ß-defensin 1 Gene Polymorphisms are Associated with Kidney Disease in Northwestern Mexicans with Type 2 Diabetes.

Diabetic kidney disease (DKD) is one of the more limiting complications to the quality of life of diabetes mellitus patients. Studies including cultured cells, animal models, and case-control studies highlight the role of human ß-defensin-1 (hBD-1) in diabetes.This study assessed the association of hBD-1 gene (DEFB1) functional variations -52 G/A (rs1799946), -44 C/G (rs1800972) and -20 G/A (rs11362) with type 2 diabetes mellitus (T2DM) in order to investigate its effects on genetic susceptibility and progression to DKD in a Mexican population. A total of 214 T2DM patients with and without DKD (n = 102 and n = 112, respectively) and 117 healthy subjects participated in this case-control study. Genotyping was made by PCR-RFLPs. Clinical and biochemical parameters of all patients were measured. There was no statistically significant difference in genotype or allele frequencies between patients and healthy individuals. Nevertheless, compared with patients without DKD, DKD patients have a reduced prevalence of AA genotype of -52 G/A (OR = 0.307, 95% CI = 0.104-0.905, p =.026), as well as a higher frequency of GA genotype of -20 G/A variant (OR = 1.875, 95%CI = 1.031-3.409, p = .038). Our results suggest that rs1799946 and rs11362 could be useful variants to stratify T2DM Mexican patients in order to prescribe closer follow-up to prevent or retard DKD. Further tests in different ethnic groups are encouraged.

Beta-defensin 1 gene polymorphisms in the pathologies of the oral cavity-Data from meta-analysis: Association only with rs1047031 not with rs1800972, rs1799946, and rs11362.

OBJECTIVES: The purpose of this meta-analysis was to reveal a potential association of the four functional polymorphisms in human Beta-defensin 1 (DEFB1) gene: rs1047031(c*5G > A) at 3'UTR and rs11362 (-20 G > A), rs1800972(-44 C > G), and rs1799946 (-52 G > A) at 5'UTR with the risk of common oral cavity pathologies that included periodontitis, caries, lichen planus, and recurrent aphthous stomatitis. METHODS: The relevant studies were obtained by the two researchers from PubMed, Scopus, and Web of Science up to April 29, 2020. The manual search of the reference lists was also performed. Studies on DEFB1 gene polymorphisms and oral cavity disorders, using the case-control genetic association analysis approach, and published as full texts in English were included. To assess the association strength, odds ratios (ORs) with their 95% confidence intervals (CIs) were extracted. RESULTS: Thirteen publications met the inclusion criteria and were incorporated in this meta-analysis. Statistically significant values of the association tests were found only for the rs1047031 polymorphism. Allele distribution in the rs1047031 polymorphism was significantly associated with susceptibility to oral cavity pathologies (adjusted P value = 0.003). The rare variant allele carriers had a significantly higher risk for oral disasters under recessive (CC vs CT + TT), and CC vs CT models. No significant correlations between rs11362, rs1800972, and rs1799946 and the risk of oral pathologies were revealed. CONCLUSIONS: Significant association between rs1047031 polymorphism and risk of oral pathologies has been found, and therefore, we suggest to include this polymorphism in future research concerning the genetic background of the oral cavity diseases.

Association between genetic polymorphisms in the promoter region of the defensin beta 1 gene and persistent apical periodontitis.

AIM: To evaluate the association between the promoter region of defensin beta 1 (DEFB1) genetic polymorphisms and persistent apical periodontitis (PAP) in Brazilian patients. METHODOLOGY: Seventy-three patients with post-treatment PAP (PAP group) and 89 patients with root filled teeth with healed and healthy periradicular tissues (healed group) were included (all teeth had apical periodontitis lesions at the beginning of the treatment). Patients who had undergone at least 1 year of follow-up after root canal treatment were recalled, and their genomic DNA was extracted from saliva. Two single nucleotide polymorphisms (SNPs) in DEFB1 at the g. -52G>A (rs1799946) and g. -20G>A (rs11362) positions were analysed using real-time polymerase chain reaction. The chi-squared test was performed, and the odds ratios were calculated using Epi Info 3.5.2. Logistic regression analysis in the codominant model, using the time of follow-up as a variable, was used to evaluate the SNP-SNP interaction. All tests were performed with an established alpha of 0.05 (P = 0.05). RESULTS: For the rs11362 polymorphism in the codominant and recessive models, patients who carried two copies of the T allele had a significantly lower risk of developing PAP (P = 0.040 and P = 0.031, respectively). For the rs1799946 polymorphism in DEFB1 in the codominant and recessive models, carrying one copy of the T allele significantly increased the risk of developing PAP (P = 0.007 and P = 0.031, respectively). In the logistic regression, both polymorphisms were associated with PAP as well as the SNP-SNP interaction (P < 0.0001). CONCLUSIONS: Polymorphisms in DEFB1 genes were associated with the development of post-treatment persistent apical periodontitis.

