Expression and modulation of a mononuclear phagocyte differentiation antigen (PAM-1) during in vitro maturation of peripheral blood monocytes.
Human macrophages obtained by in vitro maturation of peripheral blood monocytes express a surface antigen, PAM-1, recognized by a monoclonal antibody and typical of pulmonary alveolar and tissue macrophages. PAM-1, undetectable in freshly isolated peripheral blood monocytes, was expressed in monocyte-derived macrophages after 3 days of in vitro adherent culture and was maximal after 14-15 days (50%-60% of positive cells). Similar levels of PAM-1 positivity were observed in non-adherent monocyte-derived macrophages suggesting that cell adhesion was not a critical requisite for the expression of this antigen. Bacterial lipopolysaccharide and a monocyte chemotactic protein preparation respectively suppressed and upregulated PAM-1 expression in monocyte-derived macrophages. In contrast, interferon-gamma, although enhancing the levels of class II HLA-DR antigen in monocyte-derived macrophages, did not influence the kinetics of appearance and the levels of PAM-1 in these cells. Thus, expression of PAM-1, which is restricted to certain stages of the monocyte-macrophage differentiation pathway, is also differentially modulated by activation signals, which can be present in the micro-environment of inflammed tissues.
Laboratorio di Immunologia Umana, Istituto Mario Negri, Milan, Italy.
G
G
Poli
J M
JM
Wang
L
L
Ruco
S
S
Rossini
A
A
Biondi
A
A
Mantovani
S
S
Uccini
D000943:Antigens, Differentiation / Q000097:blood* / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects / Q000502:physiology; D002630:Chemotactic Factors / Q000494:pharmacology*; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology*
D000943:Antigens, Differentiation; D002630:Chemotactic Factors; D008070:Lipopolysaccharides