Third-party umbilical cord blood-derived regulatory T cells prevent xenogenic graft-versus-host disease.
OBJECTIVE
Naturally occurring regulatory T cells (Treg) are emerging as a promising approach for prevention of graft-versus-host disease (GvHD), which remains an obstacle to the successful outcome of allogeneic hematopoietic stem cell transplantation. However, Treg only constitute 1-5% of total nucleated cells in cord blood (CB) (<3 × 10⁶ cells), and therefore novel methods of Treg expansion to generate clinically relevant numbers are needed.


METHODS
Several methodologies are currently being used for ex vivo Treg expansion. We report a new approach to expand Treg from CB and demonstrate their efficacy in vitro by blunting allogeneic mixed lymphocyte reactions and in vivo by preventing GvHD through the use of a xenogenic GvHD mouse model.


RESULTS
With the use of magnetic cell sorting, naturally occurring Treg were isolated from CB by the positive selection of CD25⁺ cells. These were expanded to clinically relevant numbers by use of CD3/28 co-expressing Dynabeads and interleukin (IL)-2. Ex vivo-expanded Treg were CD4⁺25⁺ FOXP3⁺127(lo) and expressed a polyclonal T-cell receptor, Vβ repertoire. When compared with conventional T-lymphocytes (CD4⁺25⁻ cells), Treg consistently showed demethylation of the FOXP3 TSDR promoter region and suppression of allogeneic proliferation responses in vitro.


CONCLUSIONS
In our NOD-SCID IL-2Rγ(null) xenogeneic model of GvHD, prophylactic injection of third-party, CB-derived, ex vivo-expanded Treg led to the prevention of GvHD that translated into improved GvHD score, decreased circulating inflammatory cytokines and significantly superior overall survival. This model of xenogenic GvHD can be used to study the mechanism of action of CB Treg as well as other therapeutic interventions.
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA. Electronic address: sparmar@mdanderson.org.
Simrit
S
Parmar
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Xiaoying
X
Liu
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Shawndeep S
SS
Tung
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Simon N
SN
Robinson
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Gabriel
G
Rodriguez
Division of Pediatrics, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Laurence J N
LJ
Cooper
Department of Leukemia, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Hui
H
Yang
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Nina
N
Shah
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Hong
H
Yang
Department of Leukemia, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Marina
M
Konopleva
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Jeffery J
JJ
Molldrem
Department of Leukemia, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Guillermo
G
Garcia-Manero
Department of Experimental Diagnostic Imaging, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Amer
A
Najjar
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Eric
E
Yvon
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Ian
I
McNiece
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Katy
K
Rezvani
Department of Pediatrics and Immunology, Baylor College of Medicine, Houston, Texas, USA.
Barbara
B
Savoldo
Department of Pediatrics, Medicine and Immunology, Baylor College of Medicine, Houston, Texas, USA.
Catherine M
CM
Bollard
Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, USA.
Elizabeth J
EJ
Shpall
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000637:transplantation; D049109:Cell Proliferation; D064987:Cell- and Tissue-Based Therapy; D005312:Fetal Blood / Q000166:cytology / Q000637:transplantation*; D006086:Graft vs Host Disease / Q000473:pathology / Q000628:therapy*; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects; D006801:Humans; D051379:Mice; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000637:transplantation; D014184:Transplantation, Homologous / Q000009:adverse effects*
cord blood; graft vs. host disease; regulatory T cells; xenogenic GVHD model