- early fetal B cell development occurs in this organ from hematopoietic stem cells (HSC)

Fetal Liver

Secondary Lymphoid Organs

- cytokine receptors that orchestrate B cell development

Flt, IL-7 receptor

- B cell lineage specific transcription factors

EBF, PAX-5

- Genes that control Ig gene rearrangement

RAG-1, RAG-2, TdT

- these type of cells found in bone marrow influence (dependency) B cell development

- cytokines (Flt ligand, IL-7) are produced/recepted by these

Stromal Cells

- B cells (and blood) originate from these cells that are initially found in the fetal liver

Hematopoietic stem cells (HSCs)

- this protein surface marker is found on HSCs and most progenitor cells

CD34

- this protein surface marker is specific for the B lineage and the point at which they begin the pro-B stage

CD19

- this drug is used to deplete B cells in the circulation by means of complement dependent cytotoxicity, antibody-dependent cytotoxicity, and apoptosis

anti-CD20 (Rituximab)

- respectively what heavy chain rearrangement occurs in the early and late pro-B cell stage

D-->J then V-->DJ

- this process fails to give rise to a functional Ig protein (sometimes because of a premature stop codon)

Nonproductive rearrangement

- the three primary components of the pre-B cell receptor

cmew, surrogate light chains (invariant), Iga and Igb

- this process that is stimulated by a pre-BcR signal results in only one IgH chain allele expressed (single specificity)

- helps promote survival/homogeny

Allelic exclusion

- in this stage pre-B cells undergo rapid cell division until is halted so that the light chains can rearrange (V-->J)

- there are two substages (Large-->Small)

Pre-B cell stage

- this domain is responsible for mediating the process that Iga and Igb initiate following antigen binding

immunoreceptor tyrosine-based activation motif (ITAM)

cmew, light chain (k or l), and Iga and Igb

- this stage of B cell development could contain transitional stages of development (IgM only) after the BCR is expressed

Immature B cell stage

- site of B cell maturation

Spleen

- during this stage of B cell development splicing allows for IgD to be produced as well as IgM

Mature (Naive) B cell stage

- the two checkpoints that occur during B cell development before and after the pre-B cell stage check for proper expression of these two components

heavy chain (1st) and light chain (2nd)

- these cells express CD5 and arise in embryonic development

- do not have somatic hypermutation or memory

- T-independent

- dominant B cells in lung and abdominal cavities

- maintained in adults by self renewal (mitosis?)

B-1 Cells

- this surface protein can be a marker of activated B cells, "transitional" B cells, and chronic lymphocytic leukemia

CD5

- cells that generate IgM+ memory cells

- resemble mice B1 cells in specificity and function

Marginal Zone B cells

- percentage of B cells that are autoreactive at the immature B cell stage and must be eliminated

75%

- the two alternatives that will make an autoreactive B cell unproductive following self-antigen recognition

- binds multi-valent surface antigen and soluble antigen respectively

Clonal deletion & Anergy (long term inactivation)

- the process by which light chains can rearrange after their initial arrangement to be able to avoid death or inactivation following self-antigen recognition

Receptor editing

- upregulatation of expression of receptors for this cytokine helps to promote survival by upregulation expression of BCL-XL following a lack of autoreactivity

BAFF (B cell activating factor)

- the current difference between central and peripheral tolerance is that this process does not occur peripherally

Receptor editing

- direct homing of B cells in the blood to secondary lymphoid tissues through T cell zones and into primary lymphoid follicles (germinal centers)

Chemokines

- these cells are not hematopoietic in origin and touch B cells with their long processes

- make up network of stromal cells in primary lymphoid follicles

Follicular dendritic cells

- B cell responses to most antigens are thymus dependent and require these type of cells

CD4 helper T cells

- activated B cells that differentiate into plasma cells and produce IgM are found in this location in the lymph node

medullary cords of secondary lymphoid tissue

- this cell type makes antibodies but does not have any surface receptors of its own

- found in medullary cords of secondary lymphoid tissue

plasma cell

- primary lymphoid follicles that contain activated B cells differentiate into this that contains a germinal center

secondary lymphoid follicle

- the germinal center has B cells that become these type cells that proliferate and undergo somatic hypermutation and class switching

- become centrocytes after maturity

Centroblasts

Affinity Maturation

- persist for a long period of time with only intermittent stimulation in the primary follicle

- quicker/stronger response to antigen than with the primary response

Memory B cells

- the conversion B cells into tumor cells in Burkitt's lymphoma and other non-B cell tumors comes from mistakes in gene splicing during Ig gene rearrangement that result in this

Translocations

- plasma cell tumors that propagate in the bone marrow

Myeloma

- tumors derived from mature naive B cells

- retain the characteristic of the mature naive B cell during abnormal growth

Follicular center cell lymphoma