Constitutive and inducible expression of SKALP/elafin provides anti-elastase defense in human epithelia

Development of an immune-related diagnostic predictive model for oral lichen planus

Oral lichen planus (OLP) was a chronic inflammatory disease of unknown etiology with a 1.4% chance of progressing to malignancy. However, it has been suggested in several studies that immune system disorders played a dominant role in the onset and progression of OLP. Therefore, this experiment aimed to develop a diagnostic prediction model for OLP based on immunopathogenesis to achieve early diagnosis and treatment and prevent cancer. In this study, 2 publicly available OLP datasets from the gene expression omnibus database were filtered. In the experimental group (GSE52130), the level of immune cell infiltration was assessed using MCPcounter and ssGSEA algorithms. Subsequently, differential expression analysis and gene set enrichment analysis were performed between the OLP and control groups. The resulting differentially expressed genes were intersected with immunologically relevant genes provided on the immunology database and analysis portal database (ImmPort) website to obtain differentially expressed immunologically relevant genes (DEIRGs). Furthermore, the gene ontology and kyoto encyclopedia of genes and genomes analyses were carried out. Finally, protein-protein interaction network and least absolute shrinkage and selection operator regression analyses constructed a model for OLP. Receiver operating characteristic curves for the experimental and validation datasets (GSE38616) were plotted separately to validate the model's credibility. In addition, real-time quantitative PCR experiment was performed to verify the expression level of the diagnostic genes. Immune cell infiltration analysis revealed a more significant degree of inflammatory infiltration in the OLP group compared to the control group. In addition, the gene set enrichment analysis results were mainly associated with keratinization, antibacterial and immune responses, etc. A total of 774 differentially expressed genes was obtained according to the screening criteria, of which 65 were differentially expressed immunologically relevant genes. Ultimately, an immune-related diagnostic prediction model for OLP, which was composed of 5 hub genes (BST2, RNASEL, PI3, DEFB4A, CX3CL1), was identified. The verification results showed that the model has good diagnostic ability. There was a significant correlation between the 5 hub diagnostic biomarkers and immune infiltrating cells. The development of this model gave a novel insight into the early diagnosis of OLP.

Serum Elafin as a Potential Marker of Disease Activity in Behçet's Disease

Background

Elafin is a serine protease inhibitor with anti-inflammatory properties. It is expressed in various epithelial tissues with increased production under inflammatory conditions. Increased tissue elafin expression in Behçet's disease (BD) lesions has previously been demonstrated.

Aims and Objectives

We hypothesised that serum elafin might be increased in patients with BD and aimed to assess the relationship of serum elafin with disease activity and organ involvement in BD.

Materials and Methods

Fifty-four BD patients (29 active, 25 inactive) and 30 healthy controls were included in this single-centre case-control study. Serum elafin was measured using ELISA. Complete blood count, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) tests were also performed.

Results

Serum elafin levels were significantly higher in patients with BD (1.58 ± 0.47 ng/ml, range: 0.67-2.96) compared to controls (1.10 ± 0.28 ng/ml, range: 0.65-1.49) (P < 0.001). Patients with active BD had higher elafin levels than patients with inactive BD (P = 0.008). Active arthritis was associated with an increase in elafin (P = 0.012), while the presence of mucocutaneous symptoms was not. Serum elafin correlated significantly with ESR (P = 0.001). The ideal cut-off value for the diagnosis of BD was determined as 1.24 ng/ml with a sensitivity and specificity of 72.2% and 70.0%, respectively.

Conclusion

Serum elafin is significantly increased in patients with BD. It may serve as a marker of disease activity, especially articular involvement.

Antimicrobial Peptides in Early-Life Host Defense, Perinatal Infections, and Necrotizing Enterocolitis—An Update

Host defense against early-life infections such as chorioamnionitis, neonatal sepsis, or necrotizing enterocolitis (NEC) relies primarily on innate immunity, in which antimicrobial peptides (AMPs) play a major role. AMPs that are important for the fetus and neonate include α and β defensins, cathelicidin LL-37, antiproteases (elafin, SLPI), and hepcidin. They can be produced by the fetus or neonate, the placenta, chorioamniotic membranes, recruited neutrophils, and milk-protein ingestion or proteolysis. They possess antimicrobial, immunomodulating, inflammation-regulating, and tissue-repairing properties. AMPs are expressed as early as the 13th week and increase progressively through gestation. Limited studies are available on AMP expression and levels in the fetus and neonate. Nevertheless, existing evidence supports the role of AMPs in pathogenesis of chorioamnionitis, neonatal sepsis, and NEC, and their association with disease severity. This suggests a potential role of AMPs in diagnosis, prevention, prognosis, and treatment of sepsis and NEC. Herein, we present an overview of the antimicrobial and immunomodulating properties of human AMPs, their sources in the intrauterine environment, fetus, and neonate, and their changes during pre- and post-natal infections and NEC. We also discuss emerging data regarding the potential utility of AMPs in early-life infections, as diagnostic or predictive biomarkers and as therapeutic alternatives or adjuncts to antibiotic therapy considering the increase of antibiotic resistance in neonatal intensive care units.

A methylation-driven genes prognostic signature and the immune microenvironment in epithelial ovarian cancer

Aberrant gene methylation has been implicated in the development and progression of tumors. In this study, we aimed to identity methylation driven genes involved in epithelial ovarian cancer (EOC) to establish a prognostic signature for patients with EOC. We identified and verified 6 MDGs that are closely related to the prognosis of ovarian cancer. A prognostic risk score model and nomogram for predicting the prognosis of ovarian cancer were constructed based on the six MDGs. It can also effectively reflect the immune environment and immunotherapy response of ovarian cancer. These MDGs have great significance to the implementation of individualized treatment and disease monitoring of ovarian cancer patients.

Localized and Systemic Immune Response in Human Reproductive Tract

Sexually transmitted infections (STIs) are one of the significant causes of morbidity and mortality among adolescents and adults across the globe and encompass all the infections transmitted via person-to-person sexual contact. In spite of the widespread approach being used, STIs remain under-reported and many infections have taken an epidemic turn. The biggest roadblock in this is the unraveled basis of immunopathology of these infections, hindering the discovery of potential targets for immunization. Thereby, it is of utmost significance to decipher the hidden basis of these STIs to control the increasing epidemic of less commonly studied STIs. A complex interplay between innate immune defenses, with resident microbiota and mucosal immune response serves as the basis of therapeutic approaches, by targeting the vital steps of this dynamic interaction. The characterization of pathogen-specific antibodies to significant immunogenic molecules may divulge the conceivable protective effects.

Reproducing the scalp microbiota community: co-colonization of a 3D reconstructed human epidermis with C. acnes and M. restricta

OBJECTIVE

A 3D reconstructed human epidermis (RHE) model colonized with specific microbial strains was developed to model the complex interactions between strains of the human scalp hair.

METHODS

Reconstructed human epidermis was colonized with Cutibacterium acnes and Malassezia restricta for 72 h. The epidermal model was characterized in terms of morphology, using immune-labelling targeting biomarkers for barrier structure, proliferation, differentiation and anti-microbial defence. The barrier function was assessed by transepithelial electrical eesistance (TEER) measurements. In order to study the microorganisms on the epidermal model, viable counts and phenotype ultrastructure analysis were performed by scanning electron microscopy (SEM).

RESULTS

The RHE colonized with C. acnes did not lead to severe modifications of the physiological barrier integrity and viability, though it shows aggregates. M. restricta formed large aggregates by a close interaction with the RHE, thus causing both a strong decrease in barrier function and structure degradation and an increased human beta defensin 2 (HBD2) expression. The co-colonized model resulted in barrier depletion, but the overall damage was less severe, respecting the single colonization with M. restricta. The developed 'scalp model' allowed to identify morphological modifications leading to uncontrolled epidermal renewal.

