C5 - LESSON 2A: STAGES OF B CELL DIFFERENTIATION Flashcards
Antigen Independent Phase
Pro-B Cells
Pro-B Cells Important Growth or Transcription factors for differentiation
E2A, EBF, PAX and Interleukin-7
Pro-B Cells Distinctive Markers
CD19, CD45R, CD43, CD24 and c-Kit
Pro-B Cells Intracellular Proteins
TdT-important in antibody construction
RAG-1 and RAG-2 codes for antibody production
Begins at the synthesis of the heavy chain part of antibody
Pre-B Cell
Pre-B Cell Markers and proteins lost during process:
CD43, c-Kit and TdT
Pre-B Cell Surface Receptors
u chain, surrogate light chain and 2 very short chains
Pre-B cell receptor
STAGES OF B CELL DIFFERENTIATION
Immature B Cell Distinguishing characteristic
Presence of complete IgM molecule in the cell surface
Immature B Cell Other Surface markers
CD21, CD40, MHC Class II molecule
Immature B Cell 2 Destinations
Programmed cell death
Cells leave the bone marrow and seed the lymphoid organs
Takes place in the spleen
Marginal Zone B cell
Lymph nodes and Other SLO
Follicular B Cell
Mature B Cell Distinguishing characteristic
Presence of IgM and IgD- same specificity for a particular antigen or group of antigens
Mature B Cell
Antigen-dependent phase
Antigen-dependent activation
Primary Follicles of Peripheral Lymphoid tissues
Identifying Marker
CD25
found on both activated T and B cells
CD25
acts as a receptor for interleukin-2 (IL-2)
CD25
- a growth factor produced by T cells
interleukin-2 (IL-2)
Spherical or ellipsoidal
Plasma Cells
Plasma Cells Characterized by
Abundant cytoplasmic Immunoglobulin
Nucleus: eccentric or oval (heavily clamped chromatin-stains dark)
Abundant ER and well-defined golgi zone
Present in the germinal center of the peripheral lymphoid organ
Plasma Cells
Found in germinal layer
Memory Cells
Has longer life span
Memory Cells
Represents progeny of antigen stimulated B cells
Memory Cells
Similar in appearance with unstimulated B cells
Memory Cells
