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INTERFERONS1-1.pdf basic knowledge of interferons
- 1. Interferons group#2 ishmal Khalid Sehar Noor muskanYousef Sehar iftikhar uzwa Noor Fatima
- 2. Introduction: +Interferon= interfere withviral proliferation +Cytokines= cell signaling molecules and proteins . +Interferons (alpha, beta, and gamma)
- 3. Interferon are thefamily of cytokines that were first identified almost half a century ago through their antimicrobial property. interferons not only have important antiviral effect but also have a role in antitumor and immunomodulatory responses. Interferon alpha, beta and gamma are the types of cytokines. There are two major classes of interferons: type 1 (IFN alpha and beta subtype) and type 2 (IFN gamma) In particular, IFN-gamma (produced by cell following viral major ot bacterial infection)
- 4. Interferons are protiensproduced by variety of cells in the inflammatory responses to infections. Their production is triggered by the immune system in response to pathogens and cytokines. Endogenous IFNS play a role in viral infection. research suggest that interferons may also be beneficial in the treatment of other viral , autoimmune , and neoplastic condition of the nervous system. IFN gamma play important role in controlling disease caused intracellular bacteria,, parasites
- 6. Types of interferons: Type 2:(interferon gamma) Which activatemacrophages Interact with cell of the adaptive immune system Support the generation of T1 cells Produced by activated T cell and cytotoxic natural killer cells. Type 1:(interferon alpha and gamma) Which mediates early antiviral responses. Interferon alpha produced and released by leukocytes and interferon beta by fibroblast.
- 7. Type 3:(interferon lambda) •Which aresecreted by plasmacytoid dendritic cell. •Regulate viral infection. •Host cell poliferation.
- 8. Mode of action: IFN-alpha andIFN-beta exert their antimicrobial and other effect by binding to a specific receptor called IFANR (IFN alpha receptor) that is expressed by most cell type. Like many cytokines, IFN are dimers. Binding of IFN dimer to IFNAR induces receptor dimerization and activation of JAK/STAT signaling pathway , used by many cytokines to activate specifice responses.
- 9. The IFNAR dimeractivates the janus kinases JAK1 and TYK2 which recriut and phoshorylate inactive STAT transciption factors. Phosphorylated STAT1 and STAT2 dimerize and change conformation,revealing a nuclear localization signal that allows the dimer to enter the nucleus , and where it initiates transcription of specific gene.
- 11. Method of productionof interferon: +Older days: +Blood was the only source of interferon earlier. +The procedure was very tedious and the quantity of interferon isolated was very little ,thus as much as 50000 L of human blood was required to get just 100 mg of interferon. Therefore it was very difficult to conduct research and use interferon for therapeutic purpose.
- 12. 2: production ofrecombinant interferon: +Complementary DNA was synthesized from the mRNA of Specific interferon. +This is inserted to a vector (say plasmid) Which is introduced in e.coli or other cells. +The interferon can be isolated from culture media. This is basic mechanism of producing recombinant interferon. +The production of interferon is relatively less in Bacterial host. Although e.coli was the first to be used. +This is mainly most of interferons are glycoprotein in nature and bacteria don't posses the machinery glycosylation of protein's.
- 13. Step involve inthe production of rDNA derived interferon: +Isolation of mRNA coding interferon from human. +Construction of CDNA from mRNA using reverse transcriptase by reverse transcription mechanism. +Fragmentation of double standard DNA using restriction endonucleases. +Isolation of desired DNA fragment. +Amplification of the gene of the interest. +Ligation of DNA into suitable vector by the enzymes DNA ligases.
- 14. +Transfer of DNAinto to host cell. +Screening +Culturing the host cell on a suitable medium on a large scale. +Extraction of the desired product. +Downstream processing of the product.
- 15. Production of interferonby yeast: +The saccharomyces cerevisiae is more suitable for the production of Recombinant interferon. +This is mainly yeast possesses the mechanism to carry out glycosylation of protein similar to that occur In mammalian cell. +The DNA sequence coding for specific human interferon can be attach to yeast alcohol dehydrogenase gene in a plasmid and introduced into for yeast cell. +The yield of interferon is several fold higher as compared to e.coli.
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- 17. +Uses of Interferonsfor treatment of diseases +Interferons (IFNs) are attractive biological response modifiers for use as therapeutic agents in infectious diseases, because they have both antiviral and immunomodulatory activity. Their name even comes from the fact that they can “interfere” with viral replication. IFN-α (“leukocyte interferon”) and IFN-β (“fibroblast interferon”) are released by human cells infected with certain viruses, whereas IFN-γ (“immune interferon”) is produced by natural killer (NK) cells (T-cell lymphocytes) in response to antigen exposure. These cytokines then act on uninfected host tissue cells to induce a state of relative resistance to viral infections. The agents bind to specific cell-surface receptors that initiate a series of intracellular events: induction of certain enzymes, inhibition of cell proliferation, and enhancement of immune activities, including increased phagocytosis by macrophages and augmentation of specific cytotoxicity by T lymphocytes.
- 18. +IFNs role againstviruses + Even though IFNs’ role against viruses is most prominent, they can also be induced by, and active against, rickettsia, mycobacteria, and several protozoa. Therapeutically, however, their use has generally been limited to treatment or prevention of viral infections. Although their potent antiviral activity is promising—inhibiting viral replication in vitro.
