Rapid expansion of Treg cells protects from collateral colitis following a viral trigger

This study demonstrates that viral infection, specifically with LCMV, leads to a type I IFN-dependent loss of Treg cells. This loss is rapidly compensated by the conversion and expansion of Vβ5⁺ conventional T cells into iTreg cells. Using Vβ5-deficient mice, researchers showed that these Vβ5⁺ iTreg cells are crucial for preventing colitis by suppressing microbiota-dependent activation of CD8⁺ T cells. The recovery from colitis in IBD patients is linked to the expansion of the corresponding VP2⁺ Treg population in humans, highlighting a connection between viral triggers, impaired Treg compartments, and the initiation of immune pathology.

Michelle Schorer, Katharina Lambert, Nikolas Rakebrandt, Felix Rost, Kung-Chi Kao, Alexander Yermanos, Roman Spörri, Josua Oderbolz, Miro E. Raeber, Christian W. Keller, Jan D. Lünenborg, Gerhard Rogler, Onur Boyman, Annette Oxenius, Nicole Joller