Recombinant fraction 1 protein of Yersinia pestis activates murine peritoneal macrophages in vitro

Fraction 1 antigen of Yersinia pestis is a capsule protein of 17.5 kDa, known to induce thymocyte proliferation and have anti-phagocytic role in macrophages. It serves as a major protective antigen against challenge of Y. pestis by inducing high concentration of IgG1 antibody response. In the present investigation it is observed that 10 μg/ml of rF1 antigen activated murine peritoneal macrophages in vitro. rF1 induced the production of TNF-α, IL-1, IL-6, and NO. rF1 treatment also induced increased transcription of IFN-γ and its related chemokines KC, IP-10, MIP-1α, MIP-1β, MCP-1, RANTES in macrophages. Significantly increased transcription of TLR5 was observed in macrophages treated with rF1, while the expression of TLR2 and TLR4 remained unaffected.