TRANSCRIPTION OF INTERFERON-ALPHA-2 ALLELES FROM VIRUS-INDUCED HUMAN-LEUKOCYTES AND LYMPHOBLASTOID-CELLS OF AFRICAN ORIGIN

It has been previously shown that the genomic DNA of both the lymphobl astoid cell line (Namalwa) and certain human donors (of African origin ) contain sequences corresponding to two allelic variants, b and c, of the interferon-alpha 2 gene (IFNA2). Little is known however about th e relative expression of these two alleles in heterozygous cells. We h ave therefore examined the transcription of allelic variants of the hu man IFNA2 locus by both normal human leucocytes (Gem a heterozygous do nor) and Namalwa cells. Analysis of cDNA clones identified sequences o f both allelic variants, IFNA2b and c, indicating active transcription by both cell types. Analysis of tryptic and peptic peptides derived f rom purified IFN-alpha 2 also demonstrated both IFN-alpha 2b and IFN-a lpha 2c proteins. Populations of virus induced heterozygous cells can therefore effectively transcribe and secrete both forms of IFN-alpha 2 simultaneously, with no apparent restrictions on expression of either allele.