Alkan S S, Williams E B, Nitecki D E, Goodman J W
J Exp Med. 1972 Jun 1;135(6):1228-46. doi: 10.1084/jem.135.6.1228.
L-Tyrosine azobenzene-p-arsonate (RAT) induced cellular immunity without antibody production in guinea pigs. Bifunctional antigens were prepared consisting of one RAT carrier moiety linked either directly to a dinitrophenyl (DNP) haptenic determinant or through one or more 6-amino-caproyl (SAC) spacers. Each SAC unit has an extended span of 8 A. Guinea pigs immunized with these conjugates developed cellular immunity directed against the RAT determinant and antibody specific for the DNP determinant. The anti-DNP response was the same with one or three SAC spacers, but was significantly weaker when the two determinants were joined without a spacer. Animals immunized with either DNP-SAC-TYR or DNP-TYR developed neither cellular nor humoral immunity. Prior immunization with RAT potentiated the secondary anti-hapten response to DNP-SAC-RAT. Modification of RAT at either the arsonate or tyrosine positions showed that other charged groups (sulfonate and trimethylammonium) could substitute for arsonate without loss of immunogenicity. Removal of either the amino or carboxyl group from the side chain of tyrosine did not abolish immunogenicity, but immunogenicity was lost upon removal of both. Immunization with symmetrical bifunctional RAT-(SAC)(n)-RAT and cyclo-(L-RAT-D-RAT) antigens led to cellular immunity but no anti-arsonate antibody, suggesting a barrier to "self-help." These compounds were also ineffective in inducing a secondary anti-arsonate response in animals primed with arsonate-BSA conjugates and RAT.
L-酪氨酸偶氮苯-对-胂酸酯(RAT)在豚鼠中诱导了细胞免疫而未产生抗体。制备了双功能抗原,其由一个RAT载体部分直接连接到二硝基苯基(DNP)半抗原决定簇或通过一个或多个6-氨基己酰基(SAC)间隔臂组成。每个SAC单元具有8埃的延伸跨度。用这些缀合物免疫的豚鼠产生了针对RAT决定簇的细胞免疫和对DNP决定簇特异的抗体。使用一个或三个SAC间隔臂时抗DNP反应相同,但当两个决定簇无间隔臂连接时反应明显较弱。用DNP-SAC-TYR或DNP-TYR免疫的动物既未产生细胞免疫也未产生体液免疫。预先用RAT免疫可增强对DNP-SAC-RAT的二次抗半抗原反应。在胂酸酯或酪氨酸位置对RAT进行修饰表明,其他带电基团(磺酸盐和三甲基铵)可替代胂酸酯而不丧失免疫原性。从酪氨酸侧链去除氨基或羧基均不会消除免疫原性,但两者均去除后免疫原性丧失。用对称双功能RAT-(SAC)(n)-RAT和环-(L-RAT-D-RAT)抗原免疫导致细胞免疫但无抗胂酸酯抗体,提示存在“自身辅助”障碍。这些化合物在用胂酸酯-BSA缀合物和RAT致敏的动物中诱导二次抗胂酸酯反应时也无效。