Objective Intracellular retrograde transport system is critical for cytotoxicity of microbial toxin proteins.KELED sequence is a novel key amino acid fingerprint for retrograde transport and cytotoxicity of CARDS toxin.The purified recombinant CARDS protein was administered to Balb/c mice to reproduce symptoms of human diseases caused by M.pneumoniae infections.However,it remains unclear whether CARDS relies on KELED sequences to regulate pulmonary immune responses.We aims to explore related underlying mechanism in this study.Methods CARDS and KELED mutation proteins were expressed and purified in E.coil,and then their vacuolation activities were verified with LLC cells.The Balb/c mice were then exposed to recombinant protein by intratracheal injections to evaluate its effect and function.Results KELED sequence mutation attenuated the vacuolation effect caused by CARDS protein,down-regulated the mRNA expression of inflammatory factors and alleviated the pathological damage of lung tissue.Conclusion KELED sequence is essential for the effect of vacuolation and inflammation of CARDS toxin.
维普
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