医学免疫学mhc七年制 课件.ppt

Major Histocompatibility Complex
Department of Immunology
Tianjin Medical University
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OUTCOMES ?
What are Histoiscovery of the Mouse MHC
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Mice Chromosome 17 contains the major histocompatibility complex(H-2 gene).(1948)
Humans Chromosome 6 contains the major histocompatibility complex(MHC).(1954)
Human MHC molecules are called the human leukocyte anitgens (HLA) and are equivalent to the mouse H-2 molecules
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MHC（H-2）/HLA复合体
(1980NP)
Benacerraf（1920～）
Snell（1903～1996）
Dausset（1916～）
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Schematic maps of MHC loci
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Human HLA complex and Gene products
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Properties of MHC - Polymorphism （多态性）
Polymorphism: presence of multiple alternative forms (alleles) of a gene.
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Polymorphism allows the population can handle a variety of pathogens.
Help peptide loading
Present antigen peptides
to CD4+ T cells
Present antigen peptides
to CD8+ T cells
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The set of alleles that an individual carries at each locus on a single chromosome.
Haplotype is transmitted as a single unit in most cases.
Properties of MHC– Haplotype(单元型）
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MHC genes are co-dominant at the cellular level, that is, both maternal and paternal gene products are expressed in the same cells. There is no allelic exclusion in their expression.
Properties of MHC – Codominance（共显性）
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Properties of MHC – Linkage disequilibrium（连锁不平衡）
The difference between the frequency observed
for a particular combination of alleles and that
expected from the frequencies of the individual
alleles
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§2 MHC Molecules
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a1
MHC Class I
a chain
ß2 Microglobulin (invariant but essential)
a2
a3： binds CD8 molecule on T cells
peptide binding site [groove];
1. Structure and Properties
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1. Structure and Properties
MHC Class II
a chain
ß chain
a1
ß1
ß2： binds CD4 molecule on T cells
a2
peptide binding site (groove)
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Structure of MHC molecules
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