Interferon fibroblast

Interferons (lENs) (52,53), a family of species-specific vertebrate proteins, confer nonspecific resistance to a broad range of viral infections, affect cell proliferation, and modulate immune responses. AH three principal interferons, a-interferon (lEN-a) produced by blood leucocytes, P-interferon (lEN-P) by fibroblasts, and y-interferon (lEN-y) by lymphocytes, also have antiviral activity. The abiUty of interferons to inhibit growth of transplantable and carcinogen-induced tumor led to research showing the direct antiproliferative and indirect immune-mediated antitumor activities (see Chemotherapeutics, anticancer). IENs have been found to be efficacious in certain malignancies and viral infections, eg, hairy cell leukemia (85% response) and basal cell carcinoma (86% response). However, the interferons do have adverse side effects (54). 

Ah = Antibody IL = interleukin TNF =tumornecrosis factor INF = interferon LAK =lymphocyte-activated killer CSF =colony stimulating factors and FGF = fibroblast growth factor. 

Interferons [alFN, piFN and ylFN]. Interferons are a family of glycosylated proteins and are cytokines which are produced a few hours after cells have been infected with a virus. Interferons protect cells from viral infections and have antiviral activities at very low concentrations ( 3 x 10 M, less than 50 molecules are apparently sufficient to protect a single cell). Double stranded RNA are very efficient inducers of IFNs. There are three main types of IFNs. The aIFNs are synthesised in lymphocytes and the piFNs are formed in infected fibroblasts. The a and P families are fairly similar consisting of ca 166 to 169 amino acids. Although ylFNs are also small glycosylated proteins (ca 146 amino acids), they are different because they are not synthesised after viral infections but are produced by lymphocytes when stimulated by mitogens (agents that induced cell division). 

Several of these IFNs of mouse and human lymphocytes and fibroblasts are available commercially and have been best prepared in quantity by recombinant DNA procedures because they are produced in very small amounts by the cells. The commercial materials do not generally require further purification for their intended purposes. [Pestkas, Interferons and Interferon standards and general abbreviations. Methods Enzymol, Wiley Sons, 119 1986, ISBN 012182019X Lengyel, Biochemistry of interferons and their actions, Ann Bev Biochem 51 251-282 7982 De Maeyer and De Maeyer-Guignard, Interferons in The Cytokine Handbook, 3rd Edn, Thomson et al. Eds, pp. 491-516 7998 Academic Press, San Diego, ISBN 0126896623.]... 

Interferon (IFN) differs from bona fide antiviral diugs since it is a natural defense protein of the host organism and does not directly interfere with the viral replication steps. Interferons are small glycoproteins inducing immune modulatory and antiviral activities. They are secreted by lymphocytes, leukocytes and fibroblasts in response to foreign nucleic acids (dsRNA). 

Double stranded (ds) RNA is not a constituent of a normal cells but is produced during replication of many RNA and DNA viruses either as an obligatory intermediate or as a side product. As a foreign molecule, double stranded RNA induce the secretion of interferon (EFN) from lymphocytes, neutrophils and fibroblasts. 

Type I interferons. These are acid-stable and comprise two major classes, leucocyte interferon (Le-IFN, IFN-a) released by stimulated leucocytes, and fibroblast interferon (F-IFN, FN-/3) released by shmulated fibroblasts. 

The shaking of protein solutions may lead to aggregation and precipitation as a result of several mechanisms, such as air oxidation, denaturation at the interface, adsorption to the vessel, or mechanical stress. These possibilities were systematically examined for solutions of human fibroblast interferon [50]. In this example, mechanical stress was identified as the causative factor in the inactivation. The proposed mechanism of inactivation by mechanical stress was through orientation of the asymmetrical protein in the... 

IFN-a, -P and -y are all known to induce the enzyme in various animal cells. However, in human epithelial cells the kinase is induced only by type I interferons, whereas none of the interferons seem capable of inducing synthesis of the enzyme in human fibroblasts. The purified kinase is highly selective for initiation factor eIF-2, which it phosphorylates at a specific serine residue. 

The problem of the immunogenic nature of many human recombinant DNA proteins, and the potential to generate antibodies to a normal human protein, is of special interest to the immunotoxicologist. For example, 3 of 16 patients administered the rDNA-derived interferon-a (clone A) developed antibodies of the IgG class that were undetectable prior to or during therapy (Gutterman et al., 1982). These antibodies were capable of in vitro neutralization of interferon activity, although in vivo neutralization of interferon has not been documented. Since there are several different subtypes of interferon-a s, some contain epitopes not present on their own interferon subtype. Similarly, two patients treated with interferon-/ for many months developed high-titered antibody, which in one case was correlated with an inability of the patient s fibroblasts to produce interferon (Vallbracht et al., 1982). 

