensitivity reactions uniquely enables prophylaxis or the arrest of disease progression by mitigating the basis of autoimmunity. One promising approach is to induce self-antigen-specific tolerance, which specifically subdues damaging autoreactivity while otherwise retaining the normal immune responses. In this review, we will discuss hydrogel-based systems for the treatment of autoimmune disease, with a focus on those that target hypersensitivity mechanisms head-on. As the field continues to advance, it will expand the range of therapeutic choices for people coping with autoimmune diseases, providing fresh prospects for better clinical outcomes and improved quality of life.

Geohelminths: Use in the Treatment of Selected Human Diseases

Research on the therapeutic use of parasites has been ongoing since the development of the "hygiene hypothesis". Parasites can stimulate the Th2-dependent response and suppress the Th1-dependent response, which is intensified in many diseases, especially allergic and autoinflammatory ones. In this review, we present the types of parasites used in helminth therapy and the range of diseases in which they may be useful. We also present the results of clinical trials conducted so far, which confirm the safety of such therapy and provide promising outcomes.

Identification of Major Histocompatibility Complex Class II Epitopes From Lyme Autoantigen Apolipoprotein B-100 and Borrelia burgdorferi Mcp4 in Murine Lyme Arthritis

BACKGROUND

During infection with the Lyme arthritis (LA) pathogen Borrelia burgdorferi, T-cell responses to both host and pathogen are dysregulated, resulting in chronic infection and frequent development of autoimmunity.

METHODS

To assess CD4+ T-cell epitopes presented during development of LA, we used an unbiased, immunopeptidomics approach to characterize the major histocompatibility complex (MHC) class II immunopeptidome in B burgdorferi-infected C57BL/6 (B6) mice, which develop mild, self-limiting LA, and infected B6 Il10-/- mice, which develop severe, persistent LA at 0, 4, and 16 weeks postinfection (22-23 mice per group).

RESULTS

Peptides derived from proteins involved in adaptive T- and B-cell responses and cholesterol metabolism, including human Lyme autoantigen apolipoprotein B-100 (apoB-100), were enriched in infected Il10-/- mice; whereas peptides derived from proteins involved in neutrophil extracellular net formation were enriched in infected B6 mice. Presentation of apoB-100 peptides showed evidence of epitope expansion during infection. Of several identified B burgdorferi peptides, only 1, a methyl-accepting chemotaxis protein peptide Mcp4442-462, was immunogenic.

CONCLUSIONS

ApoB-100, a human Lyme autoantigen, undergoes marked epitope expansion during LA development. The paucity of immunogenic B burgdorferi epitopes supports previous findings suggesting CD4+ T-cell responses are suppressed in murine LA.

Gut microbiota as a sensor of autoimmune response and treatment for rheumatoid arthritis

Rheumatoid arthritis (RA) is considered a multifactorial condition where interaction between the genetic and environmental factors lead to immune dysregulation causing autoreactivity. While among the various genetic factors, HLA-DR4 and DQ8, have been reported to be the strongest risk factors, the role of various environmental factors has been unclear. Though events initiating autoreactivity remain unknown, a mucosal origin of RA has gained attention based on the recent observations with the gut dysbiosis in patients. However, causality of gut dysbiosis has been difficult to prove in humans. Mouse models, especially mice expressing RA-susceptible and -resistant HLA class II genes have helped unravel the complex interactions between genetic factors and gut microbiome. This review describes the interactions between HLA genes and gut dysbiosis in sex-biased preclinical autoreactivity and discusses the potential use of endogenous commensals as indicators of treatment efficacy as well as therapeutic tool to suppress pro-inflammatory response in rheumatoid arthritis.