Regulatory SNP rs5743417 impairs constitutive expression of human ß-defensin 1 and has high frequency in Africans and Afro-Americans.

The prediction of regulatory single nucleotide polymorphisms (rSNPs) in proximal promoters of disease-related genes could be a useful tool for personalized medicine in both patient stratification and customized therapy. Using our previously reported method of rSNPs prediction (currently a software called SNPClinic v.1.0) as well as with PredictSNP tool, we performed in silico prediction of regulatory SNPs in the antimicrobial peptide human ß-defensin 1 gene in three human cell lines from 1,000 Genomes Project (1kGP), namely A549 (epithelial cell line), HL-60 (neutrophils) and TH 1 (lymphocytes). These predictions were run in a proximal pseudo-promoter comprising all common alleles on each polymorphic site according to the 1,000 Genomes Project data (1kGP: ALL). Plasmid vectors containing either the major or the minor allele of a putative rSNP rs5743417 (categorized as regulatory by SNPClinic and confirmed by PredictSNP) and a non-rSNP negative control were transfected to lung A549 human epithelial cell line. We assessed functionality of rSNPs by qPCR using the Pfaffl method. In A549 cells, minor allele of the SNP rs5743417 G→A showed a significant reduction in gene expression, diminishing DEFB1 transcription by 33% when compared with the G major allele (p-value = .03). SNP rs5743417 minor allele has high frequency in Gambians (8%, 1kGP population: GWD) and Afro-Americans (3.3%, 1kGP population: ASW). This SNP alters three transcription factors binding sites (TFBSs) comprising SREBP2 (sterols and haematopoietic pathways), CREB1 (cAMP, insulin and TNF pathways) and JUND (apoptosis, senescence and stress pathways) in the proximal promoter of DEFB1. Further in silico analysis reveals that this SNP also overlaps with GS1-24F4.2, a lincRNA gene complementary to the X Kell blood group related 5 (XKR5) mRNA. The potential clinical impact of the altered constitutive expression of DEFB1 caused by rSNP rs5743417 in DEFB1-associated diseases as tuberculosis, COPD, asthma, cystic fibrosis and cancer in African and Afro-American populations deserves further research.

Trans-suppression of defense DEFB1 gene in intestinal epithelial cells following Cryptosporidium parvum infection is associated with host delivery of parasite Cdg7_FLc_1000 RNA.

To counteract host immunity, Cryptosporidium parvum has evolved multiple strategies to suppress host antimicrobial defense. One such strategy is to reduce the production of the antimicrobial peptide beta-defensin 1 (DEFB1) by host epithelial cells but the underlying mechanisms remain unclear. Recent studies demonstrate that a panel of parasite RNA transcripts of low protein-coding potential are delivered into infected host cells and may modulate host gene transcription. Using in vitro models of intestinal cryptosporidiosis, in this study, we analyzed the expression profile of host beta-defensin genes in host cells following infection. We found that C. parvum infection caused a significant downregulation of the DEFB1 gene. Interestingly, downregulation of DEFB1 gene was associated with host delivery of Cdg7_FLc_1000 RNA transcript, a C. parvum RNA that has previously demonstrated to be delivered into the nuclei of infected host cells. Knockdown of Cdg7_FLc_1000 in host cells could attenuate the trans-suppression of host DEFB1 gene and decreased the parasite burden. Therefore, our data suggest that trans-suppression of DEFB1 gene in intestinal epithelial cells following C. parvum infection involves host delivery of parasite Cdg7_FLc_1000 RNA, a process that may be relevant to the epithelial defense evasion by C. parvum at the early stage of infection.

LTF and DEFB1 polymorphisms are associated with susceptibility toward chronic periodontitis development.

