Beneficial effects of fumarate therapy in psoriasis vulgaris patients coincide with downregulation of type 1 cytokines.

Background: Fumarates have been shown to be effective in psoriasis vulgaris.

Objectives: To find out whether successful therapy is associated with modulation of cytokines.

Methods: We determined interferon (IFN)-gamma, interleukin (IL)-4 and IL-10 secretion capacities of peripheral blood mononuclear cells (PBMC) after phytohaemagglutinin stimulation, and IL-12p70 and IL-10 secretion capacities of PBMC after endotoxin stimulation in psoriasis vulgaris patients during treatment with fumarates.

Divergent role for TNF-alpha in IFN-gamma-induced killing of Toxoplasma gondii and Salmonella typhimurium contributes to selective susceptibility of patients with partial IFN-gamma receptor 1 deficiency.

Patients with defects in IFN-gamma- or IL-12-mediated immunity are susceptible to infections with Salmonella and non-tuberculous mycobacteria, but rarely suffer from infections with other intracellular pathogens such as Toxoplasma gondii. Here we describe macrophage and T cell function in eight individuals with partial IFN-gamma receptor 1 (IFN-gammaR1) deficiency due to a mutation that results in elevated cell surface expression of a truncated IFN-gammaR1 receptor that lacks the intracellular domain. We show that various effector mechanisms dependent on IFN-gammaR signaling are affected to different extents.

Arachidonic acid, but not its metabolites, is essential for FcgammaR-stimulated intracellular killing of Staphylococcus aureus by human monocytes.

Since arachidonic acid (AA) production by phospholipase A2 (PLA2) is essential for the Fcgamma receptor (FcgammaR)-mediated respiratory burst and phagocytosis of opsonized erythrocytes by monocytes and macrophages, we focused in this study on the role of AA and its metabolites in the FcgammaR-stimulated intracellular killing of Staphylococcus aureus by human monocytes. The results revealed that the PLA2 inhibitors, but not inhibitors of cyclo-oxygenase and lipoxygenase, markedly suppressed the FcgammaR-mediated killing process. The production of O-2 by monocytes upon FcgammaR cross-linking was inhibited by 4-bromophenacyl bromide in a dose-dependent fashion, indicating that inhibition of PLA2 activity impairs the oxygen-dependent bactericidal mechanisms of monocytes, which could be partially restored by addition of exogenous AA and docosahexaenoic acid, but not myristic acid.

Intracellular signalling by binding sites for the antipsoriatic agent monomethylfumarate on human granulocytes.

Monomethylfumarate (MMF), the most active metabolite of the new antipsoriasis drug Fumaderm, stimulates an anti-inflammatory mediator profile in human leucocytes and inhibits the proliferation of keratinocytes. These effects of MMF on cells in vitro may in part explain the beneficial action of Fumaderm in patients. In addition, we have reported that MMF stimulates an increase in the intracellular free Ca2+ concentration ([Ca2+]i) and the cyclic adenosine monophosphate (cAMP) concentration in granulocytes and keratinocytes.

Selective stimulation of T helper 2 cytokine responses by the anti-psoriasis agent monomethylfumarate.

Type 2 cytokines are thought to have a protective role in psoriasis vulgaris by dampening the activity of T helper 1 (Th1) lymphocytes. The aim of the present study was to determine the effect of monomethylfumarate (MMF), the most active metabolite of the new anti-psoriatic drug Fumaderm, on the production of cytokines and the development of Th subsets. MMF was found to enhance interleukin (IL)-4 and IL-5 production by CD2/CD8 monoclonal antibody-stimulated peripheral blood mononuclear cells (PBMC) in a dose-dependent manner.

Role of protein kinase C isozymes in Fc gamma receptor-mediated intracellular killing of Staphylococcus aureus by human monocytes.

Intracellular killing of Staphylococcus aureus by human monocytes after cross-linking Fc gamma R is known to be a phospholipase C (PLC)-dependent process. Activation of PLC leads to the formation of second messengers that synergistically activate protein kinase C (PKC). The aim of this study was to obtain more insight into the role of PKC in Fc gamma R-mediated killing process.

Fumaric acid derivatives evoke a transient increase in intracellular free calcium concentration and inhibit the proliferation of human keratinocytes.

