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| | ==[[Innate Immunity Barriers]]== | | ==[[Innate Immunity Barriers]]== |
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| − | ==Humoral Factors== | + | ==[[Humoral Factors of Innate Immune System]]== |
| − | ===Lysozyme===
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| − | * Lysozyme is one of the major bactericidal agents in secretions
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| − | * Helps to protect vulnerable sites such as the eyes and nasal passages
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| − | * Exerts bactericidal effects by digesting bacterial cell walls
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| − | ** Gram-positive bacteria are more sensitive to lysozyme action than gram-negative bacteria
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| − | ** The outer membrane of gram-negative bacteria helps to protect them
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| − | ===[[Complement|Complement]]===
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| − | * The Complement system is a group of about 30 proteins within the body fluids of all vertebrates and some invertebrates
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| − | * Complement promotes '''phagocytosis''' or causes lysis of an invading organism
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| − | * Complement acts as a cascade, like the blood clotting system
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| − | ** The early enzymes in the cascade are bound to invading bacteria and fungi
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| − | *** They have an affinity for components of microbial cell membranes
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| − | ** This binding initiates a cascade so that the binding of one molecule will eventually lead to the fixation of millions of later molecules
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| − | * The early components act as targets for phagocytes
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| − | * The later components punch holes in bacteria, causing their lysis
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| − |
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| − | ===Interferons===
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| − | * Lysozyme and complement have only marginal effects on virus infections because these are intracellular
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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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| − | ** 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
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| | ==Cellular responses== | | ==Cellular responses== |