The gut microbiota plays a key role in host health and disease, particularly through their interactions with the immune system. Intestinal homeostasis is dependent on the symbiotic relationships between the host and the diverse gut microbiota, which is influenced by the highly co-evolved immune-microbiota interactions. The first step of the interaction between the host and the gut microbiota is the sensing of the gut microbes by the host immune system. In this review, we describe the cells of the host immune system and the proteins that sense the components and metabolites of the gut microbes. We further highlight the essential roles of pattern recognition receptors (PRRs), the G protein-coupled receptors (GPCRs), aryl hydrocarbon receptor (AHR) and the nuclear receptors expressed in the intestinal epithelial cells (IECs) and the intestine-resident immune cells. We also discuss the mechanisms by which the disruption of microbial sensing because of genetic or environmental factors causes human diseases such as the inflammatory bowel disease (IBD).
Humans ; Inflammatory Bowel Diseases ; Gastrointestinal Microbiome ; Microbiota ; Immune System ; Intestines

Calcineurin inhibitors (CNI), including oral cyclosporin A and tacrolimus, are intensive immunosuppressants that are extensively used in the treatment of rheumatic and immunologic diseases in China. CNI selectively inhibit the activation and proliferation of T lymphocytes and the transcription of cytokines [such as tumor necrosis factor-α, interleukin (IL)-6, and IL-17] through inhibiting the activation of calcineurin in cells and reducing the release of IL-2. To standardize the use of CNI in the field of rheumatic and immunologic diseases, this consensus statement was developed by the National Clinical Research Center for Dermatologic and Immunologic Diseases (Peking Union Medical College Hospital), in conjunction with the Chinese Association of Rheumatology and Immunology Physicians, the Chinese Research Hospital Association, the Rheumatology and Immunology Professional Committee, and the Chinese Association of Rehabilitation Medicine. The 2011 Oxford Centre for Evidence-Based Medicine Levels of Evidence was used to rate the quality of the evidence and the strength of the recommendations, and the RIGHT (Reporting Items for practice Guidelines in HealThcare) checklist was followed to report the consensus. The consensus offers recommendations addressing nine clinical challenges to Chinese clinicians. The primary objective of this consensus is to deliver scientific and detailed guidance on CNI for Chinese clinicians, and to improve the quality of patient-centered medical services.
Humans ; Calcineurin Inhibitors/pharmacology* ; Immunosuppressive Agents/therapeutic use* ; Tacrolimus/pharmacology* ; T-Lymphocytes ; Immune System Diseases ; Rheumatic Diseases/drug therapy*

Pregnancy ; Humans ; Female ; Cesarean Section ; Mendelian Randomization Analysis ; Immune System Diseases

The syndrome of dampness stagnancy due to spleen deficiency (DSSD) is relatively common globally. Although the pathogenesis of DSSD remains unclear, evidence has suggested that the gut microbiota might play a significant role. Radix Astragali, used as both medicine and food, exerts the effects of tonifying spleen and qi. Astragalus polysaccharide (APS) comprises a macromolecule substance extracted from the dried root of Radix Astragali, which has many pharmacological functions. However, whether APS mitigates the immune disorders underlying the DSSD syndrome via regulating gut microbiota and the relevant mechanism remains unknown. Here, we used DSSD rats induced by high-fat and low-protein (HFLP) diet plus exhaustive swimming, and found that APS of moderate molecular weight increased the body weight gain and immune organ indexes, decreased the levels of interleukin-1β (IL-1β), IL-6, and endotoxin, and suppressed the Toll-like receptor 4/nuclear factor-‍κB (TLR4/NF-‍κB) pathway. Moreover, a total of 27 critical genera were significantly enriched according to the linear discriminant analysis effect size (LEfSe). APS increased the diversity of the gut microbiota and changed its composition, such as reducing the relative abundance of Pseudoflavonifractor and Paraprevotella, and increasing that of Parasutterella, Parabacteroides, Clostridium XIVb, Oscillibacter, Butyricicoccus, and Dorea. APS also elevated the contents of short-chain fatty acids (SCFAs). Furthermore, the correlation analysis indicated that 12 critical bacteria were related to the body weight gain and immune organ indexes. In general, our study demonstrated that APS ameliorated the immune disorders in DSSD rats via modulating their gut microbiota, especially for some bacteria involving immune and inflammatory response and SCFA production, as well as the TLR4/NF-κB pathway. This study provides an insight into the function of APS as a unique potential prebiotic through exerting systemic activities in treating DSSD.
Rats ; Animals ; NF-kappa B/metabolism* ; Spleen ; Gastrointestinal Microbiome ; Toll-Like Receptor 4 ; Polysaccharides/pharmacology* ; Astragalus Plant/metabolism* ; Immune System Diseases/drug therapy* ; Body Weight

