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One-hundred and two patients from the area of Hamburg, Germany, with vitiligo (photo-skin types II and III, Fitzpatrick classification, 1979), were examined for a possible association of the human lymphocyte antigen (HLA) complex with this disease. Antisera panels for the detection of 75 HLA antigens were utilized for this HLA typing (WHO Bulletin, 1988). The results were compared with 400 unrelated age- and sex-matched controls with photo-skin types II and III from the same geographical area. Nine of 76 vitiligo patients showed a significantly increased expression of the rare antigen HLA DRW 12 (p_c = 0.000708), and 65/102 patients showed a marginally significant increased frequency of HLA A2 (p_c = 0.04850) compared with controls. For HLA BW60 (40), a significant increase in frequency was shown only in the adult vitiligo group (p_c = 0.0126). A ‘preventive’ antigen for the manifestation of vitiligo has not been identified in this study. A comparative analysis of all published data on the possible association of HLA with vitiligo does not support a definitive linkage to the MHC so far.

Objective-Sulfatides are sulfated glycosphingolipids present on the surface of a variety of cells; however, their exact physiological function is not known. Recently, we have shown that the inhibition of sulfatide-P-selectin interactions leads to disaggregation of platelet aggregates. Methods and Results-In this study, we show that sulfatides activated platelets as they increased activation of GPIIb/IIIa (PAC-1 epitope) and expression of P-selectin on the platelet surface. Furthermore, sulfatides aggregated washed platelets in a dose-dependent manner and enhanced platelet aggregation in platelet-rich plasma. Previous activation of platelets was necessary for this effect. Monoclonal anti-P-selectin antibodies inhibited not only sulfatide-induced PAC-1 binding to platelets but also sulfatide-induced platelet aggregation, suggesting that sulfatides activate platelet GPIIb/IIIa via signaling through P-selectin. The proaggegatory effect of sulfatides was also observed in an ex vivo thrombosis model using whole blood and pulsatile flow at 37°C. In this model, sulfatides significantly enhanced platelet aggregation and the formation of platelet-leukocyte aggregates. Conclusions-We show that sulfatide-P-selectin interactions lead to subsequent platelet activation and P-selectin expression, forming a positive feedback loop that can potentiate formation of stable platelet aggregates. In addition, sulfatides enhance the aggregation of platelet-leukocyte aggregates. These mechanisms may play a significant role in hemostasis and thrombosis.

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Gelatinase A (matrix metalloproteinase-2) plays a prominent role in multiple biologic processes. Prior studies have established critical roles for gelatinase A transcriptional regulation by defined enhancer elements. To determine possible functional single nucleotide polymorphisms within these elements, we determined the single nucleotide polymorphism distribution within 1,665 bp of the gelatinase A 5 -flanking region, using a healthy homogeneous Caucasian study group of 463 individuals. Among the polymorphisms detected, a G 3 A transition at bp ؊1575 was located immediately 5 to a half-palindromic potential estrogen receptor binding site. In estrogen receptor-positive MCF-7 cells the ؊1575G allele functioned as an enhancer, whereas the ؊1575A allele reduced transcription activity significantly. Gel shift assays confirmed that the differences in allelic expression affected binding of the estrogen receptor-␣ to this region. Cotransfection experiments with an estrogen receptor-␣ expression vector in MDA-MB-231 cells, which do not constitutively express an estrogen receptor, revealed that estrogen receptor is absolutely required for enhancing activity. Allelic distribution analysis indicated that a previously reported C 3 T transition within an Sp1 binding site at ؊1306 was in linkage disequilibrium with the ؊1575G 3 A transition. Luciferase reporter studies of the linked variant ؊1575A ؊1306T allele versus the wild type ؊1575G ؊1306C allele demonstrated an additive reduction in estrogen-dependent reporter activity. The frequency of the ؊1575G 3 A transition deviated significantly from the expected Hardy-Weinberg distribution in two independently assembled study populations consisting of healthy adult blood donors and newborns of Caucasian origin, both with a calculated 21% reduction in genetic fitness. Gelatinase A is a known estrogen-responsive gene and the demonstration of a loss of function polymorphism within an operational estrogen receptor binding site associated with a decrease in genetic fitness underscores the biologic significance of promoter polymorphism analyses.The individual components of the relatively large matrix metalloproteinase gene family play multiple roles in the interaction of cells with their surrounding extracellular matrix. As such, this family of evolutionarily conserved enzymes is intimately involved in the diverse physiologic processes that make up normal growth and development, as well as neoplasia, metastasis, angiogenesis, and tissue fibrosis. One member of the matrix metalloproteinase gene family, gelatinase A or matrix metalloproteinase-2, has received considerable attention as a mediator of tumor angiogenesis and metastatic capability (1-3). In addition to the role of gelatinase A in malignancy, this enzyme has an important function in the normal growth and development of soft tissues. For example, gelatinase A-deficient mice develop normally but have significantly retarded growth rates (4) and diminished corneal and tumor neoangiogenesis (5). One form of the inherited osteolysi...

