Infection of T cells by Epstein-Barr virus (EBV) causes chronic active EBV infection (CAEBV) characterized by T cell lymphoproliferative disorders (T-LPD) of unclear etiology. Here, we identified two homozygous biallelic loss-of-function mutations in PIK3CD and TNFRSF9 in a patient who developed a fatal CAEBV. The mutation in TNFRSF9 gene coding CD137/4-1BB, a costimulatory molecule expressed by antigen-specific activated T cells, resulted in a complete loss of CD137 expression and impaired T cell expansion toward CD137 ligand–expressing cells. Isolated as observed in one sibling, CD137 deficiency resulted in persistent EBV-infected T cells but without clinical manifestations. The mutation in PIK3CD gene that encodes the catalytic subunit p110δ of the PI3K significantly reduced its kinase activity. Deficient T cells for PIK3CD exhibited reduced AKT signaling, while calcium flux, RAS-MAPK activation, and proliferation were increased, suggestive of an imbalance between the PLCγ1 and PI3K pathways. These skewed signals in T cells may sustain accumulation of EBV-infected T cells, a process controlled by the CD137–CD137L pathway, highlighting its critical role in immunity to EBV.
Concomitant PIK3CD and TNFRSF9 deficiencies cause chronic active Epstein-Barr virus infection of T cells
R. Rodriguez, B. Fournier, D. Jorge Cordeiro, and S. Winter contributed equally to this paper.
- Views Icon Views
- Share Icon Share
- Tools Icon Tools
- Search Site
Rémy Rodriguez, Benjamin Fournier, Debora Jorge Cordeiro, Sarah Winter, Kazushi Izawa, Emmanuel Martin, David Boutboul, Christelle Lenoir, Sylvie Fraitag, Sven Kracker, Tania H. Watts, Capucine Picard, Julie Bruneau, Isabelle Callebaut, Alain Fischer, Bénédicte Neven, Sylvain Latour; Concomitant PIK3CD and TNFRSF9 deficiencies cause chronic active Epstein-Barr virus infection of T cells. J Exp Med 2 December 2019; 216 (12): 2800–2818. doi: https://doi.org/10.1084/jem.20190678
Download citation file: