innate immunity

INNATE IMMUNITY

Resistance to infection which individual possesses by virtue of his genetic and constitutional make up Early defense response against microbes Immune response Non specific Innate response do not alter on repeated exposure Memory effect absent Not affected by immunisation or prior contact

 

THE INNATE IMMUNE SYSTEM

–Synonyms are the natural or native immune system

–Rapidly mobilised first line of defence

–Not dependent on prior exposure to a  foreign invader

–Non-specific

–May not be sufficient to prevent  foreign material persisting in the host

- The “Respiratory Burst” 

  aka the “oxidative burst”

  membrane-bound NADPH system  produces: superoxide radicals, hyperchlorous acid, H2O2, chloramines

- A reliable means of protecting the host  in the first instance against many  extracellular organisms

- It is a property of every living organism

-  Unable to deal with all intracellular  organisms (e.g protozoa, viruses &  certain bacteria are not killed)

 

 Innate immunity comprises:

–physicochemical barriers

–molecules normally present in body  fluids e.g. lysozyme, complement,  antiproteases

–phagocytic & cytotoxic cells such as  neutrophils, macrophages, natural  killer cells