CONCLUSION

This study shows a pre-clinical model that recapitulates the interactions that can occur between site-specific microbial strains and keratinocytes in dandruff condition. The model can be applied to assess ingredients and products' mechanism of action.

Transcriptomic profile of VEGF-regulated genes in human cervical epithelia

Cervical epithelial cells play a central role in cervical remodeling (CR) during pregnancy and cervical events during menstrual cycle, including mounting physical and immunological barriers, proliferation and differentiation, maintenance of fluid balance, and likely in withstanding the mechanical force exerted by the growing fetus prior to term. In the present study, we attempt to decipher the specific roles of VEGF in fetal human cervical epithelial cells by delineating VEGF signature genes using RNA sequencing in order to characterize the specific biological effects of VEGF in these cells.Out of a total of 25,000 genes screened, 162 genes were found to be differentially expressed in human cervical epithelial cells, of which 12 genes were found to be statistically significantly differentially expressed. The differentially expressed genes (162) were categorized by biological function, which included (1) proliferation, (2) immune response, (3) structure/matrix, (4) mitochondrial function, and (5) cell adhesion/communication and others (pseudogenes, non-coding RNA, miscellaneous genes, and uncharacterized genes). We conclude that VEGF plays a key role in CR by altering the expression of genes that regulate proliferation, immune response, energy metabolism and cell structure, and biological processes that are essential to development and likely CR.

Biomarkers of neonatal skin barrier adaptation reveal substantial differences compared to adult skin

BACKGROUND

The objective of this study was to measure skin characteristics in premature (PT), late preterm (LPT), and full-term (FT) neonates compared with adults at two times (T1, T2).

METHODS

Skin samples of 61 neonates and 34 adults were analyzed for protein biomarkers, natural moisturizing factor (NMF), and biophysical parameters. Infant groups were: <34 weeks (PT), 34-<37 weeks (LPT), and ≥37 weeks (FT).

RESULTS

Forty proteins were differentially expressed in FT infant skin, 38 in LPT infant skin, and 12 in PT infant skin compared with adult skin at T1. At T2, 40 proteins were differentially expressed in FT infants, 38 in LPT infants, and 54 in PT infants compared with adults. All proteins were increased at both times, except TMG3, S100A7, and PEBP1, and decreased in PTs at T1. The proteins are involved in filaggrin processing, protease inhibition/enzyme regulation, and antimicrobial function. Eight proteins were decreased in PT skin compared with FT skin at T1. LPT and FT proteins were generally comparable at both times. Total NMF was lower in infants than adults at T1, but higher in infants at T2.

CONCLUSIONS

Neonates respond to the physiological transitions at birth by upregulating processes that drive the production of lower pH of the skin and water-binding NMF components, prevent protease activity leading to desquamation, and increase the barrier antimicrobial properties.

IMPACT

Neonates respond to the transitions at birth by upregulating processes that drive the production of lower pH of the skin and NMF, prevent protease activity leading to desquamation, and increase the antimicrobial properties of the barrier. The neonatal epidermal barrier exhibits a markedly different array of protein biomarkers both shortly after birth and 2-3 months later, which are differentially expressed versus adults. The major biomarker-functional classes included filaggrin processing, protease inhibitor/enzyme regulators, antimicrobials, keratins, lipids, and cathepsins. The findings will guide improvement of infant skin care practices, particularly for the most premature infants with the ultimate goals mitigating nosocomial infection.

Combining Bioinformatics Techniques to Study the Key Immune-Related Genes in Abdominal Aortic Aneurysm

Approximately 13,000 people die of an abdominal aortic aneurysm (AAA) every year. This study aimed to identify the immune response-related genes that play important roles in AAA using bioinformatics approaches. We downloaded the GSE57691 and GSE98278 datasets related to AAA from the Gene Expression Omnibus database, which included 80 AAA and 10 normal vascular samples. CIBERSORT was used to analyze the samples and detect the infiltration of 22 types of immune cells and their differences and correlations. The principal component analysis showed significant differences in the infiltration of immune cells between normal vascular and AAA samples. High proportions of CD4⁺ T cells, activated mast cells, resting natural killer cells, and 12 other types of immune cells were found in normal vascular tissues, whereas high proportions of macrophages, CD8⁺ T cells, resting mast cells, and six other types of immune cells were found in AAA tissues. In the selected samples, we identified 39 upregulated (involved in growth factor activity, hormone receptor binding, and cytokine receptor activity) and 133 downregulated genes (involved in T cell activation, cell chemotaxis, and regulation of immune response mediators). The key differentially expressed immune response-related genes were screened using the STRING database and Cytoscape software. Two downregulated genes, PI3 and MAP2K1, and three upregulated genes, SSTR1, GPER1, and CCR10, were identified by constructing a protein-protein interaction network. Functional enrichment of the differentially expressed genes was analyzed, and the expression of the five key genes in AAA samples was verified using quantitative polymerase chain reaction, which revealed that MAP2K1 was downregulated in AAA, whereas SSTR1, GEPR1, and CCR10 were upregulated; there was no significant difference in PI3 expression. Our study shows that normal vascular and AAA samples can be distinguished via the infiltration of immune cells. Five genes, PI3, MAP2K1, SSTR1, GPER1, and CCR10, may play important roles in the development, diagnosis, and treatment of AAA.

Evaluation of Elafin Immunohistochemical Expression as Marker of Cervical Cancer Severity

INTRODUCTION

The main risk factor for the development of cervical cancer (CC) is persistent infection by human papillomavirus (HPV) oncogenic types. In order to persist, HPV exhibits a plethora of immune evasion mechanisms. PI3/Elafin (Peptidase Inhibitor 3) is an endogenous serine protease inhibitor involved in epithelial protection against pathogens. PI3/Elafin's role in CC is still poorly understood.

MATERIALS AND METHODS

In the present study, we addressed PI3/Elafin protein detection in 123 CC samples by immunohistochemistry and mRNA expression in several datasets available at Gene Expression Omnibus and The Cancer Genome Atlas platforms.

RESULTS

We observed that PI3/Elafin is consistently downregulated in CC samples when compared to normal tissue. Most of PI3/Elafin-positive samples exhibited this protein at the plasma membrane. Besides, high PI3/Elafin expression at the cellular membrane was more frequent in in situ stages I + II than in invasive cervical tumor stages III + IV. This indicates that PI3/Elafin expression is gradually lost during the CC progression. Of note, advanced stages of CC were more frequently associated with a more intense PI3/Elafin reaction in the nuclei and cytoplasm.

CONCLUSION

Our results suggest that PI3/Elafin levels and subcellular localization may be used as a biomarker for CC severity.

Human Neutrophil Elastase Proteolytic Activity in Ulcerative Colitis Favors the Loss of Function of Therapeutic Monoclonal Antibodies

Purpose

Proteases play an essential role in the pathophysiology of inflammatory bowel disease (IBD), contributing to the intestinal mucosal lesions through the degradation of the extracellular matrix and alteration of the barrier function. Ulcerative colitis (UC) is characterized by an extensive infiltrate of neutrophils into the mucosa and hence, increased proteolytic activity. Human neutrophil elastase (HNE) is a serine protease that has been reported to be increased in UC patients’ intestinal mucosa. Based on our previous studies, we hypothesized that HNE might induce proteolytic degradation and loss of function of therapeutic monoclonal antibodies in IBD patients.

Patients and Methods

Elastase expression and elastinolytic activity were determined in mucosal explants from ulcerative colitis patients (n=6) and cultured ex vivo in the presence or absence of recombinant elafin. Enzymatic digestions of therapeutic monoclonal antibodies were performed using recombinant HNE and elafin. The integrity of the therapeutic antibodies was evaluated by immunoblotting and protein G binding assay, whereas their TNF-neutralizing activity was assessed with a reporter cell line.

