Anoctamin-2-specific T cells link Epstein-Barr virus to multiple sclerosis.

Epstein-Barr virus (EBV) infection constitutes a prerequisite for multiple sclerosis (MS) development, and cross-reactivity between EBV nuclear antigen 1 (EBNA1) and anoctamin-2 (ANO2) antibodies was previously demonstrated in persons with MS (pwMS). Here, we show that ANO2-specific CD4+ T cells are more frequent in pwMS. Immunization of SJL/J mice with ANO2 or EBNA1 led to cross-reactive CD4+ T cell and antibody responses. ANO2 pre-immunization led to exacerbated experimental autoimmune encephalomyelitis (EAE), an effect mediated by CD4+ T cells, as confirmed by adoptive transfer experiments. T cell clones with cross-reactivity to EBNA1 and ANO2 could be isolated from natalizumab-treated pwMS, and sequencing of EBNA1- and ANO2-specific T cell receptors (TCRs) revealed a significant repertoire overlap. We thus report the first mechanistic evidence that EBNA1 CD4+ T cells can target the MS autoantigen ANO2, thereby establishing a link between EBV infection and neuroinflammation.