Expression of the diphtheria toxin A-chain coding sequence under the control of promoters and enhancers from immunoglobulin genes as a means of directing toxicity to B-lymphoid cells.
Previous results have shown that cells can be killed by the expression of an introduced gene encoding diphtheria toxin A-fragment (DT-A) and that killing can be targeted using tissue-specific transcriptional regulatory elements. Here, we describe expression plasmids containing the DT-A gene linked with promoters and enhancers from immunoglobulin heavy chain or kappa-light chain genes. When these plasmids were transfected into cultured cells, DT-A was expressed in B-lymphoid cells but not detectably in HeLa cells or fibroblasts. A high specificity for B-cells was confirmed by assaying for luciferase reporter gene expression from a plasmid containing an analogous combination of immunoglobulin heavy chain regulatory elements. A plasmid containing an immunoglobulin-kappa promoter and enhancer was substantially less active in expressing DT-A in a pre-B-cell line than in B-lymphoma cells, suggesting the possibility of targeting DT-A expression to mature, malignant B-cells while sparing normal B-cell progenitors. By means of viral delivery vehicles, the constructs described might be applied in gene therapy for B-cell leukemias or lymphomas.
Maxwell
I H
IH
Division of Medical Oncology, University of Colorado Health Sciences Center, Denver 80262.
Glode
L M
LM
Maxwell
F
F
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival; D004167:Diphtheria Toxin / Q000235:genetics* / Q000494:pharmacology; D004742:Enhancer Elements, Genetic; D005803:Genes, Immunoglobulin; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D010446:Peptide Fragments / Q000235:genetics* / Q000494:pharmacology; D010957:Plasmids; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D014162:Transfection
D004167:Diphtheria Toxin; D010446:Peptide Fragments; C029795:diphtheria toxin fragment A; D008156:Luciferases