Immunomodulatory effects of orally administered cannabinoids in multiple sclerosis.

Cannabinoids can modulate the function of immune cells. We here present the first human in vivo study measuring immune function in 16 MS patients treated with oral cannabinoids. A modest increase of TNF-alpha in LPS-stimulated whole blood was found during cannabis plant-extract treatment (p=0.037), with no change in other cytokines. In the subgroup of patients with high adverse event scores, we found an increase in plasma IL-12p40 (p=0.002). The results suggest pro-inflammatory disease-modifying potential of cannabinoids in MS.

LPS-induced IL-10 production in whole blood cultures from chronic fatigue syndrome patients is increased but supersensitive to inhibition by dexamethasone.

Several causes have been held responsible for the chronic fatigue syndrome (CFS), including an altered hypothalamus-pituitary-adrenal gland (HPA)-axis activity, viral infections and a reduced Th1 activity. Therefore, it was investigated whether the regulation of IL-10 is different in CFS. LPS-induced cytokine secretion in whole blood cultures showed a significant increase in IL-10 and a trend towards a decrease in IL-12 as compared with healthy controls. In patients and controls, IL-12 secretion was equally sensitive to suppression by dexamethasone, whereas IL-10 secretion appeared more sensitive in CFS-patients. In controls, IL-10 and IL-12 secretion were inversely correlated with free serum cortisol (r=-0.492, p<0.02 and r=-0.434, p<0.05, respectively). In CFS, such an inverse correlation was found for IL-12 (r=-0.611, p<0.02) but not for IL-10 (r=-0.341, ns). These data are suggestive for a disturbed glucocorticoid regulation of IL-10 in CFS.

Increased sensitivity to glucocorticoids in peripheral blood mononuclear cells of chronic fatigue syndrome patients, without evidence for altered density or affinity of glucocorticoid receptors.

BACKGROUND: In this study we tested the hypothesis that the increased sensitivity to glucocorticoids in chronic fatigue syndrome (CFS)-patients can be attributed to an altered functioning of their glucocorticoid receptors (GR). METHODS: For this purpose, affinity and distribution of the GR were studied in purified, peripheral blood mononuclear cells (PBMC) of 10 CFS patients and 14 controls along with the responsiveness of these cells to glucocorticoids in vitro. RESULTS: Affinity (Kd) and number of GR was not different in PBMC of CFS patients when compared with the controls (Kd, 12.9 +/- 8.9 nmol vs 18.8 +/- 16.2 nmol and GR number, 4,839 +/- 2,824/ cell vs 4,906 +/- 1,646/cell). Moreover, RT-PCR revealed no differences in GR messenger RNA expression. Nevertheless, PBMC from CFS patients showed an increased sensitivity to glucocorticoids in vitro. In CFS patients 0.01 micromol dexamethasone suppressed PBMC proliferation by 37%, whereas the controls were only suppressed by 17% (P < 0.01). Addition of phorbol 12-myristate 13-acetate to the cultures rendered the cells resistant to dexamethasone with regard to proliferation and IL-10 and IFN-gamma production, but not to IL-2 and TNF-alpha production in both patients and controls. No difference between patients and controls was observed in this respect CONCLUSIONS: In conclusion, PBMC of CFS patients display an increased sensitivity to glucocorticoids, which cannot be explained by number or affinity of the GR but should rather be attributed to molecular processes beyond the actual binding of the ligand to the GR.

CD4 T lymphocytes from patients with chronic fatigue syndrome have decreased interferon-gamma production and increased sensitivity to dexamethasone.

A disturbed hypothalamus-pituitary-adrenal gland axis and alterations at the immune system level have been observed in patients with chronic fatigue syndrome (CFS). Glucocorticoids are known to modulate T cell responses; therefore, purified CD4 T cells from CFS patients were studied to determine whether they have an altered sensitivity to dexamethasone (DEX). CD4 T cells from CFS patients produced less interferon-gamma than did cells from controls; by contrast, interleukin-4 production and cell proliferation were comparable. With CD4 T cells from CFS patients (compared with cells from controls), a 10- to 20-fold lower DEX concentration was needed to achieve 50% inhibition of interleukin-4 production and proliferation, indicating an increased sensitivity to DEX in CFS patients. Surprisingly, interferon-gamma production in patients and controls was equally sensitive to DEX. A differential sensitivity of cytokines or CD4 T cell subsets to glucocorticoids might explain an altered immunologic function in CFS patients.

