Summary of Research Project Results under JSPS FY2004
"Research for the Future Program"

1. Research Institution   Kyushu University
2. Research Area Life Sciences
3. Research Field Development, Differentiation, Regeneration
4. Term of Project FY 2000 - FY 2004
5. Project Number 00L01502
6. Title of Project Regulation of Immune Response Based on Immuno-cytology and its Clinical Application to Cell Transplantation Medicine

7. Project Leader

Name Institution, Department Title of Position
Kenzaburo, Tani Kyushu University, Medical Institute of Bioregulation Professor

8. Core Members

Names Institution, Department Title of Position
Toshio, Kitamura The University of Tokyo, The Institute of Medical Science Professor
Yoichiro, Iwakura The University of Tokyo, The Institute of Medical Science Professor
Satoshi, Takaki The University of Tokyo, The Institute of Medical Science Associate Professor

9. Summary of Research Results

  1. Efficient hematopoietic cells induction from common marmoset (CM) embryonic stem(ES) cells: We have tried various in vitro conditions to induce hematopoietic stem cells from CM ES cells. The efficiency, however, was so poor and we lentivirally transduced 6 known hematopoiesis-related genes into CM-ES cells. We found tal1/scl gene efficiently induced CM CD34 positive cells in vitro.
  2. Establishment of CM ES cells: We have established 3 new CM-ES cell lines and demonstrated their pluripotencies in vitro and in vivo, which were not demonstrated in CM-ES cell lines established by Thomson et al., previously. Our lines will be very helpful to develop human ES cell therapies as well as human disease models in monkeys.
  3. Identification and cloning of new stem cell expansion factors (1) Identification of hematopoietic stem cell or progenitors (HSC/Ps) expansion factor: The ability of HSC/Ps to reconstitute the hematopoietic system of irradiated hosts is significantly enhanced in the absence of an intracellular adaptor protein, Lnk. We have developed a Lnk mutant that dominant-negatively inhibits the functions of Lnk endogenously expressed in the HSC/Ps and potentiate them for engraftment. Inhibition of Lnk-mediated pathways could be a potent approach to augment HSC/P engraftment without obvious side effects. (2) Identification of stromal cell derived HSC/Ps expansion factor and ES cell maintenance factor: We have cloned ISF (immune suppressor factor) gene using retroviral expression cloning methods and demonstrated its supporting ability of long-term culture-initiating cells when ISF was expressed in bone marrow stromal cells. The HSC/Ps proliferative activities were induced by Wint3a and Tie2, respectively through the suppression of TIMP3 and SFRP-1. Also, our results suggested Wint3a played important roles in the maintenance of ES cells. (3) Identification of tissue homing factor: Our results suggested that the CXCR4-SDF-1 system might be useful to localize CXCR4-expressing cells to bone surface.

10. Key Words

( 1 ) common marmoset ( 2 ) embryonic stem cell ( 3 ) hematopoietic stem cells
( 4 ) lentiviral vector ( 5 ) tal1/scl ( 6 ) Lnk
( 7 ) ISF ( 8 ) CXCR4 ( 9 ) SDF-1