パラインフルエンザ1型 (HA-2) ウイルスの Vero 細胞への馴化のこころみ

Several kinds of adaptation trials of parainfluenza type 1, HA-2 virus, to a cercopithecus kidney line, Vero cells, failed to obtain such virus populations to replicate in complete cycles in the system under the ordinary conditions. With addition of a small amount of trypsin to the maintenance medium during virus cultivation, however, the virus propagated efficiently and became transferable in this trypsin-added Vero cell culture (Vrt). This was demonstrated using both the original primary cercopithecus kidney cell-grown virus and the Vrt-passaged viruses. It is, therefore, appropriate to consider that changes of viral susceptibility of Vero cell cultures, but not changes on the side of virus particles, have occurred under the Vrt conditions. These results are along the same lines with our previous data described on parainfluenza type 4 virus in Vrt system. Preliminary discussions were given on mechanism (s) of the enhancement of viral susceptibility of Vero cell cultures by the addition of trypsin and need of study for cell-synthesized proteases was indicated.