(优选)中科院细胞与分子免疫学课程课件

5
Bubble boy disease
Antigen Receptor Gene Recombination and
Expression
1. There may be 107 or more
different T and B
lymphocyte clones in one
individual, each clone
Elucidation of the mechanisms of antigen receptor gene expression is one of the landmark achievements of mordern immunology
1 胚系理论(Germline Theory) 在胚系基因组中包含了免疫基因库，可对外界的众多 抗原发生应答，并能遗传。 What are the problems with this theory?
1. The preservation of useful specificities is called positive selection: T cells in thymus. B cells maturing are not well known.
2. Negative selection is the process that eliminates developing lymphocytes with strong binding to selfantigen.
and intracellular molecules that participate in lymphocyte activation and effector functions.
8
Formation of Functional Antigen Receptor Genes in B and T Lymphocytes
4. In more mature lymphocytes, complete antigen receptor expressed, which promote 6 cell maturation.
Selection Process That Shape the B and T Lymphocyte Repertoires
produce one specific
antigen receptor.
2. By somatic recombination, each individual does not need to have such enormously genes.
3. During the pre-B cell or preT cell stage, an immature form of antigen receptor is formed which to transduce signals to induce further maturation
1. Lineage commitment and proliferation
2. Expression of antigen receptor genes
3. Selection of the mature repertories
3
Early maturation:
1. Pluripotent stem cells give rise to all lineages of blood cells
2 体细胞突变理论（Somatic Mutation Model） 基因组中的免疫球蛋白基因相对较少，抗体的多样性 主要是由体细胞基因突变引起的。 What are the problems with this theory?
9
胚系理论与体细胞突变理论所遇到的问题
1 胚系理论 1）基因的种类少于抗体的多样性 So many specificities – so few genes
（优选）中科院细胞与分子免 疫学课程课件
Chapter 7 Lymphocyte Maturation and Expression of Antigen Receptor Genes
2
General Features of Lymphocyte Maturation
The maturation of B and T lymphocytes consists of :
7
Acquisition of Functional Competence
1. B cells can secrete antibodies. 2. T cells can differentiate into distinct
subsets of T cells. 3. Expression of a variety of cell surface
i. Transcription factors
ii. Growth factors
iii. Growth factors receptor
4
Байду номын сангаасxample 1
1.Mutated in IL-7 gene and IL-7 receptor gene have profound deficiencies in mature T and B cells.
1) It is difficult to precisely define the mechanisms by which stem cells become to the lymphoid lineage.
2) B cell: bone borrow
T cell: thymus
3) By the gene mutations in experimental animals or human patients.
2. Mutations in a chain of the IL-2 receptor g chain, leads to an immunodeficiency disease: X-linked severe combined immunodeficiency disease, bubble boy.