ROLE OF PHAGOCYTES IMMUNE DEFENCE IN ANIMAL ORGANISM

Abstract

Imunološki sustav je sustav organa koji štiti organizam od napada stranih mikroorganizama. Razlikujemo nespecifičnu i specifičnu imunost. Nespecifična imunost djeluje bez prethodnog kontakta organizma sa antigenom. Nespecifična imunost se temelji na mehanizmima kao što su anatomske prepreke, fiziološke prepreke, sustav komplementa, interferon, lizozim, te stanični mehanizmi (fagociti). Neutrofili iz krvotoka migriraju kroz endotelne stanice, nakon čega se moraju aktivirati da bi započela fagocitoza. Tako se aktivirani neutrofili usmjereno kreću prema mikroorganizmima, što je posljedica djelovanja kemotatičnih molekula. Proces fagocitoze započinje ingestijom kod koje se mikroorganizam uvlači u neutrofil, azavršava digestijom kod koje se probava mikroorganizma uništava lizirajućim enzimima i antimikrobnim peptidima. Nakon djelovanja na mjestu upale slijedi apoptoza neutrofila. Apoptozu reguliraju brojni citokini. Nakon apoptoze, apoptotičke neutrofile uklanjaju stanice mononuklearnog fagocitnog sustava.The immune system is the system that protects the body against attacks by foreign microorganisms. There are two types of immunity: innate and adaptive immunity. Innate immunity acts without prior contact with the antigen of the organism. Innate immunity is based on a number of mechanisms such as anatomic barriers, physiological barriers, the complement system, interferon, lysozyme, and cellular mechanisms (phagocytes). The neutrophils migrate from the bloodstream through the endothelial cells, and they must be activated to start the phagocytosis. Activated neutrophils have directed movement to microorganisms as a result of the chemotactic molecules. The process of phagocytosis begins with ingestion where the microorganism is drawn into the neutrophil, and ends with digestion in which the microorganisms is destroyed by lysing enzymes and antimicrobial peptides. Apoptosis is regulated by numerous cytokines. After apoptosis, apoptotic neutrophils are removed by mononuclear phagocytic syste