ENHANCED ANTIINFLAMMATORY EFFECTS OF CU, ZN-SUPEROXIDE DISMUTASE DELIVERED BY GENETICALLY-MODIFIED SKIN FIBROBLASTS IN-VITRO AND IN-VIVO

The purpose of this work was to evaluate the anti-inflammatory effects of secretable human Cu, Zn-superoxide dismutase (hSOD) delivered by g enetically modified skin fibroblasts in vitro and in vivo. Methods. Ra t skin fibroblasts were transfected with pRc/CMV-ILSOD including secre table SOD-coding cDNA. The effects of host and transformants on oxidat ive stress in vitro models using the xanthine/xanthine oxidase (X/XO) system were examined to study the paracrine SOD action. The anti-infla mmatory effects by transplantation of host and transformants were eval uated in an acute inflammation model, carrageenin-induced paw edema, i n rats. Results. The transformants (ILSOD cells) secreted SOD protein into the extracellular space, and the extracellular SOD activity in IL SOD cells cultures was significantly increased compared with that in h ost cell cultures. ILSOD cells diminished the cytotoxic activity by X/ XO in a paracrine fashion. These protective effects of ILSOD cells aga inst X/XO-induced cytotoxicity correlated well with the decrease in li pid peroxidation in the damaged cells. The in vivo study showed that t ransplantation of ILSOD cell suspensions into the hind paw in rats inh ibited carrageenin-induced paw edema for at least 7 days, and the degr ee and the durability of these inhibitory effects were dependent on th e number of ILSOD cells transplanted. These inhibitory effects of ILSO D cell suspensions were reduced by co-administration of antiserum for hSOD. Furthermore, the healing of paw edema caused by carrageenin was markedly enhanced by transplantation of ILSOD cells into the edemics h ind paw. Conclusions. The findings suggested that genetically modified skin fibroblasts are a suitable delivery system for obtaining an effi cient and continuous supply of SOD to the target site, and this strate gy may be a useful drug delivery system for therapeutic proteins.