重组人^125I—CTLA4Ig在大鼠体内吸收、组织分布及排泄的药代动力学研究

目的:研究重组人单克隆抗体 CTLA4Ig 经静脉单次给药后在 Wistar 大鼠体内的药代动力学、组织分布及排泄过程,评价剂量与药代动力学参数之间的关系。方法:54只 Wistar 大鼠(雌雄各半)分为9组(雌雄各3只),3组分别单次给药(100,30,10 mg·kg~(-1),按不同时间点采血分离血浆,TCA 沉淀法测定~(125)I-CTLA4Ig 的放射强度,用所得结果评价~(125)I-CTLA41g 在大鼠体内的暴露情况,根据非房室统计矩模型用 WinNolin 药代软件进行曲线拟合并计算药代动力学参数;其余6组单次给药30mg·kg~(-1),其中4组大鼠给药后不同时间麻醉处死、解剖测定~(125)I-CTLA4Ig 组织分布,另外1组给药后收集不同时段的尿粪评价~(125)I-CTLA4Ig 的排泄过程,最后1组麻醉后插管给药收取胆汁评价胆汁排泄。结果:Wistar 大鼠分别静脉单次注射高、中、低(100,30,10mg·kg~(-1))后,T_(1/2)分别为(41.25±0.90)h、(47.25±1.79)h 和(54.81±1.96)h,CLs 与 Vss 随着剂量的减小发生减少的变化,血药浓度-时间曲线下面积 AUC_(INF)(h·μg·mL~(-1))分别为35833.37±2618.69,14171.04±1118.25,6186.85±480.35,剂量之比为10:3:1,对应的 AUC 比值为5.8:2.3:1,剂量与 AUC 成正相关性,AUC=0.524·Dose 0.5821,相关系数 R~2=0.9975,但是 AUC 的增加量小于剂量的增加量;单次静脉给药~(125)I-CTLA4Ig 30mg·kg~(-1)后,肝肾组织中~(125)I-CTLA4Ig 的含量最高,脑含量最低;120h 经尿粪排泄量占总给药量的68.98%和6.88%;胆汁在给药后28h 其排泄量相当于总给药量的5.80%。结论:在本实验的剂量范围内,剂量与 AUC 成正相关性,AUC 的增加量小于剂量的增加量,预示在以上剂量范围内 CTLA4Ig 在 Wiatar 大鼠血浆中的浓度变化可能呈非线性药代动力学特点;肾脏为~(125)I-CTLA4Ig 的主要排泄器官;胆汁的排泄量提示~(125)I-CTLA4Ig 在大鼠体内存在肝肠循环的代谢特征。     

重组人胰高血糖素类多肽-1(7-36)免疫原性的实验研究

目的:观察重组人胰高血糖素类多肽-1(7-36)[rhGLP-1(7-36)]对小猎兔犬的免疫原性。方法:健康小猎兔犬随机分为rhGLP-1(7-36)高、中、低剂量组(200、100、50μg/kg)和生理盐水对照组,每组6只,雌雄各半。皮下注射给药,每天1次,每周6次,连续9个月。采用酶联免疫吸附试验(ELISA)和碱性磷酸酶免疫斑点试验检测犬血清中的抗体。结果:连续给药3、9个月及恢复期血清均未发现抗rhGLP-1(7-36)抗体。结论:长期给予rhGLP-1(7-36)对小猎兔犬无免疫原性。     

聚乙二醇修饰尿酸酶的研究

目的:为了降低尿酸酶的免疫原性并提高其稳定性,利用PEG修饰荆对尿酸酶进行修饰,以期获得性质更优的治疗痛风的药物.方法:用相对分子质量为40kD,活化基团为羟基琥珀酰亚胺的PEG修饰剂对尿酸酶进行修饰,并比较修饰前后在酶解稳定性、pH稳定性及温度稳定性方面的差异,以及PEG修饰对体内半衰期,免疫原性的影响.结果:发现PEG修饰后尿酸酶的酶解稳定性显著提高,PEG化尿酸酶保留了原有尿酸酶80%的活性,体内半衰期从45min延长至696min.PEG化尿酸酶与抗体的结合能力为原型蛋白的1/8.体内的免疫原性也明显降低.结论:化学修饰后的尿酸酶可望成为潜在的治疗痛风的有效药物.     

