The food colorant Red 40 is an environmental risk factor for colitis development in mice with increased expression of interleukin(IL)-23.This immune response is mediated by CD4^(+)T cells,but mechanistic insights into...The food colorant Red 40 is an environmental risk factor for colitis development in mice with increased expression of interleukin(IL)-23.This immune response is mediated by CD4^(+)T cells,but mechanistic insights into how these CD4^(+)T cells trigger andperpetuate colitis have remained elusive.Here,using single-cell transcriptomic analysis,we found that several CD4^(+)T-cell subsetsare present in the intestines of colitic mice,including an interferon(IFN)-γ-producing subset.In vivo challenge of primed mice withRed 40 promoted rapid activation of CD4^(+)T cells and caused marked intestinal epithelial cell(IEC)apoptosis that was attenuated bydepletion of CD4^(+)cells and blockade of IFN-γ.Ex vivo experiments showed that intestinal CD4^(+)T cells from colitic mice directlypromoted apoptosis of IECs and intestinal enteroids.CD4^(+)T cell-mediated cytotoxicity was contact-dependent and required FasL,which promoted caspase-dependent cell death in target IECs.Genetic ablation of IFN-γconstrained IL-23-and Red 40-inducedcolitis development,and blockade of IFN-γinhibited epithelial cell death in vivo.These results advance the understanding of themechanisms regulating colitis development caused by IL-23 and food colorants and identify IFN-γ^(+)cytotoxic CD4^(+)T cells as a newpotential therapeutic target for colitis.展开更多
基金This work was supported by grants from the National Institutes of Health(R01 DK 110352 and DK 121009 to SAL)a Career Development Award(634253)from the Crohn’s&Colitis Foundation of America(CCFA)(to LC)The funders of the study had no involvement in the study design,data collection,data analysis,interpretation,writing of the report,or decision to submit the paper for publication。
文摘The food colorant Red 40 is an environmental risk factor for colitis development in mice with increased expression of interleukin(IL)-23.This immune response is mediated by CD4^(+)T cells,but mechanistic insights into how these CD4^(+)T cells trigger andperpetuate colitis have remained elusive.Here,using single-cell transcriptomic analysis,we found that several CD4^(+)T-cell subsetsare present in the intestines of colitic mice,including an interferon(IFN)-γ-producing subset.In vivo challenge of primed mice withRed 40 promoted rapid activation of CD4^(+)T cells and caused marked intestinal epithelial cell(IEC)apoptosis that was attenuated bydepletion of CD4^(+)cells and blockade of IFN-γ.Ex vivo experiments showed that intestinal CD4^(+)T cells from colitic mice directlypromoted apoptosis of IECs and intestinal enteroids.CD4^(+)T cell-mediated cytotoxicity was contact-dependent and required FasL,which promoted caspase-dependent cell death in target IECs.Genetic ablation of IFN-γconstrained IL-23-and Red 40-inducedcolitis development,and blockade of IFN-γinhibited epithelial cell death in vivo.These results advance the understanding of themechanisms regulating colitis development caused by IL-23 and food colorants and identify IFN-γ^(+)cytotoxic CD4^(+)T cells as a newpotential therapeutic target for colitis.
