70 Questions
What is a significant immunological challenge faced by xenogeneic transplantation?
High risk of rejection
In blood transfusion, what is an important consideration to minimize adverse reactions?
Matching blood types exactly
Individuals who don’t express a particular AB antigen produce what type of natural antibodies?
IgM antibodies
What is a potential complication of ABO donor-recipient mismatch in transplantation?
Hemolytic transfusion reaction
What is the primary purpose of careful matching between donor and recipient in HSC transplantation?
Minimizing the risk of GVHD
What is the primary challenge when it comes to immune response in xenogeneic transplantation?
Differences in cell surface antigens between individuals
What determines an individual's blood type in the ABO blood group system?
Specific carbohydrate chains on the surface of red blood cells
What type of antibodies are naturally produced in the plasma against antigens that are absent on an individual's red blood cells?
IgM antibodies
What happens when there is a mismatch in the ABO blood group system between a donor and a recipient during a blood transfusion?
The recipient may produce antibodies against donor's antigens
What is the most common form of transplantation mentioned in the text?
Blood transfusions
Which blood type can individuals with type A blood receive from?
Type O donors
What is the consequence of an ABO donor-recipient mismatch in blood transfusions?
Increased risk of adverse reactions
Which blood type can individuals with type O blood receive from?
Type O donors
What are the alleles responsible for the A antigen and the B antigen, respectively?
A & B
Where are glycosyltransferase enzymes encoded?
Chromosome 9
What is one of the challenges faced during HSC transplantation, as described in the text?
Rejection
In the context of blood transfusions, what can be a life-threatening consequence of ABO incompatibility?
Graft vs. Host Disease
Which type of diseases can be treated by HSC transplantation, based on the information provided?
Blood-related diseases
What is the significance of accurately determining blood types in the context of blood transfusions?
Preventing severe transfusion reactions
From where can hematopoietic stem cells be sourced for transplantation?
Umbilical cord blood
What is the reason behind individuals with type AB blood being universal recipients?
They do not produce anti-A or anti-B antibodies.
Why can individuals with type O blood only donate to individuals of any blood type?
They produce both anti-A and anti-B antibodies.
What happens during an ABO donor-recipient mismatch in blood transfusion?
Pre-existing IgMs bind to 'foreign' antigen on donor cells
What is the consequence of hemolysis of RBCs during an ABO donor-recipient mismatch?
Release of large amount of hemoglobin toxic to kidneys
What is the innate response seen during ABO incompatibility in blood transfusion?
Fever, shock, disseminated coagulation via cytokine storm
What antibodies do Type A individuals naturally produce?
Anti-B antibodies (IgM)
Why do Type AB individuals not produce natural anti-A or anti-B antibodies?
They express both A and B antigens.
Which blood type naturally produces both anti-A and anti-B antibodies?
Type O
What antibodies do Type B individuals naturally produce?
Anti-A antibodies (IgM)
Why is it important to understand the ABO blood group system for safe blood transfusions?
To minimize the risk of adverse reactions.
What is the primary source of stem cells historically used for transplantation?
Bone marrow
Which procedure is performed first in hematopoietic stem cell transplantation?
Destroying recipient's existing stem cells
What is a major risk associated with hematopoietic stem cell transplantation?
Possibility of rejection
What condition arises when the donor's immune cells attack the recipient's tissues post-transplant?
Graft-versus-host disease
What leads to an increased risk of infections during the transplant process?
Decreased immune system due to chemotherapy/radiation
Which type of cells are eliminated in the first step of the transplantation procedure?
Recipient's hematopoietic stem cells
What can happen if the recipient's immune system recognizes the donor's stem cells as foreign?
Rejection of donor stem cells
In which situation would the transplant fail to restore normal immune function?
'Immunodeficiency' post-transplant for the recipient
How do alloreactive antibodies primarily engage effector mechanisms?
