Interferon Alpha 11 (IFNa11)

The weak virus-induced expression of the IFNa11 gene compared with IFNa4 was due to the presence of two nucleotide substitutions in the IFNa11 gene promoter. Irf3 or Irf7 mediated transcription and the synergism between these factors were dramatically affected in the case of IFNa11. No stimulatory effect on IFNa11 promoter transcription was observed when ikk or tbk1 was expressed alone or in the presence of irf3, although a 4-5-fold increase was obtained in the latter case, confirming that the IFNa11 gene promoter was unresponsiveness to irf3. The differential virus-induced transcription of IFNa4 and IFNa11 promoters correlated with their differential response to irf3 stimulated by ikk or tbk1. The IFNa11 gene promoter did not respond to irf3 activation even when cells expressed a constitutively active n-terminal form of rigi, whereas the IFNa4 promoter was stimulated 15-fold in similar conditions.