猪鼻支原体乳酸脱氢酶的表达及黏附功能研究OA

Mycoplasma hyorhinis(Mhr)is a significant pathogen causing substantial economic losses to the pig industry.To investigate the role of lactate dehydrogenase(LDH)in the adhesion of Mhr to host cells,recombinant LDH(rLDH)was expressed,purified,and used to prepare hyperimmune rabbit serum.The surface expression of LDH on Mhr was confirmed by colony immunoblotting,flow cytometry,and Western blot.The cell-adhesion ability of rLDH was assessed using indirect immunofluorescence and microplate binding assays,and the inhibitory effect of anti-rLDH serum on Mhr binding to cell membrane proteins was evaluated.Finally,the binding capacity of rLDH to host plasminogen(Plg)and fibronectin(Fn)was examined.The results demonstrated that rLDH was successfully expressed and purified.Immunological assays confirmed that LDH is expressed on the Mhr surface.Functional assays revealed that rLDH adheres to PK-15 cells and binds to cell membrane proteins;notably,anti-rLDH antibodies significantly inhibited Mhr binding to cell membrane proteins.Far Western blot and microplate binding assays further demonstrated that rLDH binds to both Plg and Fn.These findings indicate that LDH is a surface-expressed protein of Mhr possessing multiple adhesive activities,playing a crucial role in colonization,invasion,and pathogenesis of Mhr.