transplantation and cancer Flashcards
(19 cards)
What is the primary question addressed in the lecture?
Why does the immune system attack a transplant but tolerate a tumour?
This question encourages deep thinking about the immune response in different contexts.
Who conducted pioneering work in transplantation in 1902?
Carrel & Guthrie
Their work was significant in vascular surgery and organ transplantation.
What technique did Carrel develop that earned him a Nobel Prize?
Suture technique for blood vessels
This technique was crucial for successful vascular anastomosis.
What was the limitation of early organ transplantation attempts?
Rejection was not yet understood
Despite successful surgical techniques, the biological basis of rejection was unknown.
Why were Carrel & Guthrie’s transplants eventually rejected?
Organs failed within days to weeks
The issue was not surgical skill but the body’s immune response.
What did Peter Medawar discover about graft rejection during WWII?
The body’s refusal to accept the stitched tissue
Medawar’s experiments highlighted the immune response to grafts.
What is the ‘First-Set’ Rejection?
Transplanted skin from Mouse A to Mouse B took ~10–14 days to be rejected
This represents the immune system’s initial response to a new invader.
What is the ‘Second-Set’ Rejection?
Transplanted skin from Mouse A to Mouse B again was rejected in ~5–6 days
This shows the concept of immune memory in the adaptive immune response.
What did the Tolerance Experiment involve?
Injecting Mouse B embryos with cells from Mouse A before birth
This experiment demonstrated how early exposure can lead to tolerance of foreign tissue.
What are the two types of MHC?
- MHC Class I: Found on all nucleated cells
- MHC Class II: On immune cells
These molecules are critical for graft recognition and immune response.
What is the genetic basis for graft recognition?
Closer MHC match = Lower rejection risk
Matching MHC is essential for successful transplantation outcomes.
What is the role of immunosuppressants in transplantation?
Target MHC-mediated responses
These drugs help prevent the immune system from rejecting the graft.
What was William Coley’s hypothesis regarding cancer treatment?
Deliberately infect patients with terminal cancer to stimulate immune response
Coley observed that infections sometimes led to tumor shrinkage.
What is the Immunosurveillance theory?
The immune system patrols the body to detect and destroy cancer cells and foreign cells
This theory suggests that immune cells play a critical role in cancer control.
What happens if immunity fails according to the Immunosurveillance theory?
Cancer escapes (tumour growth) or grafts survive (with immunosuppression)
This highlights the balance between immune response and disease progression.
What are the key immune players in cancer?
- CD8 T cells
- CD4 T cells
- NK cells
These cells are crucial for recognizing and eliminating cancer cells.
What is Cancer Immunoediting?
Tumours evolve to evade immune surveillance
This process complicates the immune response to cancer.
What are the main differences between transplantation immunology and cancer immunology?
- Immune Activation: Suppress vs. Stimulate
- Immune Goal: Promote tolerance vs. Promote immune recognition
- T Cell Role: Pathogenic vs. Therapeutic
- Main Risk: Graft rejection vs. Tumour immune evasion
- Therapeutic Approach: Immunosuppression vs. Immunostimulation
These differences illustrate the contrasting strategies in managing transplants and cancer.
True or False: Cancer treatment can reject transplants.
True
The immune mechanisms involved in cancer treatment can impact transplant viability.
