Term
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Definition
In bone marrow
Make specific contacts with developing B Cells
Produce growth factors |
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Term
Movement of B Cells as they mature |
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Definition
1. Subendosteum to central axis of marrow cavity.
2. Secondary Lymphoid Organ.
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Term
First Stage: Early Pro B Cell |
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Definition
E2A and EBF cause genes to turn on (RAGs, surrogate L chain, and Pax-5).
H chain gene rearrangement of DJ.
Go onto second stage even if they fail here |
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Term
Second Stage: Late Pro B Cell
Checkpoint 1 |
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Definition
Rearrangement of V with DJ.
Testing of Surrogate L Chain:
Surrogate Light Chain (VpreB and Lambda-5) tested on membrane of E.R.
Together with the heavy chain and IgAlpha and IgBeta it makes the Pre-B Cell Receptor
Has TWO chances |
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Term
Third Stage: Large Pre B Cell |
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Definition
Heavy Chain Rearranged
Allelic Exclusion
Rounds of cell division
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Term
Fourth Stage: Small Pre-B Cell
Checkpoint 2 |
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Definition
L Chain Rearrangement begins
85% success rate
Recombination will occur until there is a functional chain or it runs out of choices |
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Term
Fifth Stage: Immature B Cells |
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Definition
Receptors on cell surface
Express IgM
Need to be self tolerant
Make IgM AND IgD (more IgD on cell surface)
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Term
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Definition
Determines B Cell Path rather than T Cell path |
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Term
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Definition
Binds to SCF
Causes B Cell Proliferation of Large Pre B Cells |
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Term
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Definition
Genes that cause cancer when perturbed |
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Term
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Definition
Translocation of MYC gene on chromosome 8 with a chain gene
requires more than just this mutation to be expressed
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Term
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Definition
Express CD5
make up 5% of B cells in humans
few have N nucleotides in H chain (All B2 cells have them)
Polyspecific
Self Renewing |
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Term
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Definition
Successive rearrangements of L Chains in B Cells to find one that is not self reactive
Occurs with Multivalent self antigens
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Term
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Definition
B Cells that fail to make a functional receptor or are self reactive are signaled to die |
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Term
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Definition
State of developmental arrest
Self reactive with monovalent self antigens
IgM is retained inside the cell
Allowed to enter periphery if not already there |
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Term
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Definition
DNA is attacked by B Cells because escaped tolerance |
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Term
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Definition
Need access to lymphoid follicles to mature:
1. Enter organ via High Endothelial Venules (HEV). Attracted by CCL21 (binds to CCR7) & CCL19.
2. Follicular Dendritic Cells secrete CXCL13 to attract B Cell into follicle. |
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Term
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Definition
Protein on B Cells that helps maintain FDC integrity when they interact.
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Term
B Cell Activating Factor (BAFF) |
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Definition
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Term
Secondary Lymphoid Follicle |
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Definition
Activated mature B Cells congregate here and form a germinal center.
B Cells become large dividing Centroblasts ---> Centrocytes which have undergone somatic hypermutation and class switching
Some become memory cells |
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Term
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Definition
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Term
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Definition
B Cell with lost receptor
Known as Reed-Sternberg cells |
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Term
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Definition
Immature B Cells enter the secondary lymphoid organ |
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Term
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Definition
FDC attract immature B Cells into follicles |
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Term
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Definition
Chemokines that attract Immature B Cells into lymphoid organ via HEV |
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