章节大纲

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  • 抗原识别

    lesson content

    How does one recognize another cell as foreign?
    ::一个人如何承认另一个细胞是外国细胞?

    Since a cell can only recognize markers on the outside of another cell, it must be that way. Here we have cytotoxic T- lymphocytes attacking migrating cells. The cytotoxic T cells recognize the cancer cells as foreign due to antigens on the outside of the cancer cell.
    ::由于细胞只能识别另一个细胞外部的标记, 必须是这种方式。 我们这里有细胞毒性T淋巴细胞攻击迁移的细胞。 细胞毒性T细胞承认癌症细胞是外来的, 因为癌症细胞外的抗原。

    Antigen Recognition
    ::抗原识别

    B and T cells do not actually recognize and respond to , but rather they respond to the antigens carried by the pathogens. Antigens are molecules that the immune system recognizes as non-self. Any protein that can trigger an immune response because it is foreign to the body is called an antigen. Antigens include proteins on pathogens, cancer cells, and the cells of transplanted organs .
    ::B和T细胞实际上并不识别和响应病原体携带的抗原,而是对病原体携带的抗原作出反应。抗原是免疫系统确认为非自我的分子。任何蛋白可以触发免疫反应,因为它与身体无关的蛋白都被称为抗原。抗原包括病原体、癌症细胞和移植器官细胞上的蛋白质。

    Antigen Receptors
    ::抗原受体

    Both B and T cells can “recognize” specific antigens because they have receptor molecules on their surfaces that bind to particular antigen molecules or pieces of antigen molecules. As shown in  Figure , the fit between a receptor molecule and a specific antigen is like a lock and key. Receptors on each B or T cell recognize and bind to just one type of antigen. The makes lymphocytes with receptor sites for a huge number of possible antigens that may be encountered throughout a person’s life.
    ::B型和T型细胞都可以“承认”特定抗原,因为它们表面有受体分子,与特定抗原分子或抗原分子的碎片相连。如图所示,受体分子和特定抗原的相容性就像锁和钥匙一样。每个B型或T型细胞的受体识别并只与一种抗原捆绑在一起。它为一个人一生中可能遇到的大量抗原制造了带有受体点的淋巴细胞。

    lesson content

    A receptor molecule on the surface of a lymphocyte binds to a particular antigen like a lock and key.
    ::淋巴细胞表面的受体分子像锁和钥匙一样与特定抗原结合。

     

    Activation of Lymphocytes
    ::淋巴细胞活动

    Before lymphocytes can function, they must be activated. Activation occurs the first time the cells encounter their specific antigens after leaving the red bone marrow or thymus . Until these circulating B and T cells have been activated, they are called “naïve” cells. 
    ::在淋巴细胞起作用之前,必须激活它们。细胞在离开红骨髓或胸腺后首次遇到其特定抗原时,即开始激活。在这些循环的B和T细胞被激活之前,它们被称为“神经”细胞。

    Summary
    ::摘要

    • B and T cells do not actually recognize and respond to pathogens, but rather they respond to the antigens carried by the pathogens.
      ::B和T细胞实际上并不识别病原体并对病原体作出反应,而是对病原体携带的抗原作出反应。
    • Both B and T cells can “recognize” specific antigens because they have receptor molecules on their surfaces that bind to particular antigen molecules or pieces of antigen molecules.
      ::B型和T型细胞都可以“承认”特定抗原,因为它们的表面有受体分子,与特定的抗原分子或抗原分子片结合。
    • Before lymphocytes can function, they must be activated. Until circulating B and T cells have been activated, they are called “naïve” cells.
      ::淋巴细胞在起作用之前必须被激活。在循环的B和T细胞被激活之前,它们被称为“神经”细胞。

    Review
    ::回顾

    1. How do B cells and T cells recognize and respond to pathogens?
      ::B细胞和T细胞如何识别和应对病原体?
    2. How many pathogens can each B or T cell recognize?
      ::每个B或T细胞能识别多少病原体?