Immunology: An Overview

Abstract

The major role of the immune system is to maintain immunologic homeostasis and protect the host against a wide range of internal and external threats. The immune system of mammals contains two different types of immunity, innate and adaptive immunity. Innate immunity has a rapid response to external threats and protects the body against a wide range of organisms. The adaptive immune system is a specific response to a specific stimulation such as a pathologic microorganism. The role of immune system is to protect the body against microorganisms and cancers. Abnormalities in immune and responses, both overactivity and underactivity, can cause significant harm to the organ. Immune privilege protects the organ such as eye against the inflammatory processes. The immune-privileged microenvironment of the eye has multiple components including (a) blood-ocular barrier, (b) several soluble and cell-bound immunosuppressive molecules, and (c) anterior chamber-associated immune deviation (ACAID).