Exam 3: Topic 18 Flashcards
Define a cancerous cell line. What about them are different compared to your cells?
• a group of immortal cancer cells that continue to divide and grow in a laboratory setting.
Explain the role of Natural Killer cells in combating cancerous cells. Do Natural Killer cells need “permission” from Helper T cells? What are the NK cells looking for to identify cancerous cells.
• NK cells are able to recognizenormal MHC markers on the surface of healthy cells, and these MHC markers serve as an inhibitory signal preventingNK cell activation. However, cancer cells and virus-infected cells actively diminish or eliminate expression of MHCmarkers on their surface.
• When these MHC markers are diminished or absent, the NK cell interprets this as anabnormality and a cell in distress.
When a NK cell recognizes a decrease in inhibitory normal MHCmolecules the NK cell will be activated to eliminatethe cell in distress.
When would Cytotoxic T cells identify and kill cancerous cells?
• Abnormal cancer cells may also present tumor antigens.
Both NK cells and cytotoxic T cells can recognize and target cancer cells, andinduce apoptosis through the action of perforins and granzymes.
Explain why cancer can be thought of as “an immune system failure”
• malignant tumors tend to actively suppress the immune response in various ways. In some cancers,the immune cells themselves are cancerous. In leukemia, lymphocytes that would normally facilitate the immuneresponse become abnormal. In other cancers, the cancerous cells can become resistant to induction of apoptosis.This may occur through the expression of membrane proteins that shut off cytotoxic T cells or that induce regulatoryT cells that can shut down immune responses.
Describe the principles of vaccination and/or immunization. What is the end game?
• Vaccination:
○ Preventive vaccines are used to prevent a disease from occurring, whereas therapeutic vaccines are used to treat patients with the disease.
○ trigger the immune system to produce antibodies that fight off disease.
• Immunization:
immunization treatments provide almost immediate protection against certain diseases. These treatments contain pre-made antibodies.
Why are booster shots needed? Use the terms “primary immune response” and “secondary immune response” in your answer.
• because vaccines can lose effectiveness over time.
• primary immune response is the body’s initial reaction to a pathogen, while the secondary immune response is the body’s reaction to subsequent exposures to the same pathogen.
• When the body encounters the same pathogen again, it generates a secondary immune response that’s faster, stronger, and more effective than the primary response (generates memory cells).
Differentiate between active and passive immunity.
Active immunity is long-lasting and develops over time, while passive immunity is immediate but only lasts a few weeks or months
Differentiate between artificial and natural immunity.
• how the body acquires the immunity.
• During natural immunity, the body acquires immunity through exposure to a disease organism and infection.
• During artificial immunity, the body acquires immunity through vaccination, which introduces a weakened or killed form of the disease organism.
