Abstract

Enterovirus A71 (EV-A71) is the primary pathogen causing severe hand-foot-and-mouth disease (HFMD) in young children, with T-cell immune dysfunction closely linked to severe clinical outcomes. However, the molecular mechanisms underlying EV-A71-mediated T-cell impairment remain unclear, and no specific therapies are currently available. Here, we investigated the interaction between EV-A71 and T cells, and explored potential targeted therapeutic strategies. Our results showed that EV-A71 efficiently infects T cell lines (Jurkat, EL-4) and primary mouse CD3 + T cells in a dose- and time-dependent manner, inducing T-cell death and upregulating pro-inflammatory cytokines (IL-1β, IL-6, TNF-α). Mechanistically, EV-A71 infection triggers GSDME-dependent pyroptosis in T cells via caspase-3 activation, rather than GSDMD-dependent pyroptosis, as evidenced by genetic ablation and inhibitor experiments. Methylcobalamin (MeCbl), a specific GSDME inhibitor, rescued EV-A71-induced T-cell loss, and significantly improved the survival rate (80%) of EV-A71-infected newborn mice. Furthermore, the combined treatment with MeCbl and AGS-A (a T cell-dependent therapeutic agent) exerted a synergistic protective effect, achieving 90% survival rate in wild-type mice, which was abrogated in T cell-deficient BALB/c-nu - / - mice. Collectively, our findings identify GSDME-dependent T-cell pyroptosis as a key pathogenic mechanism of EV-A71 infection and highlight MeCbl as a promising targeted agent for HFMD treatment, either used alone or in combination with AGS-A.