Induction of Dendritic Cell and Cytokine Gene Expression by In situ Delivery of Flt3 Ligand Plasmid

Park, Jong Wook; Yoon, Soo Jung; Choe, Byung Kil

Abstract

Dendritic cell (DC)s are protessional antigen presenting cells and they have been used for antitumor immunotherapy or cell vaccines. However therapy using DC is restricted because the number of DC available from tissue is very low. Flt3 ligand (FL) has been known as a hematopoietic growth factor that increases proliferation of hematopoietic stem cells and progenitor cells, and recently it showed inducibility of dendritic cell (DC)s and signiticant antitumor effects in vivo. Thus FL will be frequently used for DC induction and antitumor immunotherapy in future. Here we constructed FL plasmid and studied its in vivo effect. FL plasmids were made by cloning of partial FL cDNA into pcDNA3 plasmid, and gene expression and protein producibility of FL plasmid were confirmed in Renca cells transfected with FL plasmid. Mice were injected with FL plasmid (100ug/mouse) three times and 20 days later mouse spleens were harvested for staining and RT-PCR. There were lots of blastogenic cells in the spleen of mice treated with FL plasmid. FL plasmid also induced DEC205, IL-12 and GM-CSF gene expression in mouse splenocyte. All these data suggest FL plasmid may be used for induction of DC and antitumor therapy as DNA adjuvant.