* Lysozyme and complement have only marginal effects on virus infections because these are intracellular
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The Lysozyme and complement have only marginal effects on virus infections because these are intracellular so the body has evolved non-specific mechanisms to protect against viruses with the most notable of these being the interferons.<br />
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** The body has evolved non-specific mechanisms to protect against viruses
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*** The most notable of these is the interferons
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* Interferons are small polypeptides produced mainly by virus-infected cells
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Interferons are small polypeptides produced mainly by virus-infected cells. The main functions are of interferon is to interact with uninfected cells and render them resistant to infection by increasing the production of enzymes that digest viral nucleic acids. The interferon can then also cause an increase in MHC (Major Histocompatibility Complex) Class I and II expression on all cells, so if they are infected, the immune system can recognise the infection and take further steps of limiting viral replication. An example is the lysis of the infected cell by [[Blood Cell Overview|cytotoxic T lymphocytes]], or the induction of apoptosis by Natural Killer Cells.
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** Interact with uninfected cells and render them resistant to infection
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*** This resistance is mainly due to the production of enzymes that digest viral nucleic acids