Langerhans Cells Suppress CD49a+ NK Cell-Mediated Skin Inflammation.

ABSTRACT: Recruitment of innate immune effector cells into sites of infection is a critical component of resistance to pathogen infection. Using a model of intradermal footpad injection of Candida albicans, we observed that inflammation as measured by footpad thickness and neutrophil recruitment occurred independent of adoptive immunity but was significantly reduced in MyD88(-/-) and IL-6(-/-) mice. Unexpectedly, huLangerin-DTA mice (?LC) that lack Langerhans cells (LC) developed increased skin inflammation and expressed higher amounts of IL-6, suggesting a suppressive role for LC. Increased inflammation also occurred in Rag1(-/-) ?LC mice but was reversed by Ab-mediated ablation of NK cells. CXCR6(+)CD49a(+) NK cells are a liver-resident subset that can mediate inflammatory skin responses. We found that exaggerated skin inflammation was absent in ?LC × CXCR6(-/-) mice. Moreover, the exaggerated response in ?LC mice could be adoptively transferred with liver CD49a(+) NK cells. Finally, CD49a(+) NK cells in ?LC but not control mice were recruited to the skin, and inhibition of their recruitment prevented the exaggerated response. Thus, in the absence of LC, CD49a(+) liver NK cells display an inappropriately proinflammatory phenotype that results in increased local skin inflammation. These data reveal a novel function for LC in the regulation of this recently described subset of skin tropic NK cells.

SUBMITTER: Scholz F 

PROVIDER: S-EPMC4546924 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature