The C-Type Lectin Receptor DCIR Is Crucial for the Development of Experimental Cerebral Malaria

Cerebral malaria (CM) is the most severe complication of malaria. The murine Plasmodium berghei ANKA (PbA) infection model has helped to identify crucial players in the pathogenesis of CM. However, the role of pattern recognition receptors in innate immunity to CM induction is still poorly understood. C-type lectin receptors (CLRs) represent a family of pattern recognition receptors that recognize carbohydrate structures on pathogens and self-Ags often in a Ca2+-dependent manner. In this study, we investigated the role of the CLR dendritic cell immunoreceptor (DCIR) in the genesis of CM. Using the murine PbA infection, we show in this article that DCIR is essential for the development of CM. Although PbA infection led to 80% CM in wild-type C57BL/6 mice, DCIR-deficient mice were highly protected with only 15% CM development. In accordance with the reduced CM incidence in DCIR-/- mice, CD8(+) T cell sequestration was markedly reduced in brains of PbA-infected DCIR-/- mice, which was accompanied by reduced brain inflammation. Reduced T cell sequestration in the brain was caused by decreased TNF-alpha levels in sera, as well as a modulated activation of CD4(+) and CD8(+) T cells in spleen of PbA-infected DCIR-/- mice. This study indicates that DCIR is critically involved in CM induction, thus highlighting the importance of this CLR in innate immunity during malaria infection.