Heme concentration-dependently modulates the production of specific antibodies in murine

Free heme is an endogenous danger signal to provoke innate immunity. Active innate immunity is a precondition of an effective adaptive immune response. However, heme catabolites, CO, biliverdin and bilirubin trigger immunosuppression. Furthermore, free heme induces the expression of heme oxygenase-1 to reinforce the production of CO, biliverdin and bilirubin. As such, free heme can drive two antagonistic mechanisms to affect adaptive immunity. What is the outcome of animal immune response to an antigen in the presence of free heme? The question remains to be explored. Here we report the immunization results by intraperitoneal injection of the formulations containing BSA and heme. When the us