The role of eosinophilia in allergic disorders indicates hIL-5 as a target of therapy. The conservation of hIL-5 proximal elements suggests they are important in controlling expression. Corticosteroids are important in the treatment of allergy, and are powerful inhibitors of IL-5 expression. Antisense oligonucleotides are new compounds that can specifically inhibit IL-5 production. This study aimed at understanding the role of conserved lymphokine element 0 (CLEO) in induction and inhibition of IL-5.The conserved proximal CLEO/TATA elements driving a luciferase reporter gene gave higher expression than a 500bp promoter in PER1 17 T-cell line. Two and three copies of IL-5 CLEO upstream of the silent IL-4 minimal promoter gave 150-200 fold increases in expression in forward orientation, but little activity in reverse orientation. Consequently, while CLEO is a powerful activator, it is not a classical enhancer. Antisense technology has also shown the dependence of IL-5 gene transcription on the de novo synthesis of the transcription factor Fra2.Inhibition of IL-5 reporter constructs by dexamethasone when induced by PMNcAMP, but not PMNCaI, provided a tool for understanding the mechanism. Deletion analysis identified CLEO as the key element of dexamethasone inhibition. Non-inhibition of IL-5 reporter constructs by dexamethasone in a Jurkat cell line, however, showed a possible intermediary factor involved in the inhibition mechanism.

La thérapie génique est une recherche biomédicale qui a rencontré un certain succès, notamment la mise sur le marché du premier médicament en 2013. La thérapie génique souffre d’un encadrement juridique complexe en raison d’une disparité des règles applicables. L’encadrement des recherches biomédicales met à la charge du promoteur et de l’investigateur des obligations strictes visant à assurer la sécurité et la protection du patient. Cependant, on ne peut pas parler de droit spécial des recherches biomédicales, les rapports entre le patient et l’investigateur possèdent toutes les caractéristiques classiques de la relation médicale ordinaire. Bien que largement critiquée par la doctrine, la qualification des rapports entre l’investigateur et le patient ne peut être autre que celle de contrat médical. En conséquence, l’uniformisation du droit administratif et du droit civil est nécessaire en matière médicale. La reconnaissance du contrat médical dans les établissements de soins privés et publics est la première étape de cette uniformisation. Outre les rapports contractuels existants entre le médecin et le patient, la loi fournit une protection nécessaire au patient contre les manipulations génétiques. Parfois insuffisante, cette protection mérite discussion. / Gene therapy is a biomedical research that has met some success, including the placing on the market the first drug in 2013. The frame law of gene therapy is complex due to disparity rules. The frame law of biomedical researches imposes on the sponsor and the investigator obligations to ensure the safety and the protection of the patient. However, we can not talk about special rights in biomedical researches. The relationship between the patient and the investigator is not special, it have all the classic features of current medical relationship. Although widely criticized by the doctrine, the medical contract appears useful and irreplaceable in public or private health institutions. In consequence, civil law and administrative law must be standardized in medical field. The recognition of medical contract is the first step of this standardization. In addition to the contractual relationship between the patient and the physician, the law provides necessary protection to the patient against genetic engineering. Sometimes insufficient, this protection deserves discussions.