Fig. 7: BL/6 and BALB/c cell intrinsic differences after in vivo IL-4 + LPS synergistic activation from mixed bone marrow chimeras F1 mice.

a Violin plot displays the effects of sub-lethal LPS treatment with or without prior IL-4 treatment on murine sepsis score (MSS). LPS (500 μg/kg) was administered after 4 days with or without prior IL-4-Fc injection, and the MSS score was observed the following day around 9:00 am (n = 10/group). p-values were calculated using a two-sided Mann-Whitney test. b Schematic illustration of the experimental protocol (see methods). c UMAP plot visualize clusters of peritoneal cells derived from bone marrow chimeric mice. The UMAP were generated from integrated samples, including control (Ctrl), LPS, and IL-4 + LPS treatment groups from both BL/6 and BALB/c strains. Cells are color-coded according to computationally determined cell clusters by the singleR program. d Histogram depicts the cell type composition as determined by single-cell analysis for each sample, showing a decrease in macrophage cluster (green) and an increase in neutrophil cluster (pink) after LPS treatment. e Significantly induced genes (logfc.threshold = 0.25) were identified (LPS vs Ctrl and LPS + IL-4 vs LPS). The left panel displays the overlap of genes significantly induced after LPS treatment compared to Ctrl in macrophages from both strains. The right panel displays the overlap of genes significantly induced after IL-4 + LPS treatment compared to LPS treatment alone in macrophages from both strains. f The dot plot displays gene expression patterns, illustrating examples of no synergistic effect (left), synergistic effect (middle) following IL-4 + LPS treatment, and enhanced responses in BALB/c mice after LPS treatment (right). In the plot, red color represents a higher average expression of the gene, and a larger dot size indicates that the gene is present in a larger percentage of cells within that cluster. g The macrophage subset from the scRNA-seq data was re-integrated by selecting the “FindVariableFeatures” function with “nfeatures = 50” to visualize changes in cluster composition among samples. Cluster labels are represented as numbers on the right side of the figure. h Regulon activity was computed for macrophages from (g) using SCENIC analysis. The regulon names are labeled on the right side of the figure, with orange-colored names indicating the regulons in cluster 2 that disappear after LPS treatment, green-colored names indicate the regulons in cluster 6, whose population is increased after IL-4 + LPS treatment compared to LPS treatment in BL/6 mice, and purple-colored names indicate the regulons in cluster 3,5 and 8, whose population is increased after IL-4 + LPS treatment compared to LPS treatment in BL/6. i The regulon clustering from SCENIC analysis reveals that some regulons only contribute to Ctrl condition, labeled in blue, while another group of regulons exclusively contributes to the activation state induced either by LPS treatment alone or IL-4 + LPS treatment, labeled in orange.