Effects of anti-TNF-α agents on circulating endothelial-derived and platelet-derived microparticles in psoriasis

Psoriasis involves TNF-α secretion leading to release of microparticles into the bloodstream. We investigated the effect of TNF blockers on microparticles levels before and after treatment in patients (twenty treated by anti-TNF-α agents and 6 by methotrexate) with severe psoriasis. Plasmatic microparticles were labelled using fluorescent monoclonal antibodies and were analysed using cytometry. Three months later, 70% of patients treated with anti-TNF-α agents achieved a reduction in PASI score of at least 75%. The clinical improvement in patients treated with anti-TNF-α agents was associated with a significant reduction of the mean number of platelet microparticles (2837/μl vs 1849/μl, P = 0.02) and of endothelial microparticles (64/μl vs 22/μl, P = 0.001). Microparticles are significantly decreased in psoriatic patients successfully treated by anti-TNF-α. Microparticles levels as circulating endothelial cells represent signs of endothelial dysfunction and are elevated in psoriasis. Then, TNF blockade may be effective to reduce cardiovascular risk through the reduction of circulating microparticles.

Endothelial cell-derived microparticles induce plasmacytoid dendritic cell maturation: potential implications in inflammatory diseases

BACKGROUND

Increased circulating endothelial microparticles, resulting from vascular endothelium dysfunction, and plasmacytoid dendritic cell activation are both encountered in common inflammatory disorders. The aim of our study was to determine whether interactions between endothelial microparticles and plasmacytoid dendritic cells could contribute to such pathologies.

DESIGN AND METHODS

Microparticles generated from endothelial cell lines, platelets or activated T cells were incubated with human plasmacytoid dendritic cells sorted from healthy donor blood or with monocyte-derived dendritic cells. Dendritic cell maturation was evaluated by flow cytometry, cytokine secretion as well as naive T-cell activation and polarization. Labeled microparticles were also used to study cellular interactions.

RESULTS

Endothelial microparticles induced plasmacytoid dendritic cell maturation. In contrast, conventional dendritic cells were resistant to endothelial microparticle-induced maturation. In addition to upregulation of co-stimulatory molecules, endothelial microparticle-matured plasmacytoid dendritic cells secreted inflammatory cytokines (interleukins 6 and 8, but no interferon-alpha) and also induced allogeneic naive CD4(+) T cells to proliferate and to produce type 1 cytokines such as interferon-gamma and tumor necrosis factor-alpha. Endothelial microparticle endocytosis by plasmacytoid dendritic cells appeared to be required for plasmacytoid dendritic cell maturation. Importantly, the ability of endothelial microparticles to induce plasmacytoid dendritic cells to mature was specific as microparticles derived from activated T cells or platelets (the major source of circulating microparticules in healthy subjects) did not induce such plasmacytoid dendritic cell maturation.

CONCLUSIONS

Our data show that endothelial microparticles specifically induce plasmacytoid dendritic cell maturation and production of inflammatory cytokines. This novel activation pathway may be implicated in various inflammatory disorders and endothelial microparticles could be an important immunmodulatory therapeutic target.

Immunohistochemical analysis of CD4+ and CD8+ T-cell subsets in high risk human papillomavirus-associated pre-malignant and malignant lesions of the uterine cervix

OBJECTIVES

Humoral and cellular immune responses are likely to play a key role for the clearance or persistence and progression of high risk (HR) HPV-associated cervical lesions. Although there are many studies describing the systemic T-cell responses to HPV16 and 18 proteins, few data are available regarding the cellular mucosal immune responses. We used immunohistochemistry to characterize populations of T-immune cells (CD4+, CD8+, CD45RO+) in HR-HPV-infected precancerous and cancerous lesions of the uterine cervix.

METHODS

Four biopsies from normal cervix, 9 CIN1 which have regressed (rCIN), 5 CIN1 which have progressed (pCIN) to high grade lesions, 13 CIN3 and 11 invasive carcinomas were included. All dysplasias and carcinomas were HR-HPV-positive and low-risk-HPV-negative. They were stained with monoclonal antibodies specific for CD4, CD8 and CD45RO and examined by microscopy.

STATISTICAL ANALYSIS

The Kruskal-Wallis test and the Siegel's and Castelan's method were used. RESULTS.: CD4+ cells predominated in regressing CIN1 both within the stroma and the epithelium with the highest CD4+/CD8+ ratio compared with pCIN1, CIN3 and invasive carcinoma. At the exception of CD45RO+ cells, T cells were detected with similar frequencies in both pCIN1 and CIN3. However, in 7 out of 10 CIN3, CD4+ and CD8+ cells were visible as organized lymphoid follicle structure. The CD8+ and CD45RO+ cells far exceeded the CD4+ cells in invasive cancers.

