new_n_lost
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The usual sequence of events in the development of an effective immune response to a viral infection is
A) interferon secretion, antibody synthesis, cellular immune response, NK cell ADCC.
B) antibody synthesis, interferon secretion, NK cell ADCC, cellular immune response.
C) NK cell ADCC, interferon secretion, antibody synthesis, cellular immune response
D) interferon secretion, cellular immune response, antibody synthesis, NK cell ADCC.
E) cellular immune response, interferon secretion, antibody synthesis, NK cell ADCC.
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| me007
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e?
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| indidoc1
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I think its between A & D..
Will go fr D
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| doc179
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E
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| new_n_lost
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D The usual sequence of events in the host immune response to a viral infection is interferon secretion, cellular immune response, antibody synthesis, NK cell ADCC. Interferon is produced early in the course of viral infection and serves to slow the infection of adjoining cells. Cellular immune responses in the form of cytotoxic CD8 T cells occur early in viral infection and usually precede the appearance of serum-neutralizing antibody or NK-cell-mediated ADCC (which requires specific antibody).
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| me007
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what triggers INF secretion?
There is some cell which is stimulated and secrete that INF?
how it can be secreted just by virus entering epithelial cells?
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| epica
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Very good Q
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| new_n_lost
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IFN is one of the first lines of defense against viruses because it is induced early after virus infection before any of the other defense mechanisms appear (e.g. antibody, Tc cells etc.)
Normal cells do not contain preformed IFN nor do they secret interferon constitutively. This is because the interferon genes are not transcribed in normal cells. Transcription of the IFN genes occurs only after exposure of cells to an appropriate inducer. Inducers of IFN-alpha and IFN-beta include virus infection, double stranded RNA (e.g. poly inosinic oly cytidylic acid; [poly I:C]), LPS, and components from some bacteria. Among the viruses, the RNA viruses are the best inducers while DNA viruses are poor IFN inducers, with the exception of poxviruses. Inducers of IFN-gamma include mitogens and antigen (i.e. things that activate lymphocytes).
Cellular Events in the Induction of Interferons - The IFN genes are not expressed in normal cells because the cells produce a labile repressor protein that binds to the promoter region upstream of the gene and inhibits transcription. In addition, transcription of the genes require activator proteins to bind to the promoter region and turn on transcription. Inducers of IFN act by either preventing synthesis of the repressor protein or increasing the levels of the activator proteins, thereby turning the IFN gene on. After the inducer is gone, the IFN gene is again turned off by the repressor protein and/or the lack of activator proteins. Once the gene is turned on, it is transcribed, the mRNA is translated and the protein is secreted from the cell. The IFN will bind to IFN-receptors on neighboring cells and induce an antiviral state in the second cell.
http://pathmicro.med.sc.edu/mayer/vir-host2000.ht...
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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| new_n_lost
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I hope this will clear most of ur confusions i have also given the link to the question.
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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