T-B interactions yield CD3(+) B cells and CD20(+) T cells with pathogenic features in multiple sclerosis.

T-B cell interactions produce CD3(+) B cells and CD20(+) T cells with pathogenic features, revealing new immune cell subsets in multiple sclerosis.

• Why it matters: Understanding these atypical lymphocytes is crucial because they challenge traditional immune cell classifications and may actively contribute to MS pathology, filling a knowledge gap in disease mechanisms.
• What they did: The study combined single-cell proteogenomics, FACS, and ImageStream to analyze CD3 + CD20 + cells, discovering that a significant portion of plasmablasts and follicular helper T cells display both markers, especially in tonsils and blood.
• The result: Findings show that these masquerading lymphocytes are enriched in cerebrospinal fluid, exhibit cytotoxic and myelin-reactive features, and are depleted by anti-CD20 therapy, highlighting their role in MS and potential as therapeutic targets.