Peroral vaccination with a temperature-sensitive mutant (HVJ-pB) of parainfluenza type 1 virus against respiratory tract infection

野生型(Wt)仙台病毒强毒株经鼻接种后生长在小鼠的肺中，并引起病毒性肺炎。然而，口服接种的小鼠肺中没有发现wt病毒的生长。来自仙台病毒携带者培养的温度敏感(Ts)突变株可以在32ﾟC下繁殖，但不能在34ﾟC以上繁殖，即使对新生儿也没有致病性。口服ts突变体可诱导小鼠产生特异性免疫反应，并保护小鼠免受wt病毒重叠感染引起的肺炎。紫外线照射的ts突变体不能诱导保护性免疫。经胃管直接滴注ts突变体对wt病毒的免疫无效。这些结果表明ts突变体在口腔粘膜中表达病毒蛋白，并在消化道建立粘膜免疫。通过常见的粘膜免疫系统，呼吸道粘膜也对wt病毒的攻击具有免疫力。

The virulent strain of wild-type (wt) Sendai virus grows in the lung of mice when inoculated intranasally and causes viral pneumonia. However, no wt virus growth is found in the lung of mice inoculated perorally. A temperature-sensitive (ts) mutant derived from an Sendai virus carrier culture can multiply at 32ﾟC,but not at over 34ﾟC,and shows no pathogenicity to even newborn babies. Oral administration of the ts mutant induces mice a specific immune response and protects from pneumonia caused by the wt virus superinfection. Ultraviolet-irradiated ts mutant induces no protective immunity. A direct instillation of the ts mutant into the stomach through a tube is ineffective for a vaccination against the wt virus.These results indicates the ts mutant expresses viral proteins in oral mucous membrane and establishes mucosal immunity in the alimentary tract. By the common mucosal immune system mucous membrane in the respiratory tract also becomes immune from the wt virus challenge.