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

To generate non-small cell lung cancer (NSCLC)-reactive lymphocytes, we transfected an HLA-A2-expressing human NSCLC line (1355) with the cDNA encoding the lymphocyte co-stimulatory molecule CD80. Following selection in G418, 1355.7 demonstrated stable cell-surface expression of CD80. Allogeneic mixed lymphocyte tumor cell cultures (MLTCs) were established in 600 IU/ml IL-2 using HLA-A2+ normal donor peripheral blood mononuclear cells (PBMCs) stimulated with 1355-P (parental), 1355.7 or IL-2 alone. In 7 of 9 MLTCs, those stimulated with 1355.7 demonstrated enhanced growth after 30 to 45 days of culture. The predominant lymphocyte to grow in all MLTCs was a CD3+alphabeta+CD4+ T cell. In one case, lymphocytes stimulated with 1355.7 (MLTC 2389.7) exhibited preferential lysis of 1355. MLTC 2389.7 was cloned by limiting dilution, and 2 resultant cloids were shown to be NSCLC-reactive and dependent on both MHC class 1 and CD3 in their recognition of tumor cells. Additionally, allogeneic MLTCs were established using three HLA-A2+ NSCLC patients' PBMC. The predominant lymphocyte to grow in these MLTCs was a CD3+ alphabeta+CD8+ T cell. In cytotoxicity studies, MLTC-UKY25.7 demonstrated preferential lysis of 1355-P, 1355.7 and an HLA-A2+ NSCLC cell line, 1650. Lymphocytes from this MLTC did not lyse K562, Daudi or an HLA-A2- NSCLC cell line, 647. Our data suggest that CD80-expressing NSCLC tumor cells may enhance the generation of specific CTLs in vitro. These CTLs could be important reagents for use in cellular immunotherapy and/or in isolating tumor antigens for potential tumor vaccine development.
 ...
PMID:CD80 expression in an HLA-A2-positive human non-small cell lung cancer cell line enhances tumor-specific cytotoxicity of HLA-A2-positive T cells derived from a normal donor and a patient with non-small cell lung cancer. 983 60

CD80, a molecule on the antigen presenting cells, provide costimulation signals for T cell activation and play a key role in tumor immune. Based on our previous work of human CD80 full length cDNA cloning, a retrovirus expression vector pLXSN-CD80 was constructed. CD80 expression cells were selected by G418 from pLXSN-CD80 transfected PA317 and CHO cells by calcium phosphate. Expression, distribution and molecular weight (MW) of CD80 were measured by RIA, FACs and western blot. pLXSN-CD80 transfected CHO cells expressed relatively high level of CD80 protein (approximately the same as Raji cells) with an apparent MW of 40 kD. In the presence of G418 or not, pLXSN-CD80 transfected PA317 and CHO cells maintained CD80 expression for five months of passage. The results indicate that our construct is potent for experimental use in gene therapy.
 ...
PMID:[Construction of human pLXSN-CD80 retrovirus vector and expression in CHO and PA317 cells]. 1254 59

To modulate alloreactivity after hematopoietic stem cell (HSC) transplantation, suicide gene-expressing donor T cells can be administered with an allogeneic T cell-depleted HSC graft. Immune competence of such cells is a critical issue. We have examined the impact of our ex vivo gene transfer protocol (12-day culture period including CD3/IL-2 activation, retrovirus-mediated gene transfer, and G418-based selection) on the phenotype and functional properties of gene-modified cells (GMC). GMC were compared with control cells that had been cultured in parallel with GMC, but nontransduced and nonselected, as well as with peripheral blood mononuclear cells (PBMC). Our data show that phenotypical modifications are similar in control cells and GMC, demonstrating that alterations result from the 12-day culture rather than from the transduction and/or selection process itself. Such modifications include a reversal of CD4/CD8 ratio, activated phenotype (increased expression of CD45RO, CD95, and HLA-DR), and acquisition or increased expression of co-stimulatory molecules (CD80, CD86, and CD40). This led to an enhanced allostimulating potential of GMC, as compared with resting T cells, when used as stimulating cells in mixed lymphocyte reactions. Conversely, when using them as responder cells in mixed lymphocyte reactions, GMC exhibited a rapid loss of alloreactivity that resulted both from culture-dependent and from transduction and/or selection-dependent events. In conclusion, the retrovirus-mediated gene transfer can be associated with major phenotypical and functional alterations that could have strong clinical implications (increased immunogenicity, reduced anti-leukemic effect). Thus, future T cell expansion protocols should try to improve not only cell expansion or gene transfer efficiency, but also T cell functions.
 ...
PMID:Influence of ex vivo expansion and retrovirus-mediated gene transfer on primary T lymphocyte phenotype and functions. 1259 Jul 8

