Dynamics of the cellular and humoral components of the inflammatory response elicited in skin blisters in humans

Galectin-3 Activates the NADPH-Oxidase in Exudated but not Peripheral Blood Neutrophils

Galectin-3, a lactose-binding mammalian lectin that is secreted from activated macrophages, basophils, and mast cells, was investigated with respect to its ability to activate the human neutrophil NADPH-oxidase. The galectin-3–induced activity was determined with in vivo exudated cells (obtained from a skin chamber) and compared with that of peripheral blood neutrophils. Galectin-3 was found to be a potent activator of the NADPH-oxidase only in exudated neutrophils and the binding of galectin-3 to the surface of these cells was increased compared with peripheral blood cells. Different in vitro priming protocols resulting in degranulation were used to mimic the exudation process in terms of increasing the receptor exposure on the cell surface. Galectin-3 could induce an oxidative response similar to that in exudated cells only after a significant amount of the intracellular organelles had been mobilized. This increase in oxidative response was paralleled by an increased binding of galectin-3 to the surface of the cells. The major conclusion of the study is that galectin-3 is a potent stimulus of the neutrophil respiratory burst, provided that the cells have first experienced an extravasation process. The results also imply that the neutrophil response to galectin-3 could be mediated through receptors mobilized from intracellular granules, and we report the presence of galectin-3–binding proteins in such organelles.

Galectin-3 Activates the NADPH-Oxidase in Exudated but not Peripheral Blood Neutrophils

Galectin-3, a lactose-binding mammalian lectin that is secreted from activated macrophages, basophils, and mast cells, was investigated with respect to its ability to activate the human neutrophil NADPH-oxidase. The galectin-3–induced activity was determined with in vivo exudated cells (obtained from a skin chamber) and compared with that of peripheral blood neutrophils. Galectin-3 was found to be a potent activator of the NADPH-oxidase only in exudated neutrophils and the binding of galectin-3 to the surface of these cells was increased compared with peripheral blood cells. Different in vitro priming protocols resulting in degranulation were used to mimic the exudation process in terms of increasing the receptor exposure on the cell surface. Galectin-3 could induce an oxidative response similar to that in exudated cells only after a significant amount of the intracellular organelles had been mobilized. This increase in oxidative response was paralleled by an increased binding of galectin-3 to the surface of the cells. The major conclusion of the study is that galectin-3 is a potent stimulus of the neutrophil respiratory burst, provided that the cells have first experienced an extravasation process. The results also imply that the neutrophil response to galectin-3 could be mediated through receptors mobilized from intracellular granules, and we report the presence of galectin-3–binding proteins in such organelles.

Increased serum levels of interleukin (IL)-5, IL-6 and IL-8 in bullous pemphigoid

Some cytokines have been suggested to take part in the blister formation in bullous pemphigoid (BP). However, the roles of the cytokines are only partly understood. To elucidate the involvement of cytokines in the immunological mechanisms in BP, we investigated the serum levels of interleukin (IL)-2, IL-4, IL-5, IL-6, IL-8, IL-13, soluble IL-2 receptor and soluble CD23 in patients with BP, and the correlation between cytokine levels and other clinical and laboratory data. Serum levels of these cytokines and soluble receptors were determined by enzyme-linked immunosorbent assay in 19 patients with BP and in 16 normal control subjects. Serum levels of IL-5 (P < 0.0001), IL-6 (P < 0.01) and IL-8 (P < 0.05) were significantly higher in BP patients than in the control subjects. Other cytokines and soluble receptor levels were not significantly different. Serum levels of IL-6 (P < 0.05) and IL-8 (P < 0.05) were significantly decreased after treatment when skin lesions disappeared. These results suggest that serum levels of IL-6 and IL-8 could be indicators of disease activity of BP.

