An expanded parenchymal CD8+ T cell clone in GABA<sub>A</sub> receptor encephalitis
Aline Bracher, Carmen Alcalá, Jaime Ferrer-Lozano, Nico Melzer, Reinhard Hohlfeld, Bonaventura Casanova, Eduardo Beltrán, Klaus Dornmair
Abstract
Abstract The role of T cells in autoimmune encephalitis syndromes with autoantibodies against cell surface antigens is still enigmatic. Here we analyzed the T cell receptor repertoires of CD8+ and CD4+ T cells in a patient with “idiopathic” gamma‐aminobutyric‐acid‐A receptor (GABA A ‐R) encephalitis by next‐generation sequencing and single‐cell analyses. We identified a CD8+ T cell clone that was strongly expanded in the cerebrospinal fluid and in the hippocampus but not in the operculo‐insular cortex. By contrast, CD4+ T cells were polyclonal in these tissues. Such a strong clonal expansion suggests that CD8+ T cells may play a significant role in the pathogenesis.