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Interferons

Interferons

Interferon is the name given to a group of proteins known primarily for their role in inhibiting viral infections and in stimulating the entire immune system to fight disease. Research has also shown that these proteins play numerous roles in regulating many kinds of cell functions. Interferons can promote or hinder the ability of some cells to differentiate, that is, to become specialized in their function. They can inhibit cell division, which is one reason why they hold promise for stopping cancer growth. Recent studies have also found that one interferon may play an important role in the early biological processes of pregnancy. Although once thought to be a potential cure-all for a number of viral diseases and cancers, subsequent research has shown that interferons are much more limited in their potential. Still, several interferon proteins have been approved as therapies for diseases like chronic hepatitis , genital warts, multiple sclerosis, and several cancers.

The first interferon was discovered in 1957 by Alick Isaacs and Jean Lindenmann. During their investigation, the two scientists found that virus-infected cells secrete a special protein that causes both infected and noninfected cells to produce other proteins that prevent viruses from replicating. They named the protein interferon because it interferes with infection. Initially, scientists thought there was only one interferon protein, but subsequent research showed that there are many different interferon proteins.

Interferons are members of a larger class of proteins called cytokines (proteins that carry signals between cells). Most interferons are classified as alpha, beta, or gamma interferons, depending on their molecular structure. Two other classes of interferons, omega and tau, have also been discovered. So far, more than 20 different kinds of interferon-alpha have been discovered but few beta and gamma interferons have been identified.

Interferons are differentiated primarily through their amino acid sequence. (Amino acids are molecular chains that make up proteins.) Interferon-alpha, -beta, -tau, and -omega, which all have relatively similar amino acid sequences, are classified as type I interferons. Type I interferons are known primarily for their ability to make cells resistant to viral infections. Interferon-gamma is the only type II interferon, classified as such because of its unique amino acid sequence. This interferon is known for its ability to regulate overall immune system functioning.

In addition to their structural makeup, type I and type II interferons have other differences. Type I interferons are produced by almost every cell in the body, while the type II interferon-gamma is produced only by specialized cells in the immune system known as T lymphocytes and natural killer cells. The two classes also bind to different kinds of receptors, which lie on the surface of cells, and attract and combine with specific molecules of various substances.

Interferons work to stop a disease when they are released into the blood stream and then bind to cell receptors. After binding, they are drawn inside the cell's cytoplasm , where they cause a series of reactions that produce other proteins that fight off disease. Scientists have identified over 30 disease-fighting proteins produced by interferons.

In addition to altering a cell's ability to fight off viruses, interferons also control the activities of a number of specialized cells within the immune system. For example, type I interferons can either inhibit or induce the production of B lymphocytes (white blood cells that make antibodies for fighting disease). Interferon-gamma can also stimulate the production of a class of T lymphocytes known as suppressor CD8 cells, which can inhibit B cells from making antibodies.

Another role of interferon-gamma is to increase immune system functioning by helping macrophages, still another kind of white blood cell, to function. These scavenger cells attack infected cells while also stimulating other cells within the immune system. Interferon-gamma is especially effective in switching on macrophages to kill tumor cells and cells that have been infected by viruses, bacteria , and parasites .

Interferon-tau, first discovered for its role in helping pregnancy to progress in cows, sheep, and goats, also has antiviral qualities. It has been shown to block tumor cell division, and may interfere with the replication of the acquired immune deficiency, or AIDS , virus. Because it has fewer unwanted side-effects (flu-like symptoms and decreased blood cell production) than the other interferons, interferon-tau is becoming a new focal point for research.

In 1986, interferon-alpha became the first interferon to be approved by the Food and Drug Administration (FDA) as a viable therapy, in this case, for hairy-cell leukemia. (Interferons are used therapeutically by injecting them into the blood stream.) In 1988, this class of interferons was also approved for the treatment of genital warts, proving effective in nearly 70% of patients who do not respond to standard therapies. In that same year, it was approved for treatment of Kaposi's Sarcoma, a form of cancer that appears frequently in patients suffering from AIDS. In 1991, interferon-alpha was approved for use in chronic hepatitis C, a contagious disease for which there was no reliable therapy. Interferon has been shown to eliminate the disease's symptoms and, perhaps, prevent relapse. Interferon-alpha is also used to treat Hodgkin's lymphoma and malignant melanoma.

