Sanfilippo F, Scott D W
Eur J Immunol. 1977 May;7(5):283-7. doi: 10.1002/eji.1830070508.
Lewis rats rendered tolerant to sheep IgG (SGG) show a markedly reduced antibody response to the 2,4,6-trinitrophenyl (TNP) hapten when later challenged with TNP-SGG. We have previously shown that this effect is due to functional unresponsiveness in the carrier SGG-specific helper T cell population. In this paper we demonstrate that induced helper cell tolerance is also maintained through a secondary immunogenic challenge. Furthermore, rats which are primed to the carrier SGG prior to tolerance induction also show a markedly reduced anti-TNP response upon secondary immunogenic challenge with TNP-SGG. The ability to specifically suppress a secondary response in this manner was found to be relatively long lasting, since rats showed reduced responsiveness when the secondary challenge was delayed for up to 4 weeks after tolerance induction. In addition, rats primed to the hapten (TNP) prior to carrier (SGG) tolerance induction also showed a marked reduction in anti-TNP antibody following challenge with TNP-SGG. These findings imply that helper cell tolerance can be induced in rats even after priming of carrier-specific (SGG) helper cells, or hapten-specific (TNP) B cells. These results parallel our other published findings that IgE responses in presensitized rats can be overcome by helper cell tolerance.
对绵羊免疫球蛋白G（SGG）产生耐受的刘易斯大鼠，在随后用三硝基苯（TNP）-SGG攻击时，对TNP半抗原的抗体反应明显降低。我们之前已经表明，这种效应是由于载体SGG特异性辅助性T细胞群体中的功能性无反应性所致。在本文中，我们证明诱导的辅助性细胞耐受也通过二次免疫原性攻击得以维持。此外，在诱导耐受之前对载体SGG进行致敏的大鼠，在用TNP-SGG进行二次免疫原性攻击时，其抗TNP反应也明显降低。发现以这种方式特异性抑制二次反应的能力相对持久，因为当二次攻击在诱导耐受后延迟长达4周时，大鼠的反应性降低。此外，在载体（SGG）耐受诱导之前对半抗原（TNP）进行致敏的大鼠，在用TNP-SGG攻击后，其抗TNP抗体也明显减少。这些发现表明，即使在载体特异性（SGG）辅助性细胞或半抗原特异性（TNP）B细胞致敏后，大鼠中也可诱导辅助性细胞耐受。这些结果与我们其他已发表的发现一致，即预先致敏大鼠中的IgE反应可被辅助性细胞耐受所克服。