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Staphylococcus aureus is one of the first and most prevalent pathogens cultured from the airways of cystic fibrosis (CF) patients, which can persist there for extended periods. Airway infections in CF patients are characterized by a strong inflammatory response of highly recruited neutrophils. One killing mechanism of neutrophils is the formation of neutrophil extracellular traps (NETs), which capture and eradicate bacteria by extracellular fibers of neutrophil chromatin decorated with antimicrobial granule proteins. S. aureus secretes nuclease, which can degrade NETs. We hypothesized, that S. aureus adapts to the airways of CF patients during persistent infection by escaping from NET-mediated killing via an increase of nuclease activity. Sputum samples of CF patients with chronic S. aureus infection were visualized by confocal microscopy after immuno-fluorescence staining for NET-specific markers, S. aureus bacteria and overall DNA structures. Nuclease activity was analyzed in sequential isogenic long persisting S. aureus isolates, as confirmed by whole genome sequencing, from an individual CF patient using a FRET-based nuclease activity assay. Additionally, some of these isolates were selected and analyzed by qRT-PCR to determine the expression of nuc1 and regulators of interest. NET-killing assays were performed with clinical S. aureus isolates to evaluate killing and bacterial survival depending on nuclease activity. To confirm the role of nuclease during NET-mediated killing, a clinical isolate with low nuclease activity was transformed with a nuclease expression vector (pCM28nuc). Furthermore, two sputa from an individual CF patient were subjected to RNA-sequence analysis to evaluate the activity of nuclease in vivo. In sputa, S. aureus was associated to extracellular DNA structures. Nuclease activity in clinical S. aureus isolates increased in a time-and phenotype-dependent manner. In the clinical isolates, the expression of nuc1 was inversely correlated to the activity of agr and was independent of saeS. NET-mediated killing was significantly higher in S. aureus isolates with low compared to isolates with high nuclease activity. Importantly, transformation of the clinical isolate with low nuclease activity with pCM28nuc conferred protection against NET-mediated killing confirming the beneficial role of nuclease for protection against NETs. Also, nuclease expression in in vivo sputa was high, which underlines the important role of nuclease within the highly inflamed CF airways. In conclusion, our data show that S. aureus adapts to the neutrophil-rich environment of CF airways with increasing nuclease expression most likely to avoid NET-killing during long-term persistence.

BackgroundStaphylococcus aureus is an important pathogen in cystic fibrosis (CF). However, it is not clear which factors are associated with worse lung function in patients with persistent S. aureus airway cultures. Our main hypothesis was that patients with high S. aureus density in their respiratory specimens would more likely experience worsening of their lung disease than patients with low bacterial loads.MethodsTherefore, we conducted an observational prospective longitudinal multi-center study and assessed the association between lung function and S. aureus bacterial density in respiratory samples, co-infection with other CF-pathogens, nasal S. aureus carriage, clinical status, antibiotic therapy, IL-6- and IgG-levels against S. aureus virulence factors.Results195 patients from 17 centers were followed; each patient had an average of 7 visits. Data were analyzed using descriptive statistics and generalized linear mixed models. Our main hypothesis was only supported for patients providing throat specimens indicating that patients with higher density experienced a steeper lung function decline (p<0.001). Patients with exacerbations (n = 60), S. aureus small-colony variants (SCVs, n = 84) and co-infection with Stenotrophomonas maltophilia (n = 44) had worse lung function (p = 0.0068; p = 0.0011; p = 0.0103). Patients with SCVs were older (p = 0.0066) and more often treated with trimethoprim/sulfamethoxazole (p = 0.0078). IL-6 levels positively correlated with decreased lung function (p<0.001), S. aureus density in sputa (p = 0.0016), SCVs (p = 0.0209), exacerbations (p = 0.0041) and co-infections with S. maltophilia (p = 0.0195) or A. fumigatus (p = 0.0496).ConclusionsIn CF-patients with chronic S. aureus cultures, independent risk factors for worse lung function are high bacterial density in throat cultures, exacerbations, elevated IL-6 levels, presence of S. aureus SCVs and co-infection with S. maltophilia.Trial RegistrationClinicalTrials.gov NCT00669760