OBJECTIVETo research the repair effect of transplantation of glial cell line-derived neurotrophic factor (GDNF) modified olfactory ensheathing cells (OECs) combination with injecting axonal growth inhibiting protein antibody (IN-1) in vivo.METHODSTo construct lentivirus vector with GDNF gene and infect OECs in vitro, use the immunoblotting (Western Blot) to observe the expression of GDNF was detected through Western Blot. Fifty adult female SD rats which to establish thoracic spinal cord transection injury model were randomly divided into A (control group), B (IN-1 antibody group), C (OECs group), D (GDNF-OECs group), and E (GDNF-OECs+IN-1 group) 5 groups of each 10 rats. To observe regeneration of the impaired nerve axon by NF200 immunohistochemistry, Biotinylated dextran amine (BDA) anterograde tracing corticospinal tract. Basso, Beattie and Bresnahan (BBB) score was used to evaluating hindlimb motor function recovery.RESULTSAdd up to 13 rats died post operation. OECs labeled by hoechst still survived and migrated in spinal cord 8 weeks post operation. Lots of confused and disorderly regenerated axons which crossing the injured region of spinal cord were displayed between spinal cord stumps in GDNF-OECs+IN-1 group and GDNF-OECs group; some of axons existed in OECs group, but there is no obviously continue nerve fibers crossing the injured region of spinal cord;in contrast to IN-1 and control groups, few of regenerated axons and atrophy of spinal cord stumps were observed. The results of BBB hindlimb motor rating scale were 7.70+/-0.24, 7.89+/-0.15, 10.50+/-0.25, 11.43+/-0.23 and 12.81+/-0.40 for the control group, IN-1 group, OECs group, GDNF-OECs group and the allied treatment group respectively.CONCLUSIONSThe transplantation of GDNF-OECs combination with IN-1 antibody may benefit the survival and regeneration of the injured axons, and accelerate the repair of the injured spinal cord and functional recover of hindlimb locomotor in rats in a more efficient way than that with OECs or IN-1 alone.