Review: Cell Mediated and Humoral Immunity ---------Humoral Immunity Flashcards
- What is the main lymphocyte cell in this branch of the immune system?
Main cell: B-cell
- Is Antigen material presented to Immunocompetent B-cell as in cell mediated immunity?
Immunocompetent B-cell “bumps” into free Ags released into to lymph node (3-4 days)
- Where are Ab receptors located on B- cells?
Ab receptors on B-cell surface combine with free Ag
- Are Ab receptors already genetically primed before a B-cell ever encounters antigen?
Yes
- How do B-cells recognize Ag? (free or in an MHC receptor)
Free antigen
- What is capping?
Ab-Ag complexes move to one area of B-cell surface : Capping
- Why does capping occur in B-cells?
To fully process so it can phagocitize effeciently by moving to one area
- What specific T-cell releases Interleukin 2 to stimulate proliferation of an activated B-cell?
TH (Helper T-cells)
- What are Plasma cells and why are they produced?
Antibody/Immunoglobulin
Produced by B-cells called Plasma cells
- Do plasma cells ever leave the lymph node or just the antibodies that they produce?
Just the antibodies
- Describe the 4 mechanisms of Ab-Ag interaction: neutralization, agglutination, precipitation, opsonization.
Neutralization
Ab reacts with virus blocking its attachment to host cell
Ab reacts with toxins, blocking harmful effects
Agglutination
Ab reacts with whole bacteria cells and clumps them together
Opposes spread of pathogen
Enhances phagocytosis
Precipitation
Ab reacts with soluble Ag and converts it to a solid precipitate
Ag is inactivated and easily phagocytized
Opsonization
Abs promote phagocytosis of Ags with capsules
Abs bind to capsule then MØ binds to Ab enabling phagocytosis
- What are the 5 categories of Ab molecules?
IgM IgG IgA IgE IgD
- Which antibody is described as the “maternal Ab”?
IgG
- Which antibody is described as the “secretory Ab”?
IgA
- Which antibody is made first in response to a first encounter or primary response against an antigen?
IgM
- Which antibody is involved in the secondary response or memory response to an antigen?
IgG
- What is the difference between a primary response and secondary response to Ag?
Primary Response 1st exposure to Ag Ab concentration short duration IgM main Ab 7-10 days to initiate Abs
Secondary Response 2nd and any subsequent exposure to Ag Ab concentration lasts longer Stronger Ab response IgG main Ab Anamnestic (memory) response
- Which response to antigen is better and stronger: primary response or secondary response?
Secondary Response
What are the 5 categories of Ab molecules and their functions? IgM
Involved with primary response against Ag
Largest Ab
5-10%
What are the 5 categories of Ab molecules and their functions? IgG
Involved with secondary response against Ag
Memory Ab
“Maternal Ab” crosses placenta
80%
What are the 5 categories of Ab molecules and their functions? IgA
“Secretory Ab”: tears, saliva, mother’s milk, mucous membranes
Provides protection in respiratory /gastrointestinal tracts
10%
What are the 5 categories of Ab molecules and their functions? IgE
Major role in allergic response
0.5%
What are the 5 categories of Ab molecules and their functions? IgD
Not clearly established – possibly involved with IgM
Perhaps helps in initial recognition of Ag
May be present on MØ surface to react with Ag
1-3%