Results

We found that HNE and its elastinolytic activity were increased in the gut mucosa of UC patients. We also demonstrated that HNE cleaved biological drugs, impairing the TNF-α neutralizing capacity of anti-TNF monoclonal antibodies. This proteolytic degradation was inhibited by the addition of the specific inhibitor, elafin.

Conclusion

Our results suggest that the high level of proteolytic degradation by mucosal neutrophil elastase, along with a potential imbalance with elafin, contributes to the loss of function of biologic agents, which are currently used in patients with IBD. These findings might explain the non-responsiveness of UC patients to therapeutic monoclonal antibodies and suggest the potential beneficial concomitant use of elafin in this treatment.

Faecal neutrophil elastase-antiprotease balance reflects colitis severity

Given the global burden of diarrheal diseases on healthcare it is surprising how little is known about the drivers of disease severity. Colitis caused by infection and inflammatory bowel disease (IBD) is characterised by neutrophil infiltration into the intestinal mucosa and yet our understanding of neutrophil responses during colitis is incomplete. Using infectious (Citrobacter rodentium) and chemical (dextran sulphate sodium; DSS) murine colitis models, as well as human IBD samples, we find that faecal neutrophil elastase (NE) activity reflects disease severity. During C. rodentium infection intestinal epithelial cells secrete the serine protease inhibitor SerpinA3N to inhibit and mitigate tissue damage caused by extracellular NE. Mice suffering from severe infection produce insufficient SerpinA3N to control excessive NE activity. This activity contributes to colitis severity as infection of these mice with a recombinant C. rodentium strain producing and secreting SerpinA3N reduces tissue damage. Thus, uncontrolled luminal NE activity is involved in severe colitis. Taken together, our findings suggest that NE activity could be a useful faecal biomarker for assessing disease severity as well as therapeutic target for both infectious and chronic inflammatory colitis.

A High-throughput Bead-based Affinity Assay Enables Analysis of Genital Protein Signatures in Women At Risk of HIV Infection

Women at high risk of HIV infection, including sex workers and those with active genital inflammation, have molecular signatures of immune activation and epithelial barrier remodeling in samples of their genital mucosa. These alterations in the local immunological milieu are likely to impact HIV susceptibility. We here analyze host genital protein signatures in HIV uninfected women, with high frequency of condom use, living in HIV-serodiscordant relationships. Cervicovaginal secretions from women living in HIV-serodiscordant relationships (n = 62) were collected at three time points over 12 months. Women living in HIV-negative seroconcordant relationships (controls, n = 25) were sampled at one time point. All study subjects were examined for demographic parameters associated with susceptibility to HIV infection. The cervicovaginal samples were analyzed using a high-throughput bead-based affinity assay. Proteins involved in epithelial barrier function and inflammation were increased in HIV-serodiscordant women. By combining several methods of analysis, a total of five proteins (CAPG, KLK10, SPRR3, elafin/PI3, CSTB) were consistently associated with this study group. Proteins analyzed using the affinity set-up were further validated by label-free tandem mass spectrometry in a partially overlapping cohort with concordant results. Women living in HIV-serodiscordant relationships thus had elevated levels of proteins involved in epithelial barrier function and inflammation despite low prevalence of sexually transmitted infections and a high frequency of safe sex practices. The identified proteins are important markers to follow during assessment of mucosal HIV susceptibility factors and a high-throughput bead-based affinity set-up could be a suitable method for such evaluation.

Multi-species oral biofilm promotes reconstructed human gingiva epithelial barrier function

Since the oral mucosa is continuously exposed to abundant microbes, one of its most important defense features is a highly proliferative, thick, stratified epithelium. The cellular mechanisms responsible for this are still unknown. The aim of this study was to determine whether multi-species oral biofilm contribute to the extensive stratification and primed antimicrobial defense in epithelium. Two in vitro models were used: 3D reconstructed human gingiva (RHG) and oral bacteria representative of multi-species commensal biofilm. The organotypic RHG consists of a reconstructed stratified gingiva epithelium on a gingiva fibroblast populated hydrogel (lamina propria). Biofilm was cultured from healthy human saliva, and consists of typical commensal genera Granulicatella and major oral microbiota genera Veillonella and Streptococcus. Biofilm was applied topically to RHG and host–microbiome interactions were studied over 7 days. Compared to unexposed RHG, biofilm exposed RHG showed increased epithelial thickness, more organized stratification and increased keratinocyte proliferation. Furthermore biofilm exposure increased production of RHG anti-microbial proteins Elafin, HBD2 and HBD3 but not HBD1, adrenomedullin or cathelicidin LL-37. Inflammatory and antimicrobial cytokine secretion (IL-6, CXCL8, CXCL1, CCL20) showed an immediate and sustained increase. In conclusion, exposure of RHG to commensal oral biofilm actively contributes to RHG epithelial barrier function.

Expression of Elafin in Dermatitis Herpetiformis

BACKGROUND

Elafin is a serine protease inhibitor that has various epithelial cell regulatory and immunomodulatory effects including inactivation of neutrophil elastases. This later role originated the interest of elafin in certain neutrophil-rich dermatoses. Interestingly, it has been speculated that elafin has a protective role by slowing the deamidation process of gliadin in celiac disease (CD), despite the typical absence of neutrophils in intestinal histologic samplings. Dermatitis herpetiformis (DH) is a chronic recurrent vesicular dermatitis associated with gluten hypersensitivity and also characterized by a neutrophilic infiltrate and granular immunoglobulin A deposits in papillary dermis.

MATERIALS AND METHODS

We selected 31 formalin-fixed paraffin-embedded skin specimens of DH that demonstrated typical immunopathologic findings and probed them with rabbit polyclonal immunoglobulinG antielafin antibodies through standard immunohistochemistry analysis. Negative controls consisted of normal skin from elbow and knee surgical re-excisions specimen lacking residual tumor. Positive controls included skin biopsies of active plaque psoriasis, Sweet syndrome, and pyoderma gangrenosum.

RESULTS

Similar to what has been previously reported in intestinal sampling of patients with active CD, abnormal expression of elafin was noted in virtually all probed skin biopsies of DH patients with active cutaneous disease.

CONCLUSION

Under normal circumstances, keratinocytes overexpress elafin to downregulate a neutrophil mediated inflammatory response. The deficient expression of elafin in the aforementioned probed DH specimens correlates with previous similar elafin underexpression in intestinal samples of active CD. These histological findings suggest that these 2 gluten mediated disorders carry an abnormal elafin underexpression during disease activity.

Deposition of elafin in the involved vascular wall of neutrophil-mediated cutaneous vasculitis

BACKGROUND

Neutrophil elastase plays an important role in skin inflammation induced by neutrophil infiltration. Elafin is an inducible elastase inhibitor expressed by keratinocytes, and is known to be involved in pathogenesis of neutrophilic skin disorders such as psoriasis.

METHODS

Immunohistochemical studies of elafin expression in the cases of vasculitis were performed. Induction of elafin expression in cultured vascular cells and its effect on neutrophil migration were studied in vitro.

RESULTS

A positive immunoreactivity was detected in polyarteritis nodosa, giant cell arteritis and Schönlein-Henoch purpura, but no immunoreactivity was found in Churg-Strauss syndrome. Elafin expression in cultured venous endothelial cells and arterial smooth muscle cells was undetectable, but induced by interleukin-1β (IL-1β) and IL-8. Elafin inhibited the elastin peptide-induced neutrophil chemotaxis at the concentration of 10(-8) -10(-5) mol/L.

CONCLUSION

Elafin deposition induced by cytokines (IL-1β or IL-8) will be an important regulator for the progress of leucocytoclastic vasculitis by functioning as an inhibitor for neutrophil chemotaxis as well as for vascular elastin degradation.

