Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A murine cell line, EH, expressing the gag and pol proteins of Moloney murine leukemia virus (Mo-MLV) as well as an Mo-MLV recombinant genome with a selectable marker (histidinol dehydrogenase), was transfected with a plasmid coding for the gene of the human T-cell leukemia virus type I (HTLV-I) envelope precursor (gp62), placed under the control of the human cytomegalovirus immediate early promoter. One clone, T. 14, was recovered, in which gp62 RNA and protein were detected. Supernatant from this clone transferred the HisD gene to a panel of cell lines which express receptors for HTLV-I, but was unable to pass the marker gene to cells which do not express receptors. The colony-forming units were sensitive to HTLV-I receptor interference and to specific neutralization by anti-HTLV-I serum. These data show that hybrid virions were produced in which the envelope proteins of HTLV-I had pseudotyped Mo-MLV capside particles containing a selectable recombinant viral genome.
 ...
PMID:A murine cell line producing HTLV-I pseudotype virions carrying a selectable marker gene. 184 35

A retrovirus vector has been developed that selects for instances in which the provirus integrates in close proximity to cellular promoters. Coding sequences for a selectable marker (histidinol dehydrogenase) were inserted into the 3' long terminal repeat (LTR) of an enhancerless Molony murine leukemia virus. Although 1.8 kilobase pairs in size, the elongated LTR did not appear to interfere with virus replication or integration. Thus, when the virus was passaged, the elongated LTRs efficiently duplicated, placing histidinol dehydrogenase-coding sequences in the 5' LTR just 30 nucleotides from the flanking cellular DNA. Selection for histidinol expression generated cell clones in which histidinol gene sequences in the 5' LTR were invariably expressed on transcripts initiating in nearby cellular sequences. The efficiency of transducing histidinol resistance was 2,500-fold lower than the efficiency of transducing neomycin resistance when the neomycin phosphotransferase gene was located within the retrovirus and expressed from an independent promoter. By tagging transcriptionally active sites, the vector provides a means to identify and isolate promoters active in different cell types. Furthermore, the virus may be useful as an insertional mutagen, since selection for cell populations containing proviruses only in expressed sites is expected to reduce the number of intergrants needed to screen for loss of gene function.
 ...
PMID:Identification of cellular promoters by using a retrovirus promoter trap. 254