ImmunogeneticsImmunogenetics

Sadegh Babashah, PhDDepartment of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University

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History

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Infection begins inflammatory response

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Clonal selection hypothesis

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Schematic representation of Ag receptors

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Isolation of TCR molecule

1. Production of Mab against various T-cell clones

2. Screening these antibodies against different T-cell clones

3. Finding clone-specific Mab

4. Isolation of TCR by clone-specific Mab

A. Monoclonal antibody (Mab)

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B. Cloning TCR genes

1. Isolation of mRNA from T-cell

2. Synthesis of cDNA

3. Hybridization of cDNA with B-cell mRNA for Isolation of T-cell specific cDNA by

4. Southern blotting with genomic DNA for finding rearranged cDNA

5. Rearranged cDNA is TCR gene

Isolation of TCR molecule

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Production ofLymphocyte Ag receptors

(BCR, TCR)

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Recombinase complex involved in V(D)J recombination:

- Lymphocyte-specific recombinase (RAG-1 & RAG-2)

- General enzymes (e.g. Ku heterodimer)

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The Non-homologous End-Joining repair Process (NHEJ)

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T-cell receptor

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α and β locuses in T-cell receptor gene

TCRα:

TCRβ:

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Rearrangement in T-cell receptor gene

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تنوع ترکیبی + تنوع تلفیقی

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TCRα:

TCRβ:

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TCRα:

TCRβ:

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TCRα (containing TCRδ):

TCRγ:

δ-chain locus………..…..

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TCRα (containing TCRδ):

δ-chain locus………..…..

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Pantameric IgM

Dimeric IgA

x 900’000

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Thank you for listening, any comments?