Animals ; Caffeine/adverse effects* ; Central Nervous System Stimulants/adverse effects* ; Dose-Response Relationship, Drug ; Female ; Fetal Growth Retardation/chemically induced* ; Immune System Diseases/chemically induced* ; Male ; Organ Size/drug effects* ; Pregnancy ; Pregnancy Complications/immunology* ; Rats ; Spleen/growth & development*

Child ; Dysbiosis ; Gastrointestinal Microbiome ; Humans ; Immune System Diseases ; Nephrosis, Lipoid ; Nephrotic Syndrome

Child ; Coronary Artery Disease/etiology* ; Humans ; Immune System Diseases ; Mucocutaneous Lymph Node Syndrome/complications*

BACKGROUND: Particulate matter (PM), a major component of ambient air pollution, accounts for a substantial burden of diseases and fatality worldwide. Maternal exposure to PM during pregnancy is particularly harmful to children's health since this is a phase of rapid human growth and development. METHOD: In this review, we synthesize the scientific evidence on adverse health outcomes in children following prenatal exposure to the smallest toxic components, fine (PM RESULTS: Maternal exposure to fine and ultrafine PM directly and indirectly yields numerous adverse birth outcomes and impacts on children's respiratory systems, immune status, brain development, and cardiometabolic health. The biological mechanisms underlying adverse effects include direct placental translocation of ultrafine particles, placental and systemic maternal oxidative stress and inflammation elicited by both fine and ultrafine PM, epigenetic changes, and potential endocrine effects that influence long-term health. CONCLUSION Policies to reduce maternal exposure and health consequences in children should be a high priority. PM
Adult ; Air Pollutants/adverse effects* ; Air Pollution/prevention & control* ; Animals ; Cardiovascular Diseases/chemically induced* ; Child Health ; Child, Preschool ; Disease Models, Animal ; Endocrine System Diseases/chemically induced* ; Epigenomics ; Female ; Humans ; Immune System Diseases/chemically induced* ; Infant ; Infant, Newborn ; Male ; Maternal Exposure/adverse effects* ; Nervous System Diseases/chemically induced* ; Oxidative Stress ; Particle Size ; Particulate Matter/adverse effects* ; Placenta ; Pregnancy ; Pregnancy Outcome/epidemiology* ; Prenatal Exposure Delayed Effects/epidemiology* ; Respiratory Tract Diseases/chemically induced* ; Young Adult

OBJECTIVE: To report on the clinical features and result of genetic testing for a child featuring immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome. METHODS: Clinical records, genetic testing, laboratory investigation and treatment of the child were summarized in addition with a comprehensive review of the literature. RESULTS: The 3-year-old boy was administered due to intractable diarrhea, recurrent infections, liver dysfunction and failure to thrive, though no diabetes or skin disorder was observed. Laboratory testing showed elevated liver enzymes and total IgE, decreased albumin and electrolyte imbalance. Gastrointestinal endoscopy revealed erosion and granules in the duodenum, and edema in the terminal ileum and colon. Biopsies showed villous atrophy in the duodenum and terminal ileum. Genetic testing revealed that the patient has carried a missense c.1087A>G (p.I363V) variant in the exon 10 of the FOXP3 gene. He was treated with enteral and parenteral nutrition, anti infection and Sirolimus, and was waiting for hemopoietic stem cell transplantation. CONCLUSION Although IPEX syndrome usually occur during infancy, it should not be ruled out solely based on the age, and its presentation can be variable. For male children with refractory diarrhea, autoimmune disorder and growth retardation, the diagnosis should be suspected and confirmed by genetic testing.
Child, Preschool ; Diabetes Mellitus, Type 1/genetics* ; Diarrhea/genetics* ; Forkhead Transcription Factors/genetics* ; Genetic Diseases, X-Linked/genetics* ; Genetic Testing ; Humans ; Immune System Diseases/genetics* ; Male ; Mutation ; Polyendocrinopathies, Autoimmune/genetics*

A boy, aged 4 years and 6 months, had disease onset of fever, cough, pale complexion, and weakness, with hepatosplenomegaly, lymphadenectasis, and pancytopenia. He had been having repeated respiratory and digestive tract infections. Gene detection showed a pathogenic heterozygous mutation, c.C2147 > T(p.T716M), in the
Child, Preschool ; Fever ; Heterozygote ; Humans ; Immune System Diseases/genetics* ; Male ; Mutation ; STAT3 Transcription Factor/genetics* ; Syndrome