CONCLUSIONS

Density and distribution of immune T cells depend on the malignant potential of HR-HPV lesions. These results suggest that the studied lymphocyte subsets have an important role to fulfil during the natural history of HR-HPV-associated lesions.

High-Risk Papillomavirus Infection Is Associated with Altered Antibody Responses in Genital Tract: Non-specific Responses in HPV Infection

In order to gain more information about local humoral immune responses to HPV infection, we quantified IgG, IgM, secretory-IgA (S-IgA), and total-IgA by ELISA, and lysozyme and lactoferrin by TR-IFMA, in cervical and cervicovaginal secretions of 40 healthy women and 28 high-risk HPV infected patients (11 were HPV16+). IgG, total-IgA, and S-IgA concentrations in cervicovaginal secretions (p < 0.0001) and high IgG and total-IgA concentrations (p < 0.001 and p < 0.01, respectively) in endocervical secretions were significantly higher in HPV+ patients than in the healthy group. Since the S-IgA/total-IgA ratio was significantly lower in cervicovaginal (7.5%) and endocervical secretions (36.5%) in HPV+ women compared to the control group (p < 0.003 and p < 0.001, respectively), HPV could be responsible for an increase in local production of non-secretory IgA (monomeric and dimeric forms). IgG and total-IgA concentrations in cervicovaginal and endocervical secretions fell in the same general percentage range in both HPV16+ and HPV+ groups (80% and 15%, respectively). However, the S-IgA/total-IgA ratio was much lower in HPV16+ than in HPV+ women, in both cervicovaginal secretions (3.4%) (p < 0.003) and in endocervical secretions (23.3%) (p < 0.001). Innate immunity proteins and local S-IgA response could not stop the spread of HPV infection in spite of high lysozyme and lactoferrin concentrations. HPV16+ disturbed the local humoral immune system, which could partly explain its low clearance.

Validation of a high sensitive immunoenzymatic assay to establish the origin of immunoglobulins in female genital secretions

Several studies were carried out to characterize the humoral immune response on mucosal genital surfaces. However, the results obtained so far were particularly conflicting due to the absence of validation methods. The aim of this study was to develop and validate a quantitative ELISA method, which is sensitive and reproducible, to measure immunoglobulin and secretory immunoglobulin concentrations in various biological fluids. This quantitative, sensitive (detection limit = 1 microg/L) and reproducible (coefficient of variation < 15%) method could be of interest to study the effects of viral infections on mucosal non-specific immune response in genital tract. To explore the humoral response, serum, saliva, vaginal secretions, and cervicovaginal secretions from 18 women, 20-45 years old, were evaluated for total-IgA, secretory IgA, IgM, and IgG. Albumin level was also evaluated by immuno-nephelometry. The secretion rates of immunoglobulins were measured by calculating their relative coefficients of excretion by reference to albumin. Despite large individual variations, median immunoglobulin levels were higher in the endocervical secretions than in the cervicovaginal secretions. When we compared the rates of immunoglobulins in genital fluids, IgG prevalence was higher (80%) in cervicovaginal and endocervical secretions than IgA prevalence (12%). In contrast, digestive mucosal secretions, such as saliva, contained mostly IgA (80%). In cervicovaginal and endocervical secretions, IgG and IgM originated mainly from serum, whereas a local synthesis provided total-IgA and secretory IgA. These results allowed us to raise a possible hypothesis for the origin of immunoglobulins in the genital tract. They illustrated the peculiar feature of the female reproductive tract and the difficulty for this tissue to contribute in the mucosal associated lymphoid tissue. The low secretory-IgA and total-IgA levels could explain the particular sensitivity of the vagina and the cervix to infections.

Nonspecific secretory immunity in HIV-infected patients with oral candidiasis

Buccal and digestive tract opportunistic infections occur frequently in patients infected by HIV. In this study, we measured lysozyme (Lz), lactoferrin (Lf), total IgA (T-IgA), and secretory IgA (S-IgA) levels to investigate nonspecific secretory immunity in HIV-infected patients with oral candidiasis. Serum, saliva, and stool samples were analyzed by time-resolved immunofluorometric assay for Lz and Lf levels and by enzyme-linked immunosorbent assay for T-IgA and S-IgA levels. Mean salivary Lf and T-IgA levels (66.50 mg/L and 0.10 g/L, respectively) and mean fecal Lf, T-IgA, and S-IgA outputs (0.87, 54.0, and 43.6 mg/d, respectively) were significantly higher in HIV-infected patients with oropharyngeal candidiasis than in HIV-infected patients without oropharyngeal candidiasis and healthy subjects. There was a modification in the molecular form rate, with a high increase in S-IgA and monomeric IgA transudation from the plasmatic compartment into salivary and digestive fluids and an increase in salivary Lf local synthesis by polymorphonuclear neutrophils. HIV infection appears to be associated with dysregulation of some of the nonspecific immune factors at the mucosal surface. Despite high saliva concentrations and high intestinal output, innate immunity was not able to stop yeast expansion in HIV-infected patients.

