Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
50 Cards in this Set
- Front
- Back
|
what is an antibody repertoire?
|
the collection of DIFFERENT antibody molecules in an individual, and each different antibody has a different variable amino acid sequence
|
|
|
the collection of different antibody molecules in an individual (with each different antibody having a different variable amino acid sequence) is called what?
|
antibody repertoire
|
|
|
what does it mean to have 'different' antibodies?
|
each different antibody has a different variable region amino acid sequence which is NOT dependent on an antigen
|
|
|
what is the genetic mechanism of antibody variability?
|
gene rearrangement
|
|
|
what is another term for gene rearrangement?
|
somatic recombination
|
|
|
what is another term for somatic recombination?
|
gene rearrangement
|
|
|
what are the general features of gene arrangement?
|
variable regions, joining regions, and constant regions
|
|
|
what is the process of gene rearrangement?
|
a loop forms bring a variable region in contact with a joining region, a circle of DNA is excised and cut edges of gene are spliced (with nucleotide insertions), to form a functional gene
|
|
|
what does gene rearrangement produce?
|
lymphocytes that each have different rearrangements and insertions
|
|
|
can germline configurations of genes encoding B cell and T cell receptors be transcribed?
|
no, gene rearrangement must occur first
|
|
|
how many variable regions are there at λ light chain locus?
|
29-33
|
|
|
how many variable regions are there at κ light chain locus?
|
31-36
|
|
|
how many variable regions are there at heavy chain locus?
|
38-46
|
|
|
how many constant regions are there at heavy chain locus?
|
9
|
|
|
how many constant regions are there at λ light chain locus?
|
4-5
|
|
|
how many constant regions are there at κ light chain locus?
|
1
|
|
|
when are Ig gene segments rearranged?
|
during B cell development
|
|
|
what is rearranged during B cell development?
|
Ig gene segments
|
|
|
Ig gene rearrangements BLANK antigen-dependent?
|
is not
|
|
|
light chain germline DNA undergoes gene rearrangement into what?
|
VJ-joined rearranged DNA
|
|
|
heavy chain germline DNA undergoes gene rearrangement into what?
|
VDJ-joined rearranged DNA
|
|
|
what flanks V, J, and D genes?
|
recombination signal sequences
|
|
|
where are recombination signal sequences found?
|
flanking V, J, and D genes
|
|
|
what are recombination signal sequences?
|
areas of the genome recognized by enzymes that induce recombination
|
|
|
where are gene segments joined?
|
at recombination signal sequences
|
|
|
what happens at recombination signal sequences?
|
gene segments are joined
|
|
|
what is a RAG?
|
recombination activating genes
|
|
|
what is a term for recombination activating genes?
|
RAG
|
|
|
what does RAG do?
|
recognizes recombination signal sequences (marks, doesn't ligate)
|
|
|
what can be added at the site of V-J or V-d-J joinings?
|
single nucleotides
|
|
|
what does the addition of single nucleotides at the site of V-J or V-D-J joining cause?
|
junctional diversity
|
|
|
what is junctional diversity?
|
variations in the nucleotied at which V-J or V-D or D-J genes are joined
|
|
|
how does junctional diversity occur?
|
the RAG complex cleaves the recombination signal sequences yielding DNA hairpins, opens the hairpins by nicking one strand of the DNA, generation palindromic P-nucleotides, N-nucleotides added , strands paired, unpaired nucleotides are removed by exonuclease, and gaps are filled by DNA synthesis and ligation to form coding joint
|
|
|
what does N nucleotide stand for?
|
non-template nucleotides
|
|
|
what does adding N-nucleotides cause?
|
random variability due to slight differences (junctional diversity)
|
|
|
what is another mechanism of antibody variability?
|
any heavy chain can associate with any light chain to form the Fab portion of antibody that binds antigen
|
|
|
once Ig gene rearrangement is complete, variable gene usage BLANK change
|
does not
|
|
|
Can a B cell genes change once Ig gene rearrangement is complete?
|
No
|
|
|
Each B cell can synthesize what?
|
many copies of only one heavy chain and only one light chain
|
|
|
what is the result of gene rearrangement?
|
a pool of B cells that each has a different receptor for antigen and after division and differentiation into plasma cells, each secretes different antibodies
|
|
|
in serum protein electrophoresis, why is γ-globuling fraction heterogeneous?
|
each different antibody has a different ammino acid sequence and thus a different overall charge
|
|
|
how is Ig gene rearrangement in B cell leukemia detected?
|
The probe for C region and V region will be at the same level, rather than separate because gene rearrangment brings them together, while germlines will keep them separate, if a single dominant band occurs after Ig gene PCR indicates B cell leukemia and a single dominant band after TCR gene PCR indicated T cell leukemia
|
|
|
what does TCR stand for?
|
T cell receptor
|
|
|
what does PARR stand for?
|
PCR for Antigen Receptor Rearrangement
|
|
|
what is myeloma?
|
a tumor of an antibody producing plasma cell
|
|
|
a tumor of an antibody producing plasma cell is called what?
|
myeloma
|
|
|
what do myeloma cells produce?
|
myeloma proteins
|
|
|
what are myeloma proteins?
|
antibody molecules produced by myeloma cells
|
|
|
what produces myeloma proteins?
|
myeloma cells
|
|
|
why is myeloma a monoclonal gammopathy?
|
plasma cells developing after division and differentiation of a single B cell produce the same antibody
|
