LSP1-/- DENDRITIC CELLS INDUCE DEFECTIVE ANTIGEN PRESENTATION TO CD4+ LYMPHOCYTES

DHO, NICOLÁS DANIEL; PISTORESI, MARÍA CRISTINA; CRESPO, MARÍA INÉS; MORON, VICTOR GABRIEL; PASCUAL, MARÍA MERCEDES; MALETTO, BELKYS ANGÉLICA

Congreso Virtual

Congreso; Reunión Anual de Sociedades de Biociencias; 2020

Leukocyte-specific protein 1 (LSP1) is a 52 kDa cytoplasmic F-actin binding phosphoprotein expressed in all human and murine leukocytes and endothelial cells. LSP1 is an important regulator of actin cytoskeleton remodelling. We have previously shown that CD4+ T cells from Lsp1-/- mice have a poorer proliferation than CD4+ T cells from wild type (WT) mice after antigen exposure in vivo and in vitro with bone marrow derived dendritic cells (BMDCs).In order to study the role of LSP1 in DCs to promote a CD4+ T cell-mediated response, we evaluated the capacity of Lsp1-/- DCs to present antigens in a context of major histocompatibility complex class II (MHC II). In vitro, BMDCs were derived from Lsp1-/- mice with Flt3-L. BMDCs were pulsed with soluble or particulated Ovalbumin (OVAw or OVAb, respectively), then stimulated with CpG-ODN 1826 and finally cocultured with CD4+ T cells hybridoma (TH3Z OT II). After an overnight incubation, a significantly lower activation of TH3Z OT II cells was observed with Lsp1-/- BMDCs incubated with OVAw (p< 0.0001) and OVAb (p< 0.001) compared to Lsp1+/+ BMDCs. In addition, Lsp1-/- BMDCs show a lower expression of CD40, CD80, CD86 and MHC II molecules than BMDCs from WT mice after CpG-ODN 1826 stimulus (p>0.05, p