Fish Immunology (1+1)

Unit 1- Fish Immunology

1.2. Innate immunity
Innate immunity also called natural or native immunity, takes part in the initial protection against Pathogens. Innate immunity in healthy host is prepared to block the entry of microbes and to rapidly destroy pathogens that enter into host tissues.
Innate immunity acts non specifically where the nature or quality of the reaction to a foreign substance does not change when the organism encounters repeatedly.
Innate immunity does not discriminate between the pathogens. The mechanisms of innate immunity provide the initial defense against infections. Majority of the microbes are blocked by physical barrier. If the pathogens succeed in entering the host then these pathogens are eliminated by phagocytes, NK cells, complement system etc.
There are two types of innate immunity

• Humoral immunity and
• Cell-mediated immunity

Humoral immunity
Humoral immunity is mediated by the antimicrobial peptides, cytokines etc where the cellular substance are involved.
Cell-mediated immunity
Cell-mediated immunity is mediated by the non specific immune cells like macrophages, NK cells, granular cells etc.