CRX-527 modulates IL-10 expression in BCG-MSP1C-immunized mice

Objective: To evaluate the expression of IL-10 in mice immunized with a recombinant BCG expressing the MSP1C antigen (BCG- MSP1C), in the presence and absence of a TLR4 agonist CRX-527. Methods: The BCG-MSP1C vaccine candidate was cultured and characterized using acid-fast staining and field-emission scanning electron microscopy. The mice were immunized with BCG-MSP1C in the presence or absence of CRX-527 intraperitoneally. The expression and production of IL-10 were measured via real-time PCR and ELISA in peritoneal macrophages, spleen, liver, and lymph nodes of immunized mice. Results: IL-10 expression and production were significantly increased in peritoneal macrophages and lymph nodes in the presence of CRX-527. In contrast, spleen and liver samples showed a significant decrease in IL-10 levels with CRX-527. Conclusions: BCG-MSP1C shows promise as a malaria vaccine candidate by inducing IL-10 expression in multiple immune compartments and displaying stable morphology. Tissue-specific modulation of IL-10 by CRX-527 results in increased expression in the lymph nodes and peritoneal macrophages, and decreased levels in the liver and spleen.