Exam 2- Chapter 9 Flashcards
Antibodies bind to extracellular bacteria and viruses to allow:
The effector response
How is the quality of an antibody improved?
Affinity is increased
Change of the isotope of the antibody the change the response of effector cells
How are antibodies cross linked on a mature B cell
Surface IgM antibodies link to the antigen. At least 2 antibodies are required.
What does crosslinking result in?
Intracellular signaling cascades
What does the B cell co-receptor include? (3)
Complement receptor 2- recognizes complement fragments
A signaling chain
Complement that binds to the signaling chain for attachment purposes
What do CD4 helper T cells recognize?
Pathogens presented on B cell MHC class II molecules
Results in B cells dividing and differentiating
Disease of infants without T cells
DiGeorge Syndrome
B cells need _____ to produce antibodies
T cells
B cells can produce antibodies without T cells if:
If they have a larger pathogen with lots of repeated epitose
Cells in the secondary lymphoid tissues that organize into follicles where B cells can enter
Follicular dendritic cells (FDCs)
What interact with the FDC and their presented antigens
B cells
How do FDCs differ from regular dendrites?
FDCs are
Larger
Remain in lymph nodes
Lack phagocytic activity (antigens remain on the outside of the cell with specialized receptors)
Naive B cells enter into the lymph node at the ______ ______ and checks:
Subscapular sinus
Checks the macrophages for their antigen
If the nerve B cell finds its antigen, it will:
Enter the follicle to interact with helper T cells- TFH cells
If the B cell does not find their specific antigen, they enter the follicle to:
Check the FDCs
The B cell and T cell give each other:
Cytokines
That happens to the B cell if it finds its antigen on the FDC?
If it does not?
It is activated
If not, it leaves the lymph node to recirculate
Antigen-activated B cells process and present antigen on the MHC class II molecules to allow:
Further activation by helper TFH cells
Cognate pairs:
Pairs of B cells and T cells giving each other what they need to continue activation
Result of proliferation (paired B and T cells move into the cortex and divide)
B lymphoblasts the secrete IgM
B lymphoblasts can differentiate into:
Plasma cells with a higher production of refined antibodies
Some B lymphoblasts move into primary follicles with their helper T cells to:
Proliferate into a germinal center
Rapid B cell division results in:
Centroblasts
Centroblasts become:
What happens?
Centrocytes
There is a slower division with affinity maturation and isotype switching (IgG)
Before leaving the lymph node, the centrocytes have further activation by:
Helper T cells
Affinity maturation
Improvement in antibody affinity for a particular antigen by small mutations in the binding site.
What centrocytes will be triggered to mature?
The ones with the greatest affinity
What happens to centrocytes with the lesser affinity
They are triggered to die
First immunoglobulins on cell curface
IgD and IgM
How can B cells switch their isotype to produce IgG, IgA or IgE
By rearranging their heavy chain
What determine what isotype is made?
Cytokines produces by the TFH cells
Why do T cells produce cytokines?
To determine if a B cell becomes as effector cell or memory B cell
Memory cells provide:
Faster and more efficient responses upon subsequent exposure to the pathogen
Between effector cells and memory B cells, what provide a faster and more efficient response upon subsequent exposure to the pathogen
Memory cells
First antibody produced for every infection
- Secreted as a pentamer to enter the bloodstream
- Activates the classical complement cascade
IgM
Disadvantage of IgM
Bulkiness
How is IgM transported?
Pinocytosis
How is IgA transported?
Transcytosis
IgG and IgA are transported from the blood into:
Extracellular spaces in the tissues
IgA attaches to the:
Mucosal surface to bind to microorganisms
Function of IgD
Not none, though we know it is interacting with commensalism and acts as a surface receptor
What immunoglobulin targets parasites and allergies
IgE
IgE is usually a surface receptor bound irreversibly by Fc receptors on:
Mast cells, basophils and eosinophils
What do IgE and cytokines do to smooth muscles?
Causes them to react violently by sneezing, coughing, vomiting, diarrhea to eject pathogens
Mast cells have _____ specificity with what attached?
Multiple
IgE Attached
What are responsible for mucus production and and where are they located?
Histamines
Found in mast cells