Cracking the type 1 diabetes code: Genes, microbes, immunity, and the early life environment

Type 1 diabetes (T1D) results from a complex interplay of genetic predisposition, immunological dysregulation, and environmental triggers, that culminate in the destruction of insulin-secreting pancreatic β cells. This review provides a comprehensive examination of the multiple factors underpinning T1D pathogenesis, to elucidate key mechanisms and potential therapeutic targets. Beginning with an exploration of genetic risk factors, we dissect the roles of human leukocyte antigen (HLA) haplotypes and non-HLA gene variants associated with T1D susceptibility. Mechanistic insights gleaned from the NOD mouse model provide valuable parallels to the human disease, particularly immunological intricacies underlying β cell-directed autoimmunity. Immunological drivers of T1D pathogenesis are examined, highlighting the pivotal contributions of both effector and regulatory T cells and the multiple functions of B cells and autoantibodies in β-cell destruction. Furthermore, the impact of environmental risk factors, notably modulation of host immune development by the intestinal microbiome, is examined. Lastly, the review probes human longitudinal studies, unveiling the dynamic interplay between mucosal immunity, systemic antimicrobial antibody responses, and the trajectories of T1D development. Insights garnered from these interconnected factors pave the way for targeted interventions and the identification of biomarkers to enhance T1D management and prevention strategies.

Western diets and chronic diseases

'Westernization', which incorporates industrial, cultural and dietary trends, has paralleled the rise of noncommunicable diseases across the globe. Today, the Western-style diet emerges as a key stimulus for gut microbial vulnerability, chronic inflammation and chronic diseases, affecting mainly the cardiovascular system, systemic metabolism and the gut. Here we review the diet of modern times and evaluate the threat it poses for human health by summarizing recent epidemiological, translational and clinical studies. We discuss the links between diet and disease in the context of obesity and type 2 diabetes, cardiovascular diseases, gut and liver diseases and solid malignancies. We collectively interpret the evidence and its limitations and discuss future challenges and strategies to overcome these. We argue that healthcare professionals and societies must react today to the detrimental effects of the Western diet to bring about sustainable change and improved outcomes in the future.

Calculating toxic pressure for mixtures of endocrine disruptors

Incidence of autoimmune disorders, birth defects, and neurological diseases rose over the past 50 years due to increasing variety and quantity of pollutants. To date, there appear few methods capable to evaluate and predict mixture effects by endocrine disruptors (EDs). For the first time, we have developed calculus to determine mixture effects by all kinds of EDs. Our method uses the golden ratio ϕ and draws from bifurcation and chaos theory. Using also the concept of molecular mimicry, we developed the equation: e f f e c t = 100 % 1 + e 5 · ∑ K i C i - n i ϕ 3 . We successfully tested the equation using a range of cohort studies and biomarkers, and for different pollutants like heavy metals, thyroid hormone mimickants, chromate/chlorate, etc. The equation is simple enough to use with only minor prior knowledge and understanding of basic algebra. The method is universal and calculation is data 'light', requiring only pollutant concentrations [C], potencies K and an integer n for endocrinal involvement. This study offers a comprehensive framework to assess the health effects of pollutant exposure across diverse populations, envisioning far-reaching impact, and presenting practical examples and insights.

Dietary iron deficiency impairs effector function of memory T cells following influenza infection

The establishment of memory T cell responses is critical to protection against pathogens and is influenced by the conditions under which memory formation occurs. Iron is an essential micronutrient for multiple immunologic processes and nutritional deficiency is a common problem worldwide. Despite its prevalence, the impact of nutritional iron deficiency on the establishment of memory T cell responses is not fully understood. In this study we investigate the impact of nutritional iron deficiency on the generation, phenotype, and function of memory T cell responses using a murine model of dietary iron modulation in the context of influenza infection. Iron deficient mice have decreased systemic iron levels and develop significant anemia. Increased T cell expression of the transferrin receptor (CD71) is seen in iron deficient mice at baseline. During primary influenza infection, iron deficient mice experience increased weight loss and phenotypic evidence of impairments in T cell activation. Following recovery from infection, iron deficient mice generate increased influenza specific memory T cells which exhibit impaired ability to produce IFNγ, most notably within the lung. Importantly, the ability to produce IFNγ and TNFα is not recovered by co-culture with iron replete dendritic cells, suggesting a T cell intrinsic alteration in functional memory formation. Altogether, these results isolate a critical effect of nutritional iron deficiency on T cell memory development and function.

Autoimmune conditions and gastric cancer risk in a population-based study in the United Kingdom

BACKGROUND

Although overall incidence of gastric cancer is decreasing, incidence has been increasing among young people in some Western countries. This trend may stem from the increase in autoimmune conditions.

