Fig. 4: CCR2 is required for immune cell trafficking into the pancreas.

a Heatmap of chemokines and cytokines that were upregulated in 7-day WGP-treated CD11b⁺ cells based on RNA-Seq data. b viSNE plot of the CD11b⁺ pancreatic population in PBS and 7-day WGP-trained mice, highlighting the expression of CCR2. Images made with CyTOF data. c scRNA-Seq data showing a UMAP of the myeloid clusters expressing CCR2. d CCL2 expression in whole pancreatic lysates 24 h following WGP treatment a measured by RT-PCR (n = 6). ****p = 0.0001. e GSEA generated enrichment plots of genes related to leukocyte proliferation in CD11b⁺ pancreatic cells from 7-day WGP-trained as compared to PBS mice. PBS was used as the control and compared to WGP. f Summarized data of the percent of CD45⁺ pancreatic cells that are Ki67+ in PBS and 7-day WGP-trained mice (n = 4). ***p = 0.0007. g Cells were first gated on the CD45 + Ki67+ population. Plots show the percent of the CD45⁺Ki67⁺ proliferating pancreatic cells that are CD11b⁺CCR2⁺ in PBS and 7-day WGP-trained mice (n = 4). *p = 0.0261. h Pancreatic cells from PBS and 7-day WGP-trained mice (n = 5) were restimulated with LPS and the percent of CCR2 positive and negative cells producing TNFα was measured in each condition. Cells were first gated on the CD45⁺CD11b⁺ subset. Representative dot plots and summarized data were shown. *p = 0.022, **p = 0.0073, ***p = 0.0007. i–k WT and CCR2^−/− mice were treated with PBS or WGP and the percent of i CD45⁺ cells in the pancreas (****p < 0.0001) and j the percent of CD45⁺ cells that were CD11b⁺ was assessed. **p = 0.0013. k The percent of CD45⁺CD11b⁺ cells producing TNFα. Representative flow plots and summarized data are shown. Each dot represents data from one mouse. ***p = 0.0002. (i–k: WT PBS n = 9, WT WGP n = 9, CCR2^−/− PBS n = 8, CCR2^−/− WGP n = 8). An unpaired, two-tailed student’s t-test was used in d, f, and g, while a one-way ANOVA with multiple comparisons was used in h–k. Data were represented as mean ± SEM. ns not significant. In f–k, each sample represents a biologically independent animal obtained over a single independent experiment which was repeated at least twice for verification of results.