1994 Fiscal Year Final Research Report Summary

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

Research Project

Project/Area Number	05807025
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Virology
Research Institution	Fukui Medical School
Principal Investigator	KIMURA Yosjinobu Fukui Medical School, 医学部, 教授 (90022871)
Project Period (FY)	1993 – 1994
Keywords	Paramyxovirus / Avirulent ts mutant / Peroral live vaccine
Research Abstract	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.