Transplantation of Schwann cells co-cultured with brain-derived neurotrophic factor for the treatment of experimental autoimmune neuritis.

The aim of this study was to investigate the effects of transplantation of Schwann cells (SCs) co-cultured with brain-derived neurotrophic factor (BDNF) for the treatment of experimental autoimmune neuritis (EAN). Primary SCs were co-cultured with various BDNF concentrations, and the optimum concentration was determined by cell proliferation, and NGF and FGF levels. A rat model of EAN was established by immunization with 400µg of P2 peptide dissolved in Freund's complete adjuvant. SCs were labeled with CFSE and injected into the cisterna magna 14days after immunization. We found proliferation of SCs, and NGF and FGF levels were highest at a BDNF concentration of 50ng/mL. Compared with EAN group, SCs+BDNF group showed the lower paralysis scores from day 34 to day 45, and in sciatic nerves showed a significant decrease in inflammatory cell infiltration (involved CD4-, CD8- and CD68-positive cells) at days 25 and 35, an alleviated demyelination at days 35 and 45, and an increase in S-100-positive cells and a decrease in NGF-positive cells at each time point (P<0.05). Compared with the EAN group, the SCs+BDNF group showed, in sciatic nerves, the mRNA level of NGF was significantly decreased but that of S-100 was increased at day 25, the mRNA level of CCL3 was also remarkably reduced at day 35, and the mRNA level of CD11a, CCL3 and NGF was reduced but that of S-100 was elevated at day 45 (P<0.05). There were no differences in results between the SCs group and EAN group. In the end, we draw the conclusions that the exogenous SCs injected through cisterna magna can migrate to the injured peripheral nerves, BDNF promotes the proliferation and secretory function of SCs in vitro, and BDNF-treated SCs in vivo can reduce paralysis, inflammation, and demyelination and improve the self-repair capability of body in EAN.