Gut microbiota amplifies host-intrinsic conversion from the CD8 T cell lineage to CD4 T cells for induction of mucosal immune tolerance

Combinatorial pathway disruption is a powerful approach to delineate metabolic impacts of endocrine disruptors

The prevalence of metabolic diseases, such as obesity, diabetes, metabolic syndrome and chronic liver diseases among others, has been rising for several years. Epidemiology and mechanistic (in vivo, in vitro and in silico) toxicology have recently provided compelling evidence implicating the chemical environment in the pathogenesis of these diseases. In this review, we will describe the biological processes that contribute to the development of metabolic diseases targeted by metabolic disruptors, and will propose an integrated pathophysiological vision of their effects on several organs. With regard to these pathomechanisms, we will discuss the needs, and the stakes of evolving the testing and assessment of endocrine disruptors to improve the prevention and management of metabolic diseases that have become a global epidemic since the end of last century.

Anisakis simplex: Immunomodulatory effects of larval antigens on the activation of Toll like Receptors

AIMS

The objective of this investigation is to evaluate the mechanisms Anisakis simplex employs to modify its host immune system, regarding the larval antigens interactions with Toll-Like-Receptors (TLRs).

METHODS AND RESULTS

In a previous study, we described that the stimulation of bone marrow derived dendritic cells (BMDCs) with A. simplex larval antigens drive an acute inflammatory response in BALB/c mice, but a more discrete and longer response in C57BL/6J. Moreover, when A. simplex larval antigens were combined with TLR agonists (TLR 1/2-9), they modified mainly TLR2, TLR4 and TLR9 agonists responses in both mice strains, and also TLR3, TLR5 and TLR7 in BALB/c. Antigen-presenting ability was analyzed by the detection of CD11c + cells expressing surface markers (CD80-86, MHC I-II), intracellular cytokines (IL-10, IL-12, TNF-α) and intracellular proteins (Myd88, NF-κβ) by Flow Cytometry. Secreted IL-10 was measured by ELISA.

CONCLUSION

Our findings confirm not only that the host genetic basis plays a role in the development of a Th2/Th1/Treg response, but also it states A. simplex larval antigens present specific mechanisms to modify the innate response of the host. As allergies share common pathways with the immune response against this particular helminth, our results provide a better understanding into the specific mechanisms of A. simplex allergy related diseases.

Antibiotics Drive Microbial Imbalance and Vitiligo Development in Mice

Vitiligo is impacted by environmental triggers. We studied the contribution of the microbiome in FH mice, in which depigmentation is mediated by tyrosinase-reactive T cells. The mice received oral antibiotics and were monitored for depigmentation. The microbiome was studied in fecal and skin samples using 16S rRNA analysis. The resulting T-cell distributions were evaluated. In untreated mice, pigment loss did not expand to the pelage, whereas mice in the ampicillin group were approximately 1/3 depigmented at 30 weeks. In contrast to models of autoimmunity that are less dependent on IFN-γ, ampicillin but not neomycin treatment correlated with accelerated disease and reduced bacteria in the fecal pellets. Modified cytokine patterns in the tissue and serum suggest a response that transcends the gut. Ampicillin-induced depigmentation was accompanied by gut but not skin dysbiosis, and reduced T cell numbers in both sites. Neomycin induced a redistribution of gut T cells and an accumulation of skin regulatory T cells. This treatment spurred a Bacteroides-dominated population of fecal bacteria. Reduced diversity is prominent particularly after ampicillin treatment, when the gut is dominated by Pseudomonas species. In line with current concepts relating the microbiome and the immune system, we predict that dietary measures might promote skin health and delay vitiligo onset.

The Th17/Treg Cell Balance: A Gut Microbiota-Modulated Story

The intestinal tract of vertebrates is normally colonized with a remarkable number of commensal microorganisms that are collectively referred to as gut microbiota. Gut microbiota has been demonstrated to interact with immune cells and to modulate specific signaling pathways involving both innate and adaptive immune processes. Accumulated evidence suggests that the imbalance of Th17 and Treg cells is associated with the development of many diseases. Herein, we emphatically present recent findings to show how specific gut microbiota organisms and metabolites shape the balance of Th17 and Treg cells. We also discuss the therapeutic potential of fecal microbiota transplantation (FMT) in diseases caused by the imbalance of Th17 and Treg cells

The gut microbiota promotes the pathogenesis of schizophrenia via multiple pathways

Schizophrenia is a severe mental disorder with unknown etiology. Many mechanisms, including dysregulation of neurotransmitters, immune disturbance, and abnormal neurodevelopment, are proposed for the pathogenesis of schizophrenia. The significance of communication between intestinal flora and the central nervous system through the gut-brain axis is increasingly being recognized. The intestinal microbiota plays an important role in regulating neurotransmission, immune homeostasis, and brain development. We hypothesize that an imbalance in intestinal flora causes immune activation and dysfunction in the gut-brain axis, contributing to schizophrenia. In this review, we examine recent studies that explore the intestinal flora and immune-mediated neurodevelopment of schizophrenia. We conclude that an imbalance in intestinal flora may reduce protectants and increase neurotoxin and inflammatory mediators, causing neuronal and synaptic damage, which induces schizophrenia.