Term
| On what chromosomes are the genes for kappa, lambda, and heavy chains of Ig located? |
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Definition
Heavy - Chr. 14
Kappa - Chr. 2
Lambda - Chr. 22 |
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Term
| Where are recomination recognition sequences (RSS) located? |
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Definition
3' to V gene segments
5' to J gene segments
Both sides of D segments |
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Term
| What is Junctional diversity? How does it lead to more variability? |
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Definition
Junctional diversity - occurs when recombinases leave a few nucleotides from RSS in coding gene region.
Diversity/variability occurs when p-nucleotide addition of nucleotide happens to fix hairpin loop left after recombinase cut.
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Term
| What is N-nucleotide addition? Will both heavy and light chains undergo N-nucleotide addition? |
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Definition
N-nucleotide addition occurs before ligation when terminal deoxynucleotidyl transferase (TdT) adds 1-15 random bases.
Only heavy chains undergo N-nucleotide addition, because TdT is expressed early on in B-cell maturation. |
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Term
| At what region does junctional diversity, P-nucleotide addition and N-nucleotide addition occur? |
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Definition
| CDR3 (antigen-binding region for Ig) |
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Term
| True or False. Once RAG is done with its job, it will be inactivated forever. |
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Definition
False.
RAG can be reactivated if a B-cell fails to make a light-chain on the first try
Or if the B cell membrane Ig is self-reactive. |
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Term
| Signals from which molecules deactivate RAG? |
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Definition
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Term
| What makes the surrogate light chain? |
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Definition
| Genes from V pre-B and lambda-5 (aka Pre-B receptor) |
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Term
| What is Burkitt's Lymphoma? What causes it? |
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Definition
highly-aggressive B-cell lymphoma
Cause: tranlocatons of Chr. 8 (protooncogene myc)
to Chr. 14, 2 or 22 (where H, kappa and lambda chains are)
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Term
| What dyscrasia is caused by a chromosome translocation and presents as mature B cells in the blood? |
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Definition
| Chronic lymphocystic leukemia (CLL) is mature B cells (CD5+) or B-1 cells in blood. Prognosis if no somatic hypermutaition is 3-4years |
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Term
| What dyscrasia is caused by a chromosome translocation and presents as mature B cells in lymph nodes and other tissues? |
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Definition
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Term
| What is multiple myeloma? How is it related to primary amyloidosis? |
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Definition
Multiple myeloma is a plasma cell malignancy, which produces too much monoclonal antibodies.
Primary amyloidosis
Multiple myeloma causes extra light chains in the blood and ECM which forms amyloid plaques. These plaques build up in extracellular spaces in systemic tissues and lead to multiple organ failure. |
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Term
| What causes secondary amyloidosis? |
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Definition
Chronic inflammatory conditions (i.e. TB)
or familial Mediterranean fever (hereditary) |
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Term
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Definition
| Abnormal deposition of hyaline, proteinceous material laid down extracellularly that result in atrophy, loss of cells and organ failure. |
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Term
| What is Waldenstrom's macroglobulemia? |
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Definition
plasma cells and lymphocytes secrete too much IgM.
Causes primary amyloidosis, visual impairment, neurologic problems, bleeding, hyperviscosity |
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Term
| What can cause local amyloidosis? |
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Definition
Alzheimer's (amyloid plaques in brain)
type II DM (amyloid in pancreatic islets_ |
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Term
| What dyscrasia is caused by a translocation of chromosomes 12:21, and presents as malignant Pre-B cells in blood and bone marrow? |
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Definition
| Acute lymphoblastic leukemia |
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Term
| What dyscrasia involes the Philadelphia chromosome (9:22) bcr/abl translocation and encodes a novel tyrosine kinase? |
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Definition
| Chronic myelogenous leukemia |
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Term
| What is heavy chain disease? |
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Definition
| Malignancy where heavy chain does not associated with light chain. Light chains found in urine as Bence Jones proteins. |
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Term
| Compare B cells and T cells - what is a primitive first-appearing cell? What is considered mature? What are the associated signal molecules? |
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Definition
Primitive first appearing cell:
- B cell - CD5+ cell
- T cell - gamma/delta T cell
Mature cell:
- B cell - CD5- cell
- T cell - alpha/beta T cell
Associated signal molecules
- B cell - Ig alpha/beta
- T cell - CD3 |
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