Materials and Methods.doc

<b>Rationale:</b>Despite advances in pharmacotherapy, heart failure still incurs significant morbidity and mortality. Stimulating antibodies directed against the secondextracellular loop of the human ß₁-adrenergic receptor (anti-ß₁EC2) cause myocyte damage and heart failure in rats. This receptor domain is 100% homologous between rats and humans. <b>Objective:</b>ß₁EC2-mimicking cyclopeptides (25-meric) markedly improved the development and/or course of anti-ß₁EC2-mediated cardiomyopathy. Further developments should be investigated. <b>Methods and Results:</b> The shortened 18-meric cyclic peptide COR-1, in which one of the two disulphide bonds was removed to enable reproducible GMP production, can also be used to treat cardiomyopathic rats. Echocardiography, catheterization and histopathology of the rat hearts revealed that monthly intravenous administrations of COR-1 almost fully reversed the cardiomyopathic phenotype within 6 months at doses of 1 to 4 mg/kg body weight. Administration of COR-1 resulted in markedly reduced anti-ß₁EC2-expressing memory B lymphocytes in the spleen despite con­tinued antigenic boosts, but did not significantly decrease overall peripheral anti-ß₁EC2 titers. COR-1 did not induce any anti-ß₁EC2 or other immune response in naïve rats (corresponding to findings in healthy human volunteers). It did not cause any toxic side effects in GLP studies in dogs, rats or mice, and the “no observed adverse effect level” (NOAEL) exceeded the therapeutic doses by 100-fold. <b>Conclusion:</b>The second generation immunomodulating epitope-mimicking cyclopeptide COR-1 (also termed JNJ-5442840) offers promise to treat immune-mediated cardiac diseases.

**研究依据**：尽管药物治疗领域已取得诸多进展，心力衰竭仍面临较高的发病率与死亡率。靶向人β₁-肾上腺素能受体（human β₁-adrenergic receptor）第二胞外环的刺激性抗体（anti-β₁EC2）可诱导大鼠心肌细胞损伤并引发心力衰竭。该受体结构域在大鼠与人类间具有100%同源性。
**研究目的**：β₁EC2模拟环肽（25聚体）可显著改善抗β₁EC2介导的心肌病的发生与病程，有待开展进一步开发研究。
**方法与结果**：截短型18聚体环肽COR-1通过移除两条二硫键中的一条，实现了可重复的药品生产质量管理规范（Good Manufacturing Practice，GMP）生产，同样可用于治疗心肌病模型大鼠。对大鼠心脏开展超声心动图、心导管检查及组织病理学分析结果显示，以1~4 mg/kg体重的剂量每月静脉给予COR-1，可在6个月内几乎完全逆转心肌病表型。给予COR-1后，尽管持续存在抗原刺激，大鼠脾脏中表达抗β₁EC2的记忆B淋巴细胞数量显著减少，但外周血抗β₁EC2总滴度未出现明显下降。COR-1不会在未致敏大鼠体内诱导产生抗β₁EC2或其他免疫应答，该结果与健康人类志愿者的试验结果一致。在犬、大鼠及小鼠的良好实验室规范（Good Laboratory Practice，GLP）研究中，COR-1未引发任何毒性副作用，其未观察到有害作用水平（no observed adverse effect level, NOAEL）较治疗剂量高出100倍。
**结论**：第二代免疫调节表位模拟环肽COR-1（又称JNJ-5442840）有望用于治疗免疫介导性心脏疾病。