Co-expression of sCD40LIg and CTLA4Ig mediated by adenovirus prolonged mouse skin allograft survival

Objective： To investigate the role of simultaneous blockade of CD40/CD40L and B7/CD28 pathways in the immune tolerance via co-expression of sCD40LIg and CTLA4Ig mediated by replication-defective adenovirus. Methods： Ad-sCD40LIg- IRES2-CTLA4Ig, replication-defective adenovirus co-expressing sCD40LIg and CTLA4Ig, was constructed and identified. The co-expression of sCD40LIg and CTLA4Ig was evaluated with confocal laser scanning microscope and Western blotting. Skin transplantations of C57BL/6 to BALB/c mice were performed. PBS, Ad-Shuttle-CMV and Ad-sCD40LIg-IRES2-CTLA4Ig were administered. Skin graft survival was monitored and the mRNA expression of both genes was evaluated in the skin allografts. Results： Ad-sCD40LIg-IRESE-CTLA4Ig was constructed successfully and identified. The co-expression of sCD40LIg and CTLA4Ig was identified with confocal laser scanning microscopy and Western blotting. Compared to the skin graft mean survival time （MST） of non-treated group （（5.75±0.71） d） or Ad-Shuttle-CMV-treated group （（5.50±0.53） d）, the skin graft MST was dramatically prolonged in the Ad-sCD40LIg-IRESE-CTLA4Ig-treated group （（ 16.38± 1.19） d, P〈0.001）. The mRNA expression of both genes was detected. Conclusion： Ad-sCD40LIg-IRES2-CTLA4Ig, a replication-defective adenovirus carrying genes encoding sCD40LIg and CTLA4Ig, was constructed. Simultaneous blockade of CD40/CD40L and B7/CD28 costimulatory pathway mediated by replication-defective adenovirus significantly prolonged skin allografi survival in mice.

Brain-derived neurotrophic factor and neural plasticity in a rat model of spinal cord transection

The present study employed a rat model of T10 spinal cord transection. Western blot analyses revealed increased brain-dedved neurotrophic factor （BDNF） expression in spinal cord segments caudal to the transection site following injection of replication incompetent herpes simplex virus vector （HSV-BDNF） into the subarachnoid space. In addition, hindlimb locomotor functions were improved. In contrast, BDNF levels decreased following treatment with replication defective herpes simplex virus vector construct small interference BDNF （HSV-siBDNF）. Moreover, hindlimb locomotor functions gradually worsened. Compared with the replication incompetent herpes simplex virus vector control group, extracellular signal regulated kinasel/2 expression increased in the HSV-BDNF group on days 14 and 28 after spinal cord transection, but expression was reduced in the HSV-siBDNF group. These results suggested that BDNF plays an important role in neural plasticity via extracellular signal regulated kinasel/2 signaling pathway in a rat model of adult spina cord transection.