Single-cell RNA sequencing reveals the transcriptional landscape of intestinal lymphoid cells in zebrafish challenged with SVCV

Here, utilizing a zebrafish model of intestinal spring viremia of carp virus (SVCV) infection, we profiled 46,606 single mucosal immune cells at 14 days post-infection. By comprehensively defining the T and B cell compartments, we demonstrated a high evolutionary similarity in immune cell composition between teleosts and mammals.

Single-cell transcriptomics further revealed a specialized antiviral functional division paradigm: cd8+ T cells mediate frontline cytotoxic killing via isg15+ clusters, while cd4+ Th17 cells (rorc+/il17a/f3+) repair the epithelial barrier. Moreover, intercellular communication and functional assays showed that macrophages and T cells deliver MIF signals via CD74/CXCR4 to compensate for anatomical defects, driving the local survival and clonal expansion of IgM+ B cells outside germinal centers.