| Project/Area Number |
07044293
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Keio University |
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Principal Investigator |
ISHIKAWA Hiromichi Sch.of Med.Keio University, Assoc.Prof., 医学部, 助教授 (20051667)
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| Co-Investigator(Kenkyū-buntansha) |
ITOHARA Shigeyoshi Kyoto University, Sch.Med., Assoc.Prof., ウイルス研究所, 助教授 (60252524)
TONEGAWA Susumu MIT,Prof., 生物学教室, 教授
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| Project Period (FY) |
1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥8,700,000 (Direct Cost: ¥8,700,000)
Fiscal Year 1995: ¥8,700,000 (Direct Cost: ¥8,700,000)
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| Keywords | gammadeltaT Cells / gammadelta-IEL / Intestinal Epithelial Cell / alphabeta-IEL / CD8alphaalpha IEL / MHC-Deficient Mouse / gammadelta-DETC / Cutaneous GvHR |
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| Research Abstract |
Our result shows :
1) The absence of gammadelta-IEL is associated with a reduction in intestinal epithelial cell turnover and a downregulation of the expression of MHC class II molecules.
2) The development of CD8^+ intestinal intraepitehlial T lymphocytes (IEL) was analyzed in mice that are deficient in the expression of MHC class I molecules owing to either a mutanted beta_2M gene or a mutanted TAP-1 gene and in mice doubly lomozygous for beta_2M and TAP-1 mutations. In all mutant mice, the population size of major CD8alphaalpha^+ and CD8alphabeta^+ alphabeta-IEL subsets was drastically reduced. In beta_2M*TCRdelta double mutant mice, however, the CD8alphaalpha^+ but not CD8alphabeta^+alphabeta-IEL subset expanded dramatically. Thus, in the absence of gammadelta-IEL,alphabeta-IEL in beta_2M deficient mice outnumbered those in wild-type littermates. These results indicate that the generation of CD8alphaalpha^+ lymphocyte population of alphabeta- and gammadelta-IEL is not dependent but t
… More
hat of CD8alphabeta^+ lymphocyte population of alphabeta-IEL is dependent on beta_2M- and/or TAP-1 dependent MHC class I molecules expressed by the controlling cells present in the anatomical site where the development of IEL takes place.
3) After intradermal injection of the autoreactive T cells, delta^<-/-> mice developed significantly enhanced DTH responses and cutaneous GVHD,which persisted longer than those in delta^<+/-> mice. Surprisingly, resistance to the cutaneous GVHD was not induced in the epidermis of delta^<-/-> mice after spontaneous recovery from the GVHD,while the "susceptible" epidermis of delta^<-/-> mice contained large numbers of alphabeta^+ dEC comparable to those in the "resistant" epidermis of delta^<+/-> mice. Injection of day 16 fetal thymocytes from delta^<+/+> mice into delta^<-/-> mice resulted in the appearance of donor-type gammadelta^+ dEC in the epidermis and the reconstitution with the gammadelta^+ dEC restored the protective immune response of the epidermus against the GVHD to nearly normal levels. These results indicate that gammadelta^+ dEC are responsible for the site-restricted protection against cutaneous GVHD. Less
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