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Biology subjects

Canto, F. B.

Publications and source records attributed to Canto, F. B..

2 recordsLinked to original sources

Disease tolerant mice shelter a pathogenic intestinal microbiota able to trigger lethal disease in low tolerant hosts

Disease tolerance is a defensive strategy that limits tissue damage during infection. Macrophage migration inhibitory factor (MIF)-deficient mice (Mif-/-) are protected in different models of infection and intestinal inflammation due to unclear disease tolerance mechanisms, whereas low disease-tolerant Il10-/-mice develop microbiota-dependent spontaneous gut inflammation. Here, we examined whether IL-10 is required for the phenotype seen in Mif-/-mice and, conversely, the contribution of MIF during IL-10 deficiency. While breeding for double-deficient Mif-/-Il10-/- mice, we unexpectedly observed that Il10-/- individuals died within days after co-housing with Mif-/- mice. We found that healthy Mif-/-hosts endure a highly diverse, unique and dysbiotic-like microbiota composition, including antibiotic-resistant Enterobacteriaceae species, which were sufficient to cause acute and lethal Th1-driven colitis in Il10-/- recipients. The disease was characterized by increased frequencies of IFN{gamma}+ cells and neutrophils within colonic lamina propria. Mif-/-Il10-/-mice died prematurely, and survivors developed communicable disease, - indicating that lack of IL-10 is a dominant trait. These findings suggest that tolerant individuals harbor a gut microbiota enriched in pathogens/pathobionts, which can trigger disease in susceptible hosts.

immunology↗

Cytotoxic CD4+ T cells driven by T-cell intrinsic IL-18R/MyD88 signaling predominantly infiltrate Trypanosoma cruzi-infected hearts

Increasing attention has been directed to cytotoxic CD4+ T cells (CD4CTLs) in different pathologies, both in humans and mice. The impact of CD4CTLs in immunity and the mechanisms controlling their generation, however, remain poorly understood. Here, we show that CD4CTLs abundantly differentiate during mouse infection with the intracellular parasite Trypanosoma cruzi. CD4CTLs display parallel kinetics to Th1 cells in the spleen, mediate specific cytotoxicity against cells presenting pathogen-derived antigens and express immunoregulatory and/or exhaustion markers. We demonstrate that CD4CTL absolute numbers and activity are severely reduced in both Myd88-/- and Il18ra-/- mice. Of note, the infection of mixed-bone marrow chimeras revealed that WT but not Myd88-/- cells transcribe the CD4CTL gene signature and that Il18ra-/- and Myd88-/- CD4+ T cells phenocopy each other. Moreover, adoptive transfer of WT CD4+GzB+ T cells to infected Il18ra-/- mice extended their survival. Importantly, cells expressing the CD4CTL phenotype predominate among CD4+ T cells infiltrating the infected mouse cardiac tissue and are increased in the blood of Chagas patients, in which the frequency of CD4CTLs correlates with the severity of cardiomyopathy. Our findings describe CD4CTLs as a major player in immunity to a relevant human pathogen and disclose T-cell intrinsic IL-18R/MyD88 signaling as a key pathway controlling the magnitude of the CD4CTL response.

immunology↗