Fig. 7: Pre-surgical neoadjuvant immunotherapy confers long-term humoral immune protection for preventing infection relapse.

a Schematics for the presurgical neoadjuvant immunotherapy that prevents postsurgical MRSA infection relapse. In 9 days after the establishment of implant infection model, mice were treated with MPS-PVP followed by the implant removal surgery on day 10. New implants were then inserted with fresh MRSA inoculation on day 11. b, c, f Individual infection area growth curves (b), average infection area growth curves (c) and representative photos (f) of mice after indicated treatments. (n = 5 biologically independent mice. Data are mean \(\pm\) s.d.). d, e Bacterial CFU counts of extracted implants (d) and peri-implant tissues (e) in the pre-surgical neoadjuvant immunotherapy model. g Representative images of HE staining of tissues in the infected area. The circles indicate neutrophils which are associated with the infection severity. Scale bar, 20 μm. h Representative images of tissue sections analyzed for bacterial biomass using Giemsa staining. S. aureus are indicated by circles. Scale bar, 10 μm. i, j Representative flow dot plots (i) and statistical analysis (j) of memory B cells (B_mem, IgG⁺IgD⁻) by gating on B220⁺ cells. k, l Representative flow dot plots (k) and statistical analysis (l) of CD80⁺ B_mem which can differentiate rapidly into antibody-forming cells by gating on IgG⁺IgD⁻ cells. m Levels of IL1β cytokine in the serum. n Serum IgG antibody levels in different groups. d, e, j, l, m, n Data are mean \(\pm\) s.d. (n = 3 per group) and n represents biologically independent experiments. Two-tailed, unpaired t-test, exact p-values. ns, not significant. Van, vancomycin. Note, vancomycin and MPS-PVP were administrated through local injection in the infected area. Source data are provided as a Source Data file.