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. Display omitted •CD8 T cells normally differentiate in type I vaccinated lymph nodes devoid of DC ICAM-1•Lymph node DC ICAM-1 supports firm antigen-dependent contacts with a subset of CD8 blasts•CD8 T cells normally differentiate in virus-infected skin lymph nodes devoid of DC ICAM-1•DC ICAM-1 is dispensable for skin recall responses of CD8 T cells Sapoznikov et al. use a genetic murine model deficient in dendritic cell expression of the key adhesion molecule ICAM-1 and find that CD8 lymphocytes do not require strong ICAM-1-dependent adhesion to dendritic cells for antigen-stimulated differentiation into functional skin homing effector T cells.