Expeditious recruitment of circulating memory CD8 T cells to the liver facilitates control of malaria

Circulating memory CD8 T cell trafficking and protective capacity during liver-stage malaria infection remains undefined. We find that effector memory CD8 T cells (Tem) infiltrate the liver within 6 hours after malarial or bacterial infections and mediate pathogen clearance. Tem recruitment coincides with rapid transcriptional upregulation of inflammatory genes in Plasmodium-infected livers. Recruitment requires CD8 T cell-intrinsic LFA-1 expression and the presence of liver phagocytes. Rapid Tem liver infiltration is distinct from recruitment to other non-lymphoid tissues in that it occurs both in the absence of liver tissue resident memory sensing-and-alarmfunction and -42 hours earlier than in lung infection by influenza virus. These data demonstrate relevance for Tem in protection against malaria and provide generalizable mechanistic insights

Automated summary

The study shows that effector memory CD8 T cells rapidly infiltrate the liver after malarial infection, mediating pathogen clearance through upregulation of inflammatory genes. This highlights the crucial role of Tem in protecting against malaria infection.