Co-cultures of multiple cell types mimic pulmonary cell communication in response to urban PM10

The current authors evaluated whether a system of co-cultures of relevant cells (pneumocytes (A549), macrophages (THP-1), mast cells (HMC-1) and endothelial cells (EAHY926)) would mimic the responses to particles with a 50% cut-off aerodynamic diameter of 10 pm (PM10) previously reported in vivo. The role of mast cells was considered of special interest. Single cultures, bicultures (A549 + HMC-1 in a 10:1 ratio; THP-1 + HMC-1 in a 2:1 ratio) and tricultures (A549 + THP-1 + HMC-1 in a 10:2:1 ratio) were exposed to urban PM10 (24 h at 0, 10, 30 or 100 mu g.cm(-2)). Additionally, EAHY926 cells were introduced in inserts above the tricultures. The released cytokines were evaluated with a fluorescence-activated cell sorter array system. THP-1 + HMC-1 bicultures and the tricultures released more granulocyte colony-stimulating factor (G-CSF), macrophage inflammatory protein (MIP)-1 beta, interleukin (IL)-1 beta, IL-8, IL-6, tumour necrosis factor-a and MIP-1 alpha in response to PM10 than the sum of the single cultures. Tricultures with EAHY926 released more G-CSF, MIP-1 alpha, IL-8 and MIP-1 beta than the EAHY926 single culture. The bicultures, tricultures and tricultures with EAHY926 provide results that are consistent with the local and systemic effects previously described for particulate matter effects, i.e. inflammation, endothelial dysfunction and bone marrow cell mobilisation. Mast cells seem to play a significant role in the co-culture responses.