Biochemical effects of KH 1060 and anti-TNF monoclonal antibody on human peripheral blood mononuclear cells.
The aim of this study was to investigate whether the vitamin D analogue KH 1060 could exert a suppressive action on Tumor necrosis factor-alpha (TNF-alpha). The chimeric anti-TNF-alpha monoclonal antibody (anti-TNF), alone or in combination with KH 1060, was also used. KH 1060 (0.01, 0.1, 1 nM) significantly inhibited cell proliferation, determined after 5 days by [3H]thymidine incorporation, when peripheral blood mononuclear cells (PBMC), obtained from healthy subjects, were stimulated with phytohaemagglutinin (PHA) and incubated for 24 h in the absence and in the presence of lipopolysaccharide (LPS). In the same experimental conditions, anti-TNF exerted a significant inhibition on PBMC proliferation, at the lowest doses (0.001, 0.01 microg/ml) in the absence of LPS, and at 0.001, 1, 10 microg/ml in its presence. A synergistic inhibition was registered combining KH 1060 and anti-TNF, at well-defined concentrations. 0.1 nM KH 1060 produced a significant decrease in TNF-alpha levels, determined by ELISA, although less remarkable than in the presence of anti-TNF. This decrease was synergistic, associating 0.1 nM KH 1060 and 0.1 microg/ml anti-TNF. VDR protein levels were increased by 0.1 nM KH 1060, 0.1 microg/ml anti-TNF or their combination. The protein levels of two oncogenes, Bax and Bcl-2, remained unchanged, when PBMC were incubated with KH 1060, anti-TNF or their combination in the absence of LPS, while, in its presence, an increase was registered. The demonstrated anti-TNF-alpha effect of KH 1060 may suggest for this compound an immunosuppressive action and the possibility to synergistically act with other drugs.
Stio
Maria
M
Department of Biochemical Sciences, University of Florence, Viale Morgagni 50, I-50134 Florence, Italy. maria.stio@unifi.it
Treves
Cristina
C
Martinesi
Maria
M
Bonanomi
Andrea G
AG
D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology*; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D019254:Genes, bcl-2 / Q000502:physiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects*; D008070:Lipopolysaccharides / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D018167:Receptors, Calcitriol / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000276:immunology; D051028:bcl-2-Associated X Protein
D000911:Antibodies, Monoclonal; C494826:BAX protein, human; D007166:Immunosuppressive Agents; D008070:Lipopolysaccharides; D019253:Proto-Oncogene Proteins c-bcl-2; D018167:Receptors, Calcitriol; D014409:Tumor Necrosis Factor-alpha; D051028:bcl-2-Associated X Protein; C074279:KH 1060; D002117:Calcitriol