Identification of Lineage Relationships and Novel Markers of Blood and Skin Human Dendritic Cells

Abstract

The lineage relationships and fate of human dendritic cells (DCs) have significance for a number of diseases including HIV where both blood and tissue DCs may be infected. We used gene expression profiling of human monocyte and DC subpopulations sorted directly from blood and skin to define the lineage relationships. We also compared these with monocyte-derived DCs (MDDCs) and MUTZ3 Langerhans cells (LCs) to investigate their relevance as model skin DCs. Hierarchical clustering analysis showed that myeloid DCs clustered according to anatomical origin rather than putative lineage. Plasmacytoid DCs formed the most discrete cluster, but ex vivo myeloid cells formed separate clusters of cells both in blood and in skin. Separate and specific DC populations could be determined within skin, and the proportion of CD14+ dermal DCs (DDCs) was reduced and CD1a+ DDCs increased during culture, suggesting conversion to CD1a+-expressing cells in situ. This is consistent with origin of the CD1a+ DDCs from a local precursor rather than directly from circulating blood DCs or monocyte precursors. Consistent with their use as model skin DCs, the in vitro–derived MDDC and MUTZ3 LC populations grouped within the skin DC cluster. MDDCs clustered most closely to CD14+ DDCs; furthermore, common unique patterns of C-type lectin receptor expression were identified between these two cell types. MUTZ3 LCs, however, did not cluster closely with ex vivo–derived LCs. We identified differential expression of novel genes in monocyte and DC subsets including genes related to DC surface receptors (including C-type lectin receptors, TLRs, and galectins).

Herpes Simplex Virus Type 2–Infected Dendritic Cells Produce TNF-α, Which Enhances CCR5 Expression and Stimulates HIV Production from Adjacent Infected Cells

“…Very few dually infected MDDCs (,1.5%) were observed. This is not unexpected because only 5-10% of DCs were infected with HIV-1 or HSV-2 at 24 hpi and, as we have previously shown, at these MOIs, HSV-2 infection plateaus later at ∼50-60% of the cell culture and for HIV-1 at 15-25% of MDDCs (25,28). So this HIV-1 stimulatory effect had to be a field effect.…”

“…MDDCs were generated from CD14 monocytes derived from whole blood as described previously (28)(29)(30). CD4 lymphocyte contamination was ,0.1%, and monocytes were almost completely converted to CD14 2 , DC-SIGN + DCs.…”

“…QPCR was carried out as described previously to measure MDDC gene expression (28)(29)(30), HIV-1 DNA as late reverse transcription products (35), and HSV-2 ICP8 RNA (34) infection levels using a MX3005 QPCR machine (Stratagene, La Jolla, CA).…”

“…CD4 lymphocyte contamination was ,0.1%, and monocytes were almost completely converted to CD14 2 , DC-SIGN + DCs. Human LCs were extracted from human skin via collagenase digestion as described previously (23,28) with 97% purity (31) (Supplemental Fig. 2).…”

The C-type Lectin Langerin Functions as a Receptor for Attachment and Infectious Entry of Influenza A Virus

“…(16) and Candida albicans (17), and some viruses. Human immunodeficiency virus type 1(HIV-1) is recognized by a variety of CLRs, including DC-SIGN, MMR, and langerin (18,19). While initial studies suggested that recognition by langerin resulted in uptake and degradation of HIV-1 in Birbeck granules (20), recent studies show that langerin-mediated uptake can facilitate transfer of the virus from DC to T cells, in a manner analogous to that reported for DC-SIGN (21)(22)(23)(24)(25).…”