| Project/Area Number |
03557022
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
細菌学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
YOSHIKAWA Masanosuke University of Tokyo Institute of Medical Science Professor, 医科学研究所, 教授 (80012714)
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| Co-Investigator(Kenkyū-buntansha) |
SASAKAWA Chihiro University of Tokyo, Institute of Medical Science, Associate Professor, 医科学研究所, 助教授 (70114494)
DANBARA Hirobumi Kitasato University, Faculty of Pharmaceutical Science, Professor, 薬学部, 教授 (40114558)
NARIUCHI Hideo University of Tokyo, Institute of Medical Science, Professor, 医科学研究所, 教授 (10012741)
SHIMADA Hiroyuki Tokyo Medical College, Professor, 教授 (60113487)
TAKASAKA Masao National Institute of Health Japan, Tsukuba Primate Center, Head, つくば霊長類センター, 室長 (80072924)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥16,700,000 (Direct Cost: ¥16,700,000)
Fiscal Year 1993: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1992: ¥5,800,000 (Direct Cost: ¥5,800,000)
Fiscal Year 1991: ¥7,600,000 (Direct Cost: ¥7,600,000)
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| Keywords | Shigella flexneri / pathogenicity / virulence / recombinant DNA experiments / cell invasion / vaccine / molecular genetics / 組換えDNA / 赤痢 / サル実験 / 分子遺伝学的解析 / 免疫病理学 |
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| Research Abstract |
Bacillary dysentery, caused by Shigella, is a significant cause of serious enteric illness in the world, particularly in developing countries. Efficacious vaccines are thus urgently needed. Several promising vaccine candidates are at various levels of investigations, but to date none is available for public health purposes. Recently genetic and molecular basis of the pathogenicity of Shigella and host responses to the bacterial virulence factors have been elucidated, that have made it possible to construct a live attenuated vaccine based on rational strategies. The genes required at a certain known step of infection process can be selectively mutated to impair the interaction with intestinal epithelial cells and/or survive within intestinal tissues in general. Based on the genetic and molecular studies on Shigella pathogenic properties, we have constructed and evaluated a virG thyA double mutant of S.flexneri serotype 2a for utilization as a candidate live attenuated oral vaccine against bacillary dysentery. virG is required for spreading into adjacent epithelial cells and thyA essential for the multiplication of the invading bacteria. These mutations were introduced by insertional inactivation with Tn10 followed by counterselection for a tetracycline-sensitive derivative. This double mutant completely protected guinea pigs from provoking keratoconjunctivitis. It also appeared safe when administered intragastrically to cynomolgus monkeys and gave an incomplete but highly significant protection against a challenge by the homologous wild type shigella flexneri strain as judged by bacteriological, histopathological and immunological examinations.
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