BIOL 103 Lecture Notes - Lecture 5: Myasthenia Gravis, Clonal Deletion, Rheumatoid Arthritis
Document Summary
Nk cells also kill virus-infected and cancer cells by secreting toxic chem. Recognizes general features on the surface of affected cells--> nonspecific immunity. Nk cells can be linked to target cells by antibodies. Body distinguishes b/w self and non-self components: during early development in vertebrates, t-cells are exposed to a wide variety of self proteins in the thymus. T-cells w/ receptors that bind to self proteins are destroyed via apoptosis-- deletion: clonal inactivation: occurs outside the thymus. Autoimmune disease: when these defenses fail and the body attacks itself. Humoral and cell-mediated attacks are directed against the body"s own cells + tissues attacked attacked. Myasthenia gravis: receptors for acetylcholine on skeletal muscle cells. Type 1 diabetes mellitus: islets of langerhans (produces insulin in pancreas) Primary immune response: to an initial exposure to an antigen. Secondary immune response: any subsequent infection by the same pathogen. Produces an immediate and heightened production of additional specific antibodies against that antigen.