Antigenic and in Vitro Host Range Variety in Populations of Aquatic Birnaviruses Demonstrated by Selection for Neutralization Resistance to Monoclonal Antibodies

經由中和單株抗體篩選之病毒株證明水生兩段雙股核醣核酸病毒族群中抗原及寄主範圍之變異性

王渭賢(Way-Shyan Wang) ； Bruce L. Nicholson

《Zoological Studies》 35卷2期 (1996/04) Pp. 93-104

摘要

為了研究水生兩段雙股核醣核酸病毒（birnaviruses）的族群差異性，我們以不同的病毒株培養在含有中和病毒感染力之單株抗體之培養基中以抑制原血清型病毒的複製？而今離出抗中和單株抗體的病毒族群。篩選出的抗中和單株抗體病毒經病毒斑純化，並對其抗原及各種生物特性加以鑑定。這些篩選出來的變異病毒株中，有些除了對於用以篩選的單株抗體不能反應之外，也無法與其它原可反應之單株抗體反應；另外一些變異病毒株則雖不會被用以篩選的單株抗體中和，但可與之反應。某些不能被特定單株抗體中和的變異病毒株，卻與能其它一種或多種不能與親株病毒反應之單株抗體結合，並能被其中和。此外，某些篩選出來的變異病毒株在感染細胞後，複製出比親株病毒高的力價，並產生較大的病毒斑。有三個變異病毒株的寄主範圍亦產生變化，其中兩株已無法感染fat head minnow（FHM）細胞，而一株則於感染FHM細胞後複製出較親株病毒猶高之力價。當病毒顆粒蛋白比較分子量時，發現變異株的VP1和VP3與親株幾乎沒有差異，而不同變異株的VP2大小皆不相同，有些變異株的VP2先趨物較親株為大，有些則較小。

關鍵字

感染性胰臟壞死病毒 ； 抗原變異株 ； 抗中和變異株。

並列摘要

Variation in populations of aquatic birnaviruses was investigated by propagating several virus strains in cell cultures in the presence of neutralizing monoclonal antibodies (MAbs) to inhibit replication of the parental antigenic type in the virus population and to isolate MAb neutralization-resistant viruses representing one or more subpopulations of viruses. Selected MAb neutralization-resistant viruses were plaque purified and characterized in regard to antigenic and biological properties. In addition to the MAb used for selection, some variants failed to react in immunoassays with one or more other MAbs that reacted with the parental virus type. Other viruses, although completely resistant to neutralization, reacted with the selecting MAb. Several viruses selected for resistance to neutralization with a given MAb reacted in immunobinding and neutralization assays with one or more MAbs that did not react with the parental virus type. Also, several of the selected viruses replicated to higher titers and produced largersized plaques in susceptible cell cultures. Three MAb-resistant viruses were also found to be in vitro host range variants; two were no longer capable of infecting fat head minnow (FHM) cell cultures, whereas one, in contrast to the parental virus population, replicated to high titers in FHM cells. Comparison of the molecular weights of virion proteins of the MAb-selected viruses and the parental virus type revealed little or no alterations of virion proteins VP1 and VP3. However, differences in size were demonstrated between VP2 proteins of all MAb-selected viruses. In some cases, VP2 and VP2 precursor proteins of the MAb-resistant viruses were larger whereas in other cases they were smaller in size.

並列關鍵字

Infectious pancreatic necrosis virus ； Antigenic ； Neutralization-resistant variants