FIG. 1.

Human blood mDCs and pDCs differ in their expression of TLRs and CLRs. The repertoire of CLRs expressed by pDCs includes BDCA-2, dectin-1, and possibly DEC-205. The functions of these CLRs, especially BDCA-2, are largely unknown but may include antigen uptake and presentation. mDCs express DC-SIGN, DC-LAMP, mannose receptor, and DEC-205. It is well known that mDCs can rely on their CLRs for antigen uptake and viral transmission. pDCs and mDCs express different and complementary sets of TLRs. Recently, a few reports have demonstrated cross talks between CLRs and TLRs in mDCs. It has yet to be shown whether CLRs and TLRs interact either synergistically or competitively in pDCs.