Grodnitskaia N A, Rudneva I A, Makarova N V, Kaverin N V
Vopr Virusol. 1997 Jul-Aug;42(4):161-5.
CV-1 cells were preinfected with H7-SV40 recombinant vector and superinfected with influenza viruses A/USSR/90/77 (H1N1), A/Duck/Czechoslovakia/56 (H4N6), or B/Hongkong/73. A fraction of the yields of influenza A viruses was infectious without trypsin treatment due to the incorporation of cleaved H7 hemagglutinin into virions. The specificity of the effect was confirmed by neutralization of the infectivity with anti-H7 serum. At a low multiplicity of infection the incorporation of H7 hemagglutinin into virions allowed the virus to replicate without trypsin in a multi-cycle manner. The fraction of the infectious virus and the kinetics of the multi-cycle infection in H7-expressing cells were similar in the cells superinfected with A/USSR/90/77 and with A/Duck/Czechoslovakia/56 viruses, thus demonstrating a low specificity of interaction between H7 hemagglutinin and heterologous M2 proteins. The superinfection of H7-expressing cells with influenza B/Hongkong/73 virus did not produce infectious phenotypically mixed virus, which may be regarded as an indication of inability of influenza B virus NB protein to replace functionally the influenza A virus M2 protein in its interaction with hemagglutinin.
CV-1细胞先用H7-SV40重组载体进行预感染，然后再用甲型流感病毒A/USSR/90/77（H1N1）、A/鸭/捷克斯洛伐克/56（H4N6）或乙型流感病毒B/香港/73进行超感染。由于裂解的H7血凝素掺入病毒粒子中，一部分甲型流感病毒的子代在未经胰蛋白酶处理的情况下具有感染性。用抗H7血清中和感染性证实了该效应的特异性。在低感染复数时，H7血凝素掺入病毒粒子使得病毒能够在多循环方式下无需胰蛋白酶进行复制。在被A/USSR/90/77和A/鸭/捷克斯洛伐克/56病毒超感染的细胞中，表达H7的细胞中感染性病毒的比例和多循环感染的动力学相似，从而表明H7血凝素与异源M2蛋白之间的相互作用特异性较低。用乙型流感病毒B/香港/73对表达H7的细胞进行超感染未产生具有感染性的表型混合病毒，这可能表明乙型流感病毒NB蛋白在与血凝素相互作用时无法在功能上替代甲型流感病毒M2蛋白。
