THBD and infection: To assess the effect of hMPV infection on the ability of BDCA-1+ and BDCA-3+ mDCs to stimulate T cell proliferation, allogeneic CD4+ T cells labeled with CFSE were co-cultured with BDCA-1+ and BDCA-3+ mDCs exposed to hMPV, RSV, UV-hMPV and UV-RSV for 7 days.