In 1993, another class of interferon, interferon-gamma, received FDA approval for the treatment of a form of multiple sclerosis characterized by the intermittent appearance and disappearance of symptoms. It has also been used to treat chronic granulomatous diseases, inherited immune disorders in which white blood cells fail to kill bacterial infections, thus causing severe infections in the skin, liver, lungs, and bone. Interferon-gamma may also have therapeutic value in the treatment of leishmaniasis, a parasitic infection that is prevalent in parts of Africa, America, Europe, and Asia.

Although all of the disease fighting attributes of interferon demonstrated in the laboratory have not been attained in practice, continued research into interferons will continue to expand their medical applications. For example, all three major classes of interferons are under investigation for treating a variety of cancers. Also, biotechnological advances making genetic engineering easier and faster are making protein drugs like interferons more available for study and use. Using recombinant DNA technology, or gene splicing, genes that code for interferons are identified, cloned, and used for experimental studies and in making therapeutic quantities of protein. These modern DNA manipulation techniques have made possible the use of cell-signaling molecules like interferons as medicines. Earlier, available quantities of these molecules were too minute for practical use.

See also AIDS, recent advances in research and treatment; Interferon actions; Viral genetics; Viral vectors in gene therapy; Virology; Virus replication; Viruses and responses to viral infection

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Interferons

Interferons

Definition

Interferons are a group of proteins called cytokines produced by white blood cells, fibroblasts, or T-cells as part of an immune response to a viral infection or other immune trigger. The name of the proteins comes from their ability to interfere with the production of new virus particles.

Purpose

Interferons affect the immune system in a number of ways. For example, interferon beta can enhance the activity of lymphocyte cells while simultaneously inhibiting other immune cells from becoming stimulated. Additionally, interferon beta regulates the production of interferon gamma. Interferons can also inhibit viruses from establishing an infection inside human cells. Interferon alfa displays anti-tumor activity.

The exact molecular details of how interferons act is still unclear. They may make surface-exposed antigens of tumors even more capable of stimulating the immune system, which in turn would elicit a greater response from the T-cells of the immune system. Tumor growth may also be slowed or retarded by interferon-mediated damage to the blood cells that supply the tumor with nourishment.

Description

There are three types of interferons: alfa, beta, and gamma. Alfa and beta interferons, which are grouped together as type I interferon, are produced by white blood cells and a type of connective tissue cell called a fibroblast. Gamma interferon (or type II interferon) is manufactured T-cells. Production occurs when the T-cells are activated such as during an infection.

The alfa and beta interferons share some biological activities, but also have activities that are distinct from one another. These similarities and differences reflect the common and different binding of the interferons to various targets (receptors) on the surfaces of human cells.

Alfa interferon is manufactured by Roche Products (trade name Pegasys) and Schering-Plough (Viraferon-Peg). Biogen (Avonex) and Serono (Rebif) both market an interferon-designated beta-1a. Both of the beta-1a interferons are produced in genetically engineered mammals. For example, Rebif is produced in Chinese hamster ovary cells that contain the gene coding for human interferon beta.

An interferon designated as beta-1b enhances the activity of T-cells, while simultaneously reducing the production cytokines that operate in the inflammatory response to infection and injury. As well, this interferon retards the exposure of antigens on the surface of cells (and so lessens the development of an immune response to the antigens), and retards the appearance of white blood cells (lymphocytes) in the central nervous system .

The reduction of the immune response can lessen the damage to nerve cells in diseases such as multiple sclerosis . In this disease, the immune system is stimulated to react against the myelin sheath that surrounds the cells, a phenomenon called demyelination. Demyelination produces a malfunction in the transmission of impulses from nerve to nerve and from nerve to muscle.

Infection with the virus that causes hepatitis C is hindered by interferon via the binding to a site on human cells that is also used by the virus. Thus, the virus cannot enter and infect the host cell.

In the late 1980s, a large clinical trial conducted in the United States and Canada evaluated the influence of interferon beta-1b (Betaseron, marketed by Berlex) made in bacteria using genetic engineering technology. Specifically, the bacterium Escherichia coli contained a piece of genetic material (plasmid) that contains the gene coding for human beta interferon. The study was double-blind (neither the test participants or the researchers knew which person was receiving the real drug or a placebo). The two-year study demonstrated that those people receiving the interferon had fewer reappearances of the symptoms, and fewer nerves in the brain were damaged.

Betaseron was approved in 1993 by the U.S. Food and Drug Administration for use by people affected with multiple sclerosis. Avonex was approved in 1996 and Rebif in 2002.

Recommended dosage

Interferons are normally injected. They are not taken by mouth as the strong digestive enzymes of the stomach will degrade them.

