A family of structural genes for human lymphoblastoid (leukocyte-type) interferon

Amino acid sequences of tryptic and chymotryptic peptides from human lymphoblastoid interferon (IFN-alpha) have been determined. The results show that IFN-alpha consists of a family of proteins with at least five different, but homologous, primary structures. There appears to be little, if any, glycosylation of the major components of IFN-alpha.     

Interferon-neutralizing antibodies in a patient treated with human fibroblast interferon

During recent years clinical trials have shown that human leukocyte interferon (HuIFN-alpha) may be useful in the treatment of cancer, but very little has been done concerning the possible use of human fibroblast interferon (HuIFN-beta). Treuner et al. recently reported the successful treatment of a nasopharyngeal carcinoma with HuIFN-beta: in the course of IFN-therapy a HuIFN-beta neutralizing activity appeared in the serum of this patient. We report here that such activity is due to IgG antibodies--this study is the first to present evidence for antigenicity of IFN in a homologous system.     

Glucocorticoid hormones inhibit DNA synthesis and enhance interferon production in human lymphoid cell line

Although buffy coat leukocytes have been the prime source of human interferon, cells of the Burkitt lymphoma line Namalwa are increasingly used for the large scale production of interferon. On induction with Sendai virus or Newcastle disease virus, Namalwa cells produce a substantial quantity of interferon which contains predominantly the leukocyte antigenic species and minor amounts of fibroblast-type interferon. We have recently demonstrated that inducers of erythropoietic differentiation in Friend cells are able to enhance interferon synthesis in Namalwa cells when added to cultures larger than or equal to 24 h before interferon induction by Sendai virus. The most potent compounds, n-butyrate, stimulated interferon production about 30-fold and has also been independelty described by others. All active compounds inhibited DNA synthesis in Namalwa cells and the extent of inhibition apparently paralleled the stimulatory potency of the respective compound. Induction of differentiation of Friend cells can be antagonised by various steroid hormones, which by themselves have no measurable effects on these cells. In contrast, we report here that glucocorticoid hormones inhibit DNA synthesis in Namalwa cells and augment Sendai virus-induced interferon synthesis.     

Virus-specific effects of interferon in embryonal carcinoma cells

Embryonal carcinoma (EC) cells are susceptible to infection by a variety of viruses, but do not become resistant to infection by Semliki Forest virus or vesicular stomatitis virus (VSV) on treatment with interferon. These observations have led to the conclusion that interferon does not induce an antiviral state in EC cells. We report here, however, that EC cells treated with interferon become resistant to infection by two picornaviruses and two ts mutants of VSV, whereas they remain sensitive to wild-type VSV, Sindbis and influenza virus infectin. These results suggest that a partial antiviral state is induced in EC cells by interferon and that the induced antiviral protein(s) interferes with the replication of specific viruses. A significant common feature of these viruses is their replication through structures containing double-stranded RNA (dsRNA).