Description:

Title: Early Type I IFN Blockade Improves the Efficacy of Viral Vaccines

Speaker: Nicole Palacio, Graduate Student / Penaloza-MacMaster

Host: Pablo Penaloza-MacMaster, PhD

Topic:

Type I interferons (IFN-I) play a major role in the innate immune response. These cytokines are induced within hours of infection, conferring rapid protection before the onset of adaptive immunity. IFN-I are also critical for the priming of adaptive immune responses, but it is not clear if early antiviral restriction by IFN I can also limit the amount of antigen available to prime the adaptive immune system. We found that blocking IFN-I signaling improves adaptive immunity and enhances subsequent host protection following viral re-infection in murine models. Short-term blockade of IFN-I improved the efficacy of clinically approved vaccines and experimental HIV vaccines. Adaptive immune responses were also enhanced when IFN-I was transiently blocked during acute viral infections. The improvement of virus-specific immunity following acute IFN-I blockade was mechanistically associated with an increase in antigen presentation and costimulation. These findings warrant a re-evaluation of the immunoregulatory roles of IFN-I during immune memory differentiation, which may provide a framework for rational vaccine design.