Other Topics – Relatedto Immune System• Antigens- “marker proteins”• Blood Transfusions and OrganTransplants• It is the job of the immune system todistinguish between the body’s ownmolecules and foreign molecules
If the key fits the lock = bad!!!Blood Transfusions and the ImmuneSystem• Blood cells have marker proteins or“antigens”
Organ Transplants and theImmune System• Foreign organs also have markerproteins.• If recognized as “foreign” = REJECTION.• Doctors must “match” a new organsmarker proteins to the patients.• Drugs can help suppress the immuneresponse (immunosuppresants).
What if the immunesystem fails?• Sometimes the immune system loses theability to distinguish itself from non-self.• Results in autoimmune disease• Body attacks own tissues• Ex) lupus, multiple sclerosis, arthritis
LUPUS• Person’s immune system attacks variousorgans or cells of the body (skin, joints,kidneys, heart, and lungs) causingdamage• Lupus is a multi-system disease becauseit can affect many different tissues andorgans in the body.
LUPUSSymptoms:• Fatigue• Low-grade fever, rarely exceeding 102°F• Muscle pain and joint pain or swelling• Skin rash (face, back, arms) and hair loss• Kidney problems and weight loss
MultipleSclerosis• Immune systemattacks myleinaround nerve cells• Symptoms: loss ability to walk and move,loss bladder control, paralysis and death
What if the immunesystem fails?• Sometimes the immune system collapses• Ex) HIV• Virus invades macrophages and helper Tcells• Without these WBC immune responsewill not work• Body becomes overwhelmed withpathogens (HIV AIDS)
AIDS (Acquired ImmuneDeficiency Syndrome)• Retrovirus (has RNA instead of DNA).• Lysogenic (stays dormant for a longperiod of time).• Easily evades immune system.1. Mutates quickly.2. Covers itself with marker proteins fromhost cell (difficult to detect).
Transmission of HIV• Four main ways1. Sexual intercourse.2. Intravenous drug use (sharing needles)3. Blood to blood contact4. Mother to child during pregnancy orbreast feeding.
What if the immunesystem fails?• Sometimes the immunesystem overreactsthinking something is apathogen when it is NOT• Allergy- immune systemresponse to a non-pathogenic antigen• Ex) pollen, food, insectbite, dust, etc.
Steps – AllergicReaction• 1) Pollen inhaled• 2) cells of nasalpassage called mastcells release chemical-histamine• 3) nearby capillariesswell- increases fluid*Allergies are treatedwith medication thatcontainsantihistamines(chemical that blockshistamine)
Asthma• Leading cause of serious illness amongchildren.• Causes narrowing of air passages (peoplecan’t breathe).• Can be triggered by stress, environmentalfactors, allergies, or genetic factors.• Medication (usually a steroid) needs to betaken to make breathing easier.
Immune System andCancer• Major function of immune system is topatrol for cancer cells• Called Immunological Surveillance• Killer-T cells can identify, attack, anddestroy cancer cells