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Chapter 8. B. T. B/T cell development. Innate immunity. Pattern recognition. Adaptive immunity . B/T cells. BCR/TCR: epitope recognition. Gene rearrangement of AgR. Gene rearranged receptors. Structure. BCR/TCR: Ag recognition. Extracellular Ag. Epitope.
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Chapter 8 B T B/T cell development
Innate immunity Pattern recognition Adaptive immunity B/T cells BCR/TCR: epitope recognition Gene rearrangement of AgR
Gene rearranged receptors Structure BCR/TCR: Ag recognition Extracellular Ag Epitope MHC-restriction Intracellular Ag
Techniques One cell one Ag-specific receptor Clone 細胞差異 Fate T/B: Rearranged AgR T: MHC restriction
Adaptive immunity Four characteristics 1. Antigen specificity 2. Diversity 3. Immunological memory 4. Self tolerance Foreign (non-self) Ag Self Ag (encoded by the host’s genome)
Aim of development Production of AgR • Productive rearranged AgR 2. Functional Ag recognition 3. Self tolerance Self Ag? MHC-restricted?
Hematopoiesis 2 Central lymphoid organs Microenvironment Commitment Productive rearrangement? Cell survival & death
B-cell development T-cell development Positive & negative selection Fate Self antigen Before or after gene rearrangement of AgR ?
Development of B cells Microenvironment Adhesion molecules Chemokines & R Cytokines & R Stromal cells
The dependence on bone marrow stromal cells Early stages Cell-cell interaction B cell commitment SDF-1 Migration Constitutive production
Gene rearrangement Loop
Ig gene rearrangement & B cell stages Proliferation
Cell survival or death Allelic exclusion One cell one Ag-specific receptor
Self-reactivity Fate The presence of autoreactive lymphocytes in periphery
Low frequency of Ag-specific B cells
T B-cell development B cell commitment BCR rearrangement Cell survival & death (BCR, self tolerance) Stromal cell-dependent (Spatial regulation) Temporal regulation of protein expression Proteins: receptors, cytokines, TS factors, recombinase, .. Protein-regulated gene rearrangement One cell one AgR Cell survival & death
T cell development Self MHC restriction Self tolerance Cells Microenvironment
Epithelial cell network: thymic stroma Thymus
abTCR or gdTCR ? b
Developmental control of gd T cells Ordered sequence
T cell commitment R: Notch 1
T cell development Gene rearrangement Cortex Medulla Positive selection : MHC restriction Negative selection : Self tolerance
T cell development MHC Positive selection : MHC restriction Negative selection : Self tolerance
MHC Gene locus
親代來源 H-2k 基因
Analyze all the possible types of MHC class I and II restriction for CD4 T and CD8 T cells developed in an MHCbxk F1 hybrid mouse.
Ch6 section 6-12 MHC: co-dominant d/k
TCR: MHC restriction MHC polymorphism 個體獨特性 MHC haplotype Ch6 section 6-12
MHC polymorphism Alleles / locus Formula: 100(DPa) X 100(DPb) X 100(DQa) X 100(DQb) X 100(DRa) X 100(DRb) X 100(A) X 100(B) X 100(C) =1018
MHC I Peptide presented on MHC I/II MHC II
MHC-binding ability of peptides Multiple epitopes
Positive selection : MHC restriction H-2k Self MHC restriction 3 2
d/k Self MHC restriction 3 6 2 8