Figure 4: Blood-derived macrophages become alternatively activated during T. crassiceps infection and suppress Th1 and Th2 responses in vitro.

Resident F4/80⁺/CX₃CR1⁻ and blood-derived macrophages F4/80⁺/CX₃CR1⁺ were sorted from 8 wks Taenia-infected mice (a) Evaluation of Arginase1, Chil3 and Retnla expression by qPCR in naïve resident, thioglycollate elicited macrophages, and resident and blood-derived macrophages from Taenia infected mice. Data represents fold change over resident naïve macrophages. (b) Microarray comparison (Log2 transformed data) of 72 h thioglycollate (blue dots) elicited macrophages and blood-derived macrophages (red dots) from 8wks Taenia-infected mice. (c) Heat map of log 2 transformed counts of upregulated or downregulated genes (2 fold, p < 0.05) identified in (b). (d) Biological processes associated with overexpressed genes in Taenia crassiceps-blood-derived macrophages using DAVID database. (e) Network of most downregulated and upregulated genes in Taenia crassiceps blood-derived macrophages vs thioglycollate macrophages and its association with IL-4 generated in Ingenuity pathway software. Red upregulated genes, green downregulated genes, Orange and blue arrows represent predicted activation or inhibition, respectively. (f) Naïve splenocytes were stimulated with anti CD3/CD28 and co-cultured with sorted blood-derived macrophages from Taenia-infected mice. (f) Proliferation of CD4+ cells evaluated by CFSE dilution after 72 h. (g) Cytokine production in macrophages/T cell co-cultures. In (a–c) macrophages were pooled from three mice and data represent two replicates. In (f,g) data are representative of one of two independent experiments using two replicates. Significance was calculated using t-test. *p < 0.05, **p < 0.01, ***p < 0.001.