“The 75th of Stem Cell Biology and Regenerative Medicine Forum”
Date：Nov 27th (Thu) 2014
Time : 18:00 〜 19:30
Place：8th fl of New Hospital Building------------------------------------------------------------------------------------------------------------------------------------（Internal Speaker）
18:00-18:30 Takashi Ishida（Division of Stem Cell Therapy, Center for Stem Cell Biology
and Regenerative Medicine, IMSUT, Tokyo, Japan）
A Novel Strategy to Overcome The Cell Dose Barrier to Umbilical Cord
Blood Transplants: A Proof of Benefits for Transplantation by Combined
Multiple Units of Allogeneic Stem/Progenitor Cells（External Speaker）
18:30-19:30
Takashi Okada（Department of Biochemistry and Molecular BiologyNippon Medical School）
AAV vector transduction strategy with MSCs-mediated immune-modulation
to ameliorate neuromuscular disorders

19:30-Get-Together-------------------------------------------------------------------------------------------------------------------------------------

Hosted by Center for Stem Cell Biology and Regenerative Medicine---Information--＊ Please register attendance at the reception desk.
＊ Next forum（the76th）will be held on Dec 19th（Fri）16:30〜 at Auditorium in 1st Building.
＊ Please contact tatsu-m@ims.u-tokyo.ac.jp, for Forum speaker recommendations

A Novel Strategy to Overcome The Cell Dose Barrier to Umbilical Cord Blood
Transplants: A Proof of Benefits for Transplantation by Combined Multiple
Units of Allogeneic Stem/Progenitor Cells.
Takashi Ishida (Division of Stem Cell Therapy, Center for Stem Cell Biology
and Regenerative Medicine, IMSUT)
Umbilical cord blood (UCB) currently serves as a suitable donor source inhematopoietic stem cell transplantation. However, the time to engraftment is often
delayed due to its low graft cell doses, which may limit its use in the clinicalsetting, particularly for adult patients. To overcome this cell dose barrier, UCB
transplantation (UCBT) using double units has been performed worldwide, but therapid engraftment has not yet been achieved. Besides, according to the report by
Japan Red Cross Society, the majority of UCB units remain unused clinically with
their cell doses having failed to meet the minimum standard. Overall, these facts
boosted us to look for a new strategy so as to ameliorate UCBT by using multiple(more than three) units.
We have obtained by utilizing mouse transplantation models a proof of conceptthat combined multiple units of allogeneic hematopoietic stem/progenitor cells(HSPCs) are capable of supporting early hematopoiesis during a bone marrow
suppression phase (we call this “bridging effect”). A mixture of allogeneic HSPCs,
rendered devoid of mature immune cells, was shown to protect lethally-irradiatedrecipient mice, and to accelerate hematopoietic recovery when infused additionallywith the single-unit congenic graft. Furthermore, we succeeded in enhancement of
its “bridging effect” by appropriately manipulating a mixture of allogeneic HSPCs.
The experimental details will be presented with some results regarding
manipulation of frozen human cord blood units, with which we are aiming for a
proof of concept study for future clinical application.

AAV vector transduction strategy with MSCs-mediated immune-modulation
to ameliorate neuromuscular disorders
Takashi Okada（Department of Biochemistry and Molecular Biology
Nippon Medical School）
The particular characteristics of adeno-associated virus (AAV)-based vectors withsafety and long-term expression have made it an attractive transduction tool forclinical gene therapy. Although host immune reaction against the vector as well astransgene products has been denoted in the clinical studies of neuromuscular genetherapy, there have been various successful observations. As great news for genetherapy community, European Medicines Agency finally recommended first genetherapy medicine for approval to treat LPL deficiency by using AAV vector.
However, in vivo gene transduction with the AAV-based vectors depends uponlaborious procedures for the production of the vector stocks to meet end-productspecifications. We developed a method of producing AAV vectors with scalable
purification protocol using the high-performance membrane adsorbers forconsiderable in vivo experimentation and clinical investigations.
We have adopted the efficient production system to investigate AAV
vector-mediated muscle transduction for the treatment of Duchenne muscular
dystrophy (DMD). Cardiac transduction of mdx dystrophic mice by therAAV9-microdystrophin successfully improved EKG abnormalities as well as
cardiac dysfunction. In contrast, muscle transduction with rAAV in normal Beagles
and canine X-linked muscular dystrophy in Japan (CXMDJ) resulted in thetransgene expression during a limited period. Although intramuscular rAAV
injection showed effective transgene expression, the innate immune responseshould be considered to improve transduction protocol. Therefore, to investigate
therapeutic benefits of the microdystrophin in the canine model, we transduced
fetuses of CXMDJ with systemic administration of the rAAV9-microdystrophin.
Transduced dogs demonstrated long-term transgene expression with functional
improvement. Furthermore, mesenchymal multipotent stromal cells (MSCs) shouldbe effective platform to induce immunotolerance. Interestingly, intravenous
injection of MSCs with rAAV9-microdystrophin greatly improved transgene
expression as well as locomotive function in CXMDJ. These results suggest that
long-term transgene expression with therapeutic benefits in neuromusculardisorders would be achieved by the rAAV-mediated transduction strategy with anadequate regimen to regulate host immure response.