Fig. 5: Depletion of alveolar macrophages impairs the protective activity of passively transferred immune sera against BA.5 infection.
a, Scheme for depletion of neutrophils and monocytes, passive transfer of immune sera and BA.5 challenge. b–d, Analysis of depletion of immune cell subsets in blood of mice receiving anti-Gr-1 (Ly6C/Ly6G) or isotype antibody at 3 dpi. Summary of different cell types (b) based on the gating strategy (Extended Data Fig. 5a). Representative flow cytometry dot plots showing depletion of neutrophils (c) and monocytes (d) with numbers indicating the cell population as a percentage of CD45+ cells. e,f, Analysis of infectious viral burden at 3 dpi in nasal turbinates (e) and lungs (f) after BA.5 challenge. g, Scheme for depletion of alveolar macrophages, passive transfer of immune sera and BA.5 challenge. h, Analysis of depletion of immune cell subsets in lungs of mice receiving liposomes at 3 dpi. Summary of different cell types (h) based on gating strategy (Extended Data Fig. 5b); DCs, dendritic cells. i, Representative flow cytometry dot plots showing depletion of alveolar macrophages after liposome administration with numbers indicating the cell population as a percentage of CD45+ cells. j,k, Analysis of infectious viral burden at 3 dpi in nasal turbinates (j) and lungs (k) after BA.5 challenge (boxes illustrate GMT, bars indicate mean; in order left to right n = 10, 10, 10 and 6 (b); n = 10, 9, 9 and 6 (e); n = 10, 9, 9 and 6 (f); n = 9, 10, 7 and 12 (h); n = 9, 10, 7 and 12 (j); n = 9, 10, 7 and 12 (k) mice per group, two experiments (b, e, f, h, j and k), dotted lines show limit of detection (LOD), Mann–Whitney test with Bonferroni post-test correction (b and h), Mann–Whitney test (e, f, j and k), NS, not significant, **P = 0.0077, ****P < 0.0001, ***P = 0.0003 (b); **P = 0.003, ***P = 0.0007, **P = 0.0034, **P = 0.0011 (h); ****P < 0.0001 (k).
