Adenovirus vectors for gene transduction into mobilized blood CD34+ cells.

Mobilized blood CD34+ cells from cancer patients were ex vivo infected by a recombinant adenovirus vector carrying an alkaline phosphatase gene, whose expression is evaluable by flow cytometry. A mean of 40% CD34+ cells were infected by the vector, with high levels of expression of the transgene. Among attempts to improve infection efficiency by manipulating culture conditions, only reinfection by the same vector achieved a 10% increase of transgene expression.

Mobilized peripheral blood CD34+ cells express more amphotropic retrovirus receptor than bone marrow CD34+ cells.

Background And Objective: The increased susceptibility to gene transfer by amphotropic retroviral vectors of mobilized peripheral blood (PB) CD34+ cells compared to their bone marrow (BM) counterparts may depend, among other factors, on the level of expression of the amphotropic receptor on the progenitor cell. Using a previously described flow cytometry strategy, we have studied retrovirus binding to mobilized CD+ cells, derived from cancer patients treated with high-dose chemotherapy and growth factor(s), that are efficiently transduced by N2 retrovirus vector.

Design And Methods: We measured the binding of the retrovirus to the cells using a rat monoclonal antibody reactive with the gp70 envelope glycoprotein, common to all replication-defective amphotropic retroviruses.

Induction of cyclophosphamide-resistance by aldehyde-dehydrogenase gene transfer.

The identification of genes inducing resistance to anticancer chemotherapeutic agents and their introduction into hematopoietic cells represents a promising approach to overcome bone marrow toxicity, the limiting factor for most high-dose chemotherapy regimens. Because resistance to cyclophosphamide has been correlated with increased levels of expression of the aldehyde-dehydrogenase (ALDH1) gene in tumor cell lines in vitro, we tested whether ALDH1 overexpression could directly induce cyclophosphamide resistance. We have cloned a full-length human ALDH1 cDNA and used retroviral vectors to transduce it into human (U937) and murine (L1210) hematopoietic cell lines that were then tested for resistance to maphosphamide, an active analogue of cyclophosphamide.

Generation of human monoclonal antibodies by transformation of lymphoblastoid B cells with ras oncogene.

Human monoclonal antibodies (hu-mAbs) of predetermined specificity and isotype are potentially important for a variety of applications, including therapy and diagnosis. Their efficient generation, however, is still hampered by technical difficulties. Even the most established approaches to the generation of hu-mAbs, i.

Activation of the M-CSF gene in mouse macrophages immortalized by retroviruses carrying a v-myc oncogene.

We have recently immortalized murine brain macrophages (microglial cells) with a complex of retroviruses (3RV) transducing separately the myc and mil oncogenes. Surprisingly, the immortalized cells harboured an exogenous v-myc oncogene, but no v-mil sequences. The transformed macrophage cell lines grew in vitro without the addition of exogenous growth factors and were also able to grow in vivo in nude mice.