IMMUNOLOGY

Detailed explanation-1: -Innate immunity not only recognizes nonself antigens, but also utilizes more sophisticated mechanisms of recognition. Modification of self proteins by microbial enzymes may also lead to recognition by the innate immune system.

Detailed explanation-2: -Human leukocyte antigens (HLA) are a group of identification molecules located on the surface of all cells in a combination that is almost unique for each person, thereby enabling the body to distinguish self from nonself.

Detailed explanation-3: -Self-tolerance is the ability of the immune system to recognize self-produced antigens as a non-threat while appropriately mounting a response to foreign substances.