Malaria remains one of the main global infectious diseases and cerebral malaria is a major complication, often fatal in Plasmodium falciparum-infected children and young adults [1]. Cerebral malaria pathophysiology is still poorly understood, combining cerebral vascular obstruction, and exacerbated immune responses. Indeed, investigations

in humans and mice documented STA-9090 the sequestration of erythrocytes, parasitized or not, platelets and leucocytes in cerebral blood vessels with an increased proinflammatory cytokine expression [1-3]. The specific role of T cells in cerebral malaria pathogenesis has been difficult to address in humans. In mice however, T-cell sequestration and activation in the brain are crucial steps for experimental cerebral malaria (ECM) development after Plasmodium berghei ANKA (PbA) infection [4-7]. In particular, αβ-CD8+

T cells sequestrated in the brain play a pathogenic, effector role for ECM development [6], and we showed recently a role for protein kinase C-θ (PKC-θ) in PbA-induced ECM pathogenesis [8]. Besides being a critical regulator of TCR signaling and T-cell activation, PKC-θ is involved in interferon type I/II signaling in human T cells [9]. Type II IFN-γ is essential Lenvatinib mw for PbA-induced ECM development [10-12], promoting CD8+ T-cell accumulation in the brain [7, 12-14]. Type I IFNs are induced during viral infection but they also contribute Terminal deoxynucleotidyl transferase to the antibacterial immune response. In Mycobacterium tuberculosis infection, types I and II IFNs play nonredundant protective roles [15], while type I IFNs inhibit IFN-γ hyper-responsiveness by repressing IFN-γ receptor expression in a Listeria monocytogenes infectious model [16]. Moreover, type I IFNs role in central nervous system (CNS) chronic inflammation is ambiguous [17].

IFN-β has proinflammatory properties and contributes to some auto-immune CNS diseases, while IFN-β administration is routinely used in relapsing-remitting multiple sclerosis treatment, characterized by inflammatory cell infiltration to the CNS, including Th1 and Th17 [17]. Crossregulations between type I and type II IFNs have been documented [18-21], they can have similar or antagonistic effects, and type I IFN-α/β precise role in ECM development after sporozoite or merozoite infection remains unclear. Here, we addressed the role of IFN-α/β pathway in ECM development in response to hepatic or blood-stage PbA infection, using mice deficient for types I or II IFN receptors. Unlike IFN-γR1−/− mice that were fully resistant to ECM, we show that IFNAR1−/− mice are partially protected after sporozoite or merozoite infection. Magnetic resonance imaging (MRI) and angiography (MRA) confirmed the reduced microvascular pathology and brain morphologic changes in the absence of type I IFNs signaling.