Allegretta M, Atkins M B, Dempsey R A, Bradley E C, Konrad M W, Childs A, Wolfe S N, Mier J W
J Clin Immunol. 1986 Nov;6(6):481-90. doi: 10.1007/BF00915254.
Approximately 65% (11/17) of cancer patients participating in an ongoing Phase I clinical trial with recombinant interleukin-2 developed nonneutralizing serum IgG anti-interleukin-2 antibodies within 1 month of initiating therapy. These antibodies could be detected using any of several standard techniques including immunoblots and enzyme-linked immunosorbent assays. Western blot analysis and retention experiments with protein A-Sepharose indicate that the antibodies are specific for interleukin-2. The interleukin-2 mutein utilized in this clinical trial (des-ala-ser125 r-IL-2) differs from the major species of the human T cell-derived lymphokine in that it lacks the N-terminal alanine of the native molecule, is not glycosylated, and possesses a serine-cysteine substitution at position 125. Another recombinant interleukin-2, identical to the mutein except that it retains the cysteine at position 125 (des-ala-cys125 r-IL-2), strongly competes with the mutein in competitive enzyme-linked immunosorbent assays, suggesting that the amino acid substitution is not responsible for the recognition of the molecule by serum antibodies. Conversely, nonrecombinant T cell-derived interleukin-2 fails to compete in these assays and is not retained by protein A-Sepharose columns when mixed with high-titer antiserum. These results suggest that the anti-interleukin-2 serum antibodies generated in the course of treatment do not react with the nonrecombinant lymphokine but recognize epitopes peculiar to recombinant forms which are not dependent on the amino acid substitution at position 125. The failure of the antibodies to neutralize the biological activity of recombinant interleukin-2 (IL-2) in lymphocyte proliferation assays and to bind to the native lymphokine suggests that they may not affect IL-2-dependent cellular immune functions in vivo.
参与一项正在进行的重组白细胞介素 -2一期临床试验的癌症患者中，约65%（11/17）在开始治疗后1个月内产生了非中和性血清IgG抗白细胞介素 -2抗体。这些抗体可用包括免疫印迹和酶联免疫吸附测定在内的几种标准技术中的任何一种检测到。蛋白质印迹分析以及用蛋白A - 琼脂糖进行的保留实验表明这些抗体对白细胞介素 -2具有特异性。该临床试验中使用的白细胞介素 -2突变体（去丙氨酸 - 丝氨酸125重组白细胞介素 -2）与人类T细胞衍生的淋巴因子的主要种类不同，它缺少天然分子的N端丙氨酸，未进行糖基化，并且在第125位有丝氨酸 - 半胱氨酸取代。另一种重组白细胞介素 -2，与该突变体相同，只是在第125位保留了半胱氨酸（去丙氨酸 - 半胱氨酸125重组白细胞介素 -2），在竞争性酶联免疫吸附测定中能与该突变体强烈竞争，这表明氨基酸取代并非血清抗体识别该分子的原因。相反，非重组T细胞衍生的白细胞介素 -2在这些测定中不发生竞争，并且与高滴度抗血清混合时不能被蛋白A - 琼脂糖柱保留。这些结果表明，治疗过程中产生的抗白细胞介素 -2血清抗体不与非重组淋巴因子反应，而是识别重组形式特有的表位，这些表位不依赖于第125位的氨基酸取代。抗体在淋巴细胞增殖试验中不能中和重组白细胞介素 -2（IL -2）的生物学活性且不能与天然淋巴因子结合，这表明它们可能不会影响体内依赖IL -2的细胞免疫功能。
