Journal: Nature Communications

Article Title: Deficiency of lysosomal TMEM175 in myeloid macrophages exerts anti-tumor immunity via inflammasome and cross-presentation pathway

doi: 10.1038/s41467-026-69546-2

Figure Lengend Snippet: Primary BMDMs from Tmem175 −/− and WT mice were stimulated with 500 ng/mL LPS for 4 h to activate signal 1 of NLRP3 inflammasomes, and then treated with B16-F10 supernatant (25% volum) or cell debris (2.5 × 10 5 /mL) for desired period of time, during which VX-765, CA-074, or KCl were added, whose final concentrations were 10 µg/mL, 100 µM, and 40 mM respectively. a , b The culture medium was analyzed by ELISA. B16-F10 cell debris, instead of supernatant, induced obviously more potentiated IL-1β secretion from Tmem175 −/− than from WT BMDMs ( a ) ( n = 3 biologically independent samples). BMDMs were treated with B16-F10 supernatant or B16-F10 cell debris overnight in ( a ). The differences between Tmem175 −/− and WT BMDMs became distinct after 4 h ( b ) ( n = 6 biologically independent samples). c Total protein in the culture medium was concentrated by trichloroacetic acid for western blot analysis ( n = 3 independent experiments). Tmem175 −/− BMDMs released more IL-18 than WT BMDMs. d Treatment of KCl, VX-765, or CA-074 significantly inhibited the IL-1β secretion ( n = 3 biologically independent samples). Cells were treated by B16-F10 cell debris for 8 h. e Interaction between ASC and NLRP3 was confirmed by CO-IP in the B16-F10 cell debris treated BMDMs. Nigericin (10 µM) was used as positive control ( n = 3 independent experiments). Cells were treated by B16-F10 cell debris or Nigericin for 4 h. f Tmem175 −/− and WT BMDMs were harvested for electron microscopy observation ( n = 3 biologically independent samples). B16-F10 cell debris caused lysosomal permeabilization. Scale bars indicate 500 nm. g Tmem175 −/− and WT BMDMs treated with LPS and B16-F10 cell debris were fixed and permeabilized. Then, cells were stained by cathepsin B rabbit mAb, cathepsin D rabbit mAb, or cathepsin L rabbit mAb ( n = 3 biologically independent samples). The spots of cathepsin B, cathepsin D, and cathepsin L diffused in the cytoplasm by cell debris treatment. Scale bars indicate 10 µm. h CA-074, an inhibitor of cathepsin B, suppressed the ASC-NLRP3 interaction and the cathepsin B-NLRP3 interaction ( n = 3 independent experiments). Cells were treated with B16-F10 cell debris for 4 h. i In vitro cultured WT and Tmem175 −/− BMDMs were transfected with siRNA targeting Nlrp3 or control siRNA. Then the BMDMs were adopted to wild type mice 1 day before and on day 7th after B16-F10 implantation ( n = 5 mice). Tumor bearing mice were euthanized on day 14th after B16-F10 implantation to weigh the tumors. Representative results from two independent experiments are presented as mean ± SEM; ns denotes not significant. Statistical significances in ( a , b , d , i ) were determined by two-way ANOVA followed by Holm-Sidak’s multiple comparisons test. Source data are provided as a file. i Created in BioRender. Wang, Y. (2026) https://BioRender.com/yaf354h .

Article Snippet: The following antibodies were used: Cathepsin B rabbit mAb (Cell Signaling Technology, 31718S), ASC mouse mAb (Santa Cruz Biotechnology, sc-514414), NLRP3 rabbit mAb (Cell Signaling Technology, 15101S), Rabbit IgG isotype (Cell Signaling Technology, 3900S), anti-rabbit IgG (HRP) (Thermo Fisher Scientific, 31460), anti-mouse IgG (HRP) (Thermo Fisher Scientific, 31430), and anti-rabbit IgG-Fc (HRP) (SinoBiological, SSA003).

Techniques: Enzyme-linked Immunosorbent Assay, Western Blot, Co-Immunoprecipitation Assay, Positive Control, Electron Microscopy, Staining, In Vitro, Cell Culture, Transfection, Control