Body surface/Mucosal immunity Flashcards
What are some nonimmunologic surface protective mechanisms for maintaining health?
skin, mucous, vomiting, diarrhea, tears, coughing, muco-ciliary escalator
What is the common mucosal immune system known as?
mucosal associated lymphoid tissue (MALT)
What is the difference between lymphocyte flow of the systemic immune system and the common mucosal immune system?
when lymphocytes from MALT leave from their origin and come back, they usually come back to the site they originated from or to another mucosal surface, they will not go to lymph nodes
What is movement of lymphocytes in MALT directed by?
addressin molecules and chemokine receptors
What are M cells?
dome shaped subepithelial cells located in Peyer’s patches
What is the function of M cells?
transcytosis
What is transcytosis?
the process of phagocytosing material from the gut lumem and transporting it to the subepithelial space
What antibody is in the highest quantity in the body?
IgA
Where is IgA found?
on mucosal surfaces
What is the structure of IgA as it comes out of the plasma cell?
it is a dimer with 4 heavy chain domains held together by a J chain
What are the functions of IgA?
neutralize toxons, block the entry of pathogens, and help provide intestinal immunity
Where does IgA acquire its secretory component?
from the lamina propria underneath the mucosal epithelial cell
What are the functions of the secretory component of IgA?
transportation of IgA from the basal surface to the lumen, protection from cleavage by proteases in the lumen, protection for IgA to not just get flushed out of the cell
A mare is pregnant and gets infected with a pathogen, how does the IgA for this pathogen get to the newborn?
the pathogen gets into the lymphoid tissue of the gut, they become activated and then exit the mucosa of the intesinal tissue to the mesenteric lymph node to the efferent lymphatics to the thoracic duct to the blood stream, then bind to addressins and enter in the mammary tissue of the mare to where the b-cells are fully differentiated into plasma cells, they then secrete IgA into the milk
Draw an IgA molecule and secretory IgA.
This is what they should look like.
Identify 1.
lamina propria
Identify 2.
Mucosal epithelial cell
Identify 3.
Lumen
Identify 4.
J chain
Identify 5.
IgA-producing plasma cell
Identify 6.
Poly-Ig receptor with bound IgA
Identify 7.
dimeric IgA
Identify 8.
Endocytosed complex of IgA and poly-Ig receptor
Identify 9.
Secreted component
Identify 10.
secreted IgA
Identify 11.
Proteolytic cleavage
