Expression of Recombinant Functional Fragment of Human CD40 L Gene in CHO Cells

To clone the functional fragment of human CD40L(E107-L261) gene and to express it in CHO cells.RT-PCR was used to amplify the cDNA of the functional fragment of hCD40L from the total RNA of activated human tonsillitis.After verification sequencing,the DNA fragment was cloned into expression plasmid pcDNA3.0,and the eukaryotic expression vector pcDNA 3.0-hCD40L was constructed.The recombinant cloning vetor pcDNA3.0-hCD40L was transfected into CHO cells,and the consistently transfected cells were screened with G418.The total protein was extracted from positive clones,and seperated by SDS-PAGE.Western-blotting was used to identify the immunological activity.Its biological activity was checked by enhancing lymphocytes of mice.Results The functional fragment in extracellular regin of hCD40L was cloned correctly into eukaryotic expression vector pcDNA 3.0 and expressed successfully in CHO cells.It has immunological activity and Biological activity.