Fig. 2.

Galectin-4 enchains bacteria during bacterial growth by binding to the O-antigen of LPS. (A) Bacterial chains induced by galectin-4 are derived from the cell progeny. Images of S. enterica serovar Worthington cells incubated with 100 µg/mL recombinant human galectin-4 (rhGal4) or BSA from Movies S1 and S2, at different incubation time points. (Scale bars, 5 µm.) (B) The number of connected bacteria derived from a single bacterium was tracked throughout the period of incubation with rhGal4. Data represent the mean ± SD, N = 10. (C) GFP- and RFP-expressing bacteria (G⁺-S.W and R⁺-S.W) were incubated in LB media containing 50 µg/mL human galectin-4 at 37 °C for 2 h. Scale bars, 10 µm. (D) The chaining phenotype of S. enterica serovar Worthington induced by recombinant human galectin-4 (rhGal4) was disrupted by TDG, but not by sucrose. (Scale bars, 10 µm.) (E) Wild-type (WT) and rfaL deleted (ΔrfaL) S. enterica serovar Worthington were incubated with 2 µg/mL Alexa fluor 488-labeled human galectin-4 at 4 °C for 1 h. Galectin-4 binding was determined by flow cytometry. The images of bacteria were obtained after incubation in LB containing 50 µg/mL human galectin-4 at 37 °C for 2 h. (Scale bars, 10 µm.) (F) HeLa-EGFP and HeLa-EGFP-Gal4 cells were infected with R⁺-S.W. Live images were acquired at the indicated time points post-infection (h:min). EGFP/EGFP-Gal4 (green), R⁺-S.W (red). (Scale bars, 10 µm.)