Blockade of C5aR1 resets M1 via gut microbiota-mediated PFKM stabilization in a TLR5-dependent manner

Increased researches show that complement, the codominant central mediator of humoral immunity, is a critical factor in tumor initiation, development, and chemotherapy resistance. C5a/C5aR1 signaling has been shown to promote tumor progression by recruiting MDSCs in breast malignancies And blockade of C5aR1 resets M1 via gut microbiota-mediated PFKM stabilization in a TLR5-dependent manner. We here report that TLR5 as a key regulator of tumor associated macrophages M1 polarization. Flagellin, the protein subunit of the bacterial flagellum, stimulates the innate immune receptor Toll-like receptor 5 (TLR5) after pattern recognition. Receptor activity was turned by a TLR5-flagellin interaction distal to the site of pattern recognition. Thus, activation of downstream signaling pathway is promoted. Overall design: To investigate the role of C5aR1 in regulating TAMs M1 polarization. We cultured the primary Bone marrow-derived macrophages from wild-type and C5ar1-/- mice.