Via engagement of complement or Fc receptors
In the context of tissue rejection, which cells are the prime target of graft alloantibodies?
Endothelial cells in graft vasculature
What is the main difference between the direct and indirect pathways of alloantigen presentation to recipient T cells?
Direct pathway does not involve antigen processing by recipient APCs, while indirect pathway does
Which route of alloantigen presentation involves donor dendritic cells directly presenting antigens to recipient T cells?
Direct Route
Where do antigens presented by both donor and recipient APCs travel to for presentation to naive T cells?
Lymph node
Which type of MHC molecules are most frequently recognized by alloantibodies produced by alloreactive B cells?
Class II MHC molecules
In tissue rejection, what initiates the activation of alloreactive T cells in the direct pathway of antigen presentation?
Donor dendritic cells directly presenting antigens
Which type of T cells directly attack and kill graft tissue cells presenting alloantigens?
CD8+ cytotoxic T cells
What is the role of CD4+ helper T cells in the rejection of transplanted tissue?
Inducing inflammation and cytokine production
What is the main target of antibodies produced by alloreactive B cells in response to alloantigens?
Endothelial cells
Why is the vasculature of the transplanted tissue a prime target for the recipient's immune response?
To compromise blood flow to the transplanted tissue
Which immune cells are responsible for recruiting complement proteins and further exacerbating tissue damage?
Alloreactive B cells
What is the consequence of alloreactive T cell activation in response to alloantigens?
Production of pro-inflammatory cytokines
How do CD8+ cytotoxic T cells contribute to tissue rejection in transplantation?
By directly attacking and killing graft tissue cells
What is the primary function of antibodies produced by alloreactive B cells against MHC proteins?
Recruiting complement proteins and immune cells
What is one of the key roles of CD4+ helper T cells in the immune response against transplanted tissue?
Inducing inflammation and cytokine production
What is the primary function of CD8+ cytotoxic T cells in the rejection of transplanted tissue?
Directly attacking and killing graft tissue cells presenting alloantigens
What is the consequence of an attack on the vasculature of transplanted tissue by the recipient's immune system?
Compromised blood flow to the transplanted tissue
What is the role of alloreactive B cells in response to alloantigens in transplanted tissue rejection?
Producing antibodies targeting MHC proteins
Which cells are a prime target for the recipient's immune response in transplanted tissue rejection?
Endothelial cells lining blood vessels
What is the main consequence of the production of antibodies targeting MHC proteins on donated tissue?
Exacerbating tissue damage and rejection
In what way do CD4+ helper T cells contribute to tissue damage in transplanted tissue rejection?
Inducing inflammation and cytokine production
What is the crucial aspect related to donated tissue that leads to immune responses and ultimately, rejection?
Expression of MHC proteins on graft cells
How do activated effector T cells primarily contribute to transplanted tissue rejection?
Engaging in various effector functions such as direct attack on graft cells
In the context of alloantigen presentation, which cells capture and process donor alloantigens in the indirect pathway?
Recipient dendritic cells
What is the primary role of donor dendritic cells in alloantigen presentation in the direct pathway?
Carry antigens from donated tissue and present them to recipient T cells
What is the main target of alloreactive antibodies produced by B cells?
Class I and Class II MHC molecules
Which immune response outcome occurs when alloantigens are directly presented to recipient T cells?
Alloreactive T cell activation
What is the role of naive T cells in the lymph node response to presented antigens?
Undergo activation upon antigen presentation
Which type of MHC molecules are expressed by endothelial cells in the context of transplantation?
Class I MHC only
What is the consequence of alloreactive antibodies engaging complement as an effector mechanism?
Tissue damage through complement activation
What happens when processed donor alloantigens are presented to recipient T cells in the indirect pathway?
Activation of recipient T cells
Learn about the importance of ongoing research in xenogeneic transplantation and the challenges related to immune responses. Understand the significance of cell surface antigens, specifically the ABO alloantigen system, in blood transfusions.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
