FIG 5.
LL-37 makes GAS more resistant to killing by macrophages. THP-1 macrophages were infected with GAS in the absence or presence of 300 nM LL-37. GAS 854, 854csrSTM, 854ΔhasB, 854Δslo, 854ΔcsrR, or 854ΔcsrR/ΔhasB were used for infection; data are presented in separate panels for clarity. Viable GAS released into the cell culture medium plus GAS associated with the macrophages were quantified after 90 min of incubation (time zero) and 2 and 4 h later. Data are presented for each strain as a percentage of the GAS at each time point compared to the number at time zero. Data are means and standard errors from at least three separate experiments. *, P < 0.05.