METHODS

A nested case-control study of gastric cancer in UK Clinical Practice Research Datalink. Up to ten cancer-free controls were matched to cases by age and sex. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for associations between analyzable autoimmune conditions (n = 34) and gastric cancer with Bonferroni correction. We evaluated associations between pernicious anaemia and other conditions. A meta-analysis of published prospective studies and ours was conducted.

RESULTS

Among 6586 cases (1156 cardia, 1104 non-cardia, and 4334 overlapping/unspecified tumours) and 65,687 controls, any autoimmune condition was associated with gastric cancer (OR = 1.10; 95% CI: 1.01-1.20). Individuals with pernicious anaemia had higher gastric cancer risk than those without (OR = 2.75; 2.19-3.44). Among controls, pernicious anaemia was associated with seven other conditions (OR range: 2.21-29.80). The pooled estimate for any autoimmune condition and gastric cancer was 1.17 (1.14-1.21; n = 47,126 cases).

CONCLUSION

Autoimmunity increases gastric cancer risk. Some autoimmune conditions may be indirectly associated with gastric cancer via pernicious anaemia. Pernicious anaemia could be considered for gastric cancer risk stratification and screening.

Anti-Inflammatory Responses Produced with Nippostrongylus brasiliensis-Derived Uridine via the Mitochondrial ATP-Sensitive Potassium Channel and Its Anti-Atherosclerosis Effect in an Apolipoprotein E Gene Knockout Mouse Model

Atherosclerosis (AS) has become the leading cause of cardiovascular disease worldwide. Our previous study had observed that Nippostrongylus brasiliensis (Nb) infection or its derived products could inhibit AS development by inducing an anti-inflammatory response. We performed a metabolic analysis to screen Nb-derived metabolites with anti-inflammation activity and evaluated the AS-prevention effect. We observed that the metabolite uridine had higher expression levels in mice infected with the Nb and ES (excretory-secretory) products and could be selected as a key metabolite. ES and uridine interventions could reduce the pro-inflammatory responses and increase the anti-inflammatory responses in vitro and in vivo. The apolipoprotein E gene knockout (ApoE-/-) mice were fed with a high-fat diet for the AS modeling. Following the in vivo intervention, ES products or uridine significantly reduced serum and liver lipid levels, alleviated the formation of atherosclerosis, and reduced the pro-inflammatory responses in serum or plaques, while the anti-inflammatory responses showed opposite trends. After blocking with 5-HD (5-hydroxydecanoate sodium) in vitro, the mRNA levels of M2 markers were significantly reduced. When blocked with 5-HD in vivo, the degree of atherosclerosis was worsened, the pro-inflammatory responses were increased compared to the uridine group, while the anti-inflammatory responses decreased accordingly. Uridine, a key metabolite from Nippostrongylus brasiliensis, showed anti-inflammatory and anti-atherosclerotic effects in vitro and in vivo, which depend on the activation of the mitochondrial ATP-sensitive potassium channel.

Helminth-induced impairment of humoral immunity differently contribute to their anti-arthritic effects in mice: Comparison of Schistosoma mansoni and Trichinella spiralis

AIMS

We have previously reported reduction of anti-type II collagen (IIC) IgG levels in collagen-induced arthritis (CIA) by Schistosoma mansoni (Sm) and Trichinella spiralis (Ts). To clarify the contribution of the impairment of humoral immunity to their anti-arthritic activities, we herein investigated the relationship between anti-IIC IgG levels and arthritic swelling in Sm- or Ts-infected mice.

METHODS AND RESULTS

Male DBA/1J mice were infected with Sm cercariae or Ts muscle larvae prior to the IIC immunization. In the Sm-infected mice, paw swelling and anti-IIC IgG levels were continuously lower than those of non-infected control group. In contrast, arthritic swelling in the Ts-infected mice only decreased in the early phase of CIA progression, despite the continued impairment of anti-IIC IgG production throughout the experimental period. Correlation coefficients between residual paw swelling and anti-IIC IgG titers were similar or higher in the Sm group than in the control group, but were similar or lower in the Ts group than in the control group.

CONCLUSION

The down-modulations of anti-IIC IgG levels by the two parasitic infections and the correlation analyses suggest that the anti-arthritic activity of Sm was primarily attributed to the modulation of IgG-independent arthritogenic mechanisms and secondarily to the impairment of anti-IIC IgG production. In contrast, Ts could alleviate CIA mainly via the impairment of antibody production.