Smee D F, Sidwell R W, Morrison A C, Bailey K W, Baum E Z, Ly L, Wagaman P C
Department of Animal, Dairy and Veterinary Sciences, Institute for Antiviral Research, Utah State University, Logan, UT 84322-5600, USA.
Antiviral Res. 2001 Dec;52(3):251-9. doi: 10.1016/s0166-3542(01)00168-1.
The novel influenza virus neuraminidase (NA) inhibitor, (1S,2S,3R,4R)-3-[(1S)-(acetylamino)-2-ethylbutyl]-4-[(aminoiminomethyl)amino]-2-hydroxy-cyclopentanecarboxylic acid (RWJ-270201, BCX-1812), is a potent inhibitor of influenza A and B viruses in cell culture and in infected mice. A mouse-adapted strain of influenza A/Shangdong/09/93 (H3N2) virus was serially passaged in the presence of 1 microM compound. After the fourth passage, breakthrough of resistant virus occurred. By the tenth passage, a twice plaque purified isolate was obtained which could replicate in 10 microM inhibitor. The 50% effective concentration (EC(50)) values for RWJ-270201 against wild-type and resistant viruses, determined by using a cytopathic effect inhibition assay, were 0.007 and 23 microM, respectively. Cross-resistance to zanamivir and oseltamivir carboxylate was observed. The hemagglutinin (HA) and NA genes of the virus were sequenced to determine the mutation(s) which conferred drug resistance. No differences were found between the resistant and wild-type viruses in the NA gene. However, a point mutation resulting in a single amino acid change (Lys189Glu) was found in the resistant viral HA. The wild-type and resistant viruses were compared for virulence in BALB/c mice. The resistant virus was approximately tenfold less virulent than the wild-type virus based upon virus challenge dose. Mice infected with a lethal dose of the resistant virus could still be effectively treated with RWJ-270201. Thus, the HA mutation may allow for the spread of the virus in cell culture in the presence of the NA inhibitor, but not in mice.
新型流感病毒神经氨酸酶（NA）抑制剂（1S，2S，3R，4R）-3-[(1S)-(乙酰氨基)-2-乙基丁基]-4-[(氨基亚氨基甲基)氨基]-2-羟基环戊烷羧酸（RWJ-270201，BCX-1812）在细胞培养和感染小鼠体内对甲型和乙型流感病毒均具有强效抑制作用。甲型/山东/09/93（H3N2）病毒的小鼠适应株在1微摩尔化合物存在的情况下连续传代。在第四次传代后，出现了耐药病毒的突破。到第十次传代时，获得了一株经过两次蚀斑纯化的分离株，该分离株能够在10微摩尔抑制剂中复制。通过细胞病变效应抑制试验测定，RWJ-270201对野生型和耐药病毒的50%有效浓度（EC50）值分别为0.007和23微摩尔。观察到对扎那米韦和奥司他韦羧酸盐存在交叉耐药性。对该病毒的血凝素（HA）和NA基因进行测序以确定赋予耐药性的突变。在NA基因中，耐药病毒和野生型病毒之间未发现差异。然而，在耐药病毒的HA中发现了一个导致单个氨基酸变化（Lys189Glu）的点突变。比较了野生型和耐药病毒在BALB/c小鼠中的毒力。基于病毒攻击剂量，耐药病毒毒力比野生型病毒低约10倍。感染致死剂量耐药病毒的小鼠仍可用RWJ-270201有效治疗。因此，HA突变可能使病毒在NA抑制剂存在的情况下在细胞培养中传播，但在小鼠中则不然。