[Persistent neutrophilic meningitis in a patient with the acquired immunodeficiency syndrome]

Persistent neutrophilic meningitis is rarely found and it is characterized by predominance of the number of neutrophils in samples of C SF (cerebrospinal fluid) from the patient after seven days of treatment. The above patient in HIV positive; he has developed fever and mental disorder for 4 months and has presented neutrophilic pleocytosis in analysis of CSF for more than 5 months. Since the beginning or the treatment he has taken antituberculous drugs and corticosteroids. For 3 months, the serologic evaluation, smears and cultures were negative. On the 60th day in hospital, the investigation of acid-fast bacilli in CSF was positive and culture confirmed the presence of Mycobacterium tuberculosis resistant to isoniazid. Several factors that may have caused this uncommon development were discussed: the disturbance of cell-mediated immunity, mainly in release of IL 8 and TNF, the simultaneous use of medicines that could alter the CSF concentration of antituberculous drugs, and the increasing number of multiresistant strains.

Sequential systemic platelet-activating factor and interleukin 8 primes neutrophils in patients with trauma at risk of multiple organ failure

Plasma from 33 patients at risk of multiple organ failure (MOF) after major trauma was tested for a priming effect on neutrophils, and for the presence of platelet-activating factor (PAF) activity and interleukin (IL) 8. Plasma sampled at 3, 6, 12 and 24 h after injury significantly primed normal neutrophils to release mean(s.e.m.) 1.26(0.19), 1.33(0.26), 1.04(0.14) and 0.86(0.13) nmol superoxide per min per 1.3 x 10(6) neutrophils respectively (P < 0.05). Priming at 3 h after injury was inhibited by mean(s.e.m.) 63.8(7.0) per cent by the PAF antagonist, WEB 2170 (P < 0.01). Mean(s.e.m.) plasma IL-8 was raised at 6 and 12 h after injury to 785(183) and 836(175) pg/ml (P < 0.01). At 12 h after injury the plasma IL-8 level correlated directly with the number of units of red blood cells transfused (r = 0.64, P < 0.01), and was significantly higher in the group of six patients who developed MOF (P < 0.05). These data suggest that after trauma the mediators PAF and IL-8 appear sequentially in the circulation, are potential mechanisms of circulating neutrophil priming, and that IL-8 may also be an early biochemical marker predicting the onset of MOF.

Absorption of an oxytocin antagonist (antocin) and a vasopressin analogue (dDAVP) through a standardized skin erosion in volunteers

PURPOSE

Transdermal administration of the peptides [Mpa1, D-Tyr (Ethyl)2, Thr4, Orn8]-oxytocin (antocin) and [Mpa1, D-Arg8]-vasopressin (dDAVP) was studied in healthy volunteers.

METHODS

A standardized skin erosion was formed preliminary by suctioning. The peptides were administered in plastic reservoirs through a 5 mm erosion and the absorption was followed for a six-day period with plasma concentration determinations on days 1, 3 and 6 with refilling the reservoirs daily with 15 microns and 10 mM solutions of dDAVP and antocin, respectively. Fourteen healthy non-smoking volunteers divided equally between the sexes, participated in the study. Plasma concentrations were measured using specific radioimmunoassays. Reservoir concentrations and metabolic stability of the peptides were determined using reverse-phase HPLC.

RESULTS

Both antocin and dDAVP were absorbed across the skin erosion. The absorption pattern was biphasic with a high initial absorption during days 1 and 2 followed by a lower absorption on days 3 and 6. The absorption on day 1, which was estimated at more than 50% for both peptides during a 24 h period, corresponded to a simultaneous decrease in peptide concentration in the reservoirs. The extent of absorption for antocin on days 3 and 6 was 1/3 to 1/6, respectively, of that observed on day 1. Antocin was minimally degraded in the skin reservoir while dDAVP was intact. However, accumulation of cellular material appeared in the antocin reservoirs. The absorption of antocin was reduced by exposure to intact skin surrounding the skin erosion. No pain was experienced and no scar formation was observed.

CONCLUSIONS

The observed biphasic absorption may be a consequence of the mild inflammatory response occurring subsequent to eroding the skin. The standardized skin erosion may provide a route for the short-term delivery of otherwise poorly absorbable peptide and protein drugs.