For use in multiple sclerosis, interferon beta-1a is injected into the muscle (intramuscular injection), and beta-1b is injected just below the skin (subcutaneous injection). The injections are usually given every other day. The recommended dose for beta-1a and 1b is 0.03 mg and 0.25 mg, respectively. Initial doses of beta-1b should be far less (i.e., 0.0625 mg), with a gradual increase in dose over six weeks.

Precautions

Patients who have had seizures or who are at risk for a seizure should be closely monitored following the injection of interferon, as should those with heart disorders such as angina, congestive heart failure, or an irregular heartbeat.

It is not known if interferon can be expressed in breast milk. Concerned mothers may opt to cease breast-feeding while receiving interferon therapy.

Side effects

Interferon beta 1-a and 1-b commonly produce flu-like symptoms, including fever, chills, sweating, muscle aches, and tiredness. These side effects tend to diminish with time. Menstrual cycle changes have also been documented in a significant number of women.

Far less commonly, interferon beta 1-a and 1-b can produce suicidal feelings in someone who is already clinically depressed. Death of cells around an injection site (necrosis) can occur, as can swelling and bruising. Allergic reactions are possible. The massive and sometimes fatal allergic reaction termed anaphylaxis occurs rarely. Other side effects include liver and thyroid malfunction, and altered blood chemistry (fewer platelets and red and white blood cells).

Interactions

As of December 2003, drug interaction studies have not been conducted.

Resources

BOOKS

Lotze, M. T., R. M. Dallal, J. M. Kirkwood, and J. C. Flickinger. "Cutaneous Melanoma." In Principles and Practice of Oncology, edited by V. T. DeVita, S. A. Rosenberg, and S. Hellmon. Philadelphia: Lippincott, 2001.

PERIODICALS

Aguilar, R. F. "Interferons in Neurology." Rev Invest Clin 52, no. 6 (2000): 665679.

Polman, C. H., and B. M. J. Uitdehaag. "Drug Treatment of Multiple Sclerosis." BMJ 321 (2000): 490494.

OTHER

National Multiple Sclerosis Society. Interferons. National Multiple Sclerosis Society Sourcebook. December 28, 2003. (May 22, 2004). <http://www.nationalmssociety.org/%5Csourcebook-Interferons.asp>.

ORGANIZATIONS

National Multiple Sclerosis Society. 733 Third Avenue, New York, NY 10017. (800) 344-4867. <http://www.nationalmssociety.org>.

Brian Douglas Hoyle, PhD

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Interferons

Interferons

Definition

Interferons are small, natural or synthetic protein and glycoprotein cytokines that are produced by leucocytes, T-lymphocytes, and fibroblasts in response to infection and other biological stimuli. In cancer treatment, they are used as immunotherapy against the proliferation of cancer cells.

Purpose

The goal of interferon use is to activate tumor-specific cytotoxic T-lymphocytes. T-lymphocytes are cells of the immune system that destroy foreign cells. Thus, tumor cells would be destroyed based on immunotherapy.

Description

Interferons attach to special receptors on the surface of cell membranes. They have a variety of functions, including enhancing or inhibiting enzymes, decreasing cell proliferation, or enhancing the activity of macrophages and T-lymphocytes. There are several different classes of interferons, including alpha, beta, gamma, tau, and omega. The classes can be further broken into subclasses and classified using Arabic numerals and letters. Cancer therapy research primarily focuses on alpha interferons.

In 1957 researchers discovered that the immune system produced a substance in response to a viral infection that acted as an anti-viral agent. They called that substance "interferon." Since then, recombinant DNA technology has provided a larger supply of interferons and has allowed extensive research regarding interferon's therapeutic properties against cancer.

Alpha interferons are used to treat cancers such as hairy cell leukemia , malignant melanoma , and Kaposi's sarcoma (an AIDS-related cancer). Off the label, alpha interferons are used to treat many other cancers including bladder cancer , chronic myelocytic leukemia , kidney cancer, carcinoid tumors, non-Hodgkin's lymphomas , ovarian cancer , and skin cancers. Alpha interferons can be combined with other chemotherapeutic drugs such as doxorubicin .

In the United States alpha interferons are sold under the brand names Roferon-A (Interferon Alfa-2a, recombinant) and Intron A (Interferon Alfa-2b, recombinant). There are no generic forms of these drugs.

Recommended dosage

Alpha interferons are only available by prescription and are given parenterally. A physician will determine dosage based on several factors such as what type of cancer is being treated, the patient's weight, and what other types of medications the patient is taking. Therefore, the dose will vary from patient to patient.

