G-CSF mobilized peripheral blood mononuclear cell products (G- PBMC), specifically CD14+ monocytes and CD4+ T cells, differ in function from comparable populations isolated either from aspirated marrow or from normal blood. Studies indicate that the CD14 cells in this population have reduced expression of HLA-DR as well as B7.2, a co-stimulatory molecule needed for T-cell activation. In addition, the CD14+ cells secrete significantly increased amounts of interleukin-10 (IL-10) which inhibit T-cell proliferation and gamma-interferon production. The ration of CD14+ cells to CD4+ cells in G-PBMC is increased 5-fold. Studies indicate that this increased population of CD14+ cells reduces the ability of CD4 cells to utilize the CD28 signaling pathway and respond to alloantigen. Based on these observations we hypothesize that the monocytes contained within the G-PBMC may provide immunosuppressive effects that can inhibit both graft-versus-host and host-versus- graft reactions, thereby facilitating alloengraftment. To test this hypothesis we have used an established canine transplant model involving DLA-identical donor/recipient pairs in which the endpoint of transplantation, stable mixed hematopoietic chimerism, is obtained with non-myeloablative condition regimen. Currently this is achieved using 200 cGy of total body irradiation (TBI) plus 35 days of cyclosporine and mycophenolate mofetil (MMF). However, a further decrease in the irradiation dose or the elimination of MMF results in donor graft failure. This is a unambiguous result easily documented by VNTR analysis. Using this model we have determined that unfractionated G-PBMC can replace the requirement of MMF for establishing long-term stable mixed chimerism. Importantly, the donor chimerism achieved in the marrow is greater than 70% and there was no evidence of graft-versus-host disease. Studies proposed in this application will test the hypothesis that monocytes are responsible for this graft facilitating effect. The effective G-PBMC population will be identified by selective depletion of the product prior to its use in the aforementioned transplantation model. Once this is accomplished, the G-PBMC product will be optimized and used to replace TBI. Our final goal is to use the G-PBMC product to establish a non-toxic conditioning regimen to achieve stable mixed chimerism in haploidentical donor/recipient pairs.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK051417-08
Application #
6524196
Study Section
Hematology Subcommittee 2 (HEM)
Program Officer
Badman, David G
Project Start
1995-09-30
Project End
2004-08-31
Budget Start
2002-09-01
Budget End
2003-08-31
Support Year
8
Fiscal Year
2002
Total Cost
$457,543
Indirect Cost
Name
Fred Hutchinson Cancer Research Center
Department
Type
DUNS #
075524595
City
Seattle
State
WA
Country
United States
Zip Code
98109
Kahl, Christoph; Mielcarek, Marco; Iwata, Mineo et al. (2004) Radiation dose determines the degree of myeloid engraftment after nonmyeloablative stem cell transplantation. Biol Blood Marrow Transplant 10:826-33
Junghanss, Christian; Takatu, Alessandra; Little, Marie-Terese et al. (2003) Adoptive immunotherapy against kidney targets in dog-leukocyte antigen-identical mixed hematopoietic canine chimeras. Transplantation 75:268-74
Kuhr, Christian S; Allen, Margaret D; Junghanss, Christian et al. (2002) Tolerance to vascularized kidney grafts in canine mixed hematopoietic chimeras. Transplantation 73:1487-92
Zaucha, J M; Gooley, T; Bensinger, W I et al. (2001) CD34 cell dose in granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell grafts affects engraftment kinetics and development of extensive chronic graft-versus-host disease after human leukocyte antigen-identical sibling transpla Blood 98:3221-7
Graf, L; Heimfeld, S; Torok-Storb, B (2001) Comparison of gene expression in CD34+ cells from bone marrow and G-CSF-mobilized peripheral blood by high-density oligonucleotide array analysis. Biol Blood Marrow Transplant 7:486-94
Zaucha, J M; Zellmer, E; Georges, G et al. (2001) G-CSF-mobilized peripheral blood mononuclear cells added to marrow facilitates engraftment in nonmyeloablated canine recipients: CD3 cells are required. Biol Blood Marrow Transplant 7:613-9
Iwata, M; Vieira, J; Byrne, M et al. (1999) Interleukin-1 (IL-1) inhibits growth of cytomegalovirus in human marrow stromal cells: inhibition is reversed upon removal of IL-1. Blood 94:572-8
Torok-Storb, B; Iwata, M; Graf, L et al. (1999) Dissecting the marrow microenvironment. Ann N Y Acad Sci 872:164-70
Tanaka, J; Mielcarek, M; Torok-Storb, B (1998) Impaired induction of the CD28-responsive complex in granulocyte colony-stimulating factor mobilized CD4 T cells. Blood 91:347-52
Mielcarek, M; Graf, L; Johnson, G et al. (1998) Production of interleukin-10 by granulocyte colony-stimulating factor-mobilized blood products: a mechanism for monocyte-mediated suppression of T-cell proliferation. Blood 92:215-22

Showing the most recent 10 out of 11 publications