Résumé
X-SCID, the most common form of human SCID, is due to mutations in the common γ chain gene (γc) that encodes an essential component of the cytokine receptors for interleukin-2 IIL-2), IL-4, IL-7, IL-9, and IL-15. Activation of the Janus family tyrosine kinases Jak1 and Jak3 is necessary for appropriate signalling through the IL-2 receptor (IL-2R). Neither Jak1 nor Jak3 was phosphorylated after IL-2 stimulation of an Epstein-Barr virus-transformed cell line (LCD from an X-SCID patient with a γc null mutation. However, we now show that appropriate IL-2R function can be restored in an X-SCID LCL by transduction of a wild-type γc gene. A retroviral vector, G1γcSvNa, was constructed and produced in the PG13 packaging line. Transduced X-SCID LCL expressed the G1γcSvNa transcript. IL-2 stimulation of the transduced cell line resulted in appropriate tyrosine phosporylation of both Jak1 and Jak3. Thus, retroviral-mediated transduction of normal γc can reconstitute downstream signalling through the IL-2R in X-SCID cell lines, suggesting that gene therapy may be a treatment for this disease.