51. Role of Tumor Suppressor TSC1 in Regulating Antigen-Specific Primary and Memory CD8 T Cell Responses to Bacterial Infection
- Author
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Sruti Krishna, Yu-Rong Qiu, Xiao-Ping Zhong, Hongxia Wang, and Jialong Yang
- Subjects
Adoptive cell transfer ,congenital, hereditary, and neonatal diseases and abnormalities ,Ovalbumin ,T cell ,Immunology ,Eomesodermin ,Biology ,CD8-Positive T-Lymphocytes ,Microbiology ,Tuberous Sclerosis Complex 1 Protein ,Mice ,Antigen ,medicine ,Cytotoxic T cell ,Animals ,Listeriosis ,Mechanistic target of rapamycin ,PI3K/AKT/mTOR pathway ,Mice, Knockout ,Host Response and Inflammation ,Antigens, Bacterial ,Cell Death ,Tumor Suppressor Proteins ,Listeria monocytogenes ,Cell biology ,Infectious Diseases ,medicine.anatomical_structure ,Gene Expression Regulation ,biology.protein ,Parasitology ,CD8 ,Spleen - Abstract
The serine/threonine kinase mammalian/mechanistic target of rapamycin (mTOR) integrates various environmental cues such as the presence of antigen, inflammation, and nutrients to regulate T cell growth, metabolism, and function. The tuberous sclerosis 1 (TSC1)/TSC2 complex negatively regulates the activity of an mTOR-containing multiprotein complex called mTOR complex 1. Recent studies have revealed an essential cell-intrinsic role for TSC1 in T cell survival, quiescence, and mitochondrial homeostasis. Given the emerging role of mTOR activity in the regulation of the quantity and quality of CD8 T cell responses, in this study, we examine the role of its suppressor, TSC1, in the regulation of antigen-specific primary and memory CD8 T cell responses to bacterial infection. Using an established model system of transgenic CD8 cell adoptive transfer and challenge with Listeria monocytogenes expressing a cognate antigen, we found that TSC1 deficiency impairs antigen-specific CD8 T cell responses, resulting in weak expansion, exaggerated contraction, and poor memory generation. Poor expansion of TSC1-deficient cells was associated with defects in survival and proliferation in vivo , while enhanced contraction was correlated with an increased ratio of short-lived effectors to memory precursors in the effector cell population. This perturbation of effector-memory differentiation was concomitant with decreased expression of eomesodermin among activated TSC1 knockout cells. Upon competitive adoptive transfer with wild-type counterparts and antigen rechallenge, TSC1-deficient memory cells showed moderate defects in expansion but not cytokine production. Taken together, these findings provide direct evidence of a CD8 T cell-intrinsic role for TSC1 in the regulation of antigen-specific primary and memory responses.
- Published
- 2014