Inaba K, Metlay J P, Crowley M T, Steinman R M
Rockefeller University, Irvington Institute, New York, New York 10021.
J Exp Med. 1990 Aug 1;172(2):631-40. doi: 10.1084/jem.172.2.631.
T cells recognize peptides that are bound to MHC molecules on the surface of different types of antigen-presenting cells (APC). Antigen presentation most often is studied using T cells that have undergone priming in situ, or cell lines that have been chronically stimulated in vitro. The use of primed cells provides sufficient numbers of antigen-reactive lymphocytes for experimental study. A more complete understanding of immunogenicity, however, requires that one develop systems for studying the onset of a T cell response from unprimed lymphocytes, especially in situ. Here it is shown that mouse T cells can be reliably primed in situ using dendritic cells as APC. The dendritic cells were isolated from spleen, pulsed with protein antigens, and then administered to naive mice. Antigen-responsive T cells developed in the draining lymphoid tissue, and these T cells only recognized protein when presented on cells bearing the same MHC products as the original priming dendritic cells. In contrast, little or no priming was seen if antigen-pulsed spleen cells or peritoneal cells were injected. Since very small amounts of the foreign protein were visualized within endocytic vacuoles of antigen-pulsed dendritic cells, it is suggested that dendritic cells have a small but relevant vacuolar system for presenting antigens over a several day period in situ.
T细胞识别与不同类型抗原呈递细胞（APC）表面的MHC分子结合的肽段。抗原呈递的研究大多使用原位致敏的T细胞，或体外长期刺激的细胞系。使用致敏细胞可为实验研究提供足够数量的抗原反应性淋巴细胞。然而，要更全面地理解免疫原性，就需要开发系统来研究未致敏淋巴细胞，尤其是原位未致敏淋巴细胞的T细胞反应的起始过程。本文表明，利用树突状细胞作为APC可在原位可靠地使小鼠T细胞致敏。从脾脏分离树突状细胞，用蛋白质抗原脉冲处理，然后给予未致敏小鼠。抗原反应性T细胞在引流淋巴组织中产生，并且这些T细胞仅在呈递于与原始致敏树突状细胞具有相同MHC产物的细胞上时才识别蛋白质。相比之下，如果注射抗原脉冲处理的脾细胞或腹腔细胞，则几乎看不到或根本看不到致敏现象。由于在抗原脉冲处理的树突状细胞的内吞泡中可见极少量的外源蛋白质，因此提示树突状细胞具有一个小但相关的泡状系统，用于在原位在数天时间内呈递抗原。
