Dendritic cell ICAM-1 strengthens synapses with CD8 T cells but is not required for their early differentiation
Anita Sapoznikov, Stav Kozlovski, Nehora Levi, Sara W. Feigelson, Ofer Regev, Natalia Davidzohn, Shifra Ben‐Dor, Rebecca Haffner‐Krausz, Ester Feldmesser, Noa Wigoda, Ekaterina Petrovich‐Kopitman, Moshe Biton, R. Alon
Abstract
Lymphocyte priming in lymph nodes (LNs) was postulated to depend on the formation of stable T cell receptor (TCR)-specific immune synapses (ISs) with antigen (Ag)-presenting dendritic cells (DCs). The high-affinity LFA-1 ligand ICAM-1 was implicated in different ISs studied in vitro. We dissect the in vivo roles of endogenous DC ICAM-1 in Ag-stimulated T cell proliferation and differentiation and find that under type 1 polarizing conditions in vaccinated or vaccinia virus-infected skin-draining LNs, Ag-presenting DCs engage in ICAM-1-dependent stable conjugates with a subset of Ag-specific CD8 blasts. Nevertheless, in the absence of these conjugates, CD8 lymphocyte proliferation and differentiation into functional cytotoxic T cells (CTLs) and skin homing effector lymphocytes takes place normally. Our results suggest that although CD8 T cell blasts engage in tight ICAM-1-dependent DC-T ISs, firm ISs are dispensable for TCR-triggered proliferation and differentiation into productive effector lymphocytes.