Constitutive LcK activity drives sensitivity differences between CD8+ memory T cell subsets

• Published in: The Journal of immunology (1950) 2016-05, Vol.196 (1_Supplement), p.133-133.32
• Main Authors: Krogsgaard, Michelle, Moogk, Duane, Zhong, Shi, Rittase, William, Fang, Victoria, Dougherty, Janna, Perez-Garcia, Arianne, Osman, Iman, Zhu, Cheng, Varadarajan, Navin, Restifo, Nicholas P, Frey, Alan B
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.196.Supp.133.32

CD8+ T cells develop increased sensitivity following antigen experience, and differences in sensitivity exist between T cell memory subsets. How differential T cell receptor (TCR) signaling between memory subsets contributes to sensitivity differences is unclear. We show that constitutive activity of lymphocyte-specific protein tyrosine kinase (Lck) is greater in effector memory T cells (TEM) compared with central memory T cells (TCM), leading to enhanced activation signaling, including Zeta-chain-associated protein kinase 70 (Zap-70) phosphorylation and intracellular calcium influx, and resulting in increased cytotoxic effector function in TEM. We provide evidence that the differences in Lck activity between CD8+ TCM and TEM are due to differential regulation by SH2 domain-containing phosphatase-1 (Shp-1) and C-terminal Src kinase (Csk). Together, this work demonstrates a role for constitutive Lck activity in controlling antigen sensitivity, and suggests that differential activities of TCR-proximal signaling components may contribute to establishing the divergent effector properties of TCM and TEM.