Keratinocyte-intrinsic MHCII expression controls microbiota-induced Th1 cell responses

S Tamoutounour, SJ Han, J Deckers… - Proceedings of the …, 2019 - National Acad Sciences
S Tamoutounour, SJ Han, J Deckers, MG Constantinides, C Hurabielle, OJ Harrison
Proceedings of the National Academy of Sciences, 2019National Acad Sciences
The cross-talk between the microbiota and the immune system plays a fundamental role in
the control of host physiology. However, the tissue-specific factors controlling this dialogue
remain poorly understood. Here we demonstrate that T cell responses to commensal
colonization are associated with the development of organized cellular clusters within the
skin epithelium. These organized lymphocyte clusters are surrounded by keratinocytes
expressing a discrete program associated with antigen presentation and antimicrobial …
The cross-talk between the microbiota and the immune system plays a fundamental role in the control of host physiology. However, the tissue-specific factors controlling this dialogue remain poorly understood. Here we demonstrate that T cell responses to commensal colonization are associated with the development of organized cellular clusters within the skin epithelium. These organized lymphocyte clusters are surrounded by keratinocytes expressing a discrete program associated with antigen presentation and antimicrobial defense. Notably, IL-22–mediated keratinocyte-intrinsic MHC class II expression was required for the selective accumulation of commensal-induced IFN-γ, but not IL-17A–producing CD4+ T cells within the skin. Taking these data together, this work uncovers an unexpected role for MHC class II expression by keratinocytes in the control of homeostatic type 1 responses to the microbiota. Our findings have important implications for the understanding of the tissue-specific rules governing the dialogue between a host and its microbiota.
National Acad Sciences