Biodistribution and pharmacokinetics of the (99m)Tc labeled human elastase inhibitor, elafin, in rats

Elafin is a potent reversible inhibitor of the pro-inflammatory proteases leukocyte elastase and protease 3. It is currently in clinical development for the use in postoperative inflammatory diseases. We investigated the pharmacokinetics of (99m)Tc-labeled elafin ((99m)Tc-Elafin) in blood and individual organs in rat after bolus intravenous injection using the single photon emission tomography (SPECT). (99m)Tc-Elafin predominantly accumulated in the kidney reaching a maximum of 8.5% ± 0.1% of the injected dose per gram (ID/g) at 5 min post injection (p.i) and decreased only slowly during 24 h. In contrast, the initially high radio activity recorded in the other organs rapidly decreased parallel to the radioactivity detected in blood. The blood kinetics fits to a two compartment kinetics model. The radio activity in the dissected kidney was 4.98 ± 1.24%ID/g 24 h p.i, while in other organs, including the brain, no accumulation of (99m)Tc-Elafin was detected. At this time point 30% of the detected radioactivity in the kidney was identified to be not metabolized (99m)Tc-Elafin. In conclusion, the blood and organ-specific kinetic data provide a basis for planning of adequate dosing regimens and the high accumulation of intact elafin in the kidney favors clinical developments targeting inflammatory kidney diseases, such as chronic allograft nephropathy after kidney transplantation.

Elafin drives poor outcome in high-grade serous ovarian cancers and basal-like breast tumors

High-grade serous ovarian carcinoma (HGSOC) and basal-like breast cancer (BLBC) share many features including TP53 mutations, genomic instability and poor prognosis. We recently reported that Elafin is overexpressed by HGSOC and is associated with poor overall survival. Here, we confirm that Elafin overexpression is associated with shorter survival in 1000 HGSOC patients. Elafin confers a proliferative advantage to tumor cells through the activation of the MAP kinase pathway. This mitogenic effect can be neutralized by RNA interference, specific antibodies and a MEK inhibitor. Elafin expression in patient-derived samples was also associated with chemoresistance and strongly correlates with bcl-xL expression. We extended these findings into the examination of 1100 primary breast tumors and six breast cancer cell lines. We observed that Elafin is overexpressed and secreted specifically by BLBC tumors and cell lines, leading to a similar mitogenic effect through activation of the MAP kinase pathway. Here too, Elafin overexpression is associated with poor overall survival, suggesting that it may serve as a biomarker and therapeutic target in this setting.

Antimicrobial peptides in the female reproductive tract: a critical component of the mucosal immune barrier with physiological and clinical implications

BACKGROUND

At the interface of the external environment and the mucosal surface of the female reproductive tract (FRT) lies a first-line defense against pathogen invasion that includes antimicrobial peptides (AMP). Comprised of a unique class of multifunctional, amphipathic molecules, AMP employ a wide range of functions to limit microbial invasion and replication within host cells as well as independently modulate the immune system, dampen inflammation and maintain tissue homeostasis. The role of AMP in barrier defense at the level of the skin and gut has received much attention as of late. Given the far reaching implications for women's health, maternal and fetal morbidity and mortality, and sexually transmissible and polymicrobial diseases, we herein review the distribution and function of key AMP throughout the female reproductive mucosa and assess their role as an essential immunological barrier to microbial invasion throughout the reproductive cycle of a woman's lifetime.

METHODS

A comprehensive search in PubMed/Medline was conducted related to AMP general structure, function, signaling, expression, distribution and barrier function of AMP in the FRT, hormone regulation of AMP, the microbiome of the FRT, and AMP in relation to implantation, pregnancy, fertility, pelvic inflammatory disease, complications of pregnancy and assisted reproductive technology.

RESULTS

AMP are amphipathic peptides that target microbes for destruction and have been conserved throughout all living organisms. In the FRT, several major classes of AMP are expressed constitutively and others are inducible at the mucosal epithelium and by immune cells. AMP expression is also under the influence of sex hormones, varying throughout the menstrual cycle, and dependent on the vaginal microbiome. AMP can prevent infection with sexually transmissible and opportunistic pathogens of the female reproductive tissues, although emerging understanding of vaginal dysbiosis suggests induction of a unique AMP profile with increased susceptibility to these pathogens. During pregnancy, AMP are key immune effectors of the fetal membranes and placenta and are dysregulated in states of intrauterine infection and other complications of pregnancy.

CONCLUSIONS

At the level of the FRT, AMP serve to inhibit infection by sexually and vertically transmissible as well as by opportunistic bacteria, fungi, viruses, and protozoa and must do so throughout the hormone flux of menses and pregnancy. Guarding the exclusive site of reproduction, AMP modulate the vaginal microbiome of the lower FRT to aid in preventing ascending microbes into the upper FRT. Evolving in parallel with, and in response to, pathogenic insults, AMP are relatively immune to the resistance mechanisms employed by rapidly evolving pathogens and play a key role in barrier function and host defense throughout the FRT.

Epidermal elafin expression is an indicator of poor prognosis in cutaneous graft-versus-host disease

Graft-versus-host disease (GVHD) remains a common and potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation. In the skin, GVHD can present in an acute (aGVHD), chronic lichenoid (clGVHD), or chronic sclerotic form (csGVHD). Measuring peripheral blood levels of the keratinocyte-derived protease inhibitor elafin has recently emerged as a promising tool for the diagnosis of cutaneous aGVHD. We evaluated whether the analysis of elafin expression in skin would allow distinguishing aGVHD from drug hypersensitivity rashes (DHR) and whether cutaneous elafin expression would correlate with disease severity or altered prognosis of aGVHD and clGVHD/csGVHD. Skin biopsies from aGVHD (n=22), clGVHD (n=15), csGVHD (n=7), and DHR (n=10) patients were collected and epidermal elafin expression and its association with diverse clinical/histological parameters were analyzed. Acute GVHD and DHR displayed varying degrees of elafin expression. No elafin was detectable in csGVHD, whereas the molecule was increased in clGVHD as compared with aGVHD. Elafin-high aGVHD/clGVHD lesions presented with epidermal thickening and were associated with poor prognosis-i.e., decreased overall survival in aGVHD and corticosteroid resistance in clGVHD. Although cutaneous elafin does not seem to discriminate aGVHD from DHR lesions, our study strongly suggests an association between cutaneous elafin expression and poor prognosis for patients with cutaneous GVHD.

A functional variant of elafin with improved anti-inflammatory activity for pulmonary inflammation

Elafin is a serine protease inhibitor produced by epithelial and immune cells with anti-inflammatory properties. Research has shown that dysregulated protease activity may elicit proteolytic cleavage of elafin, thereby impairing the innate immune function of the protein. The aim of this study was to generate variants of elafin (GG- and QQ-elafin) that exhibit increased protease resistance while retaining the biological properties of wild-type (WT) elafin. Similar to WT-elafin, GG- and QQ-elafin variants retained antiprotease activity and susceptibility to transglutaminase-mediated fibronectin cross-linking. However, in contrast to WT-elafin, GG- and QQ-elafin displayed significantly enhanced resistance to degradation when incubated with bronchoalveolar lavage fluid from patients with cystic fibrosis. Intriguingly, both variants, particularly GG-elafin, demonstrated improved lipopolysaccharide (LPS) neutralization properties in vitro. In addition, GG-elafin showed improved anti-inflammatory activity in a mouse model of LPS-induced acute lung inflammation. Inflammatory cell infiltration into the lung was reduced in lungs of mice treated with GG-elafin, predominantly neutrophilic infiltration. A reduction in MCP-1 levels in GG-elafin treated mice compared to the LPS alone treatment group was also demonstrated. GG-elafin showed increased functionality when compared to WT-elafin and may be of future therapeutic relevance in the treatment of lung diseases characterized by a protease burden.

