V.IMMUNITY AND CANCER Genetics of Immunity Human Immune System: evolved to keep potentially harmful organisms out of our bodies Pathogens: disease causing Bacteria: prokaryotic; treated by antibiotics Virus: single or double RNA or DNA wrapped in a protein coat Reproduce in host cell Human chromosomes harbor viral DNA (past infections) Genetic material cannot repair itself (high mutation rate) No effective vaccine against HIV or the common cold Genetic Control of Immunity: Autoimmune Condition: Immune system attacks an individuals own tissues ABO Blood Groups: Persons immune system manufactures antibodies that attack foreign antigens (Type A with antibodies against type B antigens) Rh Factor: Rh + man X Rh - woman with Rh + child (2 nd Rh + child: Bilirubin accumulates brain damage and skin/whites of eyes turn yellow) Human Leukocyte Antigens: WBC with cell surface proteins identify foreign objects Innate Immune Response: Immediate generalized response 1 st line of defense (ear wax, cilia) Inflammation: involves phagocytosis Plasma accumulates; High blood flow Participation of 3 major groups of proteins Complement System: release of histamine (dilates blood vessels) Collectins: protect against bacteria, viruses Cytokines: interferons, interleukins (cause fever) Acquired Immune Response: Humoral Immune Response: releasing of antibodies into the bloodstream B cells produce antibodies into the bloodstream (B cells are activated by T cells) Cellular Immune Response: cells themselves travel to where they act T cells stimulate B cells to manufacture antibodies, cytokines, and killer T cells Abnormal Immunity Severe Combined Immune Deficiencies (SCID): Affects both humoral and cellular immunity 50% of SCID cases are X linked Autoimmune Diseases Microchimerism: fetal cells persisting in a females circulation Appears to be an autoimmune disease Higher prevalence in women Scleroderma (hard skin): swollen joints, fatigue, stiff fingers, masklike face; between 45-60; body turning to stone Allergies: Immune System response to a substance (allergen) Asthma: chronic disease Contractions of airways, inflammation, mucus accumulation block airways Runny eyes, rashes, anaphylactic shock Environmental component Altering Immune Function Vaccine: inactive or partial form of a pathogen that stimulates the immune system to alert B cells to produce antibodies Immunotherapy: Hybridomas (artificial cells B cell fused with a cancer cell) produce monoclonal antibodies (mAbs) target specific antigens Cytokines: boost immunity and destroy cancer cells Transplants: Autograft: transfer tissue from 1 part of a persons body to another Isograft: transfer of tissue between identical twins Allograft: transfer of tissue between members of the same species Xenograft: a cross species transplant Hyperacute Rejection Reaction: donor tissue destroyed in minutes as blood vessels blacken and cut off blood supply Immunosuppressive drugs, stripping antigens from donor tissue, and matching donor to recipient improve success rate of transplants A Genomic View of Immunity Immunity against infectious disease involves interactions of two genomes ours and the pathogens Crowd Diseases: occur when infectious agents are introduced into a population that has not encountered them before Easily killed Native Americans Arose with the spread of agriculture, trade routes, and urbanization Vanished quickly Bioterrorism: use of pathogens to kill people