G-CSF expression is controlled at both the transcriptional and posttranscrip-tional levels. A sequence of 300 nucleotides upstream of the initiation codon is conserved in both the murine and human genes, and this appears to contain three regulatory sites. G-CSF (and some other cytokine genes) may be constitutively transcribed by cells such as blood monocytes, fibroblasts and endothelial cells, but the mRNA may be short-lived (fi/2 < 15 min). The mRNA contains poly-AUUUA sequences in the untranslated region, and this motif is usually associated with mRNA instability. Indeed, such regions have also been identified in mRNA for GM-CSF, IL-1, IL-6, interferons, TNF, some growth factors, c-jun, c-fos, c-myc and c-myb. Upon the addi-... 

Interferons (IFN) are glycoproteins that, among other products, are released from virus-infected cells. In neighboring cells, interferon stimulates the production of "antiviral proteins." These inhibit the synthesis of viral proteins by (preferential) destruction of viral DNA or by suppressing its translation. Interferons are not directed against a specific virus, but have a broad spectrum of antiviral action that is, however, species-specific. Thus, interferon for use in humans must be obtained from cells of human origin, such as leukocytes (IFN-a), fibroblasts (IFN-P), or lymphocytes (IFN-y). Interferons are also used to treat certain malignancies and autoimmune disorders (e.g., IFN-a for chronic hepatitis C and hairy cell leukemia IFN-p for severe herpes virus infections and multiple sclerosis). 

Interferons—a family of glycoproteins processed by macrophages—also are widely used as immunostimulants (a -interferons), made in macrophages and fibroblasts (j3-interferons), made in lymphocytes (7-interferons), which are named for their ability to react with viral RNA and affect protein synthesis. Commercially accessible a-, fi-, and y-interferons are currently used in medicine. Practically the only purely synthetic immunos-timulant drug that is used is levamisole, which was initially proposed as an anthelminthic agent, and it is currently widely used as such. 

Use, in standard culture conditions, an established cell line sensitive to the cytopathic elfect of a suitable virus (a human diploid fibroblast cell line, free of microbial contamination, responsive to interferon and sensitive to encephalomyocarditis virus, is suitable). 

The following cell cultures and virus have shown to be suitable MDBK cells (ATCC No. CCL22), or Mouse L cells (NCTC clone 929 ATCC No. CCL I) as the cell culture and vesicular stomatitis virus VSV Indiana strain (ATCC No. VR-158) as the infective agent or human diploid fibroblast FS-71 cells responsive to interferon as the cell culture, and encephalomyocarditis virus (ATCC No. VR-129B) as the infective agent. 

The enhanced production of the cytokines called interferons is one of the body s earliest responses to a viral infection. These endogenous proteins exert potent antiviral, immunoregulatory, and antiproliferative effects and are classified according to the cell type from which they were initially derived. Interferon-a (type I, leukocyte) and interferon (3-(3 (type I, fibroblast) are synthesized by most types of cells in response to viral infection, certain cytokines, and double-stranded RNA. Interferon-y (type II, immune) is produced by natural killer (NK) cells and T lymphocytes in response to antigens, mitogens, and certain cytokines. Interferon-a and interferon-(3 exert the most potent antiviral effects interferon-y is antiviral and strongly immunomodulatory. 

Expression of the human fibroblast interferon gene in Escherichia coli. Proc Natl Acad Sci USA, 1980. 77(9) 5230-3. 

Lucero, M.A., H. Magdelenat, W.H. Eridman, P. Pouillart, C. BiUardon, A. Billiau, K. Cantell, and E. Falcoff, Comparison of effects of leukocyte and fibroblast interferon on immunological parameters in cancer patients. Eur J Cancer Clin Oncol, 1982.18(3) 243-51. 

Dinney, C.P, D.R. Bielenberg, P. Perrotte, R. Reich, B.Y. Eve, C.D. Bucana, and I.J. Fidler, Inhibition of basic fibroblast growth factor expression, angiogenesis, and growth of human bladder carcinoma in mice by systemic interferon-alpha administration. Cancer Res, 1998. 58(4) 808-14. 

Interferon beta 1 (human fibroblast reduced), 17-L-serine- interferon betaser, recombinant... 

Interferon beta-lb [FDA USAN INN BAN] 2-166-Interferon betal (human fibroblast rednced), 17-L-serine-[CAS beta is Greek letter]... 

Interferon betal (human fibroblast protein reduced) [CAS]... 

Interferons are proteins that are currently grouped into three families IFN- , IFN-B, and IFN-7. The IFN- and IFN-B families comprise type I IFNs, ie, acid-stable proteins that act on the same receptor on target cells. IFN-7, a type II IFN, is acid-labile and acts on a separate receptor on target cells. Type I IFNs are usually induced by virus infections, with leukocytes producing IFN- . Fibroblasts and epithelial cells produce IFN-B. IFN-7 is usually the product of activated T lymphocytes. 

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