Figure 4

Lipoteichoic acid in L. rhamnosus JB-1 MV is responsible for immunomodulatory effects. (a) Western blot analysis was used to measure LTA associated with JB-1 MV (MV) or in lysates of whole JB-1 bacteria (Bact.). (b) Independent preparations of JB-1 MV were incubated with a TLR2 reporter cell line with or without preincubation with anti-LTA antibody (+ αLTA) or isotype control (+ Iso), and TLR2 activity was expressed as a percentage of that measured for the synthetic TLR2 ligand Pam3CSK4 (300 ng/mL). (c–e) DiO-labelled MV or vehicle were incubated with BMDCs for 18 h either with or without preincubation with dynasore or anti-LTA antibody, then (c) DiO-related or (d) IL-10-related fluorescence were measured by flow cytometry. (e) The extent to which MV internalization was associated with IL-10 expression was assessed by plotting cells as a function of DiO and IL-10 signal. Error bars represent ± 1 standard error. **p < 0.01.