Journal: bioRxiv
Article Title: Synergistic role of riboflavin-auxotrophic Enterococcus for MR1 expression and intra-tumoral mucosal associated invariant T (MAIT) cell activation
doi: 10.1101/2025.11.25.690539
Figure Lengend Snippet: A, J33-4 MAIT TCR recognition of U266 cells incubated overnight with (inverse black triangles) or without (black circles) 5-OP-RU, in presence or not of E.hirae , E. faecalis , E. faecium , E. coli and B. longum (Left graph) and E. avium (right graph, independent experiment). TCR activation is measured by bioluminescence reading. B , different APC (human dendritic cells, THP1, melanoma MeWO and hepatocellular carcinoma SNU387) were tested for the synergistic effect of E faecalis onto activation of conventional MAIT TCR J33-4 in presence (inverse black triangles) or not (black circles) of 5-OP-RU. C , Flow cytometry analysis of MR1 surface membrane expression using the 26.5 anti MR1 antibody staining of U266, THP1 and dendritic cells (DC) incubated overnight without or with 5-OP-RU in presence or not of E.faecalis . D , Inhibition by Ac-6-FP (escalating doses from 0.2 to 200 uM) of recognition by MAIT TCR J33-4 of MR1 expressed on U266 cultured or not with 5-OP-RU (6.25 uM) in presence (triangles) or not (squares) of E.faecalis (MOI:125). E , MAIT TCR J33-4 activation by Myd88 -/- THP1 cells incubated overnight with (inverse black triangles) or without (black circles) 5-OP-RU (6.25 uM), in presence or not of E. faecalis (MOI:125). F , MAIT TCR J33-4 activation by U266 cells incubated overnight with (inverse black triangles) or without (black circles) 5-OP-RU (6.25 uM), in presence or not of E. faecalis (MOI:125) and E.faecalis derived outer membrane vesicles (OMV). G , Flow cytometry analysis of MR1 surface membrane expression using the 26.5 anti MR1 antibody staining of U266 incubated overnight without or with 5-OP-RU in presence or not of E. faecalis (MOI:125), compared to LPS (TLR4 ligand; 50ng/ml; left histogram), CPG (TLR9 ligand; 5uM, middle histogram) or LTA (TLR2 ligand; 30ug/ml co; right histogram). All data are shown as mean ± SEM with technical replicates represented by number of symbols in each graph. ****:P<0.0001, ***:0.0001
Article Snippet: MeWo and SNU387 cell lines were kindly provided by Dr. Scott Wilson’s lab and cul-tured according to ATCC protocol.
Techniques: Incubation, Activation Assay, Flow Cytometry, Membrane, Expressing, Staining, Inhibition, Cell Culture, Derivative Assay, Two Tailed Test