UC知道求高手帮忙翻译论文6
来源：百度知道 编辑：UC知道 时间：2024/06/16 21:31:02
Mature B-cells and T-cells that pass the negative selection are released from the bone marrow and thymus. Both B-cells
and T-cells continuously circulate around the body in the blood and encounter antigens for activation and evolution.
The antibodies of B-cells, which recognise harmful antigens by binding to them, are activated directly or indirectly.
When B-cell antibody receptors bind to antigen epitopes with strong affinity above a threshold, they are directly
activated. On the other hand, B-cell antibody receptors can bind to antigen epitopes with weak affinity below a
threshold. In this case, B-cells need the help of T-cells and Major-Histocompatibility Complex (MHC) molecules to be
activated.
MHC molecules have two important functions to help B-cell activation. Firstly, they bind to the fragments of
antigens specially hidden inside cells, (not visible on the cell surface) and secondly, they transport these f
and T-cells continuously circulate around the body in the blood and encounter antigens for activation and evolution.
The antibodies of B-cells, which recognise harmful antigens by binding to them, are activated directly or indirectly.
When B-cell antibody receptors bind to antigen epitopes with strong affinity above a threshold, they are directly
activated. On the other hand, B-cell antibody receptors can bind to antigen epitopes with weak affinity below a
threshold. In this case, B-cells need the help of T-cells and Major-Histocompatibility Complex (MHC) molecules to be
activated.
MHC molecules have two important functions to help B-cell activation. Firstly, they bind to the fragments of
antigens specially hidden inside cells, (not visible on the cell surface) and secondly, they transport these f
成熟B细胞和T -细胞，通过阴性选择是从骨髓和胸腺。两个B细胞
和T细胞周围不断散发体内血液中的抗原和遇到的活化和演变。
该抗体的B细胞，它认识到有害的抗原结合，都是直接或间接地激活。
当B细胞受体结合的抗体抗原表位的强烈亲和力高于阈值，它们可直接
激活。另一方面， B细胞抗体受体可以结合抗原表位与弱亲低于
开始。在这种情况下， B细胞需要的帮助下， T细胞和少将组织相容性络合物（ MHC ）分子将激活。
MHC分子有两个重要的职能，以帮助B细胞活化。首先，他们结合的碎片
特别隐蔽抗原细胞内， （不可见的细胞表面）和第二，他们运输这些碎片
在B细胞表面。当B细胞受体抗体结合抗原的亲和力较弱， MHC分子的尝试
找到一些隐藏抗原细胞内。当MHC分子找到他们时，他们运输这些表面上的B细胞。
该受体的T细胞的基因结构承认的MHC分子对B -细胞表面。因此， T细胞
可以绑定到MHC分子的B细胞的表面。当T细胞的MHC分子结合的亲和力强，它发出了一个化学信号的B细胞，使其能够激活，生长和分化。是什么使T细胞确定
在B细胞激活？一个主要的区别的B细胞和T细胞是，只有B细胞进行体细胞突变，这是一个非常高的突变，以增加它的多样性时，发达国家在骨髓中。因此， β -细胞有更多的不同和新的受体的T细胞。此外，胸腺是位于市中心，而骨
骨髓分布。因此，大多数的自我细胞通过胸腺因此否定选择是在胸腺
更可靠的比骨髓中。因此，最后决定的B细胞活化弱亲了
由T细胞。