home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Software Vault: The Sapphire Collection
/
Software Vault (Sapphire Collection) (Digital Impact).ISO
/
cdr16
/
med9410e.zip
/
M94B0777.TXT
< prev
next >
Wrap
Text File
|
1994-11-11
|
5KB
|
71 lines
Document 0777
DOCN M94B0777
TI Reconstitution of viral immunity by the adoptive transfer of T-cell
clones modified by gene insertion (Meeting abstract).
DT 9412
AU Greenberg P; Watanabe K; Gilbert M; Nelson B; Riddell S; Univ. of
Washington, Seattle, WA 98195
SO EACR-12: 12th Biennial Meeting of the European Association for Cancer
Research. April 4-7, 1993, Brussels, Belgium, 1993.. Unique Identifier :
AIDSLINE ICDB/94697579
AB The essential role of CD8+ Tc for protection from CMV disease is
supported by studies in which we demonstrated that patients who
endogenously reconstitute their CMV-specific CD8+ Tc response are
protected from the development of CMV disease, whereas patients lacking
this response are at high risk for disease. Our initial adoptive T-cell
therapy protocol is described. None of the patients who received
adoptive T-cell therapy developed subsequent evidence of CMV disease.
Our laboratory is now evaluating methods to improve the efficacy and
safety of adoptive T-cell transfer by the introduction of genes into
T-cell clones. To improve safety, a retroviral vector containing an
inducible suicide gene has been constructed (Targeted Genetics
Corporation): herpes virus thymidine kinase (TK) gene has been fused in
frame with the hph gene, resulting in a gene encoding a single
bifunctional protein (HyTK) conferring hygromycin resistance and in
vitro sensitivity to ganciclovir. Studies in mice have demonstrated that
T-cell clones expressing this gene can be readily eliminated in vivo by
the administration of nontoxic doses of ganciclovir. A clinical trial
employing T cells modified with this gene, now underway in
HIV-seropositive patients undergoing allogeneic BMT for the treatment of
HIV-related lymphomas is described. The therapeutic efficacy of
transferred CD8+ T-cell clones in murine models is limited by the
inability of the clones to proliferate and survive long-term in vivo in
the absence of either exogenous IL-2 or a concurrent CD4+ helper T-cell
response. Therefore, we are attempting to modify CD8+ T cells to render
them independent of exogenous growth factors and capable of
proliferating in response to TCR ligation. Several types of gene
constructs are being evaluated. The first is designed to provide the
additional signals necessary to result in endogenous IL-2 production
following T-cell activation. Based on previous studies of bifunctional
CD8+ T cells isolated from mice, CD8+ Tc clones were transduced with a
vector containing the gene for the IL-1 receptor. Such T cells
proliferate in response to binding of ligands to both the TCR and IL-1R,
but fail to proliferate in response to either signal alone. A second
type of construct involves the generation of a hybrid gene, in which the
IL-2 coding sequence is under control of a promoter normally activated
by TCR ligation. Preliminary studies are being performed with a vector
containing the IFN-gamma promoter driving an IL-2 cDNA. Finally, a third
type of construct containing chimeric cytokine receptors potentially
capable of providing an autocrine loop and delivering to a T cell the
signal normally provided by the binding of IL-2 to its receptor is being
evaluated. Our initial studies are with a vector containing the
extracellular domain of the c-kit receptor fused in frame to the
transmembrane and intracytoplasmic domains of the IL-2 receptor beta and
gamma chains. Binding of c-kit results in dimerization of the beta and
gamma chains and delivery of the IL-2 receptor growth signal to T cells.
Constructs fusing the extracellular binding domains of GM-CSF with the
intracellular IL-2 receptor beta and gamma chains are now being
prepared.
DE Animal Antigens, CD8/CHEMISTRY Cell Division Cloning, Molecular
Cytomegalovirus Infections/IMMUNOLOGY/*THERAPY DNA,
Complementary/GENETICS Ganciclovir/THERAPEUTIC USE HIV Infections/DRUG
THERAPY Human *Immunotherapy, Adoptive Interferon Type II/GENETICS
Interleukin-2/GENETICS Mice Receptors, Antigen, T-Cell/METABOLISM
Receptors, Interleukin-1/METABOLISM Simplexvirus/GENETICS
T-Lymphocytes/PATHOLOGY T-Lymphocytes, Cytotoxic/IMMUNOLOGY Thymidine
Kinase/GENETICS Zidovudine/THERAPEUTIC USE MEETING ABSTRACT
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).