Fig. 1: OVA-specific CD8⁺ and CD4⁺ T cell activation and proliferation in distinct proximal lymph nodes depends on immunization site.

A surrogate vaccine formulation was used to test the potential of different skin routes of immunization (topical, transcutaneous, intradermal and subcutaneous) to induce antigen-specific CD8⁺ T cell (OT-I) and CD4⁺ T cell (OT-II) proliferation in the dLN. A Experimental design – OT-I/OT-II T cell adoptive transfer and vaccination scheme. B FACS plots of CD45.1⁺ OT-I and CD45.1⁺ OT-II T cells in skin dLN (Axillary-Brachial; Auricular; Inguinal): CD45.1⁺ OT-I and CD45.1⁺ OT-II T cells were pre-gated as CD8⁺ Lin^- and CD4⁺ Lin^- respectively (See Sup Fig. 1). C Absolute number of CD45.1⁺ OT-I and CD45.1⁺ OT-II T cells in respective dLNs. Non-parametric Mann-Whitney unpaired t tests; **P < 0.01, ***P < 0.001. D (left) Proliferation profiles of CD45.1⁺ OT-I and CD45.1⁺ OT-II in respective dLNs (CTV peaks). (right) Division and replication indexes of CD45.1⁺ OT-I and CD45.1⁺ OT-II T cells in respective dLNs. Non-parametric Kruskal-Wallis tests with Dunn’s multiple comparison post hoc test, *P < 0.05, **P < 0.01. Non-significant responses are not indicated. Data are representative of at least two experiments.