OBJECTIVES: Chronic periodontitis is a common pathological condition that affects the supporting tissue of the teeth, leading to progressive alveolar bone destruction and teeth loss. The disease is caused by bacteria and derives from an altered host immune and inflammatory response, also involving different factors such as the oral hygiene, smoking, and genetic background. The innate immune response, the first line of host defense, could also play an important role in the susceptibility to chronic periodontitis. In this study, we evaluated the possible association between periodontal disease and seven genetic variations within DEFB1 and LTF genes, encoding for ß-defensins 1 and lactoferrin (two members of oral innate immune system), in an Italian isolated population. SUBJECTS AND METHODS: DEFB1 5'UTR g. -52G>A (rs1799946), g. -44C>G (rs1800972), g. -20G>A (rs11362), 3'UTR c*5G>A (rs1047031), c*87A>G (rs1800971), LTF p.Ala29Thr (rs1126477), and p.Lys47Arg (rs1126478) single nucleotide polymorphisms (SNPs) were analyzed in 155 healthy individuals and 439 chronic periodontitis patients from North-East Italy. RESULTS: Significant associations were found between periodontitis and g. -20G>A (rs11362) and g. -44C>G (rs1800972) SNPs in DEFB1 gene as well as p.Ala29Thr (rs1126477) and p.Lys47Arg (rs1126478) SNPs in LTF gene. DISCUSSION: Our results suggest the involvement of DEFB1 and LTF genetic variations in the susceptibility toward development of periodontitis.

Prediction of the impact of coding missense and nonsense single nucleotide polymorphisms on HD5 and HBD1 antibacterial activity against Escherichia coli.

Defensins confer host defense against microorganisms and are important for human health. Single nucleotide polymorphisms (SNPs) in defensin gene-coding regions could lead to less active variants. Using SNP data available at the dbSNP database and frequency information from the 1000 Genomes Project, two DEFA5 (L26I and R13H) and eight DEFB1 (C35S, K31T, K33R, R29G, V06I, C12Y, Y28* and C05*) missense and nonsense SNPs that are located within mature regions of the coded defensins were retrieved. Such SNPs are rare and population restricted. In order to assess their antibacterial activity against Escherichia coli, two linear regression models were used from a previous work, which models the antibacterial activity as a function of solvation potential energy, using molecular dynamics data. Regarding only the antibacterial predictions, for HD5, no biological differences between wild-type and its variants were observed; while for HBD1, the results suggest that the R29G, K31T, Y28* and C05* variants could be less active than the wild-type one. The data here reported could lead to a substantial improvement in knowledge about the impact of missense SNPs in human defensins and their world distribution. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 633-644, 2016.

Beta defensin-1 gene polymorphisms and susceptibility to atypical squamous cells of undetermined significance lesions in Italian gynecological patients.

The role of the human beta-defensin 1 (hBD-1) in the susceptibility to the onset of the Atypical Squamous Cells of Undetermined Significance (ASCUS) lesion, in the presence or not of HPV infection, is still unknown. In the current study, the three functional single nucleotide polymorphisms (SNPs) -52G > A, -44C > G, and -20G > A at the 5' un-translated region (UTR) of DEFB1 gene, encoding hBD-1, were analyzed in ASCUS lesion gynecological patients and healthy women from the north-east of Italy (Trieste). Cervical samples from 249 European-Caucasian women were collected, screened for HPV and cytologically evaluated; DEFB1 genotyping has been performed by direct sequencing. No significant differences were found for -52G > A, -44C > G, and -20G > A SNPs allele and genotype frequencies between women with and without ASCUS lesions. DEFB1 minor haplotypes were significantly more frequent in ASCUS lesion positive than negative women, associating with an increased risk of this type of lesion. When women were stratified according to HPV infection status, significant differences in the distribution of -52G > A SNP genotype frequencies were found: the presence of the A allele in the homozygous genotype A/A associated with a lower risk of developing ASCUS lesions in HPV negative women. DEFB1 minor haplotypes were also associated with an increased risk of developing ASCUS lesions, being significantly more frequent in HPV negative women with lesions, than without lesions. Although these results highlight the possible involvement of DEFB1, further studies are needed to support the role of DEFB1 in the modulation of the susceptibility to ASCUS lesions.

Spirobenzofuran Mitigates Ochratoxin A-Mediated Intestinal Adverse Effects in Pigs through Regulation of Beta Defensin 1.

