Satoshi Kojo, Michiko Ohno-Oishi, Hisashi Wada, Sebastian Nieke, Wooseok Seo, Sawako Muroi, Ichiro Taniuchi
Life science alliance 2020 FebTemporal down-regulation of the CD8 co-receptor after receiving positive-selection signals has been proposed to serve as an important determinant to segregate helper versus cytotoxic lineages by generating differences in the duration of TCR signaling between MHC-I and MHC-II selected thymocytes. By contrast, little is known about whether CD8 also modulates TCR signaling engaged by the non-classical MHC-I-like molecule, CD1d, during development of invariant natural killer T (iNKT) cells. Here, we show that constitutive transgenic CD8 expression resulted in enhanced differentiation of innate memory-like CD8+ thymocytes in both a cell-intrinsic and cell-extrinsic manner, the latter being accomplished by an increase in the IL-4-producing iNKT2 subset. Skewed iNKT2 differentiation requires cysteine residues in the intracellular domain of CD8α that are essential for transmitting cellular signaling. Collectively, these findings shed a new light on the relevance of CD8 down-regulation in shaping the balance of iNKT-cell subsets by modulating TCR signaling. © 2020 Kojo et al.
Satoshi Kojo, Michiko Ohno-Oishi, Hisashi Wada, Sebastian Nieke, Wooseok Seo, Sawako Muroi, Ichiro Taniuchi. Constitutive CD8 expression drives innate CD8+ T-cell differentiation via induction of iNKT2 cells. Life science alliance. 2020 Feb;3(2)
PMID: 31980555
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