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: -T-cell responses to self antigens can inflict tissue damage either directly or indirectly. Cytotoxic T-cell responses and inappropriate activation of macrophages by TH1 cells can cause extensive tissue damage, whereas inappropriate T-cell help to self-reactive B cells can initiate harmful autoantibody responses.