Expression profiles of antimicrobial peptides in the genital tract of women using progesterone intrauterine devices versus combined oral contraceptives

PROBLEM

Sex hormones can influence the immune defenses of the female genital tract (FGT) and its susceptibility to infections. Here we investigated the effect of different hormonal contraceptives on the production of antimicrobial peptides (AMPs) in different compartments of the female genital mucosa (FGM), secretions and tissue.

METHOD OF STUDY

Cervicovaginal secretions (CVS) and ectocervical tissue samples obtained from women using progesterone intrauterine devices (pIUD) (n = 23) and combined oral contraceptives (COC) (n = 23) were analyzed for the expression and in situ localization of HNP1-3, BD-2, LL-37, SLPI and trappin-2 by ELISA, real-time PCR and immunohistochemistry.

RESULTS

Women using COC had significantly lower mRNA levels of BD-2 and trappin-2 in ectocervical tissue than pIUD users. The two groups showed no differences in CVS concentration, as well as similar in situ expression patterns in ectocervical tissue, of all five AMPs.

CONCLUSIONS

The use of hormonal contraceptives influences AMP expression differently in genital secretions compared to ectocervical tissue. This suggests that the impact of sex hormones on local immune defenses varies in different compartments of the FGM, and likely in different locations across the FGT.

Antiviral activity of trappin-2 and elafin in vitro and in vivo against genital herpes

Serine protease inhibitor elafin (E) and its precursor, trappin-2 (Tr), have been associated with mucosal resistance to HIV-1 infection. We recently showed that Tr/E are among principal anti-HIV-1 molecules in cervicovaginal lavage (CVL) fluid, that E is ∼130 times more potent than Tr against HIV-1, and that Tr/E inhibited HIV-1 attachment and transcytosis across human genital epithelial cells (ECs). Since herpes simplex virus 2 (HSV-2) is a major sexually transmitted infection and risk factor for HIV-1 infection and transmission, we assessed Tr/E contribution to defense against HSV-2. Our in vitro studies demonstrated that pretreatment of endometrial (HEC-1A) and endocervical (End1/E6E7) ECs with human Tr-expressing adenovirus (Ad/Tr) or recombinant Tr/E proteins before or after HSV-2 infection resulted in significantly reduced virus titers compared to those of controls. Interestingly, E was ∼7 times more potent against HSV-2 infection than Tr. Conversely, knockdown of endogenous Tr/E by small interfering RNA (siRNA) significantly increased HSV-2 replication in genital ECs. Recombinant Tr and E reduced viral attachment to genital ECs by acting indirectly on cells. Further, lower viral replication was associated with reduced secretion of proinflammatory interleukin 8 (IL-8) and tumor necrosis factor alpha (TNF-α) and decreased NF-κB nuclear translocation. Additionally, protected Ad/Tr-treated ECs demonstrated enhanced interferon regulatory factor 3 (IRF3) nuclear translocation and increased antiviral IFN-β in response to HSV-2. Lastly, in vivo studies of intravaginal HSV-2 infection in Tr-transgenic mice (Etg) showed that despite similar virus replication in the genital tract, Etg mice had reduced viral load and TNF-α in the central nervous system compared to controls. Collectively, this is the first experimental evidence highlighting anti-HSV-2 activity of Tr/E in female genital mucosa.

Human rElafin Inhibits HIV-1 Replication in Its Natural Target Cells

Trappin-2/elafin is a novel innate immune factor that belongs to the serine protease inhibitor family and has known antibacterial, antifungal, and antiviral properties. In this study, we further investigated the anti-HIV activity of elafin using different cellular models and both X4– and R5–HIV-1 laboratory strains. We compared the antiviral activity of human recombinant elafin (rElafin) with three well-known antiretroviral drugs, AZT, tenofovir, and enfuvirtide. We have found that when the virus is pre-incubated with rElafin prior to the infection of the cells, HIV-1 replication is significantly inhibited. In target T cells and human peripheral blood mononuclear cells, maximal inhibition was achieved using submicromolar concentrations, and rElafin was found to be as potent as enfuvirtide, showing its potential for therapeutic application. We also show data on the mechanism of the antiviral activity of rElafin. We have demonstrated that rElafin neither binds to CD4, CXCR4, or CCR5 host cell receptors, nor to the viral glycoproteins gp120 and gp41. Furthermore, in our cell-to-cell fusion assays, in contrast to enfuvirtide, rElafin failed to block cell fusion. Altogether our results indicate that rElafin interferes with HIV replication at the early steps of its cycle but with a different mechanism of action than enfuvirtide. This study provides the first experimental evidence that elafin inhibits HIV replication in its natural target cells; therefore, elafin might have potential for its development as a new anti-HIV drug or microbicide.

Vascular endothelial growth factor induces growth of uterine cervix and immune cell recruitment in mice

Knowledge of uterine cervical epithelial biology and factors that influence its events may be critical in understanding the process of cervical remodeling (CR). Here, we examine the impact of exogenous vascular endothelial growth factor (VEGF) on uterine cervical epithelial growth in mice (nonpregnant and pregnant) treated with VEGF agents (recombinant and inhibitor) using a variety of morphological and molecular techniques. Exogenous VEGF altered various uterine cervical epithelial cellular events, including marked induction of growth, edema, increase in inter-epithelial paracellular space, and recruitment of immune cells to the outer surface of epithelial cells (cervical lumen). We conclude that VEGF induces multiple alterations in the uterine cervical epithelial tissues that may play a role in local immune surveillance and uterine cervical growth during CR.

Innate immunity in the vagina (part I): estradiol inhibits HBD2 and elafin secretion by human vaginal epithelial cells

PROBLEM

Vaginal epithelial cells (VEC) are the first line of defense against incoming pathogens in the female reproductive tract. Their ability to produce the anti-HIV molecules elafin and HBD2 under hormonal stimulation is unknown.

METHOD OF STUDY

Vaginal epithelial cells were recovered using a menstrual cup and cultured overnight prior to treatment with estradiol (E₂), progesterone (P₄) or a panel of selective estrogen response modulators (SERMs). Conditioned media were recovered and analyzed for protein concentration and anti-HIV activity.

RESULTS

E₂ significantly decreased the secretion of HBD2 and elafin by VEC over 48 hrs, while P4 and the SERMs (tamoxifen, PHTTP, ICI or Y134) had no effect. VEC conditioned media from E₂ -treated cells had no anti-HIV activity, while that from E₂ /P₄ -treated cells significantly inhibited HIV-BaL infection.

CONCLUSION

The menstrual cup allows for effective recovery of primary VEC. Their production of HBD2 and elafin is sensitive to E₂, suggesting that innate immune protection varies in the vagina across the menstrual cycle.

Neutrophil-mediated inhibition of proinflammatory cytokine responses

Neutrophils (polymorphonuclear neutrophils [PMNs]) play an elaborate role in the innate immune response against invading pathogens. Recent research provided evidence that PMNs can play a modulatory role in inflammation next to their primary role of phagocytosis. In the current study, we investigated whether neutrophils can modulate the innate immune response against Candida albicans. Production of the proinflammatory cytokines IL-1β and TNF-α by human PBMCs in response to C. albicans or LPS was decreased by coculture of PMNs; however, the anti-inflammatory cytokine IL-10 remained unaffected. Using Transwells and cells of patients with chronic granulomatous disease, we show that this downregulation of proinflammatory cytokine production was independent of phagocytosis and reactive oxygen species but was dependent on a soluble factor. We suggest that neutrophil-derived proteases are responsible for the downregulation of IL-1β and TNF-α, as cytokine production could be recovered by addition of α1-antitrypsin, an endogenous inhibitor of serine proteases. PMN lysates and neutrophil elastase could degrade recombinant human IL-1β and TNF-α but not IL-10, and this could be inhibited by addition of α1-antitrypsin. Moreover, we also provide evidence that the dampening effect of PMNs is present in vivo in a murine zymosan-induced arthritis model and a murine experimental endotoxemia model. Altogether, our data show that PMNs can dampen the proinflammatory response to C. albicans by protease-mediated degradation of cytokines. This observation suggest that PMNs might play a important regulatory role in the host defense against C. albicans and can be important for understanding the regulation of inflammation in general.

