Cell culture
THP-1-CWT cells containing the recruitment marker YFP-CWT (recognizing
Gram-positive peptidoglycan) (Grosz et al., 2013) were grown in RPMI
1640 medium (Biochrom) with 2mM glutamine, 10% heat-inactivated foetal
bovine serum (Sigma), 2% HEPES (Biochrom), 1% penicillin/streptomycin
(Gibco) and 1mM sodium pyruvate (SigmaAldrich). Cell viability was
determined by trypan blue staining and was at least 90% before all
experiments. To induce differentiation, 1 × 106cells/ml were treated with 160nM phorbol-12-myristate-13-acetate (PMA)
for 48 h. After differentiation, the cells became adherent to the
culture dishes. The day of infection differentiated cells were washed
twice with Hank’s Balanced Salt Solution (HBSS) and further incubated
with RPMI medium with 10% heat-inactivated fetal bovine serum and 10%
human Serum (Sigma) until infection.