弓形虫主要表面抗原1截短型片段的纯化与鉴定

目的:表达和纯化弓形虫SAG1,分析其免疫原性。方法:将诱导表达SAG1后菌体裂解,离心,分别收集其上清和沉淀;亲和层析分离纯化裂解上清液中的SAG1,SDS-PAGE和Western blot鉴定SAG1纯度和免疫原性。结果:诱导后重组体pGEX-SAG1/Bl21超声裂解上清液、8M脲溶解沉淀的上清中都含有融合蛋白GST-SAG1,从超声裂解上清液中纯化获得融合蛋白GST-SAG1。结论:亲和层析获得具有免疫原性的SAG1。     

生物技术药物免疫原性的评价及面临的挑战

随着大量生物技术药物的研发，免疫原性的评价成为阐明这些药物临床安全性和有效性的关键因素。评价非期望出现的免疫原性是生物技术药物临床前和临床评价的重要内容。完整的免疫原性评价应是方法学的验证，选择合理的免疫学和生物学方法检测抗体滴度的变化及分析抗体亚型和特性、测定抗体的中和活性、免疫复合物的形成及沉积，分析抗体产生对药物药动学、药效和毒性反应等影响。目前免疫原性评价面临的挑战是免疫学检测方法的优化以及提高动物和体外模型的预测性。     

Reaction to the paper: Interaction of Polysorbate 80 with Erythropoietin: A Case Study in Protein–Surfactant Interactions

Micelle-associated epoetin is still a possible explanation for the upsurge of pure red blood cell aplasia associated with subcutaneous use of epoetin alpha in patients with chronic renal failure.     

Phase 1 trial of 13-valent pneumococcal conjugate vaccine in Japanese adults

Background: A 7-valent pneumococcal conjugate vaccine (7vPnC) has markedly reduced invasive pneumococcal disease (IPD) in routine use in the USA and is in clinical development in Japan. But a 13-valent pneumococcal conjugate vaccine (13vPnC) would cover even more serotypes. Because vaccines are administered to children by s.c. injection in Japan but by i.m. injection in the USA, a phase I study of s.c. injected 13vPnC in healthy Japanese adults was appropriate before commencing trials in Japanese children and older adults.
Methods: This was a randomized comparison in healthy Japanese adults of s.c. administered 13-valent pneumococcal conjugate vaccine and s.c. administered 23-valent plain polysaccharide pneumococcal vaccine (23vPn). Local and systemic reactions were recorded in a daily diary for 14 days after injection. IgG antibodies to serotype-specific capsular polysaccharide were measured on enzyme-linked immunosorbent assay on samples taken before and approximately 1 month after immunization.
Results: A total of 15 subjects were evaluable for safety review in each treatment group. There was a trend towards more local reactions in the 13vPnC group, which may be associated with s.c. administration of aluminum-containing vaccines as used routinely in Japan; but the local reactogenicity was mostly mild or moderate. Both 13vPnC and 23vPn were immunogenic for all types, with the exception of 6A, which is not included in 23vPn and for which only 13vPnC was immunogenic.
Conclusions: Overall, immunogenicity and tolerance was adequate to lead to studies of 13vPnC in both infants and older adults in Japan, using the s.c. route if appropriate.     

The immunogenicity of hookworm (Necator americanus) acetylcholinesterase (AChE) in man

A number of different but complementary approaches have been used to demonstrate the immunogenicity of Necator americanus acetylcholinesterase to infected individuals. Western blotting of parasite somatic extracts with human post-infection sera and a specific rabbit antiserum to AChE resulted in the development of almost identical antigen-recognition profiles. AChE-containing fractions produced by preparative iso-electric focusing were subsequently shown to be antigenic in ELISA using post-infection sera. This preliminary data was reinforced by the affinity-purification of AChE by immobilized post-infection IgG, and the immunoprecipitation of AChE activity from ES by post-infection IgG. Finally, AChE purified by affinity chromatography on edrophonium chloride was shown to be antigenic by Western blotting, and in ELISA, against post-infection sera, although a degree of re-activity was also seen with normal human sera. This data is discussed in the context of the host-parasite relationship.     

Study on the comparative immunogenicity of a recombinant DNA hepatitis B vaccine containing pre-S components of the HBV coat protein with non pre-S containing vaccines

Abstract A new recombinant hepatitis B vaccine (SCI-B-VAC), derived from Chinese hamster ovary (CHO) cells and consisting of both the major S protein and the minor pre-S₁ and pre-S₂ proteins of the viral coat were compared with two yeast-derived vaccines containing only S proteins (B-Hepavac II and Engerix-B) for immunogenicity in human volunteers in a randomized controlled study. Two hundred and ninety-five healthy subjects completed the 12 month follow up. There was no difference in the mean age and sex distribution among the three study groups. Seroconversion rates for all the three groups were similar at months 6, 9 and 12. However, hepatitis B surface antibody (anti-HBs) geometric mean titres (GMT) were significantly higher with 10 μg SCI-B-VAC and 20 μg Engerix-B than with 10 μg B-Hepavac-II at months 6, 9 and 12. SCI-B-VAC at month 6 also showed a significantly higher anti-HBs GMT than Engerix-B (295 vs 143 miu/mL, P < 0.02).