A Single‐Cell Atlas Revealed Altered B Cells and Neutrophils Immune Signatures and Inflammatory Responses in SFTSV Infection

ABSTRACT Severe fever with thrombocytopenia syndrome virus (SFTSV) presents an emerging public threat due to its high mortality rate and ever‐expanding geographic distribution. However, characterization of SFTSV infection pathogenesis and immunological impact at single‐cell level remains underexplored. Here, we employ single‐cell transcriptome‐wide sequencing in peripheral blood mononuclear cells (PBMCs) from hospitalized SFTSV‐infected patients to map the immune landscape across acute and convalescent stages of infection. The results reveal significant alterations in immune cell compositions, along with profound disruption in intercellular crosstalk. B cells and neutrophils appear to be the primary target for SFTSV infection besides monocytes, as evidenced by heightened virus‐related pathways in these two cell types during the acute phase. In addition, SFTSV infection induces a substantial inflammatory response, which were prominently reflected in monocytes and neutrophils. These data illustrate the complex immune remodeling and inflammatory cascades triggered by SFTSV, with a particular focus on its effects on B cells and neutrophils, bringing novel insights into future therapeutic developments.