60 Questions
Which of the following is the main function of the mesenteric lymph nodes (MLN)?
To collect lymph, cells, and antigens from the intestinal mucosa
What is the definition of oral tolerance?
The avoidance of an immune response to foodstuffs and other matter
Which of the following is NOT a location of the mesenteric lymph nodes (MLN)?
Pancreas
Which of the following is considered an organ in its own right since 2012?
Mesentery
What is the main site for oral tolerance induction?
Mesenteric lymph nodes (MLN)
Which of the following is NOT a function of the mesenteric lymph nodes (MLN)?
Attaching the gut to the posterior abdominal wall
Which type of immunoglobulin is the main immunoglobulin secreted in the gut mucosa?
IgA
What is the role of commensal gut flora in IgA responses?
Inducing low affinity IgA responses
How do antigen-primed B-cells and T-cells reach the gut mucosa?
Via the blood stream
What is the process by which antigen-primed B and T-cells enter the gut mucosa called?
Homing
What is the role of Vitamin A in the 'homing' patterns of naïve B and T-cells?
Imprinting the 'homing' patterns
Besides Peyer's patches, which lymph nodes play a major role as induction sites in the gut mucosa?
Mesenterial lymph nodes
Which antibody is the main antibody found in secretions?
IgA
What is the role of the Poly-Ig receptor?
It allows IgA binding to the basolateral surface of gut endothelial cells.
What is the function of secreted IgM?
Its role is not entirely clear.
What is the reason that ligation of TLRs on the basolateral surface of gut epithelial cells does not trigger inflammation?
The TLRs are not activated by antigens in the gut.
What does gut homing of B- and T-cells mean?
The cells are instructed to return to the gut after being primed in other tissues.
What induces the expression of the chemokine receptor CCR9 and increased expression of integrin α4β7 on primed T-cells and B-cells?
Retinoic acid
Which of the following is true about Mesenteric Lymph Nodes (MLN)?
MLN drain lymph from intestinal mucosa
Which organ is responsible for maintaining food tolerance and protecting against microbes/microbial products in the portal vein?
Liver
What are the features of Intraepithelial Lymphocytes (IEL)?
All of the above
What types of T-cells are found in the Lamina propria and intraepithelial lymphocyte compartment?
All of the above
What is the role of NKG2D receptor expressed on T-cells in the gut?
All of the above
What cytokines are produced by T regulatory (Treg) cells in response to harmless commensals?
IL-10
Which of the following best describes the role of mucosal immunity in regards to infections?
Mucosal immunity is the primary defense mechanism against infections
What is the main function of Peyer's patches and 'M cells' in the gut?
Peyer's patches and 'M cells' are involved in immune surveillance and antigen sampling in the gut
Which of the following best describes the role of T-cell and B-cell effector mechanisms in the gut?
T-cell and B-cell effector mechanisms play a crucial role in the immune response in the gut
How is tolerance to food antigens achieved in the gut?
Tolerance to food antigens is achieved through a complex process involving various sites, cells, and molecules in the gut
What is the main role of IELs (Intraepithelial Lymphocytes) in the gut?
IELs are involved in immune surveillance and defense in the gut
What is the structure, role, transport, and location of IgA in the gut?
IgA is an antibody that plays a crucial role in immune defense at the gut mucosal surfaces
Which of the following immune cell types is found in higher numbers in the gut compared to the bloodstream?
NK cells
Which immune cell type has receptors that can interact with non-classical MHC molecules and ligands on other cells?
NK cells
Which immune cell type is associated with autoimmune components in diseases like ulcerative colitis and Crohn's disease?
T cells
Which immune cell type is specialized in removing infected epithelial cells in the gut?
NK cells
Which type of immune cells can be activated by intraepithelial T cells in the gut?
Dendritic cells
What is the main function of CD8+ T cells in the gut epithelium?
Kill infected epithelial cells
Which molecules can stressed cells express to be recognized by T cells carrying specific receptors?
MHC class I
What is the main role of intraepithelial lymphocytes (IELs) in the gut?
Kill stressed cells
Which of the following is true about the induction of tolerance in the gut mucosa?
Tolerance induction is the main function of Peyer's patches
What is the role of immune cells in the liver sinuses?
To capture antigens and prevent their entry into the general circulation
What happens when the liver is severely damaged, such as in an alcoholic?
Toxins can pass through the liver sinuses and enter the general circulation
What is the main function of IgA in the gut mucosa?
To bind to antigens and prevent bacteria from adhering to the epithelium
Which type of T-cell produces interleukin 17 (IL-17)?
T-helper 17 (Th17) cells
What is the role of T-regulatory (Treg) cells in regulating immune responses?
Suppressing immune responses
Which cytokine is produced by Treg cells to establish and maintain tolerance to commensals in the gut?
Interleukin 10 (IL-10)
What happens to the gut during HIV infection?
Depletion of T-regulatory (Treg) cells
Which of the following is NOT a function of the mesenteric lymph nodes (MLN)?
Induce tolerance to food antigens
What is the main function of Peyer's patches and 'M cells' in the gut?
Facilitate the uptake of antigens from the gut lumen
What is the main role of IELs (Intraepithelial Lymphocytes) in the gut?
Protect against pathogens in the gut epithelium
What is the definition of oral tolerance?
An avoidance of immune response to food antigens
Which of the following is NOT a characteristic of the mesenteric lymph nodes (MLN)?
They are responsible for maintaining food tolerance and protecting against microbes/microbial products in the portal vein
What is the main function of the lamina propria in the gut?
It is where the frontline staff of the immune system is located
Which of the following best describes the role of mucosal immunity in regards to infections?
Mucosal immunity prevents infections by promoting immune tolerance to pathogens
What is the main role of intraepithelial lymphocytes (IELs) in the gut?
IELs provide immune surveillance and rapidly respond to pathogens
Which of the following is NOT a possible type of antigen that generic cells can be confronted with?
Bad antigens
What happens to a regulatory T cell in the presence of TGF beta?
It becomes a tolerated T cell
What is the main difference between a pathogenic antigen and a tolerated antigen?
Pathogenic antigens activate T cells, while tolerated antigens do not
What are two different ways in which antigen responses can go?
Pathogenic or commensal
Where do antigen-primed B and T cells sit in the gut?
Under the epithelium
What is the role of TGF beta in the transformation of a regulatory T cell?
To become a tolerated T cell
Test your knowledge on mucosal B cells and IgA in this quiz! Explore the questions surrounding how antibodies enter the mucus and how antigen-primed B and T cells navigate their way back to the right location. Discover the guiding factors that help these cells find their way in the mucosal immune system.
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