A newly developed immunofluorescent assay for determining the Pichinde virus-inhibitory effects of selected nucleoside analogues

An immunofluorescent assay (IFA) for Pichinde virus (PCV), a member of the family Arenaviridae, was developed for antiviral drug assays against the virus. The assay was performed by adding fluorescein-labeled anti-PCV monoclonal antibody to virus-infected cells at 24 h after the initial infection and counting the infected cells with an epifluorescence microscope. The average 50% effective dose (ED50) for a series of nucleoside analogues tested against PCV using this IFA was: 2-beta-D-ribofuranosylselenazole-4-carboxamide (selenazofurin), less than 1.0 microgram/ml; 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin), 6.0 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide- 5'-phosphate hydrate (ribavirin-5'-monophosphate), 15.8 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide-5'-hemisuccinate (ribavirin-5'-hemisuccinate), 14.7 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide-5'-(2,3- dimethyl)hemisuccinate [ribavirin-5'-(2,3-dimethyl)hemisuccinate], 213.5 micrograms/ml; 4-hydroxy-1-beta-D-ribofuranosyl-2-pyridone (3-deazauridine), 5.2 micrograms/ml; and (S)-9-(2,3-dihydroxypropyl)adenine, ([S]-DHPA), 471.0 micrograms/ml. In comparison, the ED50 of ribavirin using inhibition of marginal PCV-induced cytopathogenic effect after 12 days was 6.0 micrograms/ml and using plaque reduction after 5 days was 2.5 micrograms/ml, indicating that this IFA was of comparable sensitivity to these other tests.     

Inhibitors of IMP dehydrogenase stimulate the phosphorylation of the anti-human immunodeficiency virus nucleosides 2',3'-dideoxyadenosine and 2',3'-dideoxyinosine.

2',3'-Dideoxyadenosine (ddAdo) and its deamination product 2',3'-dideoxyinosine (ddIno) (didanosine) inhibit the replication and infectivity of the human immunodeficiency virus (HIV) in a number of in vitro assay systems. Early clinical studies (phase I) have indicated a role for ddIno in the treatment of patients with severe HIV infection. In the present in vitro study, the formation in human T cells (MOLT-4, ATH8, and CCRF-CEM) of the pharmacologically active metabolite of ddIno and ddAdo, 2',3'-dideoxyadenosine-5'-triphosphate (ddATP), was found to be stimulated 2-4-fold by appropriate concentrations of inosinate dehydrogenase (IMPD) inhibitors such as ribavirin, tiazofurin, and mycophenolic acid. Concomitant with this increase in ddATP formation from ddIno was an increase in anti-HIV activity of this agent when it was combined with ribavirin in the ATH8 cell assay system and with tiazofurin in the MOLT-4 assay system. No change was noted in the intracellular concentration of the corresponding physiological deoxynucleoside-5'-triphosphate, dATP; positive correlation was observed, however, between the increase in ddATP formation from ddIno and the increase in intracellular IMP occurring as a consequence of IMPD inhibition. The results support the hypothesis that the stimulation of ddATP formation seen when ddIno is combined with ribavirin or other IMPD inhibitors is a consequence of an increased concentration of IMP, the major phosphate donor for the initial phosphorylation step in the anabolism of ddIno to ddATP, i.e., ddIno----ddIMP.     

利巴韦林用于病毒感染性疾病国内外文献分析

目的为新型冠状病毒肺炎(COVID-19)的治疗提供参考。方法计算机检索Ovid Medline,Ovid EMBase,Cochrane Central Register of Controlled Trials(CENTRAL),以及中国知识基础设施工程(CNKI)数据库,检索时限均为建库至2020年3月10日,对符合纳入标准的文献进行描述性分析,探讨利巴韦林用于感染性疾病的有效性和安全性。结果初筛文献392篇,筛选后最终纳入利巴韦林用于病毒感染性疾病文献99篇,其中关于流行性感冒37篇、获得性免疫缺陷综合征(HIV)9篇、严重急性呼吸综合征(SARS)8篇、中东呼吸综合征(MERS)13篇、COVID-191篇、寨卡病毒(ZIKV)3篇、登革热病毒(DENV)9篇、拉沙病毒(LV)8篇、汉坦病毒(HV)5篇、基孔肯尼亚病毒(CHIKV)6篇。流行性感冒治疗中,多采用利巴韦林与其他药物(多为奥司他韦)联合抗病毒治疗。体外试验显示,利巴韦林对HIV,SARS-CoV,MERS-CoV均有抑制作用,但临床研究效果不确切;DENV动物实验显示无效;ZIKV,HV,CHIKV体外试验显示有效;建议重新评估对LV的临床疗效。利巴韦林用于COVID-19的研究仅1篇。结论仍需开展更多规范的回顾性临床病例研究,验证利巴韦林治疗COVID-19的疗效。