Conventional CD4+ T cells regulate IL-22-producing intestinal innate lymphoid cells.
The innate and adaptive immune systems in the intestine cooperate to maintain the integrity of the intestinal barrier and to regulate the composition of the resident microbiota. However, little is known about the crosstalk between the innate and adaptive immune systems that contribute to this homeostasis. We find that CD4+ T cells regulate the number and function of barrier-protective innate lymphoid cells (ILCs), as well as production of antimicrobial peptides (AMPs), Reg3γ and Reg3β. RAG1-/- mice lacking T and B cells had elevated ILC numbers, interleukin-22 (IL-22) production, and AMP expression, which were corrected by replacement of CD4+ T cells. Major histocompatibility class II-/- (MHCII-/-) mice lacking CD4+ T cells also had increased ILCs, IL-22, and AMPs, suggesting that negative regulation by CD4+ T cells occurs at steady state. We utilized transfers and genetically modified mice to show that reduction of IL-22 is mediated by conventional CD4+ T cells and is T-cell receptor dependent. The IL-22-AMP axis responds to commensal bacteria; however, neither the bacterial repertoire nor the gross localization of commensal bacteria differed between MHCII+/- and MHCII-/- littermates. These data define a novel ability of CD4+ T cells to regulate intestinal IL-22-producing ILCs and AMPs.
Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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LL
Korn
Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
H L
HL
Thomas
1] Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA [2] Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania, USA.
H G
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Hubbeling
Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Spencer
Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Sinha
Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
H Ma
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Simkins
Department of Pediatrics, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
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Salzman
Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Bushman
1] Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA [2] Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania, USA.
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Laufer
D056704:Adaptive Immunity; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016654:Genes, RAG-1 / Q000235:genetics; D007113:Immunity, Innate; D007378:Interleukins / Q000378:metabolism*; D007422:Intestines / Q000276:immunology*; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D000097043:Interleukin-22
D023181:Antimicrobial Cationic Peptides; D007378:Interleukins; D000097043:Interleukin-22