Lack of Sprouty 1 and 2 enhances survival of effector CD8(+) T cells and yields more protective memory cells
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Authors: Shehata, Hesham M.; Khan, Shahzada; Chen, Elise; Fields, Patrick E.; Flavell, Richard A.; Sanjabi, Shomyseh
Abstract
Identifying novel pathways that promote robust function and longevity of cytotoxic T cells has promising potential for immunotherapeutic strategies to combat cancer and chronic infections. We show that sprouty 1 and 2 (Spry1/2) molecules regulate the survival and function of memory CD8(+) T cells. Spry1/2 double-knockout (DKO) ovalbumin (OVA)-specific CD8(+) T cells (OT-I cells) mounted more vigorous autoimmune diabetes than WT OT-I cells when transferred to mice expressing OVA in their pancreatic beta-islets. To determine the consequence of Spry1/2 deletion on effector and memory CD8(+) T cell development and function, we used systemic infection with lymphocytic choriomeningitis virus (LCMV) Armstrong. Spry1/2 DKO LCMV gp33-specific P14 CD8(+) T cells survive contraction better than WT cells and generate significantly more polyfunctional memory T cells. The larger number of Spry1/2 DKO memory T cells displayed enhanced infiltration into infected tissue, demonstrating that absence of Spry1/2 can result in increased recall capacity. Upon adoptive transfer into naive hosts, Spry1/2 DKO memory T cells controlled Listeria monocytogenes infection better than WT cells. The enhanced formation of more functional Spry1/2 DKO memory T cells was associated with significantly reduced mTORC1 activity and glucose uptake. Reduced p-AKT, p-FoxO1/3a, and T-bet expression was also consistent with enhanced survival and memory accrual. Collectively, loss of Spry1/2 enhances the survival of effector CD8(+) T cells and results in the formation of more protective memory cells. Deleting Spry1/2 in antigen-specific CD8(+) T cells may have therapeutic potential for enhancing the survival and functionality of effector and memory CD8(+) T cells in vivo.
Spred negatively regulates lens growth by modulating epithelial cell proliferation and fiber differentiation
EXPERIMENTAL EYE RESEARCH
Authors: Susanto, Alyssa; Zhao, Guannan; Wazin, Fatima; Feng, Yue; Rasko, John E. J.; Bailey, Charles G.; Loyicu, Frank J.
Abstract
Spred, like Sprouty (Spry) and also Sef proteins, have been identified as important regulators of receptor tyrosine kinase (RTK)-mediated MAPK/ERK-signaling in various developmental systems, controlling cellular processes such as proliferation, migration and differentiation. Spreds are widely expressed during early embryogenesis, and in the eye lens, become more localised in the lens epithelium with later development, overlapping with other antagonists including Spry. Given the synexpression of Spreds and Spry in lens, in order to gain a better understanding of their specific roles in regulating growth factor mediated-signaling and cell behavior, we established and characterised lines of transgenic mice overexpressing Spred1 or Spred2, specifically in the lens. This overexpression of Spreds resulted in a small lens phenotype during ocular morphogenesis, retarding its growth by compromising epithelial cell proliferation and fiber differentiation. These in situ findings were shown to be dependent on the ability of Spreds to suppress MAPK-signaling, in particular FGF-induced ERK1/2-signaling in lens cells. This was validated in vitro using lens epithelial explants, that highlighted the overlapping role of Spreds with Spry2, but not Spry1. This study provides insights into the putative function of Spreds and Spry in situ, some overlapping and some distinct, and their importance in regulating lens cell proliferation and fiber differentiation contributing to lens and eye growth.