Post on 06-Sep-2015
description
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 genesB 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 SelectionB 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)*
B cell differentiation
Affinity MaturationSomatic Hyper mutationAntigen selectionClass switchingPlasma cells Memory cells*
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 cellsReferences
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