An IFN-alpha2 cDNA and the monoclonal antibodies NK2 and 4F2 were used as probes to screen a human Namalwa cDNA library to find the cDNA coding for component 0.21 positive clones which strongly hybridize with IFN-alpha2 cDNA were obtained. Due to the strong sequence similarity of the human IFN-alpha family, a specific oligonucleotide was applied to the 21 positive clones for component o to find cDNA coding for component o. We have performed the partial amino acid sequence of IFN-alpha component o isolated from human IFN-alpha results from sequence analysis of component o revealed that it is very similar to IFN-alphaF. In order to know the relationship between component o and IFN-alphaF, we cloned the gene for IFN-alpha into several expression vectors. Analysis by western blotting, SDS PAGE and antiviral activity revealed IFN-alphaF gene was expressed well in an pKK 223-3 expression system. We are now preparing sufficient quantities of IFN-alphaF to perform further studies.