IL-4 abrogates the inhibitory effect of IL-10 on the development of experimental allergic encephalomyelitis in SJL mice.

IL-10 and IL-4 were studied with respect to their capacity to inhibit experimental allergic encephalomyelitis (EAE) induced in SJL/J mice by immunization with the proteolipid protein peptide PLP139-151. Treatment with 2 micrograms IL-10/day from day 0 until day 12 delayed onset of disease and inhibited the severity of EAE. By contrast, a daily dose of 0.5 microgram IL-4 was ineffective. Instead of acting in a synergistic fashion, IL-4 even abrogated the inhibitory effect of IL-10. The effects of IL-10 and IL-4 treatment were largely consistent with the (lack of) ability of these cytokines to down-regulate the inflammatory response in brain tissue. Although IL-4 was ineffective in the inhibition of EAE, lymph node cells from IL-4-treated mice displayed a strongly inhibited peptide-specific IFN-gamma production. By contrast, IL-10, which was effective in inhibiting EAE, showed no significant inhibition of IFN-gamma at this level. Neither cytokine treatment resulted in detectable levels of peptide-specific IL-4. Indirect evidence for the activity of Th2 cells in vivo came from the observation that IL-10 inhibited the primary PLP139-151-specific IgG2a and IgG3 response in favor of IgG1, whereas IL-4 inhibited the primary antibody response to the peptide, regardless of subclass. The combination of IL-4 and IL-10 did not affect the subclass composition. The observation that IL-10-treated mice remained sensitive to re-induction of EAE is not in support of an important role of Th2 cells in regulating disease activity in this model of actively induced EAE.

Squamous epithelial proliferative lesions associated with rhesus Epstein-Barr virus in simian immunodeficiency virus-infected rhesus monkeys.

Proliferative lesions were found on the squamous epithelium of the tongue, esophagus, or penis or haired skin of the lip, hand, or thorax of 8 simian immunodeficiency virus-infected rhesus monkeys that died of simian AIDS. The lesions were focal and consisted of hyperkeratosis, parakeratosis, and acanthosis in the skin, with additional ballooning degeneration in the tongue, esophagus, and penis. The epithelial surfaces were frequently colonized by Candida species or gram-positive cocci. Intranuclear inclusion bodies were seen in cells in the middle and superficial layers. Herpesvirus virions were found in inclusion-bearing cells by transmission electron microscopy. An Epstein-Barr-like virus was identified in inclusion-bearing cells by immunohistochemistry and in situ hybridization. No virus was detectable in basal layers of the epithelium. These lesions resemble oral hairy leukoplakia in AIDS patients and may thus provide a useful primate model to study permissive epithelial infection by Epstein-Barr-like viruses.

Ultrastructure of epidermis of mice with chronic proliferative dermatitis.

C57BL/Ka mice with chronic proliferative dermatitis (cpdm/cpdm) develop chronic persistent skin lesions characterized by epidermal hyperplasia, infiltration by granulocytes and macrophages, and vascular dilatation. Similar lesions are present in other orthokeratotic epithelia in affected mice, in particular the esophagus and forestomach. Here, we report on further characterization of epidermal hyperplasia and the granulocytes. Keratinocytes of lesional skin, but not of normal skin, show round and electron-dense mitochondrial inclusions that are present in all layers of the epidermis. Similar inclusions are also present in the esophagus and forestomach of affected mice. There appears to be a direct relation between the presence of intramitochondrial inclusions and epidermal hyperplasia in the mouse. Furthermore, the presence of keratinocyte-derived apoptotic bodies in the epidermis, esophagus, and forestomach was frequently observed in the lesions, which is consistent with previous light microscopic observations of single cell death of keratinocytes. The granulocytes present in the skin, esophagus, and forestomach were mainly eosinophils. There were widespread gaps observed in the lamina densa in the epidermis that were mostly directly associated with dermal or epidermal eosinophils. This type of gap is also observed in psoriasiform diseases in humans. This electron microscopic study demonstrated that this mouse model should be useful to screen potential therapeutic strategies for psoriasiform and other inflammatory skin disorders.

Alcohol in combination with malnutrition causes increased liver fibrosis in rats.

