Antibodies, Antibody diversity and T cell Development Flashcards
B cells are _____ part of immune response whereas T cells are ____ immune response
humoral, cell mediated
“memory cells” are unique to what part of the immune system, innate or adaptive ?
adaptive immune response
what Ab cell can recognize naked Ag
B cells
when would clonal expansion occur ?
Starts after one Ag-specific cell is activated via binding of an Ag
what is hematopoeisis
formation of blood cells in bone marrow
what is the difference in where B and T cells fully mature
B cells mature in bone marrow
T cells mature in thymus
what is the difference b/w positive and negative selection of lymphocytes
Positive selection - means they bind self-Ag w/low avidity so they are kepl
Negative selection - bind self-Ag w/high avidity = deleted
in what organ do B cells develop their specificity for antigens
spleen
what are the 2 primary functions of B cell antibodies
1 - Recognize and bind naked Ag
2 - Trigger elimination of foreign Ag
What are the two fragment regions of an Ab ?
Fab - antigen binding fragment
Fc - crystalline fragment
explain the chain structure of an Ab
2 heavy chains spanning Fab and Fc
2 light chains spanning Fab only
which immunoglobin (Ab) is pentameric in structure
IgM
what Ab isotype is found most commonly in mucosal areas like saliva, tears etc
IgA
What Ab isotypes are B cell receptors
IgD
IgM
what Ab isotype is prevalent in allergies and parasitic infections
IgE
which Ab isotype is most prevalent in the blood serum and can cross the placental border
IgG
In Ab isotype IgG the Fab and Fc region are linked by the _____ ?
hinge
the 2 light chains of IgG exist in what two forms ?
kappa and lambda
what are the 4 subclasses of IgG
gamma 1, gamma 2, gamma 3, gamma 4
what is antibody diversity
the ability to produce billions of different Ab even though there are only 20-25 k genes that code for them
how is the human body able to accomplish Ab diversity and create so many different Ab with such few genes ?
B/c the heavy chain variable region is made up of 3 different segments/regions and can make countless combinations b/w these
what are the 3 segments/regions of the heavy chain variable region in B cells
V (variable) - 100 genes
D (diversity) - 30 genes
J (joining) - 6 genes
what does V(D)J recombination mean
accounts for combinatorial diversity through the joining of various gene segments in B cells
what does somatic hypermutation mean and when does it occur
ability to make single base changes in the V(D)J genes to allow for a higher affinity of the Ab of B cells
-occurs after the Ab FIRST discovers its Ag
