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The immune repertoire, is defined as, the number of different sub-types an organism's immune system makes, of any of the 6 key types of protein, either immunoglobulin or T cell receptor. In most vertebrates, immune systems have 6 key types of proteins, which help the immune system recognise viruses, germs, etc. The 6 main types are: immunoglobulins (2), and T cell receptors (4). Immunoglobulin proteins consist of 2 parts, a light chain and a heavy chain. T cell receptors come in 4 types, labelled alpha, beta, gamma and delta. In an organism, each of the 6 types of protein, in fact consists of a large number of sub-types, all differing slightly from each other. In one organism, There can be tens of thousands, or millions of different sub types of each of the 6. The differences are not obvious, and require complex research to detect, e.g. DNA sequencing, or antigen binding tests. Every day, we are exposed to a wide range of disease causing organisms. thus, how well our immune system is able to detect them—depends on how many sub types of the proteins, it is able to produce. An immune system that produces a wide variety, will likely have one or two subtypes that recognise any germ we are exposed to. An immune system that produces just a few, will likely miss or "not see" certain germs or viruses—and these could then go on, unchallenged, to cause disease. Immune repertoire is defined, as the number of sub-types that exist in an organism's immune system, of one or other of the 6 key types of proteins, in a certain "compartment" of the immune system (i.e. a certain set of cells from the immune system). == How large is the immune repertoire? == A few researchers have measured immune repertoires for humans, but as the task until recently was technically difficult, it was seldom attempted. Estimates will depend on the precise type or 'compartment' of immune cells studied; and the protein studied. * Pasqual et al. JEM (2002) publication showed that the expected billions of combinations were over-estimated. The authors described the genetic spatio temporal rule which governs the TCR locus rearrangements and were able to demonstrate for the first time that the V(D)J rearrangements are not random, hence resulting in a smaller V(D)J diversity.〔http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2194109/〕 * Dare et al. (2006) estimated repertoire for TCR gamma genes, in CD8+CD45RO+ memory T cells in blood, as 40,000–100,000 sub-types, in 3 healthy young adults. In healthy older adults, (over 75) they found smaller repertoires, being 3,600; 5,500; 14,000 and 97,000. * Artsila et al. (1999) estimated repertoire for TCR alpha and TCR beta in CD4+/CD8+ T-cells, as approx 100,000. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Immune repertoire」の詳細全文を読む スポンサード リンク
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