Antiviral protein
Encyclopedia
Antiviral proteins are protein
s that are induced by human or animal cells
to interfere with viral replication
. These proteins are isolated to inhibit the virus
from replicating in a host's cells and stop it from spreading to other cells. The Pokeweed antiviral protein
and the Zinc-Finger antiviral protein are two major antiviral proteins that have undergone several tests for viruses, including HIV
and influenza
.
plant is a common plant that is often used as a dye
; it is also eaten when the plant is young and tender. Studies and experiments have shown that a specific protein, the Pokeweed Antiviral Protein (PAP), could possibly be used as a thereputical use in T-cell leukemia
, lymphoma
, Hodgkin's lymphoma
, and AIDS
. In an experiment posted in the Journal of Virology
, mice immune systems were integrated to mimic that of humans. The mice were then infected with HIV and later given the PAP. The experiment showed that the PAP cured the mice from the HIV and with no side-effects. Due to these experiments, the U.S. Food and Drug Administration
approved of using PAP on HIV
patients in the U.S., and the Medicines Control Council of South Africa
approved the use for African HIV patients. Research is still being conducted with PAP to see the effectiveness on other viruses including the common cold.
-Finger
Antiviral Protein (ZAP) is a specific antiviral protein that aids in the destruction of virus cells, specifically the Moloney murine leukemia virus
(MLV) and the Sindbis virus
(SIN). ZAP prevents the viral mRNA from building up inside the cell
. ZAP is specifically coded for certain target mRNA. Once a correct viral mRNA is detected, it recruits an RNA exosome complex
to break down and destroy the viral RNA. S. Miller and colleagues at the Bernhard Nocht Institute for Tropical Medicine
stated that:
(HMS) have found an antiviral protein that could slow and even prevent deadly viruses from infecting and spreading. These proteins account for up to half of the immune system
in humans and the other half is composed of interferons. In one experiment, this certain antiviral protein defended cells from viruses such as influenza (including influenza A virus subtype H1N1), West Nile virus
, and dengue virus
. The protein, interferon-inducible transmembrane proteins (IFITM), was discovered about 25 years ago and is activated by an interferon. Not much is known about this protein, but it is found in many creatures and has been around for possibly millions of years. "The most distinctive property of the first-line IFITM3 defense is its preventive action before the virus can fuse with the cell," said virologist Michael Farzan, associate professor of microbiology
and molecular genetics
at HMS and the New England Primate Research Center. A person's susceptibility to viral infections could be linked to variations in this antiviral protein and also how severe a person reacts to certain viruses like influenza or the more dangerous H1N1 strain.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s that are induced by human or animal cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
to interfere with viral replication
Viral replication
Viral replication is the term used by virologists to describe the formation of biological viruses during the infection process in the target host cells. Viruses must first get into the cell before viral replication can occur. From the perspective of the virus, the purpose of viral replication is...
. These proteins are isolated to inhibit the virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
from replicating in a host's cells and stop it from spreading to other cells. The Pokeweed antiviral protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
and the Zinc-Finger antiviral protein are two major antiviral proteins that have undergone several tests for viruses, including HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
and influenza
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
.
Pokeweed Antiviral Protein
The pokeweedPokeweed
The pokeweeds, also known as pokebush, pokeberry, pokeroot, poke sallet, polk salad, polk salat, polk sallet, inkberry or ombú, comprise the genus Phytolacca, perennial plants native to North America, South America, East Asia and New Zealand...
plant is a common plant that is often used as a dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
; it is also eaten when the plant is young and tender. Studies and experiments have shown that a specific protein, the Pokeweed Antiviral Protein (PAP), could possibly be used as a thereputical use in T-cell leukemia
Leukemia
Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...
, lymphoma
Lymphoma
Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...
, Hodgkin's lymphoma
Hodgkin's lymphoma
Hodgkin's lymphoma, previously known as Hodgkin's disease, is a type of lymphoma, which is a cancer originating from white blood cells called lymphocytes...
, and AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
. In an experiment posted in the Journal of Virology
Journal of Virology
The Journal of Virology is an academic journal that covers research concerning viruses, using cross-disciplinary approaches including biochemistry, biophysics, cell and molecular biology, genetics, immunology, morphology, physiology and pathogenesis...
, mice immune systems were integrated to mimic that of humans. The mice were then infected with HIV and later given the PAP. The experiment showed that the PAP cured the mice from the HIV and with no side-effects. Due to these experiments, the U.S. Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
approved of using PAP on HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
patients in the U.S., and the Medicines Control Council of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
approved the use for African HIV patients. Research is still being conducted with PAP to see the effectiveness on other viruses including the common cold.
