人免疫缺陷病毒I型抗AZT抗药株的体外研究

人免疫缺陷病毒Ⅰ型（ＨＩＶ－１）抗３＇─叠氮─３＇─脱氧胸腺嘧啶（ＡＺＴ）抗药株经体外感染Ｃ８１６６淋巴细胞在高浓度ＡＺＴ条件下筛选获得,并暂命名为ＨＩＶ─１─Ｒ株。该抗药株与ＨＴＬＶ─ⅢＢ株相比,在同一感染复数（Ｍ０１）病毒量感染Ｃ８１６６细胞,经不同浓度的ＡＺＴ处理后,其复制的病毒量和对ＡＺＴ的敏感性有显著的差异,抗药株感染Ｃ８１６６细胞,加ＡＺＴ处理后,分离细胞ＤＮＡ作ＰＣＲ扩增后分析,特异性病毒的ＤＮＡ量比敏感株高１００倍以上,显示其抗药性作用点在病毒逆转录ＤＮＡ前。     

In vitro evaluation of the synergistic antiviral effects of acemannan in combination with azidothymidine and acyclovir.

The antiviral effects of selected combinations between acemannan (ACE-M), a long-chained, polydispersed, beta-(1,4)-acetylated mannan, were tested in combination with azidothymidine (AZT) and acyclovir (ACY) in vitro. The rationale for such combinations was based on the antiviral and immunomodulatory properties exhibited by ACE-M. In addition, the observed antiviral effects of ACE-M against human immunodeficiency virus type 1 (HIV-1) and other enveloped viruses appear to be related to modification of the glycosylation of viral glycoproteins. Therefore, the inhibitory effect of ACE-M does not overlap with that of AZT or ACY. The studies presented herein show that ACE-M combined with suboptimal noncytotoxic concentrations of AZT or ACY act synergistically to inhibit the replication of HIV-1 and herpes simplex virus type 1 (HSV-1), respectively. The median effect method was not applicable for analysis because the test compounds show mutually nonexclusive drug effects. For a meaningful evaluation and interpretation of the effects of drug combinations, the biological significance of combinations must be considered, that is, the protective effect of the combination, the noncytotoxicity of the combination, the mechanism(s) of action of the individual compounds comprising the combination, and so forth. With respect to effects on U1 cells latently infected with HIV-1, treatment with combinations of AZT and ACE-M does not potentiate virus replication.     

Human immunodeficiency virus type 1 pol gene mutations in an AIDS patient treated with multiple antiretroviral drugs.

Multiple mutations were found in the human immunodeficiency virus pol gene following treatment of an AIDS patient with antiretroviral drugs. After approximately 2.5 years of monthly alternating therapy with 3'-azido-3'-deoxythymidine (AZT) and 2',3'-dideoxycytidine (ddC), most of the pol sequences amplified from the patient's peripheral blood mononuclear cell DNA contained known AZT resistance mutations at codons 41, 67, and 215 and a putative ddC resistance mutation at codon 69 as well as other novel mutations. These mutations persisted for 6 months after the patient was switched to 2',3'-dideoxyinosine monotherapy. Mutations known to be associated with 2',3'-dideoxyinosine resistance did not occur during this time. Antiviral susceptibility testing of point mutants, introduced into the genetic background of laboratory strain NL4-3, showed that the codon 41 mutation antagonized ddC resistance when present with the codon 69 mutation. However, this antagonism was not found with a chimeric mutant containing the patient's pol gene sequence from codons 25 to 218, implying that other mutations compensated for the antagonism. Thus, alternating therapy with AZT and ddC resulted in the selection of viruses resistant to both drugs.