LEUKOCYTE-SPECIFIC PROTEIN 1 ABSENCE REDUCES CYTOTOXIC RESPONSE GENERATION BY AFFECTING DENDRITIC CELLS AND CD8+ T CELL FUNCTION

MARIA MERCEDES PASCUAL; NICOLAS DHO; CONSTANZA MARIN; M INES CRESPO; BELKYS MALETTO; M CRISTINA PISTORESI; GABRIEL MORON

Congreso; LXX REUNIÓN SAI; 2022

LSP1 is an intracellular F-actin binding phosphoprotein expressed in leukocytes and endothelial cells from humans and mice. LSP1 polymorphisms or reduced expression are risk factors for some types of cancer. We demonstrated that B16-OVA tumors in LSP1 KO mice reach bigger sizes and grow faster than in wild type (WT) mice. Also, there is a reduced extravasation efficiency of LSP1 KO leukocytes into tumors harvested from WT and LSP1 KO mice. In dendritic cells (DCs), capture of tumoral antigen and its transport to draining lymph node (dLN) is affected by LSP1 absence. In addition, LSP1 KO DCs cannot activate and induce CD8+ T cell proliferation in an appropriate way.Taking into account these previous results, we aimed to investigate if intratumoral CD8+ T cell functionality is affected by LSP1 absence. We observed a reduced frequency of CD8+ T cell producing perforin and granzyme B in LSP1 KO tumors (p