B cell CD19 is transferred between immune cells in mice and humans
Summary
When immune cells interact, they frequently exchange membrane-bound antigens. Our evolving understanding of these processes challenges the cellular specificity of lineage markers and therapeutic monoclonal antibodies. By using mouse and human B-T cell co-cultures, we report that CD19, an assumingly exclusive B cell marker, is transferred via trogocytosis when B cells activate T cells. In a B cell-driven model of experimental autoimmune encephalomyelitis, CD19+ T cells expand and show enhanced features of activation, differentiation, and encephalitogenic potential ex vivo. Additionally, co-transfer of CD19 and functional IgM from B cells results in the gain of B cell function by T cells. In patients with chronic central nervous system (CNS) demyelination, CD19+ T cells display a pro-inflammatory phenotype and are concomitantly depleted by inebilizumab, an approved anti-CD19 antibody, which raises important considerations for the therapeutic use of monoclonal antibodies overall. Finally, we report that myeloid cells acquire CD19 and functional IgM after phagocytosis of apoptotic B cells and thereby gain functional B cell properties. These findings highlight the commonness of membrane and antigen-transfer between cells, resulting in transmission of cellular function. © 2026. The Author(s).
| Authors | Ochs J, Schweineberg P, Thode J, Blenkle A, Husseini L, Klein M, Bopp T, Schindler P, Paul F, Weber MS |
|---|---|
| Journal | Nature communications |
| Publication Date | 2026 Jul 29;17(1) |
| PubMed | 42527393 |
| PubMed Central | PMC13421502 |
| DOI | 10.1038/s41467-026-75534-3 |