Rats were malnourished for 12 months with a highly inadequate fat-rich, calorie-sufficient but otherwise poly-deficient liquid diet composed of mashed potatoes with mayonnaise, comparable with the nutritional intake of many chronic alcoholics. When alcohol was incorporated into this diet, administered as whisky in drinking water available ad libitum, the livers of all eight rats showed increased fibrosis and cirrhosis as compared to the livers of the eight non-alcohol-treated, isocalorically fed, paired control rats. Alcohol-treated rats developed fibrosis and cirrhosis on a dietary fat content of 38% of total caloric intake and low blood alcohol levels, ranging from 50 to 126 mg/dl, due to gradual intake over the day and to low absolute intake (mean 11.9 +/- 0.6 g/kg per day). None of the rats died spontaneously. Malnutrition is likely to be an important factor in the development of the fibrosis of alcoholic liver disease, and this rat model may be used to study aspects of the pathogenesis.

Fat-storing cells and myofibroblasts are involved in the initial phase of carbon tetrachloride-induced hepatic fibrosis in BN/BiRij rats.

This study on the appearance, distribution and kinetics of fibroblast-like cells (fat-storing cells, transitional cells, myofibroblasts and fibroblasts) after CCl4-treatment was undertaken to delineate further the respective roles of these cell types in liver fibrogenesis. The different cell types were distinguished on the basis of their immunophenotypic pattern with a combination of marker antibodies and on the basis of ultrastructural characteristics. Combined staining for alpha-smooth muscle actin (sma) and desmin (Des) revealed perisinusoidal fat-storing cells (FSC) as d+ sma- and myofibroblasts around the central veins of the normal rat liver as d+ sma+. During the initial phase of CCl4-induced hepatic fibrosis (week 1 and 2), the number of d+ sma+ cells increased in the degenerating area around the central veins and d+ sma+ cells appeared in the very thin fibrotic septa at week 2. Ultrastructural examination of the affected central areas showed the presence of myofibroblasts. These sma+ cells proliferated, as shown by double staining for bromodeoxyuridine (BrdU) and sma. In degenerating parenchymal areas, d+ sma- FSC were present. The FSC in the perisinusoidal space of areas which were not affected by CCl4 intoxification, remained d+ sma-. These immunostaining findings support the electron microscopical results, which show the presence of cells with the typical ultrastructural characteristics of FSC in both the degenerating areas and the perisinusoidal space of unaffected areas. After one week of CCl4-treatment, enhanced deposition of procollagen type III was observed around the central veins. Enhanced deposition of collagen type IV was seen subendothelially along the sinusoids, notably in degenerating parenchymal areas where the septa were later formed. FSC appear to be the principal source of collagen type IV during fibrogenesis. These observations further support and specify the role of FSC in early fibrogenesis. With the progression of the CCl4-induced fibrosis, d+ sma+ myofibroblasts remained localized in the fibrotic septa, but now along their outer edge. The majority of the cells in the septa were formed by d- sma- cells indicating a prominent role of fibroblasts in the septal formation. Septal fibroblasts are not only likely to produce matrix components, but also were shown to degrade collagen, as evidenced by the increased number of collagen-containing vacuoles during the course of fibrosis. In conclusion, myofibroblasts and FSC appear to be the main cell types involved in the initial phase of liver fibrogenesis induced by CCl4. Both myofibroblasts and FSC divide and transform.(ABSTRACT TRUNCATED AT 400 WORDS)

Baculovirus-directed high level expression of the hepatitis delta antigen in Spodoptera frugiperda cells.

The hepatitis delta antigen (HDAg) is a multifunctional protein. It forms the core-like structure of the hepatitis delta virus (HDV) but also enhances replication of HDV in the nucleus of the hepatocyte. A cDNA fragment encoding HDAg was inserted adjacent to the polyhedrin promoter of Autographa californica nuclear polyhedrosis virus present in the baculovirus transfer vector pVL941. After transfection of Spodoptera frugiperda (Sf9) cells a recombinant baculovirus Ac delta 1 was isolated and purified using filter hybridization techniques. Sf9 cells infected with Ac delta 1 express the HDAg as a non-fused, non-glycosylated protein with an abundance of up to 25% of the total cellular protein mass. Immunoblot analysis using a human polyclonal anti-HD conjugate identified a 22K and a 24K protein in the nucleus of Ac delta 1-infected Sf9 cells. Electron microscopic studies using immunogold labelling showed that the recombinant HDAg (recHDAg) was associated with the hetero-chromatin of the Sf9 cells. The recHDAg produced by Sf9 cells elicited anti-HD antibodies in chimpanzees when injected intramuscularly.