Patients can inject this drug themselves. Their physician may recommend that they drink extra water to avoid low blood pressure while on this medication. Since this drug can have flu-like side effects, it is recommended that patients inject the drug prior to bedtime so that they are sleeping during the worst part of the side effects.

Precautions

Alpha interferons have not been shown to cause problems in the fetus of pregnant women. Because it is not known whether this drug can cross over into breast milk, it is not recommended for use in women who are breast-feeding. Before this drug is given, patients should notify their doctors if they are allergic to immunoglobulins or egg whites.

There are several medical conditions that should be considered prior to deciding whether to use alpha interferons. There can be an increase in the following disorders: bleeding problems, mental problems, convulsions, diabetes mellitus, heart attack, heart disease, liver disease, kidney disease, and lung disease. People with an overactive immune system could also have this disorder exacerbated when using alpha interferons.

Caution should be taken when using alpha interferons because they can depress the number of white blood cells. This can make patients more susceptible to infection. Therefore, they should avoid contact with others who have infections and should contact their physician immediately if they think they are developing an infection. Patients should take care not to cut themselves, should not touch their eyes or inside of their nose with unwashed hands, and should take care when brushing their teeth so as not to cause bleeding.

The effects of alcohol can be exaggerated while taking alpha interferons. Alcohol should only be used by permission from a physician.

Side effects

Alpha interferons can have side effects that range from minor and irritating to major and severe, needing immediate attention. Some of the less serious side effects are muscle aches, unusual metallic taste in the mouth, fever and chills, and general flu-like symptoms such as headache, loss of appetite (anorexia ), nausea and vomiting , and fatigue . To reduce the flu-like symptoms physicians may suggest that the patient take acetaminophen (e.g., Tylenol) before each dosage.

Other side effects may need medical attention. Any changes with the central nervous system such as confusion, trouble thinking and focusing, mental depression , nervousness, or numbness or tingling of fingers, toes and face require immediate medical attention.

The side effects are dependent on the dose. As a result, the physician may modify the dose if the side effects are severe.

Interactions

Alpha interferons can interact with several different drugs, increasing their effects. Most drugs that interact with alpha interferons are those used with disorders of the central nervous system. Some of the depressants include antihistamines, sedatives, tranquilizers, sleeping medications, prescription pain medicines, seizure medications, muscle relaxants, narcotics, and barbiturates. Prior to treatment, the doctor should be notified if the patient is taking any of these medications because this could impact the dosage prescribed.

Sally C. McFarlane-Parrott

KEY TERMS

Cytokines

Molecules released by cells to regulate the length and intensity of an immune response and to mediate intercellular communication.

Glycoprotein

A protein that has a carbohydrate group attached.

Immunotherapy

Treating cancer using molecules that are intended to stimulate the patient's own immune system to fight the disease.

Macrophages

A type of white blood cell that produces antibodies and molecules for cell-to-cell immune responses.

Parenteral

Medications that are administered by some means other than through the gastrointestinal tract, including through intravenous, subcutaneous, or intramuscular injection.

T-lymphocytes

A part of the immune system that fights foreign cells.

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McFarlane-Parrott, Sally C.. "Interferons." Gale Encyclopedia of Cancer. 2002. Encyclopedia.com. (October 1, 2016). http://www.encyclopedia.com/doc/1G2-3405200240.html

McFarlane-Parrott, Sally C.. "Interferons." Gale Encyclopedia of Cancer. 2002. Retrieved October 01, 2016 from Encyclopedia.com: http://www.encyclopedia.com/doc/1G2-3405200240.html

Interferon

Interferon

Interferon is a protein produced by animals in response to viral infections. It is a defensive mechanism by the body to prevent multiplication of the virus. The action of interferon was first demonstrated in 1957 by British virologist Alick Isaacs (1921-1967) and his Swiss colleague Jean Lindenmann. Isaacs was born in Glasgow, Scotland, in 1921, to a Russian Jewish family. He studied medicine at Glasgow University but found he preferred research to the actual practice of medicine.

Viral Interference

Early in his studies of influenza (flu) at the World Influenza Centre at the National Institute for Medical Research in England, Isaacs became interested in the viral interference phenomenon, first described in 1935. It was observed that an RNA virus in a cell inhibits (restrains) the growth of any other viruses in that cell. While trying to discover the mechanism by which this occurs, Isaacs found that the interference seemed to be caused by something inside the cell.

