This lesson explains how immune recognition of cell-surface markers affects pregnancy and organ transplantation. These examples show how immune defenses can protect the body but also damage fetal or transplanted tissues.
Red blood cells carry surface antigens that can be used to classify blood. The ABO system divides blood into types A, B, AB, and O. The Rh antigen is a separate marker: a person who is Rh-positive has this antigen, while an Rh-negative person lacks it. Thus, A-positive blood has both the A antigen and the Rh antigen.
All flashcards
What is the Rh antigen?
A red blood cell surface marker separate from the ABO antigens; Rh-positive cells carry it, while Rh-negative cells lack it.
What do MHC polygeny and polymorphism mean?
Polygeny means several genes encode MHC proteins; polymorphism means each MHC gene has many possible alleles in the population.
What is graft-versus-host disease?
A complication in which donor immune cells attack the transplant recipient's tissues.
What is cancer immunoediting?
The interaction in which immune defenses eliminate or restrain tumor cells and select for variants that can escape recognition.
What does psychoneuroimmunology study?
Communication and interactions among psychological processes, the nervous system, endocrine signals, and immunity.
Quiz questions
Why can a later Rh-positive pregnancy be at risk after an Rh-negative parent has been exposed to Rh-positive fetal blood?Answer: The parent may produce anti-Rh IgG that crosses the placenta and damages fetal red blood cells.
Why can a transplanted organ with MHC molecules that differ from the recipient's be rejected?Answer: Recipient T cells may recognize the donor MHC molecules as foreign and attack the graft.
After a bone marrow transplant, donor lymphocytes attack the recipient's tissues. What is this complication called?Answer: Graft-versus-host disease, in which donor immune cells damage recipient tissues.
How does a therapeutic cancer vaccine differ from an HPV vaccine?Answer: It aims to stimulate immunity against an existing tumor rather than prevent a viral infection.
What effect is chronic stress associated with in otherwise healthy adults?Answer: Suppression of both innate and adaptive immune responses.
Based on Anatomy and Physiology 2e by J. Gordon Betts, Kelly A. Young, James A. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark Womble, Peter DeSaix (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.