Glycoproteins interferons

The glycoprotein interferon-p-la (IFN-p-la), an essential biotherapeutic for the treatment of multiple sclerosis, was synthesized by Kajihara and coworkers (Scheme 11.17) [88], IFN-p-la consists of 166 amino acids and has one N-glycosylation site. IFN-p-la... 

Virus infection stimulates the production of protective glycoproteins (interferons) which act (1) directly on uninfected cells to induce enzymes that degrade viral RNA (2) indirectly by stimulating the immune system. Interferons will also modify cell regulatory mechanisms and inhibit neoplastic... 

Glycoproteins Interferons Blood clotting factors (factors VIII, IX) Glycoprotein hormones, EPO Plasminogen activators, t-PA... 

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). 

Virtually all therapeutic glycoproteins, even when produced naturally in the body, exhibit such heterogeneity for example, two species of human interferon-y (IFN-y), one of molecular mass 20 kDa and the other of 25 kDa, differ from each other only in the degree and sites of (N-linked)... 

Studies have actually revealed two type I interferon receptor polypeptides. Sequence data from cloning studies place both in the class II cytokine receptor family. Both are transmembrane N-linked glycoproteins. Studies using isolated forms of each show that one polypeptide (called the a/p receptor) is capable of binding all type I interferons. The other one (the ap receptor) is specific for IFN-a-B (a specific member of the IFN-a family). Both receptors are present on most cell types. 

IFN-co represents an additional member of the interferon (type I) family. This 170 amino acid glycoprotein exhibits 50-60 per cent amino acid homology to IFN-as, and appears even more closely related to IFN-x. 

It was found that the HIV envelope glycoprotein in vitro increases the production of NO by human monocyte-derived macrophages [114]. NO production is increased in patients who have AIDS [115], and the increased concentrations of nitrite in AIDS patients with opportunistic infections is caused by T gondii, Pneumocystis carinii, Mycobacterium tuberculosis, and Mycobacterium avium, whereas nitrite concentrations are normal in symptom-free patients. It was also confirmed that there was increased production of NO in the sera of children with HIV-1 infection, and of circulating cytokines, such as interleukin lp, tumor necrosis factor a, and interferon y. It is postulated that rises in the concentrations of these cytokines may represent a substantial stimulation of NO production [116]. In contrast, it has been shown that there was no altered endogenous nitrate formation in eight patients with AIDS, most of whom had opportunistic infections [117]. It has also been noted that there were high... 

Medicinal thrombocytopenia can emerge under the use of different medicines, including interferon. The main mechanism of medicinal thrombocytopenia pathogenesis is assisted by the destruction of thrombocytes by the complement which is activated during antibody preparation. On withdrawal, the content of thrombocytes in blood is normalized. The formation of antibodies to thrombocytes in patients with viral hepatitis C occurs due to the destruction of membrane glycoproteins by the viruses. 

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. 

Interferon. Any of a family of glycoproteins that exert virus-nonspecific but host-specific antiviral activity by inducing the transcription of cellular genes coding for antiviral proteins that selectively inhibit the synthesis of viral RNA and proteins. Interferons have immunoregulatory functions and can inhibit the growth of nonviral intracellular parasites. 

The interferons (IFN) are a family of cytokine molecules cytokines are described in more detail in section 6.3.1. Interferons are glycoproteins that can be divided into three families IFN-a, IFN-P, and IFN-y. IFN-a and IFN-P are sometimes collectively referred to as Type... 

Interferons are cellular glycoproteins produced by the host cells which exert complex antiviral, immunoregulatory and antiproliferative activities. After binding to interferon receptors it acts through cellular metabolic processes which involves synthesis of viral RNA and proteins. Interferon receptors are tyrosine protein kinase receptors which on activation phosphorylate cellular proteins. These then induce transcription of interferon induced proteins which exert antiviral effects. There are three type of interferons - alpha, beta and gamma. 

A class name for a family of species-specific proteins (or glycoproteins) that are produced according to information encoded by species of interferon genes, and exert complex antineoplastic, antiviral, and immunomodulating effects... 

These studies demonstrating a protective effect of sialic acid residues on serum glycoproteins provide an explanation for earlier, conflicting observations about the biological effect of, for example, desialylated erythropoietin, which stimulates erythropoiesis only after direct application to bone-marrow cell-cultures, and not after injection into the blood stream.469 In the latter experiment, only the native, sialylated hormone was active. Rapid clearance and inactivation of follicle-stimulating hormone,470 or interferon,471 after treatment with sialidase may be explained by uptake into liver cells. 

Avonex (interferon beta- Biogen-Idec la) [CHO-expressed glycoprotein-recombinant human interferon beta-la]... 

REBIF (interferon beta-la) Pfizer SC injection [CHO-expressed recombinant glycoprotein]... 

Nasal mucus. The nasal mucus protects the body against airborne substances. Nasal mucus consists of mucopolysaccharides complexed with sialic acid, sloughed epithelial cells, bacteria, water (95 percent), glycoproteins and lipids (0.5 to 5 percent), mineral salts (0.5 to 1 percent), and free proteins (albumin, immunoglobulins, lysozyme, interferon, lactoferin, etc., 1 percent).13 45 111 112 The surface pH of the nasal mucosa is 5.5 to 6.5.113... 

The principal compounds that act as inhibitors of viral protein synthesis are the interferons. These compounds are members of a naturally occurring family of glycoprotein hormones (RMM 20 000-160 000), which are produced by nearly all types of eukaryotic cell. Three general classes of interferons are known to occur naturally in mammals, namely the a-interferons produced by leucocytes, P-interferons produced by fibroblasts and y-interferons produced by T lymphocytes. They form part of the human immune system. It is believed that the presence of virons and pathogens in the body switches on the mRNA that stimulates the production and release of interferons. These interferons are thought to stimulate the production of proteins that inhibit the synthesis of viral mRNA and viral proteins. a-Interferons also enhance the activity of T killer cells. 

Interferons are proteins or glycoproteins that are produced either by animal cells or plant cells in response to stimuli or DNA recombinant technology. These drugs are active against malignant neoplasms and have immunomodulating effects. These are useful in chronic hepatitis B, hepatitis C, hairy cell leukemia, myeloid leukemia, follicular lymphoma, carcinoid tumor, multiple myeloma, renal cell carcinoma, multiple sclerosis, chronic granulomatous diseases, blood disorders, common cold, herpes simplex, inflammatory bowel disease, and leishmaniasis. 

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