Fig. 3
Effect of mAb to CD9, CD63 and CD81 on MNGC formation induced by B. thailandensis strains CDC272 and E264 in J774.2 A and RAW264.7 macrophages B. Macrophages were pre-treated with test mAb or isotype-matched controls for 1 h prior to infection with bacteria and MNGC formation was assessed as described previously. The data are presented as a percentages of the MNGC formed (% of MNGC) (left panel) or average MNGC size (right panel) compared to the untreated (no antibody) control. The results are representative of at least three independent experiments, with error bars showing standard error of the mean. Statistical analysis was carried out between the test mAb (black fill) and the matched isotype control (white fill) using Welch’s t test. *p < 0.05, **p < 0.001, ***p < 0.0001. Pairs with no asterisk showed no significant difference. Representative images of untreated, anti-CD9, anti-CD81 and isotype control-treated J774.2 cells infected with CDC272 and fixed and stained after 16 h are shown in the lower panel of B. C shows the effect of mAb to the tetraspanins (black fill) and corresponding isotype control (white fill) on B. thailandensis infection. J774.2 cells were pre-incubated with antibodies as described above prior to infection (2 h) and after kanamycin protection to remove extracellular bacteria (2 h), macrophages were lysed and the number of surviving intracellular bacteria determined (cfu/10,000 host cells). Data were analysed as for A and B, but no significant differences were found between anti-tetraspanin mAb and the isotype control-treated samples