[Establishment of the transfected cell line expressing the mouse OX40 gene and its potency to induce differentiation of B cells].

AIM: To establish HUVECs line expressing mouse OX40(CD134) and to study its promotive effect on proliferation of B cells. METHODS: The cDNA fragment encoding mouse OX40 was obtained from the total RNA of ConA-activated lymphocytes of thymus by using RT-PCR and cloned into pUCm-T vector. The cDNA was then inserted into the eukaryotic expression vector pIRES2-EGFP. The recombinant vector was transfected into HUVECs with lipofectin reagent, and the positive cellular clones were selected by G418. Expression of mouse OX40 in the transfected cells was analyzed by FCM. The differentiation of B cells in vitro induced by OX40 signal was studied by means of (3)H-TdR method. RESULTS: The cDNA fragment in the recombinant plasmid was consistent with the reported mouse OX40 cDNA in GenBank, which was confirmed by DNA sequencing, PCR and enzyme digestion. The HUVECs stably expressing the mouse OX40 were successfully cloned. The transfected cells promoted the differentiation of B cells in vitro and there existed a synergic effect between OX40/OX40L and CD40/CD40L signals. CONCLUSION: Transfected cell line expressing the mouse OX40 gene is established successfully. OX40 enhances the proliferation of B cells.