CD8 ⁺ T Cells Can Mediate Short-Term Protection against Heterotypic Dengue Virus Reinfection in Mice

Abstract

Dengue virus is present in more than 120 countries in tropical and subtropical regions. Infection with dengue virus can be asymptomatic, but it can also progress into the potentially lethal severe dengue disease. There are four closely related dengue virus serotypes. Infection with one serotype results in a transient period of resistance against all serotypes (cross-protection), followed by lifelong resistance to the infecting serotype, but not the other ones. The duration and mechanisms of the transient cross-protection period remain elusive. This study investigates the contribution of cellular immunity to cross-protection using mouse models of DENV infection. Our results demonstrate that cellular immunity is crucial to mediate cross-protection against reinfection with a different serotype, but not for protection against reinfection with the same serotype. A better understanding of the mediators responsible for the cross-protection period is important for vaccine design, as an ideal vaccine against dengue virus should efficiently protect against all serotypes.