Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038362 (stomatitis)
 8,852 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Retroviral vectors have had limited success in mediating gene transfer to hematopoietic stem cells, particularly in primates, due in part to low or absent expression of the amphotropic receptor (RAM-1). We have been interested in determining whether retrovirus pseudotyped with vesicular stomatitis virus G protein (VSV-G) would allow more efficient gene delivery to hematopoietic stem cells as the VSV-G receptors appear to be ubiquitously present phospholipids. However, we previously found that completion of retroviral vector reverse transcription does not occur in CD34+ CD38- hematopoietic stem cells that were exposed to VSV-G pseudotyped retrovirus. To determine at which stage the block to infection of CD34+ CD38- cells occurs, we confirmed by FACS analysis that VSV-G pseudotyped viral particles could bind to CD34+ CD38- cells. Virus binding to CD34+ cells was saturable at 4 degrees C but nonsaturable at 37 degrees C, up to a multiplicity of infection of 1080. This suggests that surface levels of phospholipid receptors available for viral binding are limiting on CD34+ cells. Cytokine stimulation increased virus binding to CD34+ cells. However, no increase in the level of surface phosphatidylserine (PS), a strong candidate for the VSV-G receptor, was seen as detected by the PS-specific reagent, annexin V. This suggests that another molecule is serving as the VSV-G receptor on CD34+ cells. Here, we show that once virus binding to cytokine-stimulated CD34+ CD38- cells has occurred, virus fusion proceeds efficiently as determined by octadecyl rhodamine (R18) fusion assays. Taken together with our previous observation that reverse transcription does not occur in CD34+ CD38- cells, we suggest that there are intracellular mechanisms leading to blockage of complete reverse transcription of the retrovirus in CD34+ CD38- cells. This has important implications for retrovirus-mediated gene transfer to quiescent stem cells.
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PMID:Interaction of vesicular stomatitis virus-G pseudotyped retrovirus with CD34+ and CD34+ CD38- hematopoietic progenitor cells. 934 28

The major limitations of Moloney murine leukemia virus (MoMLV)-based vectors for human stem cell applications, particularly those requiring bone marrow (BM) stem cells, include their requirement for mitosis and retroviral receptor expression. New vectors based upon lentiviruses such as HIV-1 exhibit properties that may circumvent these problems. We report that novel third-generation, self-inactivating lentiviral vectors, expressing enhanced green fluorescent protein (EGFP) and pseudotyped with vesicular stomatitis virus G glycoprotein (VSV-G), can efficiently transduce primitive human repopulating cells derived from human BM and cord blood (CB) tested by the SCID-repopulating cell (SRC) assay. Highly purified CD34+ CD38- CB or BM cells were efficiently transduced (4-69%) and stably expressed in EGFP for 40 days in culture following infection for only 24 h without fibronectin, polybrene, or cytokines. Nonobese diabetic/severe combined immune-deficient (NOD/SCID) mice transplanted with transduced cells from either CB or BM donors were well engrafted, demonstrating maintenance of SRC during the infection procedure. Serially obtained femoral BM samples indicated that the proportion of EGFP+ cells within both myeloid and lymphoid lineages was maintained or even increased over time, averaging 42.3 +/- 6.6% for BM donors and 23.3 +/- 7.2% for CB at 12 weeks. Thus, the third-generation lentivectors readily transduce human CB and BM stem cells, under minimal conditions of ex vivo culture, where MoMLV-based vectors are ineffective. Since CB is inappropriate for most therapeutic applications, the efficient maintenance and transduction of BM-derived SRC during the short infection procedure are notable advantages of lentivectors.
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PMID:Transduction of human CD34+ CD38- bone marrow and cord blood-derived SCID-repopulating cells with third-generation lentiviral vectors. 1093 81