Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT01586 (G418)
 2,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study reports on the use of gene transfer by retrovirus-derived shuttle vectors in the generation of hybrid hybridomas secreting bispecific monoclonal antibodies. neo- and dhfr- genes were infected into distinct murine hybridomas, thus conferring a dominant resistance trait to geneticin (G418) and to methotrexate. The vectors employed were replication-deficient and dependent on complementation by a helper virus provided by the irradiated packaging lines. After cocultivation with the relevant packaging cell lines, stable hybridoma lines expressing the selectable markers were easily obtained and were then suitable for conventional somatic fusion. This high-efficiency method was used to generate two bispecific monoclonal antibodies simultaneously targeting molecules expressed on cytotoxic cells (i.e., T lymphocytes and natural killer cells) against a human melanoma-associated antigen.
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PMID:Gene transfer by retrovirus-derived shuttle vectors in the generation of murine bispecific monoclonal antibodies. 232 56

This report deals with the use of gene transfer by retrovirus-derived shuttle vectors in a novel model aimed at the generation of hybrid hybridomas secreting bispecific monoclonal antibodies (biMAbs). Following this approach, two genes conferring dominant resistance trait to the neomycine analogue geneticin (G418) and to methotrexate (MTX) respectively, were infected in two established hybridoma lines, each producing a well characterized MAb. The vectors used here were replication-deficient, being dependent on the complementation of helper virus provided by packaging lines. The infection procedure involved co-cultivation of the hybridomas with irradiated packaging cell lines, previously transfected with the vectors and producing the recombinant retroviruses, not inclusive of helper virus in their genome. The packaging lines used were psi2 ecotropic cells made able to produce high titers of virus. Further, the vector pMV7 was carrying G418 resistance while the pSDHT render the cells able to survive MTX. Easy and fast transfer of the dominant selection markers yielded lines of hybridomas to be fused according to the conventional somatic fusions. The resulting double hybridomas were tested for the production of hybrid molecules retaining parental specificity and successively underwent extensive cloning. The purification system featuring the most efficiently between the true biMAbs and the parental immunoglobulins (or other combination products) proved to be HPLC on hydroxylapatite column. The method described above was successful in producing two biMAbs targeting simultaneously molecules expressed on cytotoxic cells (such as CD3 on T-lymphocytes and CD16 on NK cells) and the melanoma-associated antigen Ep2.
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PMID:Gene transfer by retrovirus-derived shuttle vectors in the generation of murine bispecific MAbs. 240 81

Experimental models of vaccination with tumor cells engineered to produce interleukin-4 (IL-4) have shown that the local release of this cytokine is associated with the development of antitumor immunity that may induce regression of established cancer. The aim of this study was to transduce a human melanoma cell line with the gene coding for human IL-4, and to analyze cytokine production, phenotypic characteristics, and antigen expression after transduction. A retroviral vector, constructed by inserting IL-4 cDNA into the LXSN vector, was used to infect the human melanoma cell line Me14932, known to express the MHC class I HLA-A2 and the melanoma-associated antigen Melan-A/MART-1, recognized by HLA-A2-restricted T-cells. The confluence of all G418-resistant cells (Me14932/IL-4) was then analyzed for proviral integration and IL-4 mRNA expression. Substantially stable IL-4 release was detected by ELISA in the supernatant of transduced cells, ranging from 1.6 to 4.6 ng/ml per 10(5) cells per 24 hr; such a cytokine displayed a specific biologic activity, as revealed by the stimulation of blast cell proliferation and the inhibition of lymphokine activated killer cell (LAK) induction by IL-2. After 200 Gy irradiation, IL-4 release remained detectable for 5 weeks, whereas cell proliferation ceased within 7 days. Morphology and immunophenotypic characteristics of the parental cell line (expression of MHC classes I and II, ICAM-1, LFA 3, melanoma-associated antigens, etc.) were retained by the IL-4 gene-transduced melanoma as assayed by microscopy and immunofluorescence; likewise, susceptibility to lysis by LAK cells as well as a T-cell clone recognizing the Melan-A/MART-1 antigen did not change. These results, together with the lack of replication-competent retrovirus, suggest that the Me14932/IL-4 cell line displays suitable characteristics for its use in the treatment of HLA-matched melanoma patients.
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PMID:A human melanoma cell line transduced with an interleukin-4 gene by a retroviral vector releases biologically active IL-4 and maintains the original tumor antigenic phenotype. 857 15