1. Recall the cells of the immune system.

2. To illustrate the life history of B cell.

3. To demonstrate the stages in the developmental process of B cell maturation

B cell Maturation

Bone MarrowIG RearrangementsPre B Cell ReceptorSelection of Immature Self Reactive B cellsNegative SelectionRescue Editing of Light chain genes

B Cell Activation & Proliferation

T dependent and T independent antigensOrigins of activating signalsTransduction of activating signalsB cell co-receptor complexT helper cellsFormation of T-B conjugateMediation by CD-40Induction of Progression signalsNegative Selection

B cell Activation

B cell Activation

Thymus-dependent (TD) antigensB cell required direct contact with TH cellB-2 B cells, majority of B cellsThymus-independent antigens (TI)These antigens activate B cells by pattern recognition receptors (bacteria that might be in high amount)Type I (TI-1) lipopolysaccharideType 2 (TI-2) highly repititous molecules (bacterial flagella)

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B cell differentiation

Affinity MaturationSomatic Hyper mutationAntigen selectionClass switchingPlasma cells Memory cells

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4. Criticize the factors involved in the B cell development and maturation.

Regulation

Humoral and cell-mediated branches must be heavily regulatedCytokines play important roleAntigenic competitionPrevious encounter with antigen can render animal tolerant or may result in formation of memory cellsPresence of antibody can suppress response to antigenSome vaccines are given to babies after maternal IgG (that was transferred across placenta) has left systemVaccination before this will prevent proper response and development of long-lasting memory cells

References

Thomas J. Kindt, Barbara A. Osborne and Richard A. Goldsby, Kuby Immunology, W.H. Freeman & Company, 2006.Melchers F and Rolink A, B-Lymphocyte Development and Biology, Fundamental Immunology, 4th Edition, Lippincott-Raven Publishers, 1999