Objective To study the effects of blockade of CD40-CD40L pathway on the survival of xenogeneic skin graft. Methods The extracellular domain of human CD40 ligand (CD40L) was cloned by RT-PCR, and thereby a skin-specific transgene expression vector for the soluble CD40L molecule (sCD40L) was constructed by keratine 14 (K14) promoter. Using the sCD40L skin-specific transgene construct, transgenic mice were generated by pronuclear microinjection. ResultsThe sCD40L fragment with expected size and sequence was correctly cloned and its skin-specific expression vector correctly constructed. By microinjection, embryo transfer, and PCR screening test, one of 49 G0 mice had amplified specific bands, which was absent in the negative controls. ConclusionWe have successfully established a sCD40L transgenic positive mouse model.