MacLeod J N, Tetreault J W, Lorschy K A, Gu D N
Department of Biomedical Sciences, James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Am J Vet Res. 1998 Sep;59(9):1144-8.
To produce recombinant canine erythropoietin (rcEPO) and compare its biological activity with that of recombinant human EPO (rhEPO).
C57BL/6J mice.
The gene encoding cEPO was isolated from a genomic library and subcloned into an eucaryotic expression vector. Production of rcEPO was achieved by stable transfection of the expression construct into Chinese hamster ovary cells. Biological activity was evaluated in vitro by analyzing the mitogenic activity of rcEPO on murine erythroid progenitor cells. In vivo bioactivity was assessed in mice by measuring the ability of rcEPO to increase blood reticulocyte counts.
Size and glycosylation of rcEPO expressed in Chinese hamster ovary cells were similar to values for commercial rhEPO. Canine and human EPO stimulated proliferation of murine erythroid progenitor cells in vitro and murine reticulocytosis in vivo in a dose-dependent manner.
Comparable biological activity was observed for rcEPO and rhEPO in the 2 murine-based assay systems studied. By avoiding interspecies variation in protein structure and the resulting potential for immunogenicity, rcEPO should represent a better option than rhEPO for treatment of dogs with erythropoietin-dependent anemia.
Therapeutic use of rhEPO in companion animals is limited by its immunogenicity and the resulting potential to induce pure red cell aplasia. Development and availability of species-specific EPO preparations should avoid this problem.
生产重组犬促红细胞生成素（rcEPO），并将其生物学活性与重组人促红细胞生成素（rhEPO）进行比较。
C57BL/6J小鼠。
从基因组文库中分离出编码cEPO的基因，并亚克隆到真核表达载体中。通过将表达构建体稳定转染到中国仓鼠卵巢细胞中来生产rcEPO。通过分析rcEPO对小鼠红系祖细胞的促有丝分裂活性在体外评估其生物学活性。通过测量rcEPO增加小鼠血液中网织红细胞计数的能力在体内评估其生物活性。
在中国仓鼠卵巢细胞中表达的rcEPO的大小和糖基化与市售rhEPO的值相似。犬促红细胞生成素和人促红细胞生成素在体外刺激小鼠红系祖细胞增殖，在体内刺激小鼠网织红细胞增多，呈剂量依赖性。
在研究的两种基于小鼠的检测系统中，rcEPO和rhEPO具有可比的生物学活性。通过避免蛋白质结构中的种间差异以及由此产生的免疫原性潜力，rcEPO应该比rhEPO更适合用于治疗依赖促红细胞生成素的贫血犬。
rhEPO在伴侣动物中的治疗应用受到其免疫原性以及由此诱导纯红细胞再生障碍的可能性的限制。开发和提供物种特异性促红细胞生成素制剂应可避免此问题。
