Understanding Immunological Concepts: Tolerance, Autoimmunity, Tumor Immunity, and Congenital Deficiencies
Tolerance and its induction: - Tolerance is the immune system's ability to recognize and tolerate self-antigens. - Induced centrally in the thymus (T cells) and bone marrow (B cells) during development. - Mechanisms include negative selection, receptor editing, anergy, regulatory T cells (Tregs), and immune privilege. Autoimmune diseases and their factors and mechanisms: - Autoimmune diseases occur when the immune system attacks the body's own tissues. - Factors include genetic predisposition, environmental triggers, and immune dysregulation. - Mechanisms include molecular mimicry, breakdown of tolerance, aberrant lymphocyte activation, and inflammation. - Examples: rheumatoid arthritis, lupus, type 1 diabetes, multiple sclerosis. Tumor immunity and associated antigens: - Tumors express tumor-specific antigens (TSAs) or tumor-associated antigens (TAAs). - Immune responses target tumors through CTLs, NK cells, and tumor-infiltrating lymphocytes (T