IFNAR1 Controls Progression to Cerebral Malaria in Children and CD8+ T Cell Brain Pathology in Plasmodium berghei –Infected Mice

Abstract

Development of cerebral malaria (CM), a severe and fatal form of clinical Plasmodium falciparum infection, results from a damaging cascade of vascular, inflammatory, and immunological host responses that leads to brain injury. Progression to CM can be modified by host genetic factors. Our case-control study in Angolan children aimed at highlighting the role of IFN (α, β) receptor 1 (IFNAR1) in progression to CM. We report a robust association between IFNAR1 and CM protection, as well as detailed studies showing analogous protection from experimental CM in Ifnar1−/− mice infected with P. berghei ANKA. We developed a novel cell-transfer protocol that enables spleen cell priming in the absence of disease. This led to the discovery that IFNAR1 expression in CD8+ T cells is crucial and can abrogate resistance to experimental CM in Ifnar1−/− mice. Splenic CD8+ T cells from Ifnar1−/− mice are functionally activated upon infection, yet are unable to mediate experimental CM development within the brain tissue. Our findings prove that IFNAR1 signaling unleashes CD8+ T cell effector capacity, which is vital for CM, and raises the hypothesis that the cohesive role of IFNAR1 in both human and mouse CM operates through CD8+ T cell triggering.