Comparative analysis of integrin expression on monocyte‐derived macrophages and monocyte‐derived dendritic cells

Abstract

SUMMARYBoth macrophages (MAC) and dendritic cells (DC) are members of the mononuclear phagocyte system (MPS) with monocytes (MO) as common precursor cells. Cells of the MPS are able to take up, process and present antigens to T lymphocytes, thereby inducing a primary or secondary immune response. Adhesion molecules are of crucial importance for the interaction of antigenpresenting cells with immune cells, especially T lymphocytes. By representational difference analysis, we identi®ed CD49c (VLA-3), a member of the b 1 -integrin family of adhesion receptors, as differentiation-associated antigen in MO-derived MAC. In contrast, MO-derived DC did not express CD49c mRNA. These data prompted us to compare the integrin expression pattern of MAC and DC. Both cell types showed a low expression of the a-chains of the b 1 -integrins CD49a, CD49b, CD49d and CD49e, whereas a marked difference was observed for CD49c and CD49f. Expression of both integrins increased during MO to MAC differentiation, but was not detectable on DC. In parallel the b 1 -chain (CD29) was clearly up-regulated during MO to MAC differentiation but was only weakly expressed on DC. On the other hand, the b 2 -integrins CD11a, CD11b, CD11c and CD18 were all expressed on MAC and DC. Beside their role in cell±cell interaction and adhesion, b 2 -integrins are also known as possible binding molecules for bacteria and lipopolysaccharide (LPS), especially for high LPS concentrations. Therefore we investigated the LPS response of MAC versus DC in terms of tumour necrosis factor-a (TNF-a) release. DC were less responsive to low doses of LPS, which can easily be explained by the very low CD14 expression on DC compared for MAC. In contrast, the TNF-a response was comparable to MAC when DC were stimulated with high LPS concentrations. Our results show a speci®c, differentiationdependent pattern of b 1 -and b 2 -integrin expression on in vitro-generated MAC and DC. We suggest that the high expression of CD11/CD18 on DC could be involved in the LPS binding of DC. As LPS is not only an activation but also a differentiation stimulus for DC, the expression of CD11/CD18 on DC may be important for the successful maturation of DC and thereby the initiation of a primary immune response.

Stimulation of human monocytic cells by the medicinal mushroom Agaricus blazei Murill induces expression of cell surface markers associated with activation and antigen presentation

“…The β (or leukocyte)-integrins, i.e. the CD11/CD18 complex, including CD11b and CD11c receptors are expressed on both macrophages and MDDC and play a role in cell-to cell adhesion [35]. These antigens are rapidly upregulated after activation and promote strong attachment of leukocytes to the vascular endothelium and subsequent transendothelial migration.…”

Soybean protein fraction digested with neutral protease preparation, “Peptidase R”, produced by Rhizopus oryzae, stimulates innate cellular immune system in mouse

“…CD11b is a typical cell surface antigen of macrophages and DC [17]. IL-12 is one of the major cytokines produced by these cells [18].…”

Mature But Not Immature Fas Ligand (CD95L)-Transduced Human Monocyte-Derived Dendritic Cells Are Protected from Fas-Mediated Apoptosis and Can Be Used as Killer APC

“…PBMC were isolated from leukapheresis concentrates of healthy donors, and monocytes were separated by countercurrent elutriation (26). To induce the in vitro differentiation of monocytes to DC, monocytes were cultured for 7 days in serum-free CellGro culture medium (CellGenix, Freiburg, Germany) in the presence of 500 U/ml IL-4 (Promocell, Heidelberg, Germany) and 500 U/ml GM-CSF (Leukomax; Essex, Munich, Germany).…”