Fig. 3

LAMTOR1 induced lysosome degradation to inhibit exosomal PD-L1 secretion. (A, B) Transfect the GFP-PD-L1 plasmid into NSCLC cells (H1975 and H358) and employ western blot analysis to assess the PD-L1 expression in whole-cell lysates (WCL) and exosomes (EXO). (C) Furthermore, transfect NSCLC cells (H1975 and H358) with GFP-PD-L1 plasmid and conduct western blot analysis to investigate the upregulated LAMTOR1’s impact on exosomal PD-L1 expression through the lysosomal degradation pathway. Subsequently, NSCLC cells (H1975 and H358) were treated with OE-LAMTOR1 in the presence or absence of 50 μM bafilomycin A1 (Baf-A1) treatment. (D) Western blot analysis to assess the PD-L1 expression in whole-cell lysates (WCL) and exosomes (EXO). Subsequently, NSCLC cells (H1975 and H358) were treated with OE-LAMTOR1 in the presence or absence of 50 μM bafilomycin A1 (Baf-A1) treatment. (E) Additionally, utilizing immunofluorescence staining, it was observed that LAMTOR1 facilitates the co-localization of PD-L1 with lysosomes (LAMP1). NSCLC Cells (H1975 and H358) were treated with OE-LAMTOR1 along with or without 50 μM bafilomycin A1 (Baf-A1). The scale bars indicate 10 μm. The results are presented as mean ± SEM from six independent experiments. Statistical significance was denoted as *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 based on Student’s t-test