Molecular cloning, expression and characterization of programmed cell death 10 from sheep (Ovis aries)

• A full-length cDNA of sheep PDCD10 (OaPDCD10) was cloned and characterized for the first time.
• Tissue distribution of OaPDCD10 mRNA was investigated.
• Differential expression of OaPDCD10 between infected sheep and vaccinated ones was assessed.
• The recombinant OaPDCD10 could induce cell apoptosis and promote cell proliferation.

Programmed cell death 10 (PDCD10) is a highly conserved adaptor protein. Its mutations result in cerebral cavernous malformations (CCMs). In this study, PDCD10 cDNA from the buffy coat of Small Tail Han sheep (Ovis aries) was cloned from a suppression subtractive hybridization cDNA library, named OaPDCD10. The full-length cDNA of OaPDCD10 was 1343 bp with a 639 bp open reading frame (ORF) encoding 212 amino acid residues. Tissue distribution of OaPDCD10 mRNA determined that it was ubiquitously expressed in all tested tissue samples, and the highest expression was observed in the heart. The differential expression of OaPDCD10 between infected sheep (challenged with Brucella melitensis) and vaccinated sheep (vaccinated with Brucella suis S2) was also investigated. The results revealed that, compared to the control group, the expression of OaPDCD10 from infected and vaccinated sheep was both significantly up-regulated (p < 0.05). Moreover, the expression levels of OaPDCD10 from the vaccinated sheep were significantly higher than the infected sheep (p < 0.05) after 30 days post-inoculation. The recombinant OaPDCD10 (rOaPDCD10) protein was expressed in Escherichia coli BL21 (DE3), and then purified by affinity chromatography. The rOaPDCD10 protein was demonstrated to induce apoptosis and promote cell proliferation. Our studies are intended to discover potential diagnostic biomarkers of brucellosis to discern infected sheep from vaccinated sheep, and OaPDCD10 could be considered as a potential diagnostic biomarker of brucellosis.