|Budget Amount *help
¥2,300,000 (Direct Cost : ¥2,300,000)
Fiscal Year 1996 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1995 : ¥1,300,000 (Direct Cost : ¥1,300,000)
During my term of project, following results were obtained.
1) Thymic stromal cell lines were established from BALB/c and AKR/J strains of mice.
2) One of stromal cell lines from BALB/c strain expressed Thy 1 molecules. An inhibitory signal for growth was shown to be transduced from Thy 1 molecules.
3) Some of stromal cell lines were shown to express Src-family protein tyrosine kinases, such as Src and Fgr. And medullary stromal cells were positive for Fgr proteins by immunohistology with anti-Fgr mAb, 2H2 which was established in our laboratory. (Microbiol.Immunol.40 : 223,1996.)
4) Selective activation for effector functions of DB14 T-cell clone was exhibited when an antigenic peptide was presented with thymic cortical and medullary epithelial cell lines (ibid.41 : 51,1997).
5) Fifteen mAbs were established against stromal cells of AKR/J origin. Four clones of hydridoma were established with limiting dilution method. With mAbs, HI-C,HI-M,HI-E,and HI-F,tissue and strain distributions were
6) Stromal cells were cultured in 3-dimension in gel or on highly porous beads for in vivo transfer. Among materials tested, gelatin-based porous beads (Cultispher^<TM>, Percell Biolytica) and fibrin clot in combination with gelatin beads could be candidates for biocompatible carriers for transfer or transplantation of re-organized stromal cells, or artificial thymus. Biocompatibility, especially on adhesion between stromal cells and bead surface should be improved.
7) Transplanted stromal cells in gel under kidney capsule were observed as one to several layrs of stromal cells with an infiltration of mononuclear cells. These artificial thymi in situ did not seem to function as thymic tissues but induced inflammatory responses.
8) Re-organization of thymic tissue with stromal cells of defined origins should be performed without any loss of certain types of stromal cells, since negative selection seemed perturbed in the thymus of aly/aly (alymphoplasia) mutant mouse that has a defect in medullary function due to a loss of a certain cell type or a molecule on certain cell (Proc.Natl.Acad.Sci.USA 94 : 2472,1997). Less