While working with the visiting Swiss scientist Jean Lindenmann in 1957, Isaacs found that chick embryos (developing eggs) injected with influenza virus released very small amounts of a protein that destroyed the virus. The protein also inhibited the growth of any other viruses in the embryos. Isaacs and Lindenmann named the interfering protein interferon.

It is now known that interferon is produced within hours of a viral invasion and that most living things, including plants, can make the protective protein. Interferon was initially seen as the cell's first line of defense against viral infections, and its discovery was expected to pave the way for successful treatment of viral diseases. Researchers soon found, however, that interferon is "species-specific." (Only human interferon, for example, will work in human beings.) The body also produces interferon in only small amounts, making it extremely expensive to obtain. These difficulties caused interferon research to inch forward at only a slow pace.

New Interest

The late 1960s saw renewed interest in interferon when Ion Gresser (1928-), an American researcher in Paris, discovered that the protein stopped or slowed the growth of tumors in mice and also stimulated the production of tumor-killing lymphocytes (white blood cells). Gresser and Finnish virologist Karl Cantell both developed a way to make interferon in useful amounts from human blood cells. Monoclonal antibodies, first produced in 1975, made large-scale purification of interferon possible. The mid-1980s saw the advent of genetically-engineered interferon, the first example of which was produced from bacteria by Swiss scientist Charles Weissmann in 1980.

Research of interferon's ability to kill cancer cells has yielded only mixed results. It has been successfully used, however, against leukemia and osteogenic sarcoma (a bone cancer). Interferon shows varied promise in treating one type of multiple sclerosis, melanoma, renal cell cancer, and a few AIDS-related Kaposi's sarcomas. Interferon is also used to treat viral diseases like rabies, hepatitis, and herpes infections.

[See also Gene ]

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Interferon

Interferon


Interferon, a small protein containing fewer than two hundred amino acids, is an interesting example of a biologically active polypeptide. There are three classes of interferon, labeled by the first three letters of the Greek alphabet. Interferon-α is used to treat leukemia, hepatitis B and C, and Kaposi's sarcoma. Interferon-γ finds use as a treatment for multiple sclerosis and interferon-γ has applications in treating a rare genetic disorder called granulomatous disease.

Cells within the body synthesize interferon when experiencing stress from incidents such as viral attack. When interferon is released into the bloodstream by an infected cell, it helps signal an immune response to the invader. Other mechanisms that interferon activates in the fight against viral infections are less understood. It is hypothesized that in addition to signaling the immune system they somehow inhibit the ability of viruses and tumor cells to reproduce. Research to further the understanding of how interferon works is inhibited by the fact that, aside from humans, only a few other animals have cells that make interferon. Many studies of how drug molecules work are carried out first with animals, but for interferon, this type of study is less productive.

Dr. Alick Isaacs and Dr. Jean Lindenmann discovered interferon in 1957 in Great Britain. In an experiment, they mixed live viruses with egg membranes and unexpectedly found that the viruses did not grow. They did not know what caused this observation and simply indicated something interfered with the virus, so the term "interferon" was coined. They eventually identified the polypeptide and were able to isolate it from various cells, including those taken from calves, monkeys, and humans.

Interferon is produced naturally in very small quantities. When it originally was introduced as a form of medical treatment, the expense associated with isolating the compound from sources such as blood made it prohibitively expensive. Interferon became viable as a medical intervention only through the application of genetic engineering. The gene that tells a cell how to construct interferon is introduced into Escherichia coli bacteria. These bacteria are grown in culture and they produce the interferon. Because the bacteria can be grown relatively quickly, large quantities of interferon can be generated with this method. While many people tend to react to the phrase "genetic engineering" with some fear, interferon represents an excellent example of how advances in medical treatment were made possible only by its application.

see also Amino Acid; Protein.

Thomas A. Holme

Bibliography

Becker, Yechiel, ed. (1984). Antiviral Drugs and Interferon: The Molecular Basis of Their Activity. New York: Kluwer.

Cantell, K. (1998). The Story of Interferon: The Ups and Downs in the Life of a Scientist. River Edge, NJ: World Scientific.

Lindenmann, J., and Schleuning, W. D., eds. (1999). Interferon: The Dawn of Recombinant Protein Drugs. New York: Springer-Verlag.

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Holme, Thomas A.. "Interferon." Chemistry: Foundations and Applications. 2004. Encyclopedia.com. 1 Oct. 2016 <http://www.encyclopedia.com>.