Anti-HIV-1 activity of elafin is more potent than its precursor's, trappin-2, in genital epithelial cells

Cervicovaginal lavage fluid (CVL) is a natural source of anti-HIV-1 factors; however, molecular characterization of the anti-HIV-1 activity of CVL remains elusive. In this study, we confirmed that CVLs from HIV-1-resistant (HIV-R) compared to HIV-1-susceptible (HIV-S) commercial sex workers (CSWs) contain significantly larger amounts of serine antiprotease trappin-2 (Tr) and its processed form, elafin (E). We assessed anti-HIV-1 activity of CVLs of CSWs and recombinant E and Tr on genital epithelial cells (ECs) that possess (TZM-bl) or lack (HEC-1A) canonical HIV-1 receptors. Our results showed that immunodepletion of 30% of Tr/E from CVL accounted for up to 60% of total anti-HIV-1 activity of CVL. Knockdown of endogenous Tr/E in HEC-1A cells resulted in significantly increased shedding of infectious R5 and X4 HIV-1. Pretreatment of R5, but not X4 HIV-1, with either Tr or E led to inhibition of HIV-1 infection of TZM-bl cells. Interestingly, when either HIV-1 or cells lacking canonical HIV-1 receptors were pretreated with Tr or E, HIV-1 attachment and transcytosis were significantly reduced, and decreased attachment was not associated with altered expression of syndecan-1 or CXCR4. Determination of 50% inhibitory concentrations (IC(50)) of Tr and E anti-HIV-1 activity indicated that E is ∼130 times more potent than its precursor, Tr, despite their equipotent antiprotease activities. This study provides the first experimental evidence that (i) Tr and E are among the principal anti-HIV-1 molecules of CVL; (ii) Tr and E affect cell attachment and transcytosis of HIV-1; (iii) E is more efficient than Tr regarding anti-HIV-1 activity; and (iv) the anti-HIV-1 effect of Tr and E is contextual.

War and peace between WAP and HIV: role of SLPI, trappin-2, elafin and ps20 in susceptibility to HIV infection

Despite tremendous advances in our understanding of HIV/AIDS since the first cases were reported 30 years ago, we are still a long way from understanding critical steps of HIV acquisition, pathogenesis and correlates of protection. Our new understanding of the importance of the mucosa as a target for HIV infection, as well as our recent observations showing that altered expression and responses of innate pattern recognition receptors are significantly associated with pathogenesis and resistance to HIV infection, indicate that correlates of immunity to HIV are more likely to be associated with mucosal and innate responses. Most of the heterosexual encounters do not result in productive HIV infection, suggesting that the female genital tract is protected against HIV by innate defence molecules, such as antiproteases, secreted mucosally. The present review highlights the role and significance of the serine protease inhibitors SLPI (secretory leucocyte protease inhibitor), trappin-2, elafin and ps20 (prostate stromal protein 20 kDa) in HIV susceptibility and infection. Interestingly, in contrast with SLPI, trappin-2 and elafin, ps20 has been shown to enhance HIV infectivity. Thus understanding the balance and interaction of these factors in mucosal fluids may significantly influence HIV infection.

Protease inhibitor levels in periodontal health and disease

BACKGROUND AND OBJECTIVE

Our previous study showed that protease inhibitors were attenuated by the periodontal pathogen Porphyromonas gingivalis in cultured gingival epithelial cells. We hypothesize that fewer protease inhibitors would be present in more advanced periodontal disease sites, where the level of P. gingivalis may be high. The goal of this study was to investigate the relationship between the protease inhibitor [secretory leukocyte protease inhibitor (SLPI), elastase-specific inhibitor (ELAFIN) and squamous cell carcinoma antigen (SCCA)] levels in gingival crevicular fluid and the number of P. gingivalis micro-organisms in subgingival plaque.

MATERIAL AND METHODS

Plaque samples from subjects without (n = 18) and with moderate to advanced periodontitis (n = 41) were used to quantify P. gingivalis using real-time PCR. Protease inhibitor levels in the gingival crevicular fluid of all the subjects were determined by ELISA.

RESULTS

P. gingivalis was detected in 68.3% of patients with periodontitis, while 16.7% of subjects without periodontitis had a detectable level of P. gingivalis. Patients with periodontitis and P. gingivalis in their plaque exhibited lower SLPI and ELAFIN levels (p < 0.001) compared with control subjects without periodontitis. Secretory leukocyte protease inhibitor was also reduced (p < 0.05) in gingival crevicular fluid of periodontitis patients without a detectable level of P. gingivalis. Periodontitis patients with high vs. low levels of P. gingivalis exhibited reciprocal mean levels of SLPI and ELAFIN concentrations.

CONCLUSION

The reduced concentrations of SLPI and ELAFIN may contribute to the loss of host protective capacity and increase susceptibility to breakdown from chronic infection. The work of this investigation may aid in finding diagnostic and prognostic markers in periodontal health and disease and may also help in finding pharmacological targets directed against periodontal inflammation.

Therapeutic potential of human elafin

Elafin is an endogenous human protein composed of an N-terminal transglutaminase substrate motif and a C-terminal WAP (whey acidic protein)-domain with antiproteolytic properties. Elafin is expressed predominantly in epithelial tissue and potently inhibits the neutrophil-derived serine proteases elastase and proteinase-3 by a competitive tight-binding mechanism. Furthermore, it inhibits EVE (endogenous vascular elastase). Studies on several animal models show that antiprotease augmentation with human elafin is an effective strategy in the treatment of inflammatory vascular, systemic and pulmonary diseases and of inflammation triggered by reperfusion injury. This raises the possibility that elafin might be effective in the treatment of a variety of human inflammatory diseases. In a Phase I clinical trial, elafin was well tolerated. Phase II trials are underway to investigate the therapeutic effects of elafin on post-operative inflammation and the clinical consequences of major surgery. Of particular interest is the reduction of post-operative morbidity after oesophagus cancer surgery, coronary artery bypass surgery and kidney transplantation.

Innate immunity in the human female reproductive tract: endocrine regulation of endogenous antimicrobial protection against HIV and other sexually transmitted infections

Mucosal surfaces of the female reproductive tract (FRT) contain a spectrum of antimicrobials that provide the first line of defense against viruses, bacteria, and fungi that enter the lower FRT. Once thought to be a sterile compartment, the upper FRT is periodically exposed to pathogens throughout the menstrual cycle. More recently, secretions from the upper FRT have been shown to contribute to downstream protection in the lower FRT. In this review, we examine the antimicrobials in FRT secretions made by immune cells and epithelial cells in the upper and lower FRT that contribute to innate protection. Because each site is hormonally regulated to maintain fertility, this review focuses on the contributions of hormone balance during the menstrual cycle to innate immune protection. As presented in this review, studies from our laboratory and others demonstrate that sex hormones regulate antimicrobials produced by innate immune cells throughout the FRT. The goal of this review is to examine the spectrum of antimicrobials in the FRT and the ways in which they are regulated to provide protection against pathogens that compromise reproductive health and threaten the lives of women.

