Understanding the mechanisms of reversibility of functionality in CD4 T cells is a long-lasting question in Immunology. This is tremendously important to find new or improved therapeutic approaches to reverse harmful immune responses such as Th1/Th17 during autoimmunity or Th2 during allergy and asthma.
M. Löhning and colleagues demonstrate that in vivo viral infection reveal plasticity of virus-specific in vitro differentiated Th2 cells, and induce their transformation into GATA3+/Tbet+-responding IL-4+/IFN-g+-producing CD4 T cells.