IMMUNE SYSTEM, ILLUSTRATION. IMMUNE SYSTEM, ILLUSTRATION An organism´s defense mechanisms. An organism´s defense mechanisms. Illustration of a body´s immune responses to invasions by antigens, viruses or bacteria. - On the left, fragments of antigens are presented by the dendritic cells to the T CD4 lymphocytes which trigger an immune response which incites ´killer´ T CD8 lymphocytes to destroy the infected cells and ´memory´ T CD8 lymphocytes to be stored in case of a new attack. - On