Antimicrobial peptides and pregnancy

Antimicrobial peptides (AMPs) are small proteins produced by epithelial surfaces and inflammatory cells, which have broad-spectrum antimicrobial and immunomodulatory activities. They are known to be important in a number of infectious and inflammatory conditions and have been shown to be present in a number of sites throughout the female reproductive tract. Inflammation and infection are associated with a number of complications of pregnancy including preterm labor, and AMPs may play a key role in maintaining and protecting pregnancy. The aim of this review is to describe the expression and function of AMPs in the pregnant female reproductive tract and their relation to preterm labor.

Secretory leukocyte protease inhibitor and elafin/trappin-2: versatile mucosal antimicrobials and regulators of immunity

Elafin and secretory leukocyte protease inhibitor (SLPI) are pleiotropic molecules chiefly synthesized at the mucosal surface that have a fundamental role in the surveillance against microbial infections. Their initial discovery as anti-proteases present in the inflammatory milieu in chronic pathologies such as those of the lung suggested that they may play a role in keeping in check extracellular proteases released during the excessive activation of innate immune cells such as neutrophils. This soon proved to be a simplistic explanation, as other functions were also soon ascribed to these molecules (antimicrobial, modulation of innate and adaptive immunity, regulation of tissue repair). Data emanating from patients with chronic pathologies (in the lung and elsewhere) have shown that SLPI and elafin are often inactivated in inflammatory secretions, either through the action of host or microbial products, justifying attempts at antiprotease supplementation in clinical protocols. Although these have been sparse, proof of principle has been demonstrated, and future challenges will undoubtedly rest with improvements in methods of delivery in the context of tissue inflammation and in careful selection of patients more likely to benefit from SLPI/elafin augmentation.

Elafin is specifically inactivated by RgpB from Porphyromonas gingivalis by distinct proteolytic cleavage

Abstract Porphyromonas gingivalis, the major causative bacterium of periodontitis, contributes significantly to elevated proteolytic activity at periodontal pockets owing to the presence of both bacteria and host, predominantly neutrophil-derived, serine proteases. Normally the activity of the latter enzymes is tightly regulated by endogenous proteins, including elafin, a potent neutrophil elastase and proteinase 3 inhibitor released from epithelial cells at sites of inflammation. Here, we report that all three gingipains (HRgpA, RgpB, and Kgp) have the ability to degrade elafin, with RgpB being far more efficient than other gingipains. RgpB efficiently inactivates the inhibitory activity of elafin at subnanomolar concentrations through proteolysis limited to the Arg22-Cys23 peptide bond within the surface loop harboring the inhibitor active site. Notably, elafin resists inactivation by several Staphylococcus aureus-derived serine and cysteine proteases, confirming the high stability of this protein against proteolytic degradation. Therefore, we conclude that elafin inactivation by RgpB represents a specific pathogenic adaptation of P. gingivalis to disturb the protease-protease inhibitor balance in the infected gingival tissue. This contributes to enhanced degradation of host proteins and generation of a pool of peptides serving as nutrients for this asaccharolytic pathogen.

Proteases and antiproteases in chronic neutrophilic lung disease - relevance to drug discovery

Chronic inflammatory lung diseases such as cystic fibrosis and emphysema are characterized by higher-than-normal levels of pulmonary proteases. While these enzymes play important roles such as bacterial killing, their dysregulated expression or activity can adversely impact on the inflammatory process. The existence of efficient endogenous control mechanisms that can dampen or halt this overexuberant protease activity in vivo is essential for the effective resolution of inflammatory lung disease. The function of pulmonary antiproteases is to fulfil this role. Interestingly, in addition to their antiprotease activity, protease inhibitors in the lung also often possess other intrinsic properties that contribute to microbial killing or termination of the inflammatory process. This review will outline important features of chronic inflammation that are regulated by pulmonary proteases and will describe the various mechanisms by which antiproteases attempt to counterbalance exaggerated protease-mediated inflammatory events. These proteases, antiproteases and their modifiers represent interesting targets for therapeutic intervention.

Human gammadelta T cells produce the protease inhibitor and antimicrobial peptide elafin

Human gammadelta T cells rapidly secrete pro-inflammatory cytokines in response to T cell receptor-dependent recognition of pyrophosphates produced by many bacteria and parasites. In further support of an important role of gammadelta T cells in the immune defence against infection, human gammadelta T cells have been shown to produce the antimicrobial peptide LL37/cathelicidin. In this study, we have investigated whether gammadelta T cells can produce additional antimicrobial peptides. To this end, we have screened human gammadelta T cell clones by RT-PCR for mRNA expression of a broad range of antimicrobial peptides. While alpha-defensins were absent and beta-defensins (HBD1) present only in rare gammadelta T cell clones, elafin mRNA was induced by supernatant of Pseudomonas aeruginosa grown under static conditions. Elafin is a protease inhibitor that also displays antimicrobial activity. Constitutive intracellular expression of elafin was demonstrated by flow cytometry and Western blot analysis. Furthermore, trappin-2 (pre-elafin) could be immunoprecipitated in cell lysates but also in the supernatant of gammadelta T cells stimulated by Ps. aeruginosa supernatant. Taken together, our studies reveal a novel effector function of gammadelta T cells which might be important for local immune defence.

Elafin (SKALP/Trappin-2/proteinase inhibitor-3) is produced by the cervix in pregnancy and cervicovaginal levels are diminished in bacterial vaginosis

OBJECTIVES

To examine cervicovaginal elafin production in pregnancy and determine its relationship in bacterial vaginosis.

STUDY DESIGN

Samples of cervicovaginal secretions were collected from women with uncomplicated singleton pregnancies (n = 112) below 20 weeks gestation. Bacterial flora was assessed using Nugent's criteria, and levels of elafin were measured by enzyme-linked immunosorbent serologic assay (ELISA). Elafin expression in the cervix was also examined by immunohistochemistry. In vitro expression of elafin was examined using cervix and vaginal cell lines.

RESULTS

Elafin is expressed in the cervical glandular epithelium. Elafin was found in all 112 samples of cervicovaginal secretions and levels were diminished in women with bacterial vaginosis (P < .05). Interleukin 1beta (IL-1beta) stimulated elafin expression in cells derived from the endocervix, but not in those derived from the vaginal epithelium.

CONCLUSIONS

Elafin is a component of cervicovaginal secretions in pregnancy, and levels are diminished in bacterial vaginosis. It may be an important component of innate immunity in the lower genital tract.

Trappin-2/Elafin: a novel innate anti-human immunodeficiency virus-1 molecule of the human female reproductive tract

Trappin-2/Elafin is a serine protease inhibitor that plays a major role as an anti-inflammatory mediator at mucosal surfaces. In addition, Trappin-2/Elafin has antibacterial activity against Gram-positive and Gram-negative bacterial and fungal pathogens. In this study we examined the production of Trappin-2/Elafin by epithelial cells from the human upper and lower female reproductive tract as well as its activity as an anti-human immunodeficiency virus (HIV)-1 molecule. We found that primary uterine, Fallopian tube, cervical and ectocervical epithelial cells produce Trappin-2/Elafin constitutively and that production of Trappin-2/Elafin is enhanced following stimulation with Poly(I:C), especially by the uterine cells. Given the presence of Trappin-2/Elafin in the reproductive tract, we tested the ability of recombinant Trappin-2/Elafin to inhibit HIV-1, an important sexually transmitted pathogen. We found that recombinant Trappin-2/Elafin was able to inhibit both T-cell-tropic X4/IIIB and macrophage-tropic R5/BaL HIV-1 in a dose-dependent manner. The inhibitory activity was observed when virus was incubated with Trappin-2/Elafin but not when Trappin-2/Elafin was added to cells either before infection or after infection. This suggests that the mechanism of inhibition is likely to be a direct interaction between HIV-1 and Trappin-2/Elafin. Additionally, we measured the levels of secreted Trappin-2/Elafin in cervico-vaginal lavages (CVL) from both HIV-positive and HIV-negative women and found that average levels of secreted Trappin-2/Elafin were higher in the CVL from HIV-negative women, although the values did not reach statistical significance. We also found that women at the secretory phase of the menstrual cycle produced more Trappin-2/Elafin in CVL relative to women at the proliferative phase of the menstrual cycle. Our data suggest that Trappin-2/Elafin might be an important endogenous microbicide of the female reproductive tract that is protective against HIV-1.