Zinc-Finger Antiviral Protein
The ZincZinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
-Finger
Finger
A finger is a limb of the human body and a type of digit, an organ of manipulation and sensation found in the hands of humans and other primates....
Antiviral Protein (ZAP) is a specific antiviral protein that aids in the destruction of virus cells, specifically the Moloney murine leukemia virus
Murine leukemia virus
The murine leukemia viruses are retroviruses named for their ability to cause cancer in murine hosts. Some MLVs may infect other vertebrates. MLVs include both exogenous and endogenous viruses...
(MLV) and the Sindbis virus
Sindbis virus
Sindbis Virus is a member of the Togaviridae family, in the alphavirus subfamily. The virus was first isolated in 1952 in Cairo, Egypt. The virus is transmitted by mosquitoes SINV causes sindbis fever in humans and the symptoms include arthralgia, rash and malaise...
(SIN). ZAP prevents the viral mRNA from building up inside the cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
. ZAP is specifically coded for certain target mRNA. Once a correct viral mRNA is detected, it recruits an RNA exosome complex
Exosome complex
The exosome complex is a multi-protein complex capable of degrading various types of RNA molecules...
to break down and destroy the viral RNA. S. Miller and colleagues at the Bernhard Nocht Institute for Tropical Medicine
Bernhard Nocht Institute for Tropical Medicine
Bernhard Nocht Institute for Tropical Medicine; is a medical institution based in Hamburg, Germany which is dedicated to research, treatment, training and therapy of tropical and infectious diseases....
stated that:
Antiviral effects were observed after infection of cells expressing the N-terminal part of ZAP fused to the product of the zeocin resistance gene (NZAP-Zeo) as well as after infection of cells inducibly expressing full-length ZAP. EBOV was inhibited by up to 4 log units, whereas MARV was inhibited between 1 to 2 log units. The activity of ZAP was dependent on the integrity of the second and fourth zinc finger motif, as tested with cell lines expressing NZAP-Zeo mutants. HeterologousHeterologousIn medicine a heterologous transplant means 'between species' or 'from one species to another'.In cell biology and protein biochemistry, heterologous expression means that a protein is experimentally put into a cell that does not normally make that protein...
expression of EBOV-and MARV-specific sequences fused to a reporter gene suggest that ZAP specifically targets L gene sequences. The activity of NZAP-Zeo in this assay was also dependent on the integrity of the second and fourth zinc finger motif. Time-course experiments with infectious EBOV showed that ZAP reduces the level of L mRNA before the level of genomic or anti genomic RNA is affected. Transient expression of ZAP decreased the activity of an EBOV replicon system by up to 95%. This inhibitory effect could be partially compensated for by overexpression of L protein.
Fighting Influenza
Researchers at Harvard Medical SchoolHarvard Medical School
Harvard Medical School is the graduate medical school of Harvard University. It is located in the Longwood Medical Area of the Mission Hill neighborhood of Boston, Massachusetts....
(HMS) have found an antiviral protein that could slow and even prevent deadly viruses from infecting and spreading. These proteins account for up to half of the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
in humans and the other half is composed of interferons. In one experiment, this certain antiviral protein defended cells from viruses such as influenza (including influenza A virus subtype H1N1), West Nile virus
West Nile virus
West Nile virus is a virus of the family Flaviviridae. Part of the Japanese encephalitis antigenic complex of viruses, it is found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, domestic...
, and dengue virus
Dengue virus
Dengue virus in one of four serotypes is the cause of dengue fever. It is a mosquito-borne single positive-stranded RNA virus of the family Flaviviridae; genus Flavivirus...
. The protein, interferon-inducible transmembrane proteins (IFITM), was discovered about 25 years ago and is activated by an interferon. Not much is known about this protein, but it is found in many creatures and has been around for possibly millions of years. "The most distinctive property of the first-line IFITM3 defense is its preventive action before the virus can fuse with the cell," said virologist Michael Farzan, associate professor of microbiology
Microbiology
Microbiology is the study of microorganisms, which are defined as any microscopic organism that comprises either a single cell , cell clusters or no cell at all . This includes eukaryotes, such as fungi and protists, and prokaryotes...
and molecular genetics
Molecular genetics
Molecular genetics is the field of biology and genetics that studies the structure and function of genes at a molecular level. The field studies how the genes are transferred from generation to generation. Molecular genetics employs the methods of genetics and molecular biology...
at HMS and the New England Primate Research Center. A person's susceptibility to viral infections could be linked to variations in this antiviral protein and also how severe a person reacts to certain viruses like influenza or the more dangerous H1N1 strain.