Hantaan virus (HTNV) infection causes an epidemic of hemorrhagic fever with renal syndrome (HFRS) mainly in Asia. It is well known that T cells mediated anti-viral immune response. Although previous studies showed that double positive T (DP T) cells, a little portion of T lymphocytes, were involved in adaptive immune response during virus infection, their kinetic changes and roles in HTNV infection have not yet been explored. In this study, we characterized DP T cells from HFRS patients based on flow cytometry data combined with scRNA-seq data. We showed that HTNV infection caused the upregulation of DP T cells in the peripheral blood, which were correlated with disease stage. The scRNA-seq data clustered DP T cells, unraveled their gene expression profile, and estimated the ordering of these cells. The production of granzyme B and CD107a from DP T cells and the abundant TCR distribution indicated the anti-viral property of DP T cells. In conclusion, this study identified, for the first time, an accumulation of DP T cells in the peripheral blood of HFRS patients and suggested these DP T cells belonging to CD8⁺T cells lineage. The DP T cells shared the similar characteristics with cytotoxic T cells (CTL) and exerted an anti-viral role in HFRS.

China is one of the main epidemic areas for hemorrhagic fever with renal syndrome (HFRS). Currently, there is no human antibody specific to Hantaan virus (HTNV) for the emergency prevention and treatment of HFRS. To prepare human antibodies with neutralizing activity, we established an anti-HTNV phage antibody library using phage display technology by transforming peripheral blood mononuclear cells (PBMCs) of patients with HFRS into B lymphoblastoid cell lines (BLCLs) and extracting cDNA from BLCLs that secreted neutralizing antibodies. Based on the phage antibody library, we screened HTNV-specific Fab antibodies with neutralizing activities. Our study provides a potential way forward for the emergency prevention of HTNV and specific treatment of HFRS.

(1) Background: Acetamiprid, a widely used neonicotinoid insecticide, has increasingly drawn people’s attention to its potential reproductive toxicity risks. Although existing studies have shown that exposure to acetamiprid can cause testicular damage, its underlying molecular mechanism has not been fully elucidated. (2) Methods: This study established a mouse model of acetamiprid exposure via free drinking water and combined it with in vitro culture of TM3 cells, aiming to explore the toxic effects of acetamiprid on testicular tissue and its potential mechanism. (3) Results: Acetamiprid exposure induced significant pathological damage to the testicular tissue of mice and significantly reduced sperm quality. Further mechanism studies have shown that acetamiprid down-regulates the expression of RNA demethylase ALKBH5, leading to an overall increase in m⁶A modification levels, thereby inhibiting the activity of the PI3K/AKT signaling pathway and ultimately inducing apoptosis of TM3 cells. (4) Conclusions: In conclusion, this study, by integrating both internal and external models, has revealed a molecular mechanism by which acetamiprid is involved in testicular injury through epigenetic pathways, providing scientific basis and mechanism clues for assessing reproductive hazards caused by exposure to environmental toxins.