Expression of the vanin gene family in normal and inflamed human skin: induction by proinflammatory cytokines

The vanin gene family encodes secreted and membrane-bound ectoenzymes that convert pantetheine into pantothenic acid and cysteamine. Recent studies in a mouse colitis model indicated that vanin-1 has proinflammatory activity and suggest that pantetheinases are potential therapeutic targets in inflammatory diseases. In a microarray analysis of epidermal gene expression of psoriasis and atopic dermatitis lesions, we identified vanin-3 as the gene showing the highest differential expression of all annotated genes that we studied (19-fold upregulation in psoriasis). Quantitative real-time PCR analysis confirmed the microarray data on vanin-3 and showed similar induction of vanin-1, but not of vanin-2, in psoriatic epidermis. Immunohistochemistry showed that vanin-3 is expressed in the differentiated epidermal layers. Using submerged and organotypic keratinocyte cultures, we found that vanin-1 and vanin-3 are induced at the mRNA and protein level by psoriasis-associated proinflammatory cytokines (Th17/Th1) but not by Th2 cytokines. We hypothesize that increased levels of pantetheinase activity are part of the inflammatory-regenerative epidermal differentiation program, and may contribute to the phenotype observed in psoriasis.

Genetic polymorphisms of peptidase inhibitor 3 (elafin) are associated with acute respiratory distress syndrome

Peptidase inhibitor 3 (PI3, elafin) is a protease inhibitor produced locally in the lung, where it plays a central role in controlling excessive activity of neutrophil elastase. Our previous study revealed that PI3 gene expression is down-regulated during the acute stage of acute respiratory distress syndrome (ARDS). We conducted a case-control study to investigate whether genetic variants in PI3 gene are associated with ARDS development. Based on resequencing data from 29 unrelated white subjects, three tagging single-nucleotide polymorphisms were selected and genotyped in a prospective cohort consisting of 449 white patients with ARDS (cases) and 1,031 critically ill patients (at-risk control subjects). We found that the variant allele of rs2664581 (T34P) was significantly associated with increased ARDS risk (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.09-1.67; P = 0.006; false discovery rate adjusted P = 0.018). Moreover, this association was stronger among subjects with extrapulmonary injury. The common haplotype Hap2 (TTC), containing the variant allele of rs2664581, was also identified as a risk haplotype for ARDS (OR, 1.31; 95% CI, 1.05-1.64; P = 0.015). Furthermore, the rs2664581 polymorphism was associated with circulating PI3 levels in multivariate analyses. Patients with ARDS homozygous for the wild-type A allele of rs2664581 showed significant lower PI3 plasma level (P = 0.019) at ARDS onset as compared with those homozygous or heterozygous for the variant C allele. Our data suggest that polymorphisms in PI3 gene are significantly associated with ARDS risk and with circulating PI3 levels.

The serine protease marapsin is expressed in stratified squamous epithelia and is up-regulated in the hyperproliferative epidermis of psoriasis and regenerating wounds

The trypsin-like serine protease marapsin is a member of the large protease gene cluster at human chromosome 16p13.3, which also contains the structurally related proteases testisin, tryptase epsilon, tryptase gamma, and EOS. To gain insight into the biological functions of marapsin, we undertook a detailed gene expression analysis. It showed that marapsin expression was restricted to tissues containing stratified squamous epithelia and was absent or only weakly expressed in all other tissues, including the pancreas. Marapsin was constitutively expressed in nonkeratinizing stratified squamous epithelia of human esophagus, tonsil, cervix, larynx, and cornea. In the keratinizing stratified squamous epidermis of skin, however, its expression was induced only during epidermal hyperproliferation, such as in psoriasis and in murine wound healing. In fact, marapsin was the second most strongly up-regulated protease in psoriatic lesions, where expression was localized to the upper region of the hyperplastic epidermis. Similarly, in the hyperproliferative epithelium of regenerating murine skin wounds, marapsin localized to the suprabasal layers, where keratinocytes undergo squamous differentiation. The transient up-regulation of marapsin, which closely correlated with re-epithelialization, was virtually absent in a genetic mouse model of delayed wound closure. These results suggested a function during the process of re-epithelialization. Furthermore, in reconstituted human epidermis, a model system of epidermal differentiation, members of the IL-20 subfamily of cytokines, such as IL-22, induced marapsin expression. Consistent with a physiologic role in marapsin regulation, IL-22 was also strongly expressed in re-epithelializing skin wounds. Marapsin's restricted expression, localization, and cytokine-inducible expression suggest a role in the terminal differentiation of keratinocytes in hyperproliferating squamous epithelia.

Innate immunity and disorders of the female reproductive tract

Sexually transmitted infections, and their associated sequelae, such as tubal infertility, ectopic pregnancy and preterm labour, are a major worldwide health problem. Chlamydia trachomatis infection is thought to be the leading global cause of tubal infertility and tubal ectopic pregnancy. Preterm birth occurs in around 10% of all deliveries, and nearly 30% of preterm deliveries are associated with intrauterine infection. The mucosal innate immune system of the female reproductive tract has evolved to eliminate such sexually transmitted pathogens whilst maintaining its ability to accommodate specialized physiological functions that include menstruation, fertilization, implantation, pregnancy and parturition. The aim of this review was to describe the role and distribution of key mediators of the innate immune system, the natural antimicrobial peptides (secretory leukocyte protease inhibitor, elafin and the defensins) and the pattern recognition toll-like receptors in the normal female reproductive tract and in the context of these pathological processes.

Delineation of VEGF-regulated genes and functions in the cervix of pregnant rodents by DNA microarray analysis

BACKGROUND

VEGF-regulated genes in the cervices of pregnant and non-pregnant rodents (rats and mice) were delineated by DNA microarray and Real Time PCR, after locally altering levels of or action of VEGF using VEGF agents, namely siRNA, VEGF receptor antagonist and mouse VEGF recombinant protein.

METHODS

Tissues were analyzed by genome-wide DNA microarray analysis, Real-time and gel-based PCR, and SEM, to decipher VEGF function during cervical remodeling. Data were analyzed by EASE score (microarray) and ANOVA (Real Time PCR) followed by Scheffe's F-test for multiple comparisons.

RESULTS

Of the 30,000 genes analyzed, about 4,200 genes were altered in expression by VEGF, i.e., expression of about 2,400 and 1,700 genes were down- and up-regulated, respectively. Based on EASE score, i.e., grouping of genes according to their biological process, cell component and molecular functions, a number of vascular- and non-vascular-related processes were found to be regulated by VEGF in the cervix, including immune response (including inflammatory), cell proliferation, protein kinase activity, and cell adhesion molecule activity. Of interest, mRNA levels of a select group of genes, known to or with potential to influence cervical remodeling were altered. For example, real time PCR analysis showed that levels of VCAM-1, a key molecule in leukocyte recruitment, endothelial adhesion, and subsequent trans-endothelial migration, were elevated about 10 folds by VEGF. Further, VEGF agents also altered mRNA levels of decorin, which is involved in cervical collagen fibrillogenesis, and expression of eNO, PLC and PKC mRNA, critical downstream mediators of VEGF. Of note, we show that VEGF may regulate cervical epithelial proliferation, as revealed by SEM.

CONCLUSION

These data are important in that they shed new insights in VEGF's possible roles and mechanisms in cervical events near-term, including cervical remodeling.