PATTERN OF CYTOKINE RECEPTORS EXPRESSED BY HUMAN DENDRITIC CELLS MIGRATED FROM DERMAL EXPLANTS

Different reasons account for the lack of information about the expres sion of cytokine receptors on human dendritic cells (DC): (a) DC are a trace population; (b) the proteolytic treatment used to isolate DC ma y alter enzyme-sensitive epitopes; and (c) low numbers of receptors pe r cell. In the present work the expression of cytokine receptors was a nalysed by flow cytometry on the population of dermal DC (DDC) that sp ontaneously migrate from short-term culture dermal explants. DDC obtai ned after dermal culture were CD1a(low), CD1b(+), CD1c(+), human leuco cyte antigen (HLA)-DR+, CD11c(high), CD11b(+) and CD32(+). The DC line age was confirmed by ultrastructural analysis. DDC expressed interleuk in (IL)-1R type I (monoclonal antibody (mAb) hIL-1R1-M1; and 6B5); IL- IR type 2 (mAb hIL-1R2-M22); IL-2R alpha chain (mAb anti-Tac; and hIL- 2R-M1) and IL-2R gamma chain (mAb 3B5; and AG14C). DDC did not stain f or IL-2R beta chain using four mAbs recognizing two different epitopes of IL-2R beta (mAb 2R-B; Mik-beta 1; and CF1; Mik-beta 3 respectively ). DDC were also positive for the cytokine binding chains (alpha chain s) of IL-3R (mAb 9F5); IL-4R (mAb hIL-4R-M57; and S456C9); and IL-7R ( mAb hIL-7R-M20; and R3434). DDC showed low levels of IL-6R alpha chain (mAb B-F19; B-R6; and B-E23) and its signal transducer gp130 (mAb A2; and B1). DDC strongly expressed interferon-gamma receptor (IFN-gamma R) (mAb GIR-208) and were negative for IL-8R (mAb B-G20; and B-F25). A ll DDC were highly positive for granulocyte-macrophage colony-stimulat ing factor receptor (GM-CSFR) alpha chain (mAb hGM-CSFR-M1; SC06; SC04 , and 8G6) and to a lesser extent for the common beta chain of GM-CSFR , IL-3R and IL-SR (mAb 3D7). On the other hand, reactivity was not fou nd for granulocyte colony-stimulating factor receptor (G-CSFR) (mAb hG CSFR-M1) nor macrophage colony-stimulating factor receptor (M-CSFR) (m Ab 7-7A3-17) confirming the DC lineage of DDC. As previously reported for lymphoid DC, DDC expressed tumour necrosis factor receptort (TNFR) 75000 MW (mAb utr-1; hTNFR-M1; and MR2-1) but lacked TNFR 55 000 MW ( mAb htr-9; MR1-1; and MR1-2). In summary, DDC express receptors for a broad panel of cytokines, even receptors for cytokines whose effects o n DC are still unknown (i.e. IL-2R alpha gamma; IL-6R alpha/gp130; IL- 7R alpha gamma).