Systemic administration of fumaric acid (FA) derivatives was originally an empirical antipsoriatic treatment, which showed promising clinical results. In the present study, FURA-2-loaded suspensions of cultured normal keratinocytes and SV40-transformed keratinocytes (SVK-14 cells) were used to study the effects of FA derivatives on the intracellular free calcium concentration ([Ca2+]i). Monomethylfumarate (MMF), dimethylfumarate (DMF) and monoethylfumarate (MEF) induced a rapid, transient [Ca2+]i increase in both cell types.

Protein tyrosine kinase activity is essential for Fc gamma receptor-mediated intracellular killing of Staphylococcus aureus by human monocytes.

Our previous study revealed that the intracellular killing of Staphylococcus aureus by human monocytes after cross-linking Fc gamma receptor I (Fc gamma RI) or Fc gamma RII is a phospholipase C (PLC)-dependent process. The aim of the present study was to investigate whether protein tyrosine kinase (PTK) activity plays a role in the Fc gamma R-mediated intracellular killing of bacteria and activation of PLC in these cells. The results showed that phagocytosis of bacteria by monocytes was not affected by the PTK inhibitors genistein and tyrphostin-47.

Pulmonary surfactant inhibits monocyte bactericidal functions by altering activation of protein kinase A and C.

Pulmonary surfactant, the main function of which is to reduce surface tension in the alveoli, is also known to affect the functions of monocytes. Two protein kinases play a role in the regulation of the bactericidal functions of phagocytes, i.e.

Effects of monomethylfumarate on human granulocytes.

Monomethylfumarate (MMF) is the most active metabolite of the new antipsoriasis drug Fumaderm. Because granulocytes play an important role in the pathophysiology of psoriasis, the effects of this drug on the functional activities of these cells were investigated. MMF stimulated polarization and elastase release, and enhanced the intracellular killing of bacteria by granulocytes.

A new competition binding assay for determination of the cAMP content of human leukocytes.

We developed a competition binding assay for measurement of the cAMP content of human cells based on specific binding sites for this messenger in a crude bovine adrenocortical preparation. The mean cAMP content of human granulocytes and lymphocytes was 1.13 +/- 0.

A competition binding assay for determination of the inositol (1,4,5)-trisphosphate content of human leucocytes.

We developed a competition binding assay for estimation of the intracellular inositol (1,4,5)-trisphosphate (Ins(1,4,5)P3) and optimalized it for the measurement of the Ins(1,4,5)P3 content of human blood leucocytes. The present method is considerably cheaper and requires five times fewer cells than the commercial Ins(1,4,5)P3 kit. The mean Ins(1,4,5)P3 content of human blood monocytes, granulocytes, and lymphocytes amounted to 3.

Mean cell volume of human blood leucocytes and resident and activated murine macrophages.

The mean cell volume (MCV) of human blood leucocytes and resident and activated murine macrophages was measured with a Coulter counter connected to a 256 channelyzer. The values found for human blood monocytes, granulocytes, and lymphocytes were 421 +/- 24 femtolitre (fl), 334 +/- 32 fl, and 204 +/- 19 fl, respectively. Resident murine peritoneal macrophages were significantly smaller than rIFN-gamma-activated and BCG/PPD-activated peritoneal macrophages and resident alveolar macrophages.

Characterization of fastidious adenovirus types 40 and 41 by DNA restriction enzyme analysis and by neutralizing monoclonal antibodies.

The DNA of 48 strains of adenovirus type 40 (Ad40) and of 128 strains of adenovirus type 41 (Ad41), isolated between 1971 and 1986 from various countries, was characterized by restriction enzyme analysis using nine and ten restriction endonucleases respectively. Five new DNA variants of Ad40 and 18 new DNA variants of Ad41 were detected. Most of the restriction sites which differed among the various DNA variants appeared to be distributed at random over the entire length of the viral genomes of the two serotypes.

Molecular epidemiology of adenovirus type 21 in the Netherlands and the Federal Republic of Germany from 1960 to 1985.

After a period of high prevalence in the early 1960s, adenovirus serotype 21 (Ad21) was identified in The Netherlands only very sporadically for more than 20 years. From December 1984 to July 1985, Ad21 was isolated relatively often from hospitalized children living in different parts of The Netherlands. The patients in question suffered from respiratory, gastrointestinal, meningeal, or ocular disorders.