Thomas D W, Solvay M J, Irani D N, Nairn R
J Immunol. 1985 Dec;135(6):4086-9.
To more carefully determine how a peptide antigen interacts with the antigen-presenting cell (APC), we have begun an analysis of the fate of APC-associated peptide antigens. These studies have shown that a stable cell-bound form of APC-associated peptide exists, which is a complex of the peptide with surface membrane structures (peak A). In the experiments described here, we have begun to examine the chemical mechanism of this peak A complex formation. By modifying either the carboxyl terminal or amino terminal group of the octapeptide antigen angiotensin II we have established that the terminal carboxyl group, but not the terminal amino group, was critical for forming the peak A complex with APC membrane structures. In addition, blocking the carboxyl but not the amino terminal dramatically reduced the antigenicity of the peptide for AII-immune T cell in vitro proliferation. These results show that the carboxyl terminal of AII is essential for both peak A formation and antigenicity, and suggest that peak A is critical for antigen presentation to T cells.
为了更仔细地确定肽抗原如何与抗原呈递细胞（APC）相互作用，我们已开始分析与APC相关的肽抗原的命运。这些研究表明，存在一种稳定的与细胞结合的APC相关肽形式，它是肽与表面膜结构的复合物（峰A）。在本文所述的实验中，我们已开始研究这种峰A复合物形成的化学机制。通过修饰八肽抗原血管紧张素II的羧基末端或氨基末端基团，我们确定末端羧基而非末端氨基对于与APC膜结构形成峰A复合物至关重要。此外，阻断羧基末端而非氨基末端可显著降低该肽对AII免疫T细胞体外增殖的抗原性。这些结果表明，AII的羧基末端对于峰A的形成和抗原性均至关重要，并提示峰A对于向T细胞呈递抗原至关重要。