Antimicrobial peptides (AMPs) function to extensively suppress various problematic factors and are considered a new alternative for improving livestock health and enhancing immunomodulation. In this study, we explored whether AMP regulation has positive influences on Ochratoxin A (OTA) exposure using a porcine intestinal epithelial cell line (IPEC-J2 cells). We constructed a beta-defensin 1 (DEFB1) expression vector and used it to transfection IPEC-J2 cells to construct AMP overexpression cell lines. The results showed that OTA induced cytotoxicity, decreased cell migration, and increased inflammatory markers mRNA in IPEC-J2 cells. In DEFB1 overexpressing cell lines, OTA-induced reduced cell migration and increased inflammatory markers mRNA were alleviated. Additionally, a natural product capable of inducing DEFB1 expression, which was selected through high-throughput screening, showed significant alleviation of cytotoxicity, cell migration, and inflammatory markers compared to OTA-treated IPEC-J2 cells. Our finding provides novel insights and clues for the porcine industry, which is affected by OTA exposure.

ß-Defensin-1 Regulates Influenza Virus Infection in Human Bronchial Epithelial Cells through the STAT3 Signaling Pathway.

Understanding the host response to influenza A virus (IAV) infection is vital for developing intervention strategies. The primary barriers for invading respiratory pathogens are the respiratory tract epithelial cells and antimicrobial proteins generated by these cells. The antimicrobial peptide, ß-defensin-1, has antiviral activity against both enveloped and non-enveloped viruses. Significant downregulation of ß-defensin1 gene (DEFB1) expression was observed when human bronchial epithelial cells (HBEpCs) were exposed to IAV. HBEpCs overexpressing DEFB1 caused a significant reduction in IAV, that was confirmed by IAV matrix gene analysis, plaque assay, and confocal microscopy. DEFB1 expression after transfection with two micro RNAs (miRNAs), hsa-miR-186-5p and hsa-miR-340-5p, provided evidence that DEFB1 expression could be modulated by these miRNAs and hsa-miR-186-5p had a higher binding efficiency with DEFB1. Overexpression of DEFB1 in IAV-infected HBEpCs led to increased NF-κB expression. In a PCR array analysis of 84 transcription factors, either overexpressing DEFB1 or siRNA silencing of DEFB1 expression significantly modulated the expression of signal transducer and activator of transcription 3 (STAT3). In addition, Ingenuity Pathway Analysis (IPA) integrated with PCR array data showed that the JAK1/STAT3 pathway was significantly altered in cells overexpressing DEFB1, suggesting this to be one of the pathways by which defensin regulates IAV replication in HBEpCs. In conclusion, the reduction in IAV copy number in DEFB1 overexpressing cells suggests that ß-defensin-1 plays a key role in regulating IAV survival through STAT3 and is a potential target for antiviral drug development.

Evaluation of Beta-Defensin 1 and Mannose-Binding Lectin 2 Polymorphisms in Children with Dental Caries Compared to Caries-Free Controls: A Systematic Review and Meta-Analysis.

Background and objective: Some variants in defensin beta 1 (DEFB1) and mannose-binding lectin 2 (MBL2) genes can be associated with oral diseases. Herein, we designed a systematic review and meta-analysis to evaluate the association of DEFB1 (rs11362, rs1799946, and rs1800972) and MBL2 (rs7096206 and rs1800450) polymorphisms with the susceptibility to dental caries (DC) in children. Materials and methods: A systematic literature search was conducted in the PubMed/Medline, Web of Science, Scopus, and Cochrane Library databases until 3 December 2022, without any restrictions. The odds ratio (OR), along with a 95% confidence interval (CI) of the effect sizes, are reported. Analyses including a subgroup analysis, a sensitivity analysis, and funnel plot analyses were conducted. Results: A total of 416 records were identified among the databases, and nine articles were entered into the meta-analysis. A significant relationship was found between the T allele of DEFB1 rs11362 polymorphism and DC susceptibility, and the T allele was related to an elevated risk of DC in children (OR = 1.225; 95%CI: 1.022, 1.469; p = 0.028; I2 = 0%). No other polymorphisms were associated with DC. All articles were of moderate quality. Egger's test in homozygous and dominant models demonstrated a significant publication bias for the association of DEFB1 rs1799946 polymorphism with DC risk. Conclusions: The results demonstrated that the T allele of DEFB1 rs11362 polymorphism had an elevated risk for DC in children. However, there were only few studies that evaluated this association.

Tumor-Infiltrating CD4+ Central Memory T Cells Correlated with Favorable Prognosis in Oral Squamous Cell Carcinoma.

