Molecular structure of human fibroblast and leukocyte interferons: probe by lectin and hydrophobic chromatography

Structural differences between human leukocyte virus-induced interferon and human fibroblast polyinosinic-polycytidylic acid (rIn-rCn)-induced interferon have been noted in previous studies. This study reports the behavior of human leukocyte and fibroblast interferon, induced by virus and by rIn-rCn, in several lectin and hydrophobic chromatographic systems. Differences in both glycosylation and in hydrophobicity of human leukocyte and fibroblast interferons are documented. Human fibroblast interferon is a glycoprotein, whereas our evidence suggests that human leukocyte interferon probably is not. Also, fibroblast interferon is more hydrophobic than leukocyte interferon, as probed on several hydrophobic adsorbents. The possible relationships of these differences to each other and to antigenic variations are discussed. Generally, the differences appear to be attributable to the cell type in which the interferon was induced. However, our results suggest that at least subtle differences in the processing of the induction signal (virus or rIn-rCn) within the same cell type may occur, slightly altering some structural features.