Here, we report the first human defect in IL-2Rβ, occurring in two infant siblings with a homozygous <i>IL2RB</i> mutation in the WSXWS motif, manifesting as multisystem autoimmunity and susceptibility to CMV infection.
During murine CMV (MCMV) infection, CD4<sup>+</sup> Tcells maintain inflationary virus-specific CD8<sup>+</sup> T-cell responses via IL-2 but not IL-21.
Serum IL-2 was not detectable in mice treated with Ad-pRSV-IL-2, whereas expression peaked at a total of 1--2 ng at 24 hours but declined very rapidly in the Ad-pCMV-IL-2-treated group.