The Friend virus (FV) is a strain of
murine leukemia virus identified by
Charlotte Friend in 1957.
The virus infects adult
immunocompetent mice and is a well-established model for studying genetic resistance to
infection
An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...
by an
immunosuppressive retrovirus
A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase e ...
. The Friend virus has been used for both immunotherapy and
vaccines
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an ag ...
. It is a member of the
retroviridae
A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase ...
group of viruses, with its
nucleic acid
Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a pentose, 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nuclei ...
being
ssRNA.
Vaccination
Experiments have shown that it is possible to protect against Friend virus infection with several types of vaccines, including
attenuated viruses, viral proteins,
peptides
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Dalton (unit), Da or more are called proteins. Chains of fewer t ...
, and recombinant vaccinia vectors expressing the Friend virus gene. In a study of vaccinated mice, it was possible to identify the immunological epitopes required for protection against the virus, thus determining the types of immunological responses necessary or required for protection against it. The research discovered protective epitopes that were localized to F-MuLV gag and env proteins. This was achieved using recombinant vaccinia viruses expressing the gag and env genes of FV.
Implications
Friend virus models showed valuable information regarding genetic resistance to retroviral disease. A particular
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
of interest is the Rfv-3 gene, which cause susceptibility to suppression of the FV specific antibody response. The greater understanding by which the mechanisms work may aid in the development of immunotherapies and vaccines that may be applicable to human diseases.
References
External links
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{{DEFAULTSORT:Friend Virus
Gammaretroviruses