Fig. 3
From: Key role of the CCR2-CCL2 axis in disease modification in a mouse model of tauopathy
Upregulation of circulating CCR2+ monocytes and FOXP3+ regulatory CD4+ T cells following anti-PD-L1 antibody immunotherapy. This experiment included four groups of DM-hTAU mice treated either with: IgG, αPD-L1, αCCR2 + αPD-L1, or αCCR2. An additional group of WT mice served as healthy controls. (A) Schematic presentation of experimental design: αCCR2 was i.p. injected to DM-hTAU mice 3 days prior (Day − 3) to αPD-L1 or IgG (Day 0), and again 1 day after αPD-L1 treatment (Day 1). Blood was sampled 3 days following αPD-L1 treatment and analyzed by CyTOF. (B) FlowSOM clustering over tSNE plot showing different immune cell populations. (C) Heatmap of the CyTOF data showing Z-score of mean expression levels of the different markers across distinct CD45+ immune cell populations. (B, C) Representative results of one of three independent experiments. (D) Quantification of CCR2+ monocytes as measured by CyTOF. The percentage of the entire cell population per mouse is presented relative to the control IgG group. One-way ANOVA F(4,22) = 14.14, ***p < 0.0001. Post-hoc uncorrected Fisher’s LSD multiple comparisons between DM-hTAU groups and WT: #p < 0.05, ##p < 0.01, ###p < 0.001. Post-hoc uncorrected Fisher’s LSD multiple comparisons between the DM-hTAU groups: **p < 0.01, ***p < 0.001. (E) Quantification of Tregs as determined by CyTOF and analyzed by manual gating. The abundance of each cell population per mouse is presented as the ratio relative to the control IgG group. One-way ANOVA F(4,22) = 2.986, *p = 0.0392. Post-hoc uncorrected Fisher’s LSD multiple comparisons between the DM-hTAU groups: *p < 0.05, **p < 0.01. n = 5–6 mice per group. Data are presented as mean ± s.e.m. (F) WT mice were injected with αPD-L1, and after 3 and 7 days, blood was sampled and analyzed by multiparametric flow cytometry. (G) Flow cytometry analysis of blood Tregs (One-way ANOVA F(2,15) = 4.762, *p = 0.025. Post-hoc uncorrected Fisher’s LSD multiple comparisons between αPD-L1 to IgG groups: *p < 0.05). (H) Flow cytometry analysis of CCR2 expression by blood Tregs, and (I) representative dot plot of the gating strategy. Splenocytes were used as FMO; n = 6 mice per group. Data are presented as mean ± s.e.m.