IFNAR1 controls progression to cerebral malaria in children and CD8+ T cell brain pathology in Plasmodium berghei-infected mice
Elizabeth Ann Ball, Maria Rosário Sambo, Madalena Martins, Maria Jesus Trovoada, Carla Benchimol, João Costa, Lígia Antunes Gonçalves, António Coutinho, Carlos Penha-Gonçalves
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.