Kanamori S, Walsh W D, Hansen T H, Tse H Y
J Immunol. 1984 Dec;133(6):2811-4.
To further delineate the functional defects of bm12 mice in antigen presentation, we analyzed antigen-specific T lymphocyte clones derived from B6 or bm12 for their ability to recognize antigens presented on either B6 or bm12 APC. Both complex antigens, such as PPD and GAT, and restricted antigens, such as beef insulin, were used. Our results indicate that for complex antigens, more than 50% of the B6 T lymphocyte clones recognized antigens only if presented by B6 APC, whereas the rest could not discriminate B6 from bm12 APC. Similarly, bm12 T lymphocyte clones responding to complex antigens could be divided into two groups depending on the sources of the APC. We have also isolated B6 T lymphocyte clones specific for the more restricted antigen, beef insulin, to which bm12 failed to respond. All B6 T lymphocyte clones could be stimulated only with B6 APC and not with bm12 APC. These data are consistent with the notion that there are antigen-specific association sites on the Ia molecule, and that complex antigens have more than one such association site. Furthermore, these studies demonstrate that both the gain and loss determinants associated with the bm12 mutation are recognized by a significant number of bm12 and B6 antigen-specific T lymphocyte clones, respectively, thus defining the importance of this region of the A beta polypeptide chain in antigen presentation.
为了进一步阐明bm12小鼠在抗原呈递方面的功能缺陷，我们分析了源自B6或bm12的抗原特异性T淋巴细胞克隆识别在B6或bm12抗原呈递细胞（APC）上呈现的抗原的能力。使用了两种复合抗原，如PPD和GAT，以及受限抗原，如牛肉胰岛素。我们的结果表明，对于复合抗原，超过50%的B6 T淋巴细胞克隆只有在由B6 APC呈递时才能识别抗原，而其余的则无法区分B6和bm12 APC。同样，对复合抗原作出反应的bm12 T淋巴细胞克隆可根据APC的来源分为两组。我们还分离出了对更受限抗原牛肉胰岛素特异的B6 T淋巴细胞克隆，bm12对此无反应。所有B6 T淋巴细胞克隆只能被B6 APC刺激，而不能被bm12 APC刺激。这些数据与以下观点一致：Ia分子上存在抗原特异性结合位点，复合抗原具有不止一个这样的结合位点。此外，这些研究表明，与bm12突变相关的获得性和缺失性决定簇分别被大量bm12和B6抗原特异性T淋巴细胞克隆识别，从而确定了Aβ多肽链这一区域在抗原呈递中的重要性。
