Other Topics – Related to Immune System• Antigens- “marker proteins”• Blood Transfusions and Organ Transplants• It is the job of the immune system to distinguish between the body’s own molecules and foreign molecules
Blood Transfusions and the Immune System• Blood cells have marker proteins or “antigens” If the key fits the lock = bad!!!
Organ Transplants and the Immune System• Foreign organs also have marker proteins.• If recognized as “foreign” = REJECTION.• Doctors must “match” a new organs marker proteins to the patients.• Drugs can help suppress the immune response (immunosuppresants).
What if the immune system fails?• Sometimes the immune system loses the ability 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 various organs or cells of the body (skin, joints, kidneys, heart, and lungs) causing damage• Lupus is a multi-system disease because it can affect many different tissues and organs 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 system attacks mylein around nerve cells• Symptoms: loss ability to walk and move, loss bladder control, paralysis and death
What if the immune system fails?• Sometimes the immune system collapses• Ex) HIV• Virus invades macrophages and helper T cells• Without these WBC immune response will not work• Body becomes overwhelmed with pathogens (HIV AIDS)
AIDS (Acquired Immune Deficiency Syndrome)• Retrovirus (has RNA instead of DNA).• Lysogenic (stays dormant for a long period of time).• Easily evades immune system. 1. Mutates quickly. 2. Covers itself with marker proteins from host 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 or breast feeding.
What if the immune system fails?• Sometimes the immune system overreacts thinking something is a pathogen when it is NOT• Allergy- immune system response to a non- pathogenic antigen• Ex) pollen, food, insect bite, dust, etc.
Steps – Allergic Reaction• 1) Pollen inhaled• 2) cells of nasal passage called mast cells release chemical- histamine• 3) nearby capillaries swell- increases fluid*Allergies are treated with medication that contains antihistamines (chemical that blocks histamine)
Asthma• Leading cause of serious illness among children.• Causes narrowing of air passages (people can’t breathe).• Can be triggered by stress, environmental factors, allergies, or genetic factors.• Medication (usually a steroid) needs to be taken to make breathing easier.
Immune System and Cancer• Major function of immune system is to patrol for cancer cells• Called Immunological Surveillance• Killer-T cells can identify, attack, and destroy cancer cells