Journal: Cells
Article Title: Cardiolipin Induces CXCL9/CXCL10 Expression in Tumor-Infiltrating Lymphocytes
doi: 10.3390/cells15090798
Figure Lengend Snippet: Cardiolipin-mediated NLRP3 signaling orchestrates a pro-inflammatory tumor microenvironment and facilitates TIL reactivity. ( A ) RNA sequencing analysis of TIL expanded with 275 nM CL compared to vehicle controls. Differential expression analysis identified upregulation of the CXCR3 ligands CXCL9 and CXCL10, alongside downregulation of KBTBD11. ( B ) To assess the role of the NLRP3 inflammasome in antigen recognition, TIL were expanded in the presence or absence of the specific inhibitor MCC950 (10 µM). Functional reactivity was evaluated against a library of KRAS wild-type (WT) and mutant peptides. A significant reduction in the breadth of KRAS mutation recognition (measured by IFN-γ) was observed in the MCC950-treated group (* p < 0.01). Stimulation with α-CD3 (right panel) confirmed comparable T-cell fitness and viability between both groups (mean 253 pg/mL vs. 211 pg/mL; p > 0.05), ensuring that the observed inhibition was not due to non-specific toxicity. ( C ) To validate the pharmacological findings, TIL were transfected with either a non-targeting (scrambled) siRNA or an NLRP3-specific siRNA for 72 h. Following knockdown, TIL were co-cultured with KRAS mutant peptides for 72 h to assess functional recognition. Reduction in IFN-γ production was noted in the NLRP3-silenced group as compared to both the scrambled control cells and the untreated (nil) cells; red: positive controls (PHA and anti-CD3 crosslinking). ( D ) Tumor microfragments were cultured with or without 275 nM CL, in the presence or absence of the cytokine cocktail (IL-7/IL-15/IL-21). Analysis of the cell culture supernatants showed that CL induces a robust increase in the pro-inflammatory cytokines IL-1β, IL-18, and TNF-α (measured by Legendplex). Notably, this induction occurred independently of exogenous cytokine supplementation. ( E ) Consistent with the transcriptomic data in ( A ), CL-treated microfragments showed an increase in secreted CXCL10, as measured by ELISA. Statistical significance was determined using a two-tailed Student’s t -test for head-to-head comparisons. A p -value < 0.05 was considered statistically significant.
Article Snippet: TIL were expanded from tumor tissue as described above (see TIL expansion), in the presence of CL with or without MCC950 (10 μM/mL) (Invivogen, San Diego, CA, USA), a specific inhibitor of the NLRP3 pathway, starting from culture initiation throughout the entire expansion process.
Techniques: RNA Sequencing, Quantitative Proteomics, Functional Assay, Mutagenesis, Inhibition, Transfection, Knockdown, Cell Culture, Control, Enzyme-linked Immunosorbent Assay, Two Tailed Test