Les systèmes alternatifs de production d’anticorps monoclonaux thérapeutiques

Les anticorps monoclonaux thérapeutiques commercialisés ou en développement sont produits à partir de cellules de mammifères en culture, dont notamment la cellule de hamster CHO. Ces systèmes cellulaires permettent la production industrielle de protéines complexes possédant des structures, activités biologiques et propriétés pharmacodynamiques proches des protéines naturelles. Mais des coûts de production élevés et un prix du traitement prohibitif pourraient dans l’avenir limiter l’accessibilité de ces thérapies innovantes au plus grand nombre et freiner ce marché pourtant en très fort développement. Parallèlement à l’optimisation de la productivité des systèmes mammaliens, l’industrie pharmaceutique et biotechnologique développe activement des systèmes de production alternatifs espérés moins coûteux, plus efficaces et permettant une amélioration de l’efficacité thérapeutique des anticorps thérapeutiques

Les genes de maintenance : etude du gene HMGCoA reductase in vitro et dans les souris transgeniques

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Transcription Map and Expression of Bovine Herpesvirus-1 Glycoprotein D in Early Region 4 of Bovine Adenovirus-3

AbstractEarly region 4 (E4) of bovine adenovirus type 3 (BAV-3) was analyzed by Northern blotting, RT–PCR analysis, cDNA sequencing, and S1 nuclease protection assays. The transcriptional map of the E4 region of BAV-3 has marked dissimilarities from those of mouse adenovirus-1, ovine adenovirus-287, and human adenovirus-2, for which the transcriptional maps have been constructed. The E4 region of BAV-3, located between 98.6 and 89.8 MU transcribes seven distinct classes of bovine adenovirus type 3 mRNA. The seven mRNA species formed by the removal of one to three introns share both the 3′ end and a short 5′ leader (25 nucleotides). The E4 mRNAs can encode at least five unique polypeptides, namely, 143R1, 69R, 143R2, 268R, and 219R. Isolation of a replication-competent recombinant “BAV404” containing 1.9-kb insertion [glycoprotein (gD) of bovine herpesvirus 1, under the control of a SV40 early promoter and poly(A)] in the region between E4 and the right ITR suggested that this region is nonessential for BAV-3 replication. Expression of gD by BAV404 recombinant virus was confirmed by immunoprecipitation with gD-specific monoclonal antibodies. Analysis of the kinetics of protein expression indicated that gD is expressed at both early and late times postinfection. These results suggest that: (a) E4 produces seven 5′–3′ coterminal mRNAs and (b) the right terminal region of BAV-3 can be used for the expression of vaccine antigens

Induced Expression of B7-1 on Myeloma Cells Following Retroviral Gene Transfer Results in Tumor-Specific Recognition by Cytotoxic T Cells

Abstract The aim of this study was to evaluate whether tumor cells from patients with multiple myeloma activate allogeneic and autologous T cells. Results showed that myeloma cells expressed few B7-2 and no B7-1 in six cell lines and primary cells from 11 patients. They expressed substantial levels of HLA class I, CD40, and a set of adhesion molecules. In accordance with the low density of B7 molecules on these cells, they were poor allogeneic CD8+ T cell stimulators. Neither IFN-γ plus TNF-α nor CD40 stimulation significantly induced B7-1 or up-regulated B7-2 on human myeloma cell line or primary myeloma cells from six of seven patients. However, such induction was found on autologous bone-marrow nontumoral cells and on autologous dendritic cells following CD40 stimulation. High B7-1 expression was stably obtained on human myeloma cell line using transduction with a B7-1 retrovirus, enabling these cells to stimulate allogeneic CD8+, though not CD4+, T cell proliferation. For one patient with advanced disease, B7-1 gene transfer made it possible to amplify autologous cytotoxic T cells that killed autologous myeloma cells in an HLA class I-restricted manner, but not autologous PHA blasts. These results suggest that B7-1 gene transfer could be a promising immunotherapeutic approach in multiple myeloma.</jats:p