Kakiuchi T, Okada Y, Kokuho T, Gyotoku Y, Mizuguchi J, Nariuchi H
Department of Immunology, Toho University School of Medicine, Tokyo, Japan.
Immunobiology. 1995 Jun;193(1):84-97. doi: 10.1016/S0171-2985(11)80157-9.
We have previously shown that a specific Ag presentation by B cells is different from a nonspecific one in the sensitivity to protein synthesis inhibition. In the present study we have compared the sensitivity of these Ag presentations to antigenic competition. A20-HL cells expressing TNP-specific IgM were pulsed with anti-mouse IgM goat IgG (aMGG) or trinitrophenylated goat IgG (TNP-NGG) as an Ag internalized through Ag receptor or NGG as an Ag internalized by fluid-phase pinocytosis. The pulsed cells induced IL-2 production by NGG-specific cloned T cells. The presence of dog IgG during pulsing A20-HL cells severely inhibited the presentation of NGG but not of aMGG or TNP-NGG. The presence did not decrease the internalization of 125I-NGG into A20-HL cells, suggesting that the inhibition was localized into the complex formation of antigenic peptides with MHC class II molecules. Thus, a specific Ag presentation by A20-HL cells is different from a nonspecific one in its sensitivity to antigenic competition.
我们之前已经表明，B细胞的特异性抗原呈递在对蛋白质合成抑制的敏感性方面不同于非特异性抗原呈递。在本研究中，我们比较了这些抗原呈递对抗原竞争的敏感性。用抗小鼠IgM山羊IgG（aMGG）或三硝基苯基化山羊IgG（TNP-NGG）作为通过抗原受体内化的抗原，或用NGG作为通过液相胞饮作用内化的抗原，对表达TNP特异性IgM的A20-HL细胞进行脉冲处理。脉冲处理后的细胞诱导NGG特异性克隆T细胞产生白细胞介素-2。在对A20-HL细胞进行脉冲处理期间存在犬IgG会严重抑制NGG的呈递，但不会抑制aMGG或TNP-NGG的呈递。这种存在并没有减少125I-NGG进入A20-HL细胞的内化，这表明抑制作用定位于抗原肽与II类主要组织相容性复合体分子的复合物形成。因此，A20-HL细胞的特异性抗原呈递在对抗原竞争的敏感性方面不同于非特异性抗原呈递。
