Autio, AnuWang, HuanVelázquez, FranciscoNewton, GailParkos, Charles A.Engel Rocamora, PabloEngelbertsen, DanielLichtman, Andrew H.Luscinskas, Francis W.2025-06-252025-06-252022-04-121932-6203https://hdl.handle.net/2445/221756The SIRPα-CD47 axis plays an important role in T cell recruitment to sites of immune reaction and inflammation but its role in T cell antigen priming is incompletely understood. Employing OTII TCR transgenic mice bred to Cd47-/- (Cd47KO) or SKI mice, a knock-in transgenic animal expressing non-signaling cytoplasmic-truncated SIRPα, we investigated how the SIRPα-CD47 axis contributes to antigen priming. Here we show that adoptive transfer of Cd47KO or SKI Ova-specific CD4+ T cells (OTII) into Cd47KO and SKI recipients, followed by Ova immunization, elicited reduced T cell division and proliferation indices, increased apoptosis, and reduced expansion compared to transfer into WT mice. We confirmed prior reports that splenic T cell zone, CD4+ conventional dendritic cells (cDCs) and CD4+ T cell numbers were reduced in Cd47KO and SKI mice. We report that in vitro derived DCs from Cd47KO and SKI mice exhibited impaired migration in vivo and exhibited reduced CD11c+ DC proximity to OTII T cells in T cell zones after Ag immunization, which correlates with reduced TCR activation in transferred OTII T cells. These findings suggest that reduced numbers of CD4+ cDCs and their impaired migration contributes to reduced T cell-DC proximity in splenic T cell zone and reduced T cell TCR activation, cell division and proliferation, and indirectly increased T cell apoptosis.21 p.application/pdfengcc-by (c) Autio A et al., 2022http://creativecommons.org/licenses/by/4.0/Cèl·lules dendrítiquesCèl·lules TRatolins (Animals de laboratori)ImmunologiaMelsaDendritic cellsT cellsMice (Laboratory animals)ImmunologySpleeninfo:eu-repo/semantics/article7310862025-06-25info:eu-repo/semantics/openAccess