| |
|
|
|
|
|
|
|||
|
T Kuhr, GJ Dougherty and HG Klingemann
Leukemia/Bone Marrow Transplant Program of British Columbia, Terry Fox
Laboratory, Vancouver, Canada.
Relapse of leukemia is the major cause of failure after autologous stem
cell transplantation due to reinfusion of residual clonogenic cells and the
absence of an immune-mediated graft-versus-leukemia effect. To provide an
antileukemia effect, immune-activating cytokines have been given to
patients after transplantation. Systemic administration of such cytokines
early after transplantation is often accompanied by substantial side
effects, and it is unknown whether sufficient concentrations reach the
sites of residual disease in the marrow. As a method of site-directed
immunotherapy provided early after stem cell transplantation, we have
tested in a murine model whether (1) marrow can be retrovirally transduced
with the tumor necrosis factor alpha (TNF alpha) gene, (2) local production
of TNF alpha by marrow cells after transplantation can be achieved, and (3)
adverse effects of TNF alpha occurred. Balb/c mice were treated with
5-fluorouracil and bone marrow (BM) was obtained 4 days later. Whole BM was
transduced in the presence of interleukin-3 (IL-3), IL-6, and stem cell
factor by coculture with the packaging cell line GP+E-86, producing the
cDNA for TNF alpha. Irradiated (1,300 cGy) syngeneic recipient mice were
given 10(6) transduced BM cells on day 0. Integration of the TNF alpha gene
into the host genome was documented by Southern blotting in spleen and BM
cells on days 7 and 12 and in BM on day 40 after marrow infusion, but was
no longer found on day 90. Messenger RNA for TNF alpha was present on day
12, but could no longer be shown on day 40 or 90. Although no measurable
(L929 bioassay) levels of TNF alpha were found in serum of mice who had
received TNF alpha transduced marrow, the supernatant of 10(6) unstimulated
BM cells obtained 12 days after marrow infusion was found to have 7 pg of
TNF alpha compared with 1.8 pg in nontransduced marrow. Mice that had
received TNF alpha transduced marrow showed no side effects suggestive of
systemic TNF alpha release, and cellularity of the TNF alpha-transduced
marrow was not different from control mice that had received unmanipulated
marrow or cells transduced with the neomycin resistance gene only. The
studies suggest that gene transfer of immune-activating cytokines into
hematopoietic cells could be used as a means to achieve their temporary
local production early after transplantation by cells located in the BM.
This article has been cited by other articles:
| |||||||||||
| Copyright © 1994 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||