CD80, a costimulatory molecule, plays an important role in eliciting antitumor immunity. Without costimulation, recognition of antigens by T cells may not cause a response, even if tumor cells express MHC class I molecules and specific antigens. On the basis of the recombinant GFP-tagged Kb molecule, we constructed a co-expression vector of CD80 and GFP-tagged Kb molecules. The recombinant fusion was transfected into mouse melanoma B16 cells by electroporation; positive cells were obtained by G418 screening. Highly expressing monoclonal cells, irradiated by 137Cs, were used to immunize mice to obtain specific T cells, which were then cultivated with tumor cells in vitro and examined with a laser confocal microscope. The evident and intense uptake of the antigen peptide-MHC class I-GFP complex by specific T cells was visualized from the culture of B16/CD80-Kb-GFP and T cells. However, little uptake was observed from the culture of B16/Kb-GFP and T cells. These results show that co-expression of CD80 molecules with Kb, an MHC class I molecule, on the surface of B16 tumor cells can enhance the response of specific T cells and thus increase the uptake of the antigen peptide-MHC class I-GFP complex. The absorbed green fluorescence was concentrated mainly on the T cell surface, and this result might pave the way to eluting specific antigen peptides directly from T cells to find and isolate novel tumor-specific antigen peptides.
 ...
PMID:The effect of co-expression costimulatory molecule CD80 on uptake of antigen peptide-MHC class I-GFP complex by specific T cells. 1748 59

A strong CTL response is dependent upon a high level of expression of specific class I major histocompatibility complex (MHC)/peptide complexes at the cell surface. An epitope-linked beta2-microglobulin (beta2m) molecule could provide a simple and more efficient means to enhance the formation of defined MHC/peptide complexes. However, the ability of an epitope-linked beta2m molecule to elicit primary CTL responses in vivo is still unknown. In this study, we modified the P1A tumor cell vaccine by addition of the tumor-associated epitope (TAE)-linked beta2m molecule and co-stimulatory molecule CD80 to improve the efficiency in the application of the vaccine. A eukaryotic co-expression vector consisting of the P1A35-43-linked beta2m molecule and the murine CD80 gene was constructed. P815 cell lines stably expressing P1A35-43-linked beta2m molecule and/or CD80 were established after transfection, by selection under G418. Administration of these inactivated tumor cell vaccines allowed the TAE-specific CD8+ T cell responses to be examined in vivo. Our results indicate that immunization with P815 cells expressing both the P1A35-43-linked beta2m molecule and the murine CD80 gene elicited a significantly stronger antitumor immune response than the single-modified tumor cell vaccines (expressing either P1A35-43-linked beta2m or CD80 alone). These findings support the feasibility and effectiveness of developing a dual-modified tumor cell vaccine consisting of the epitope-linked beta2m molecule and a co-stimulatory molecule.
 ...
PMID:Co-expression of P1A35-43/beta2m fusion protein and co-stimulatory molecule CD80 elicits effective anti-tumor immunity in the P815 mouse mastocytoma tumor model. 1978 42