CD8αα+ Innate-type Lymphocytes in the Intestinal Epithelium Mediate Mucosal Immunity

Van Kaer L, Algood HM, Singh K, Parekh VV, Greer MJ, Piazuelo MB, Weitkamp JH, Matta P, Chaturvedi R, Wilson KT, Olivares-Villagómez D.

Immunity. 2014 Sep 18;41(3):451-64. doi: 10.1016/j.immuni.2014.08.010. Epub 2014 Sep 11.

From left to right: Keith Wilson, Blanca Piazuelo, Luc Van Kaer, Hendrik Weitkamp, Danyvid Olivares-Villagomez, Holly Algood, and Kshipra Singh

From left to right: Keith Wilson, Blanca Piazuelo, Luc Van Kaer, Hendrik Weitkamp, Danyvid Olivares-Villagomez, Holly Algood, and Kshipra Singh

Innate immune responses are critical for mucosal immunity. In this publication we describe an innate lymphocyte population, iCD8alpha cells, characterized by expression of CD8alpha homodimers. iCD8alpha cells exhibit innate functional characteristics such as the capacity to engulf and kill bacteria. Development of iCD8alpha cells depends on expression of interleukin-2 receptor gamma chain (IL-2Rgamma-c), IL-15, and the major histocompatibility complex (MHC) class Ib protein H2-T3, also known as the thymus leukemia antigen or TL. While lineage tracking experiments indicated that iCD8alpha cells have a lymphoid origin, their development was independent of the transcriptional suppressor Id2, suggesting these cells do not belong to the family of innate lymphoid cells. Finally, we identified cells with a similar phenotype in humans, which were profoundly depleted in newborns with necrotizing enterocolitis. These findings suggest a critical role of iCD8alpha cells in immune responses associated with the intestinal epithelium. PubMed: 25220211