Fig. 6: TLR2 expression by the hematopoietic lineage is required for optimal T-cell responses in the lung following mucosal vaccination and boosting with Pam₂Cys Spike.

a Experimental outline (week; wk). Tlr2−/− (KO) or wild type (WT) mice were irradiated then received transfer of Tlr2−/− or WT bone marrow (BM) cells i.v. Mice were rested for 12 weeks to allow hematopoietic reconstitution and replacement, then immunized with Pam₂Cys Spike intra-nasally (i.n) three times, two weeks apart. Immune responses in the lungs were characterized at one week post final vaccination. b To verify bone marrow replacement, unsupervised clustering of lung CD45⁺ cells was performed on flow cytometry data and relative expression of TLR2 was examined by FIt-SNE for each experimental group. c Mean (n = 6) proportions of CD45⁺ cell populations in the lungs determined by flow cytometry, representative of two independent biological experiments, with (d) quantitation of populations of interest (KO host KO BM, black; KO host WT BM, red; WT host KO BM, blue; WT host WT BM, purple). Data are for individual mice from two independent biological experiments (n = 6 animals in each). Box and whiskers plots show median (centre), 25th and 75th percentile (box), lowest and highest value (whiskers). Statistics: p-values indicated, Kruskal–Wallis test, Dunn’s multiple comparisons. Source data are provided as a Source Data file.