The role of immune cells in Hantaan-induced hemorrhagic fever with renal syndrome.

Hemorrhagic fever with renal syndrome (HFRS) is a severe and often fatal zoonotic disease primarily caused by the Hantaan virus (HTNV), a member of the Orthohantavirus genus. Although immune cells are known to play critical roles in HTNV-induced HFRS, the detailed dynamic changes, phenotypic alterations, and functional profiles of distinct immune subsets over the course of the disease remain poorly understood. In this review, we summarize current understanding of key immune populations during HTNV infection, including monocytes, macrophages, dendritic cells (DCs), natural killer (NK) cells, neutrophils, T cells and B cells. We highlight a central immunological duality in which these cells are necessary for viral clearance while also participating in immunopathological tissue damage. By integrating clinical and mechanistic insights, we present a detailed framework for understanding how the balance between protective immunity and immunopathology determines disease outcome. Recognizing these complex dynamics will be crucial for directing future studies and determining potential therapeutic targets in HFRS.