Activation of macrophages by polysaccharide isolated from Paecilomyces cicadae through toll-like receptor 4

► PCP isolated from Paecilomyces cicadae increases NO production and cytokine gene expression in macrophages. ► PCP activates macrophages through TLR4 membrane receptor. ► PCP activates MAPKs and NF-κB signaling downstream from TLR4. ► NF-κB and p38 play a crucial role in PCP-induced NO production by macrophages.