- 19. +Interferons and interferoninducers available commercially IFNs are not absorbed orally because of their large amino acid sequence, which is susceptible to the proteolytic enzymes in the digestive tract. However, IFN-α is readily absorbed after both intramuscular and subcutaneous injection. This rapid absorption combined with a short half-life means that frequent injections are needed to maintain adequate concentrations in the body. Both commercially available IFN-α products in the United States have now been chemically attached to polyethylene glycol (PEG) to enhance their half-life and make once-weekly dosing possible. This coupling not only makes administration easier, but also reduces side effects by having a predictably lower peak concentration of the exogenous cytokines
- 23. Human leukocytes derived INFs Alpha IFN BetaIFN 1.Alpha IFNs IFN Alferon N IFN alfacon-1
- 24. 1.IFN-Alferon N Human leukocytederived IFN-αn3 (Alferon N) injection contains a spectrum of α IFNs, and is only approved for the treatment of refractory or recurring condylomata acuminata in adult patients. A low-dose oral version is in development for use in the treatment and prevention of influenza. Both versions have been studied against human immunodeficiency virus (HIV)-1 infection, but with little success. 2.IFN alfacon-1 IFN alfacon-1 (Infergen) is considered the synthetic “consensus interferon” because it contains a nonnatural sequence of IFN-α amino acids all chosen for the highest activity against viral hepatitis. To date, no pegylated formulation of this product has been brought to market.
- 25. 2.Beta IFNs IFN-β1a (Avonexor Rebif) and IFN-β1b (Betaseron) are recombinant proteins with 166 and 165 amino acids, respectively. These β IFNs have antiviral and immunomodulatory properties too, but their use at this time is limited to treatment of multiple sclerosis, not infections. IFN-γ1b (ACTIMMUNE) injection is used regularly for the prevention of infections in patients with chronic granulomatous disease along with antibacterials and antifungals. Its mechanism of action for this purpose is not entirely known, but long-term studies show a definite benefit. IFN-γ can also be used as a salvage therapy for mycobacterial infections, but is not routinely used for treatment of this or other infections
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- 27. + Use ofinterferons for hepatitis viruses + Chronic infection with hepatitis B virus (HBV) and HCV affects over 400 million people worldwide. Chronic viral hepatitis is a leading cause of cirrhosis, liver transplantation, and hepatocellular carcinoma. With the development of a vaccination series for hepatitis B in the mid- 1980s, along with increased public education and awareness, acute infection rates of both HBV and HCV in the United States have declined steadily. + HBV is a double-stranded DNA virus whereas HCV is a single-stranded RNA virus, both of which are capable of significant morbidity and mortality in chronic infection. The exact mechanisms of hepatic injury from HBV and HCV infection are not completely understood. Because asymptomatic carriers with normal liver transaminases exist, it is likely multiple immune-mediated mechanisms result in hepatocyte damage as opposed to the virus itself being directly cytotoxic.
- 28. Hepatitis B Interferon (IFN)can successfully treat chronic hepatitis B virus (HBV) infection. Treatment with IFN can lead to: - Loss of viral DNA - Antibody formation (a sign of immune response) IFN works differently depending on the type of HBV infection - in HBeAg-positive patients, IFN stimulates an immune response - In HBeAg-negative patients, IFN acts directly as an antiviral. HBeAg-negative disease is harder to treat and may lead to more complications like cirrhosis. Other oral medications like entecavir, tenofovir, and lamivudine are also available to treat HBV. While IFN is still a first-line option, these oral meds are often preferred due to ease of use and fewer side effects. However, IFN offers the advantage of a defined treatment duration, whereas oral meds may require lifelong administration."
- 29. Hepatitis C + HepatitisC virus (HCV) is a sneaky virus that can evade the immune system, leading to long-term infection, increased transmission risk, and liver disease complications. Research has focused on using Interferon (IFN) to treat chronic HCV. Here's what happens when IFN is used: + HCV RNA levels decrease in two phases: a rapid drop in the first 1-2 days, followed by a slower clearance of infected cells. + HCV is a clever virus that can evade the immune system, and IFN treatment can be helpful, but not always effective due to HCV's ability to avoid recognition and inhibit IFN production."
- 30. Use of interferonsas vaccine adjuvants +Adjuvants (adjuvare, Latin for “to help”) are substances that augment the immunogenicity of an antigen when mixed with the antigen for use in a vaccine. Adjuvants +(1) Stimulate granuloma (which is a macrophage-rich mass), +(2) Enhance costimulatory signals, +(3) Stimulate nonspecific lymphocyte production, +(4) Prolong the antigen concentration in a site for lymphocyte exposure, +(5) Induce cytokines.
- 31. +research in vaccinedevelopment has shown that one of the most promising uses of IFNs is as an adjuvant with specific antigens in prophylactic vaccines. Toporovski and colleagues provide a current review of the use of IFN-α, IFN-β, IFN-γ, and IFN-λ in vaccine studies that focus primarily on murine, avian, porcine, and nonhuman species. Regardless of the species, the use of IFNs as adjuvants seems to improve the efficacy and safety of most vaccines while providing the immunomodulatory effect of stimulating the T- helper 1 response.
- 32. Side effects ofIFNs(Interferons) All the α IFNs include a black-box warning in their prescribing information about how their use …may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory evaluations. Therapy should be withdrawn in patients with persistently severe or worsening signs and symptoms related to side effects. In many, but not all cases, these resolve after stopping therapy.
- 33. +The development ofIFNs as clinically useful drugs has been largely disappointing. This fact can be attributed partly to their short half-life in vivo and their extensive side effects. In fact, many symptoms of viral infections such as influenza can be blamed on endogenous IFN release. The adverse effects prevalent at therapeutic doses include fever, myalgia, and headache, dubbed “flulike symptoms,” along with bone marrow suppression leading to leukocytopenia and thrombocytopenia, plus central nervous system manifestations including depression.