Species Of Leukocyte Interferon Research Articles

Antiproliferative and antiviral activities of human leukocyte interferons

The antiproliferative effects of purified human leukocyte interferons were measured by their ability to inhibit cell multiplication of the human lymphoblastoid Daudi cell line. The growth-inhibitory and antiviral activities fractionate together throughout the purification of leukocyte interferon. In all cases, those fractions which exhibited antiviral activity also inhibited proliferation of Daudi cells. The final stage of protein purification, high-performance liquid chromatography on octyl-silica particles (pH 4.0), separated at least eight species of leukocyte interferon, all of which possessed growth-inhibitory activity. Because these two biological activities purify together and because the homogeneous species exhibit both activities, we conclude that the antiproliferative and the antiviral activities are both intrinsic properties of these human leukocyte interferons. However, the ratio of the growth-inhibitory to antiviral activity was not constant among the species. In addition, the ratio of the antiviral activity on human cells to that on bovine cells varied from species to species. We conclude that the individual members of the family of human leukocyte interferon proteins differ in structure and that these structural differences manifest themselves as variations in their intrinsic biological activities.

68] Purification of interferon produced in a culture of human granulocytes

Publisher Summary Coupling of a fluorescence detection system for molecules containing free amino groups with high-performance liquid chromatography (HPLC) has provided a sensitive method for purifying peptides at the picomole level. These techniques are successfully applied to the purification of interferon from normal leukocytes and from leukocytes from patients with chronic myelogenous leukemia. In addition, these methods are used to purify to homogeneity interferon from a myeloblastoid KG-1 cell line. Human leukocyte interferon is produced by induction of a continuous culture of the KG-1 cell line with Sendai virus in the presence of casein. There are several species of leukocyte interferon from the KG-1 cell line that can be distinguished by HPLC, and their purification is summarized. Although amino acid compositions of the interferons are very similar, the species can be distinguished by differences in molecular weight, activity on MDBK and AG-1732 cells, and separation by HPLC.