Edematogenic responses induced by Bothrops jararaca venom in rats: role of lymphocytes

The intraplantar injection of Bothrops jararaca venom (Bjv) caused an edematogenic response in the rat which was of rapid onset, and reached a peak in about 60 min. The response was markedly attenuated in animals rendered leucopenic by the administration of amethopterin. This inhibition was partially reverted when leucopenic rats were given i.v. suspensions of lymphocytes. Suspensions of neutrophils were ineffective. If the animals were submitted to an experimental obstruction of the thoracic duct, which leads to specific lymphocytopenia, similar inhibition of the edematogenic response was observed. These results suggest that lymphocytes can directly influence the development of the edema induced by Bothrops jararaca venom.

Intracellular and extracellular penetration of azithromycin into inflammatory and noninflammatory blister fluid

The penetration of azithromycin into the blister fluids of six volunteers was analyzed after a 5-day regimen (total of 1.5 g). Differences in drug concentrations in a paper disk and serum and in the mass of azithromycin from inflammatory blister chamber leukocytes and noninflammatory blister chamber leukocytes were significant (P < 0.05).

IL-4 down-regulates IL-2-, IL-3-, and GM-CSF-induced cytokine gene expression in peripheral blood monocytes

IL-4, a product of the T-helper 0 (Th0) and 2 (Th2) subset, was originally described as a B-cell stimulatory factor and has subsequently been found to suppress IL-1 alpha, IL-1 beta, IL-6, IL-8, and TNF-alpha gene expression in monocytes stimulated with LPS, and to upregulate IL-1 receptor antagonist (IL1-RA) gene expression. In this study we investigated the effect of IL-4 on the expression of cytokine genes in monocytes evoked by other T-helper cell cytokines: IL-2, IL-3, and GM-CSF. IL-4 down-regulated mRNA accumulation of the proinflammatory cytokines IL-1 beta, IL-8, and TNF-alpha in monocytes stimulated with IL-2, IL-3, and GM-CSF. IL-4 also suppressed the IL-2-induced IL-6 mRNA expression. Temporal analysis of the IL-4 down-regulatory effect on the IL-2-, IL-3-, or GM-CSF-induced proinflammatory cytokine gene expression in monocytes provided evidence that IL-4 acts predominantly on the post-transcriptional level. This was supported by the observation that the down-regulatory capacity of IL-4 appeared to be dependent on de novo protein synthesis. IL-4 did not exert significant influence on the induction of expression of IL-1-RA or various CSFs by IL-2, IL-3, and GM-CSF.(ABSTRACT TRUNCATED AT 250 WORDS)

92-kD gelatinase is produced by eosinophils at the site of blister formation in bullous pemphigoid and cleaves the extracellular domain of recombinant 180-kD bullous pemphigoid autoantigen

Eosinophils are prominent in bullous pemphigoid (BP), and proteases secreted from these and other inflammatory cells may induce disruption of the basement membrane. We used in situ hybridization and immunohistochemistry to localize the sites of 92-kD gelatinase expression in BP lesions. In all samples (20/20), a strong signal for gelatinase mRNA was detected only in eosinophils and was most pronounced where these cells accumulated at the floor of forming blisters. No other cells were positive for enzyme mRNA. Both eosinophils and neutrophils, however, contained immunoreactive 92-kD gelatinase indicating that active expression occurred only in eosinophils. Degranulated eosinophils were also seen near blisters, and as demonstrated by gelatin zymography, immunoblotting, and ELISA, 92-kD gelatinase protein was prominent in BP blister fluid. No other gelatinolytic activity was specifically detected in BP fluid, and only small amounts of 92-kD gelatinase were present in suction blister fluids. As demonstrated in vitro, 92-kD gelatinase cleaved the extracellular, collagenous domain of recombinant 180-kD BP autoantigen (BP180, BPAG2, HD4, type XVII collagen), a transmembrane molecule of the epidermal hemidesmosome. Our results suggest that production and release 92-kD gelatinase by eosinophils contributes significantly to tissue damage in BP.