Human papillomavirus detection by non isotopic in situ hybridization, in situ hybridization with signal amplification and in situ polymerase chain reaction

Classical in situ hybridization (ISH) with biotinylated probes makes it possible to detect and localize human papillomavirus (HPV) nucleic acid sequences in cytological and histological materials. This method is however of limited value in the detection of a few copies of the virus. Moreover the specificity of such a technique is not always convincing when ISH signals are small and/or of low intensity. Recently, much attention has been focused on the utility of the in vitro polymerase chain reaction (PCR) and especially on PCR-single strand conformation polymorphism (SSCP) to amplify small amounts of viral DNA with accurate hybrid specificity. But the latter method requires nucleic acid extraction and tissue destruction. Thus, correlation between the PCR results and histological findings is not possible. Hence, the aim of our current study was to apply to HeLa cells and cervical formalin-fixed and paraffin-embedded biopsies, a novel procedure of ISH signal amplification, the catalyzed signal amplification (CSA). Such a procedure is based on the deposition of streptavidin-horseradish peroxidase catalyzing the deposition of biotinylated tyramide molecules on the location of the probed target. The biotin accumulation is then detected with streptavidin peroxidase and diaminobenzidine. The results were compared with those obtained by direct and indirect in situ PCR. The catalysed signal amplification successfully increased the sensitivity and efficiency of ISH for the detection of rare sequences in HPV infected cells and histological materials. Such a method was found simpler and faster than in situ PCR and tissue morphology was better preserved.

Alteration in the production of free oxygen radicals and proinflammatory cytokines by peritoneal and alveolar macrophages in old mice and immunomodulatory effect of RU 41740 administration. Part I: Effect of short and repetitive noise stress

The aim of this study was to analyze the effects of stress on natural immunity in old mice, and the potential of an immunomodulating drug to correct stress-induced immune abnormalities. We analyzed both the alveolar (ALM) and peritoneal macrophage (PerM) oxidative responses and cytokine productions of TNF-alpha and IL-1alpha, in old mice after exposure to 3 days of noise stress, with and without treatment with RU 41740, an immunomodulating compound. Production of Free Oxygen Radicals (FOR) by ALM and PerM macrophages was evaluated using a luminol-dependent chemiluminescence method at the basal state and after stimulation. Serum corticosterone was also measured. Three groups of 22-24 month-old C57BL/6 mice were studied. Seven mice were treated with RU 41740 (10 mg kg(-1)) every day for 5 days and then exposed to sound stress (110 dB, 1000 Hz, for 3 nights). Ten mice were treated with saline, then submitted to a sham stress. Eight animals received neither treatment nor stress. There was no difference in corticosterone level between the three groups and between these groups and a control group nonstressed, noncannulated. After stimulation by fMetLeuPhe, production of FOR by ALM and PerM significantly increased after stress and returned to normal values after RU 41740 treatment (p < 0.001). The cytokine levels (TNF-alpha and IL-1alpha) decreased after stress and returned to normal levels after RU 41740 treatment. This study shows that, in aged mice, auditory stress is associated with modifications of macrophage functions which are different, depending on their localization and on the function under study. It confirms the immunomodulatory capacities of RU 41740 that was shown to counteract these effects of stress in elderly animals.

Auditory stress induces changes in membrane functions of mouse peritoneal macrophages

Stressful events induce responses in the endocrine and immune systems. The authors analysed the influence of repetitive noise stress on peritoneal macrophage oxidative and phagocytic responses. Plasma corticosterone levels were also measured. Different groups of 6- to 8-week-old C57BL/6 male mice were exposed for 1 night (n = 14) and 3 nights (n = 21) to a sound stress of 110 dB in an audiogenic stress chamber. Control animals were submitted to a sham stress for 1 night (n = 13) and 3 nights (n = 17). A marked decrease was observed in the phagocytic response to yeast (P = 3 x 10(-4)) while a mild increase in the oxidative response stimulated by opsonized zymosan was noted only after the 3 night stress (P = 0.02). Corticosterone levels of control and stressed mice did not differ. These results indicate that the stress resulting from repetitive noise causes modifications in peritoneal macrophage activity, and that these changes are dependent on the duration of stress. These functional alterations seem more complex than a simple general suppression or activation.

[Study of the membrane oxidative response of phagocytes after treatment with marbofloxacin in healthy cattle]

In addition to their antibacterial properties, quinolones are capable of modulating the immune response. The aim of this paper was to study the effects of a new fluoro-4-quinolone on the respiratory burst. We evaluated the effects of marbofloxacin on the activation of peripheral phagocytes in non-infected bovines after a 5-day treatment. The immunopharmalogical study measured the chemiluminescence response of phagocytic cells obtained from total blood. Serum cortisol and albumin levels were also measured. Data showed that the treatment with marbofloxacin induced a mild decrease in the oxidative response. There was no significant difference between serum albumin levels of normal values and those of before and after treatment, and the levels of serum cortisol were also not significantly different before and after treatment. These results suggest that marbofloxacin treatment could modulate the inflammatory response of phagocytic cells by counteracting the oxidative burst.

Serum secretory IgA and secretory component in patients with non-cirrhotic alcoholic liver diseases

Elevated levels of secretory IgA in serum have been demonstrated in several liver dysfunctions such as hepatic cytolysis and cholestasis. However, these possible alterations at an early stage of liver diseases have not yet been investigated. We studied a cohort of chronic alcoholic patients without cirrhosis in order to assess the changes in serum secretory IgA and other forms of secretory component, the split product of the polymeric Ig-receptor of epithelial cells. The possible diagnostic value of these measurements in the assessment of alcoholic disease was compared to that of serum gamma-glutamyl transpeptidase activity. Serum levels of secretory IgA and IgM and free secretory component, were quantified by an enzyme-linked immunosorbent assay in 71 patients with chronic alcoholic liver disease without cirrhosis and in 45 healthy controls. Patients were divided into two groups according to the severity of the liver abnormalities. In addition, the reversibility of serum secretory IgA, IgM and free secretory component abnormalities after alcohol withdrawal was evaluated in 15 patients. Serum levels of the three molecular forms of secretory component were significantly higher than those measured in control subjects, both in the whole population of patients and in the two groups of alcoholic patients without cirrhosis. In all groups, serum secretory IgA levels were correlated to free secretory component but not to total IgA levels. Serum secretory IgA levels were as discriminative as gammaglutamyl transferase activity in distinguishing between chronic alcoholic patients without cirrhosis and non-alcoholic subjects. The abnormalities of serum secretory IgA concentrations were reversible after alcohol withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum secretory IgA and IgM and free secretory component in IgA nephropathy

IgA nephropathy (IgAN) is characterized by the presence of IgA and C3 deposits in the mesangium. Mesangial IgA is mostly dimeric IgA1 with a J chain, lacking a secretory component. In view of the recent demonstration of elevated serum levels of secretory component and secretory IgA in liver disease and HIV infection associated with hyper-IgA, we measured the serum secretory component in 50 IgAN patients and 45 controls. Free secretory component and secretory IgA and IgM levels were determined by enzyme-linked immunosorbent assay. Normal or low levels were found patients. These data support previous work suggesting that in IgAN circulating and probably mesangial IgA do not originate from the epithelial compartment of the mucosal immunoglobulins as it is the case in other hyper-IgA diseases.

[IgA and its different molecular forms in the mesenteric, portal and peripheral venous blood in man]

The aim of this study was to assess the role of mesenteric blood in polymeric IgA (p-IgA) and IgA2-transport from the intestinal mucosa into plasma and the role of the liver in the clearance of these molecular forms of IgA. The concentrations of IgA, p-IgA and IgA2 were measured in mesenteric, splenic, portal, and hepatic veins of 7 control subjects without liver disease and in portal and peripheral veins of 4 patients with alcoholic cirrhosis. In control subjects, the concentration of the different molecular forms of IgA were not significantly different in mesenteric and in splenic vein. No significant decrease of IgA concentrations was observed in hepatic vein, as compared with portal vein. In cirrhotic patients IgA concentrations were significantly higher than in control subjects, but concentrations of IgA, p-IgA and IgA2 were not different in portal and peripheral blood. These results show that mesenteric vein is not a major way for p-IgA and IgA2 from the gut lamina propria to plasma, and suggest that the origin of a significant part of these molecular forms of IgA could be peripheral lymph-nodes more than gut-associated-lymphoid-tissue. The absence of significant clearance of p-IgA by the liver in normal subjects suggests that abnormalities of hepato-biliary transport of p-IgA is not responsible for the increased IgA levels observed in cirrhotic patients.