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interferon

interferon (Ĭn´tərfēr´ŏn), any of a group of proteins produced by cells in the body in response to an attack by a virus. A cell infected by a virus releases minute amounts of interferons, which attach themselves to neighboring cells, prompting them to start producing their own protective antiviral enzymes. The result is impairment of the growth and replication of the attacking virus. Interferon has also been shown to have some antitumor properties. There are three known classes of interferons: alpha-, beta-, and gamma-interferons.

Although they were discovered in the 1950s, the medical use of interferons was impractical until the recombinant DNA techniques of genetic engineering made it possible to mass produce them. Interferons used as drugs include alpha-interferon, for hepatitis B and C, human papillomavirus, hairy-cell leukemia, and Kaposi's sarcoma (a cancer associated with AIDS), and beta-interferon, for multiple sclerosis.

See also immunity.

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interferon

interferon (IFN) Any of a number of proteins (see cytokine) that increase the resistance of a cell to attack by viruses by unmasking genes that synthesize antiviral proteins. In humans, three groups of interferons have been discovered: α-interferons from white blood cells; β-interferons from connective tissue fibroblasts; and γ-interferons from lymphocytes (see interleukin). Interferons are also produced by lymphocyte killer cells, which attack altered tissue cells, such as cancer cells. This converts other normal lymphocytes to killer cells and effects other changes in the immune system. Interferons produced using genetically engineered bacteria are used for treating some forms of hepatitis, some cancers, and multiple sclerosis.

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"interferon." A Dictionary of Biology. 2004. Encyclopedia.com. 1 Oct. 2016 <http://www.encyclopedia.com>.

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interferon

interferon (inter-feer-on) n. a substance that is produced by cells infected with a virus and has the ability to inhibit viral growth. Particular interferons are effective only in the species that produces them. Preparations of human interferon produced by genetic engineering are used clinically in treating hepatitis B and certain lymphomas and other cancers (i. alfa), hepatitis C (i. alfa and peginterferon alfa), and multiple sclerosis (i. beta).

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interferon

interferon Protein produced by cells when infected with a virus. Interferons can help uninfected cells to resist infection by the virus, and may also impede virus replication and protein synthesis. In some circumstances they can inhibit cell growth; human interferon is now produced by genetic engineering to treat some cancers, and hepatitis and multiple sclerosis (MS).

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interferon

interferon A group of proteins that are produced in very small quantities, by leucocytes and related cells, in response to viral infection. As a group they appear to induce the synthesis of a protein that interferes with a viral-specific function. This often confers a temporary resistance to subsequent infection by other viruses.

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MICHAEL ALLABY. "interferon." A Dictionary of Zoology. 1999. Encyclopedia.com. 1 Oct. 2016 <http://www.encyclopedia.com>.

MICHAEL ALLABY. "interferon." A Dictionary of Zoology. 1999. Encyclopedia.com. (October 1, 2016). http://www.encyclopedia.com/doc/1O8-interferon.html

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interferon

in·ter·fer·on / ˌintərˈfi(ə)rˌän/ • n. Biochem. a protein released by animal cells, usually in response to the entry of a virus, that has the property of inhibiting virus replication.

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"interferon." The Oxford Pocket Dictionary of Current English. 2009. Retrieved October 01, 2016 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-interferon.html

interferon

interferonAgamemnon, Memnon •ninon, xenon •noumenon • Trianon • xoanon •organon • Simenon • Maintenon •crampon, kampong, tampon •Nippon • coupon •Akron, Dacron, macron •electron • natron • Hebron • positron •Heilbronn • micron •boron, moron, oxymoron •neutron • interferon •fleuron, Huron, neuron •Oberon • mellotron • aileron •cyclotron • Percheron • Mitterrand •vigneron • croissant • Maupassant •garçon • Cartier-Bresson • exon •frisson • Oxon • chanson • Tucson •soupçon • Aubusson • Besançon •penchant • torchon • cabochon •Anton, canton, Danton •lepton •piton, Teton •krypton • feuilleton • magneton •chiton •photon, proton •croûton, futon •eschaton • peloton • contretemps •telethon •talkathon, walkathon •Avon • tableau vivant • vol-au-vent

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"interferon." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. 1 Oct. 2016 <http://www.encyclopedia.com>.

"interferon." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. (October 1, 2016). http://www.encyclopedia.com/doc/1O233-interferon.html

"interferon." Oxford Dictionary of Rhymes. 2007. Retrieved October 01, 2016 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O233-interferon.html

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