T cell-specific expression from Mo-MLV retroviral vectors containing a CD4 mini-promoter/enhancer.
BACKGROUND
Gene therapy of various immunological disorders will greatly benefit from improved retroviral vectors (RVs) with T cell specificity. Such vectors can be designed by placing a gene of therapeutic interest under the control of tissue-specific transcriptional elements. However, low titers and loss of specificity are frequently encountered with tissue-specific vectors. The aim of the present study was to develop a T cell-specific RV.


METHODS
We constructed a series of Moloney murine leukemia virus (Mo-MLV)-based RVs expressing enhanced green fluorescent protein (EGFP) under the control of a mini-promoter/enhancer cassette derived from the CD4 gene (CD4pmE) and tested them in cell lines and peripheral blood lymphocytes. Expression of EGFP was monitored by fluorescence microscopy and analyzed by flow cytometry.


RESULTS
The CD4pmE cassette was inserted between the viral long terminal repeats (LTRs) in self-inactivating vectors (SIN vectors) or was substituted to the 3' U3 viral promoter/enhancer (hybrid vectors). High vector titers but poor specific expression of EGFP were achieved when CD4pmE was inserted in sense orientation in SIN vectors. Low titers but high specificity were observed when the CD4pmE cassette was in anti-sense orientation. In contrast, high titers and good T cell specificity were obtained with hybrid vectors.


CONCLUSIONS
An efficient T cell-specific retroviral vector was obtained.
Zhao-Emonet
J C
JC
Laboratoire de Biologie et Thérapeutique des Pathologies Immunitaires UPMC-CNRS ESA 7087-CERVI-H pital de la Pitié, Paris, France.
Marodon
G
G
Pioche-Durieu
C
C
Cosset
F L
FL
Klatzmann
D
D
D016475:3T3 Cells; D000818:Animals; D015704:CD4 Antigens / Q000235:genetics*; D004274:DNA, Recombinant; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D005822:Genetic Vectors / Q000235:genetics; D049452:Green Fluorescent Proteins; D006801:Humans; D019169:Jurkat Cells; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008979:Moloney murine leukemia virus / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism* / Q000821:virology; D014162:Transfection; D014407:Tumor Cells, Cultured
D015704:CD4 Antigens; D004274:DNA, Recombinant; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins