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Last updated: 13th August 2010

Pathogenesis of tinea.
Brasch J
Department of Dermatology, Venereology and Allergy, University Clinic of Schleswig-Holstein, Campus Kiel, Kiel, Germany.
Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG 2010 Jul
Summary Dermatophytes are hyphomycetes that can degrade keratin. This puts them in a position to cause infections of the keratin-containing superficial skin. The resulting clinical picture is called tinea. The pathogenesis and course of tinea is decisively determined by pathogen-related factors and by the defense mechanisms of the host. An infection starts with an adherence of fungal propagules, followed by the formation of hyphae that can spread within the tissue. This process is accompanied by a release of fungal enzymes and other pathogenic factors. Next keratinocytes are activated, the epidermal barrier is destroyed, epidermal proliferation is enhanced and defensins are expressed within the epidermis. In addition, innate and specific immune responses are initiated, involving neutrophilic granulocytes, macrophages, antibodies and T cells. The cellular mechanisms are thought to be crucial for healing. Special conditions apply to nail infections, because within nail plates the fungi are not accessible to effective defense mechanisms, as well as to infections of hair follicles that contain specific concentrations of steroid hormones. Dermatophytes that penetrate into the dermis can cause granulomatous inflammatory reactions and systemic immune reactions are supposed to be a trigger of so-called id reactions.
A genetic association study of maternal and fetal candidate genes that predispose to preterm prelabor rupture of membranes (PROM).
Romero R, Friel LA, Velez Edwards DR, Kusanovic JP, Hassan SS, Mazaki-Tovi S, Vaisbuch E, Kim CJ, Erez O, Chaiworapongsa T, Pearce BD, Bartlett J, Salisbury BA, Anant MK, Vovis GF, Lee MS, Gomez R, Behnke E, Oyarzun E, Tromp G, Williams SM, Menon R
Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development/National Institutes of Health/Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI; Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI.
American journal of obstetrics and gynecology 2010 Jul
OBJECTIVE: We sought to determine whether maternal/fetal single-nucleotide polymorphisms (SNPs) in candidate genes are associated with preterm prelabor rupture of membranes (pPROM). STUDY DESIGN: A case-control study was conducted in patients with pPROM (225 mothers and 155 fetuses) and 599 mothers and 628 fetuses with a normal pregnancy; 190 candidate genes and 775 SNPs were studied. Single locus/haplotype association analyses were performed; false discovery rate was used to correct for multiple testing (q* = 0.15). RESULTS: First, a SNP in tissue inhibitor of metalloproteinase 2 in mothers was significantly associated with pPROM (odds ratio, 2.12; 95% confidence interval, 1.47-3.07; P = .000068), and this association remained significant after correction for multiple comparisons. Second, haplotypes for Alpha 3 type IV collagen isoform precursor in the mother were associated with pPROM (global P = .003). Third, multilocus analysis identified a 3-locus model, which included maternal SNPs in collagen type I alpha 2, defensin alpha 5 gene, and endothelin 1. CONCLUSION: DNA variants in a maternal gene involved in extracellular matrix metabolism doubled the risk of pPROM.
X-ray crystallographic structure of an artificial beta-sheet dimer.
Khakshoor O, Lin AJ, Korman TP, Sawaya MR, Tsai SC, Eisenberg D, Nowick JS
Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
J Am Chem Soc. 2010 Aug 25;132(33):11622-8.
This paper describes the X-ray crystallographic structure of a designed cyclic beta-sheet peptide that forms a well-defined hydrogen-bonded dimer that mimics beta-sheet dimers formed by proteins. The 54-membered ring macrocyclic peptide (1a) contains molecular template and turn units that induce beta-sheet structure in a heptapeptide strand that forms the dimerization interface. The X-ray crystallographic structure reveals the structures of the two "Hao" amino acids that help template the beta-sheet structure and the two delta-linked ornithine turn units that link the Hao-containing template to the heptapeptide beta-strand. The Hao amino acids adopt a conformation that resembles a tripeptide in a beta-strand conformation, with one edge of the Hao unit presenting an alternating array of hydrogen-bond donor and acceptor groups in the same pattern as that of a tripeptide beta-strand. The delta-linked ornithines adopt a conformation that resembles a hydrogen-bonded beta-turn, in which the ornithine takes the place of the i+1 and i+2 residues. The dimers formed by macrocyclic beta-sheet 1a resemble the dimers of many proteins, such as defensin HNP-3, the lambda-Cro repressor, interleukin 8, and the ribonuclease H domain of HIV-1 reverse transcriptase. The dimers of 1a self-assemble in the solid state into a barrel-shaped trimer of dimers in which the three dimers are arranged in a triangular fashion. Molecular modeling in which one of the three dimers is removed and the remaining two dimers are aligned face-to-face provides a model of the dimers of dimers of closely related macrocyclic beta-sheet peptides that were observed in solution.
The role of inflammation in the genesis of the cystic component of craniopharyngiomas.
Pettorini BL, Inzitari R, Massimi L, Tamburrini G, Caldarelli M, Fanali C, Cabras T, Messana I, Castagnola M, Di Rocco C
Institute of Neurosurgery, Division of Paediatric Neurosurgery, Catholic University of Rome, Largo Agostino Gemelli, 8, 00168, Rome, Italy,
Child´s nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery 2010 Jul
BACKGROUND: Craniopharyngioma accounts for 5-10% of childhood tumors and, despite of the benign histological features, its clinical course can be malignant because of critical anatomical relationships with neural and vascular structures and the possible morbidity associated to resection. Only a few studies have addressed the molecular characterization of the cyst fluid so far and the mechanisms of action of intracystic agents are not clearly understood yet. METHODS: The acidic soluble proteins contained in the cystic fluid of six patients with cystic craniopharyngioma, three of them treated with intratumoral interferon-alpha, were analyzed. A high performance liquid chromatography electrospray ionization mass spectrometry analysis was performed. FINDINGS: The antimicrobial peptides alpha-defensins 1-3 relevant for innate immunity were detected in the cystic fluid before the intratumoral treatment. Amount of peptides significantly decreased in cystic fluid during pharmacological treatment. INTERPRETATION: Detection of alpha-defensins 1-3 excludes that cyst fluid formation can derive from disruption of blood-brain barrier and suggests the involvement of innate immune response in pathology of craniopharyngioma cyst formation. The reduction of alpha-defensins could derive both from direct antitumoral effect of interferon-alpha on squamous epithelial cells of craniopharyngioma cyst and from its immuno-modulatory effects on the recruitment of cells of innate immune systems. Interestingly, the clinical patient outcome well correlates with the gradual reduction of alpha-defensins 1-3 amount. Additional studies will be necessary to establish the role of these molecules in the pathogenesis of craniopharyngioma, and further investigations will be necessary to confirm the efficacy of the antitumoral activity of interferon-alpha.
Expression of antimicrobial peptides such as LL-37 and hBD-2 in nonlesional skin of atopic individuals.
Goo J, Ji JH, Jeon H, Kim MJ, Jeon SY, Cho MY, Lee SH, Choi EH
Department of Dermatology, Yonsei University Wonju College of Medicine, Wonju, Korea.
Pediatr Dermatol ;27 (4):341-8
Recurrent skin infection is one of the major complications of atopic dermatitis and can be partly explained by decreased expression of antimicrobial peptides such as human beta-defensin-2 and cathelicidin (LL-37). In the human epidermis, human beta-defensin-2 is packed in the lamellar body and LL-37 is co-localized with intercellular lipid lamellae of the stratum corneum; together, these antimicrobial peptides constitute the primary defense system. IL-1alpha, a potent inducer of LL-37 and human beta-defensin-2, is also secreted from the disrupted epidermis for barrier homeostasis. In this study, we investigated whether expression of human beta-defensin-2 and LL-37 is constitutively decreased in the skin of atopic individuals. Nonlesional foreskins from atopic (n=7) and nonatopic (n=7) individuals were analyzed. The expression of LL-37, human beta-defensin-2 and IL-1alpha was analyzed using immunohistochemical staining, Western blot, and real-time polymerase chain reaction. Lamellar body density and secretion were evaluated by electron microscope. Quantitative analysis showed that the expression of each parameter was not significantly different between groups. Thus, basal expression of LL-37 and human beta-defensin-2 was not changed in atopic individuals. These results indicate that the expression of antimicrobial peptides at baseline was not different between nonlesional skin of atopic individuals and normal skin of nonatopic individuals.
Innate immunity proteins in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis.
Tsoumakidou M, Bouloukaki I, Thimaki K, Tzanakis N, Siafakas NM
Department of Thoracic Medicine, University Hospital of Heraklion, Heraklion, Greece.
Exp. Lung Res. 2010 Aug;36 (6):373-80
Chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) may be caused by epithelial cell injury. Epithelial cells respond to injury by secreting innate immunity proteins. To investigate whether altered levels of innate immunity proteins are observed in COPD and IPF, the authors assessed secretory leukocyte protease inhibitor (SLPI), elafin, CC16, and beta-defensin-2 levels by enzyme-linked immunosorbent assay (ELISA) in sputum supernatants from COPD patients (n = 19), smokers without COPD (n = 21), and never-smokers (n = 10) and in BALF supernatants from patients with IPF (n = 11) and subjects without IPF (n = 11). CC16 levels were decreased, whereas SLPI and elafin levels were increased in COPD patients (0.8 [0-4.2] microg/mL, 2.5 [0.3-10.5] microg/mL, 213 [152-318] pg/mL, respectively) compared to smokers without COPD (1.8 [0.1-21.2] microg/mL, 0.8 [0.2-2.6] microg/mL, 172 [71-473] pg/mL, respectively) and never-smokers (0.5 [0-4.8] microg/mL, 0.1 [0.05-0.6] microg/mL, 188 [129-218] pg/mL, respectively) (CC16: P = .001; SLPI: P <.001; elafin: P = .041). beta-Defensin-2 was detected in smokers without COPD (98 [10-729] pg/mL) and never-smokers (74 [35-410] pg/mL), but not in COPD. SLPI and elafin levels did not differ between IPF patients and controls, but CC16 levels were increased in IPF (0.5 [0-2.3] versus 0.2 [0-0.3] microg/mL; P = .019). beta-Defensin-2 was not detected in BALF. In conclusion, in COPD, secretion of CC16 and beta-defensin-2 might be suppressed, whereas SLPI and elafin secretion is up-regulated. In IPF, only CC16 secretion is up-regulated.
[Expression of human beta-defensin after endoscopic sinus surgery for chronic sinusitis.]
Xiao CZ, He GX, Deng WG, Zhang HY, Sun W
Department of Otolaryngology and Head-Neck Surgery, Yangang Hospital, Shenzhen 518083, China.E-mail:
Nan Fang Yi Ke Da Xue Xue Bao 2010 Jul;30 (7):1580-3
OBJECTIVE: To observe the expressions of human beta-defensin 1 and 2 (hBD-1 and hBD-2) in nasal mucosa before and after the endoscopic sinus surgery and investigate the effects of hBD-1 and hBD-2 on the healing process after the surgery. METHODS: The patients undergoing endoscopic sinus surgery for chronic sinusitis were divided into 3 groups according to the response to the surgery, namely cured group, response group and non-response group. With those from healthy control subjects as the control, nasal mucosa samples were collected from the patients at 1 week, 2 weeks, 1 month, 3 months and 6 months after the surgery for detection of hBD-1 and hBD-2 mRNA and protein expressions by RT-PCR and Western blotting. RESULTS: hBD-1 and hBD-2 were expressed in both normal and chronic sinusitis mucosa, but the expression levels varied significantly between the individuals. The expression levels of hBD-2 was significantly correlated to the patients´ response to the surgical treatment (P<0.05). hBD-1 showed slight differences between the individuals, but was not associated with the patients´ prognosis. CONCLUSION: The expressions of hBD-2 mRNA and protein are significantly increased in patients with good response to endoscopic sinus surgery for chronic sinusitis, suggesting the value of hBD-2 as an indicator of the patients´ prognosis.
CpG oligodeoxynucleotide promotes protective immunity in the enteric mucosa and suppresses enterotoxigenic E. coli in the weaning piglets.
Cheng Q, Jiang Z, Xu C, Li H, Cao D, Yang Z, Cao G, Linghua Z
College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
International immunopharmacology 2010 Jul
CpG oligodeoxynucleotide (CpG ODN) has been described as an effective activator of the innate immune system, with potential to protect against infection caused by a range of pathogens in a non-specific manner. We therefore investigated if intranasal (IN), oral (OR)-mucosal, and intramuscular (IM)-systemic administrations of CpG ODN without antigen codelivery could all enhance innate immunity in the enteric mucosa and control the extent of enterotoxigenic Escherichia coli (ETEC) infection in weaning piglets. Here our data showed that CpG ODN dosed by IN, OR or IM routes protected weaning piglets against a subsequent challenge with ETEC. The level of protection was greater when CpG ODN was administered IN and OR than IM, demonstrating a clear relationship between the route of CpG dosing and protection. IN and OR treatments with CpG ODN reduced bacterial load in the phases at days 3-5 post challenge. The CXC chemokine (CXCL10 and CXCL11) and CC chemokine (CCL4 and CCL5) mRNA expressions were elevated in the intestinal tissues from animals treated IN or OR with CpG ODN compared to untreated controls. Significantly enhanced mRNA expressions for cathelicidins (PR-39 and protegrin-1), but moderately for beta-defensin (pBD1 and pBD2), were observed in IN or OR CpG-treatments. Also, significant production of cytokines (IL-12, IFN-gamma, and MCP-1) and F4-specific antibodies (IgG/IgA) was detected in intestinal washings following IN and OR CpG-treatments. In contrast, IM delivery induced marked production of sera F4-specific antibodies. It was possible that these chemokines, cytokines, cathelicidins and antibodies played a role in the clearance of ETEC. These findings suggested that IN or OR administration of CpG ODN without antigen codelivery might represent a valuable strategy for induction of innate immunity against ETEC infection.
An insight into the sialotranscriptome of the brown dog tick, Rhipicephalus sanguineus.
Anatriello E, Ribeiro JM, de Miranda Santos IK, Brandao LG, Anderson JM, Valenzuela JG, Maruyama SR, Silva JS, Ferreira BR
BMC genomics 2010 Jul;11 (1):450
ABSTRACT: BACKGROUND: Rhipicephalus sanguineus, known as the brown dog tick, is a common ectoparasite of domestic dogs and can be found worldwide. R. sanguineus is recognized as the primary vector of the etiological agent of canine monocytic ehrlichiosis and canine babesiosis. Here we present the first description of a R. sanguineus salivary gland transcriptome by the production and analysis of 2,034 expressed sequence tags (EST) from two cDNA libraries, one consctructed using mRNA from dissected salivary glands from female ticks fed for 3-5 days (early to mid library, RsSGL1) and the another from ticks fed for 5 days (mid library, RsSGL2), identifying 1,024 clusters of related sequences. RESULTS: Based on sequence similarities to nine different databases, we identified transcripts of genes that were further categorized according to function. The category of putative housekeeping genes contained 56% of the sequences and had on average 2.49 ESTs per cluster, the secreted protein category contained 26.6% of the ESTs and had 2.47 EST´s/clusters, while 15.3 % of the ESTs, mostly singletons, were not classifiable, and were annotated as "unknown function". The secreted category included genes that coded for lipocalins, proteases inhibitors, disintegrins, metalloproteases, immunomodulatory and antiinflammatory proteins, as Evasins and Da-p36, as well as basic-tail and 18.3 kDa proteins, cement proteins, mucins, defensins and antimicrobial peptides. Comparison of the abundance of ESTs from similar contigs of the two salivary gland cDNA libraries allowed the identification of differentially expressed genes, such as genes coding for Evasins and a thrombin inhibitor, which were over expressed in the RsSGL1 (early to mid library) versus RsSGL2 (mid library), indicating their role in inhibition of inflammation at the tick feeding site from the very beginning of the blood meal. Conversely, sequences related to cement (64P), which function has been correlated with tick attachment, was largely expressed in the mid library. CONCLUSIONS: Our survey provided an insight into the R. sanguineus sialotranscriptome, which can assist the discovery of new targets for anti-tick vaccines, as well as help to identify pharmacologically active proteins.
Inducible expression of human {beta}-defensin 2 by Chlamydophila pneumoniae in brain capillary endothelial cells.
Tiszlavicz Z, Endrsz V, Nmeth B, Megyeri K, Orosz L, Seprnyi G, Mndi Y
Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary.
Innate immunity 2010 Jul
Defensins are an important family of natural antimicrobial peptides. Chlamydophila pneumoniae, a common cause of acute respiratory infection, has a tendency to cause persistent inflammatory diseases such as atherosclerosis, which may lead to cardiovascular disease or stroke. As endothelial cells are related to the physiopathology of stroke, the effects of in vitro C. pneumoniae infection on the expression of human beta-defensin 2 (HBD-2) in brain capillary endothelial cells (BB19) was investigated. A time-dependent increase in HBD-2 mRNA was observed by means of real-time reverse transcription PCR (RT-PCR) in BB19 cells following C. pneumoniae infection, with a maximum increase at 24 h. A gradual induction of HBD-2 protein in the C. pneumoniae-infected endothelial cells was detected by immunoblotting. Immunofluorescence revealed the staining of HBD-2 in the cytoplasm of endothelial cells following C. pneumoniae infection. The secretion of HBD-2 (confirmed by ELISA) was significantly elevated 24 h after C. pneumoniae infection. These novel results indicate that HBD-2 is expressed and produced in the human brain capillary endothelial cells upon infection with C. pneumoniae, and provide evidence that HBD-2 plays a role in the early immune responses to C. pneumoniae and probably in the immunopathogenesis of atherosclerosis.