Objective:To investigate the effect and mechanism of the gastric cancer cells-derived exosome miR-382-5p in-duced by Helicobacter pylori(H.pylori)on the autophagy and polarization of macrophages,providing new clues for further elucidating the carcinogenic mechanism of H.pylori.Methods:Ultracentrifugation and exosome extraction kit were used to extract the exosomes re-leased by the H.pylori stimulated group and the blank control group AGS cells cells,then transmission electron microscopy(TEM),nanoparticle tracking analysis(NTA)and Western blot were employed to identify exosomes.qRT-PCR was used to detect the expres-sion of miR-382-5p in H.pylori induced AGS-derived exosomes.miR-382-5p mimic was transfected into THP-1 macrophages,then the expressions of autophagy markers(LC3Ⅱ,p62,and Beclin-1)were evaluated by Western blot,the number of autophagosomes was detected by immunofluorescence.The expression levels of PTEN protein,downstream proteins PI3K,AKT,mTOR and its phosphory-lated proteins p-PI3K,p-AKT,p-mTOR were detected by Western blot.Flow cytometry was used to detect the expression levels of macrophage phenotypic molecules CD206 and HLA-DR.ELISA was used to detect the secretion of cytokines TNF-α,IL-6,IL-10 and Arginase1 in macrophage supernatants.Results:The extracted exosomes were consistent with exosome morphology and highly ex-pressed the surface marker proteins CD9,CD63 and TSG101.Compared with the blank control group,the expression level of exosom-al miR-382-5p in H.pylori-infected group was significantly increased.miR-382-5p mimic transfection resulted in decreased expression of LC3 Ⅱ and Beclin-1 in macrophages,increased expression of P62 and decreased number of autophagosomes.Moreover,the protein expression level of PTEN was significantly decreased in the miR-382-5p mimic transfection group,while the expression levels of p-PI3K,p-AKT and p-mTOR were significantly increased.miR-382-5p mimic transfection also resulted in increased expression of mac-rophage M2 type marker protein CD206 and decreased expression of M1 type marker protein HLA-DR,as well as increased expres-sions of IL-10 and Arginine1,whereas decreased expression of IL-6 and TNF-α.Pretreatment with the pathway inhibitor BEZ235 par-tially reverses the effects of miR-382-5p on macrophage autophagy and polarization.Conclusion:H.pylori-induced gastric cancer cells-derived exosomal miR-382-5p suppresses macrophage autophagy and induces M2 polarization through down-regulation of PTEN ex-pression and activation of the PI3K/AKT/mTOR signaling pathway.