OBJECTIVE: Oral squamous cell carcinoma (OSCC) is the most frequent oral malignancy with a poor prognosis, in which tumor-infiltrating immune cells may play a critical role. Therefore, our study aims to screen potential immune cells and immune-related genes for predicting OSCC prognosis. METHODS: A total of 310 OSCC patients with full transcriptional data and clinical characteristics were extracted from the TCGA database. Then, we obtained their abundance of tumor-infiltrating immune cells on TIMER 2.0 and analyzed them using xCell method. Univariate and multivariate Cox regressions were applied successively to identify the immune cells associated with overall survival of OSCC patients. Furthermore, we screened the prognostic genes that related to the identified immune cells and validated their expressions by immunohistochemistry. RESULTS: CD4+ central memory T (TCM) cell was recognized as the sole independent immune cell correlated with OSCC prognosis (p = 0.0085). A novel nomogram based on CD4+ TCM cell abundance was established for predicting the prognosis of OSCC patients, with calibration plots showing good performance for 1-, 3-, 5-year overall survival. Thirty-four related prognostic genes were screened according to the differential abundance of CD4+ TCM cell infiltration. In immunohistochemistry analysis, DEFB1 showed a significant positive relationship with the density of CD4+ TCM cells (p = 0.0075). CONCLUSION: CD4+ central memory T cell was proposed as an independent prognostic biomarker for OSCC patients. DEFB1 might positively regulate the abundance of tumor-infiltrating CD4+ TCM cells, thus improving OSCC prognosis. Our findings may provide a new insight into better prognosis prediction and precise medicine for OSCC.

Beta-defensin 1 gene polymorphisms at 5' untranslated region are not associated with a susceptibility to recurrent aphthous stomatitis.

OBJECTIVE: The purpose of this study was to evaluate the possible association between two single nucleotide polymorphisms of the ß-defensin 1 gene: -20 G > A and -44 C > G at 5 untranslated region and recurrent aphthous stomatitis in a cohort of Polish patients. DESIGN: One hundred and six patients suffering from recurrent aphthous stomatitis and 96 healthy volunteers were genotyped at ß-defensin 1-20 G > A and -44 C > G using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach. The results were statistically analysed with the difference test between two proportion and chi-square tests with p < 0.05 as a significance level (Dell Statistica data analysis software system, version 13, Dell Inc. 2016). RESULTS: No statistically significant differences between the tested groups were revealed in the genotype distribution for -20 G > A and -44 C > G polymorphisms of the ß-defensin 1 gene. Stratification into carriers and non-carriers of alleles did not unequivocally show the single nucleotide polymorphism recognized as a risk factor for recurrent aphthous stomatitis. However, after gender stratification, statistically significant differences in the distribution of some DEFB1 genotypes were observed. Heterozygotes of G[-20]A and C[-44]G genotypes were found more frequently in males with RAS than in males from the control group. Moreover, a significantly higher rate of carriers of the polymorphic *A[-20] allele was found in males with RAS compared to the controls. CONCLUSIONS: The role of the tested single nucleotide polymorphisms of the ß-defensin 1 gene in the aetiology of recurrent aphthous stomatitis has not been confirmed. Further observations are required to clarify this potential association.

Association of systemic beta-defensin-1 and -20G/A DEFB1 gene polymorphism with Behçet's disease.

BACKGROUND: Behçet's disease (BD) is a multisystem inflammatory disease of unknown etiology. Beta-defensins are antimicrobial peptides involved in epithelial host defense. To explore whether beta-defensins might be involved in BD pathogenesis, we examined plasma human beta-defensin-1 (hBD-1) and DEFB1 -20G/A polymorphism in BD patients. METHODS: This case-control study included 106 BD patients fulfilling the criteria of the International Study Group for BD and 156 controls. The -20G/A genotypes were determined by PCR-RFLP analysis in all participants, and plasma hBD-1 was assessed by ELISA in 77 BD patients and 44 controls, only. Stepwise multiple regression models were applied to determine independent predictors for plasma hBD-1 in BD patients. RESULTS: Distribution of -20G/A genotypes was different between BD patients and controls. Compared to GG genotype, "GA" genotype [OR (95% CI), 3.12 (1.56-6.16); p = .001] and "AA" genotype [2.57 (1.10-5.96); p = .027)] were associated with increased risk for BD. Plasma hBD-1 concentrations were significantly higher in BD patients than controls (9.81 ±â€¯3.52 ng/mL vs. 5.30 ±â€¯3.02 ng/mL; p < .001), and in BD patients with neurological involvement than those without (11.1 ±â€¯4.12 ng/mL vs. 9.19 ±â€¯3.10 ng/mL; p = .040). No variation was noted according to other clinical features, treatment received or -20G/A genotypes. In multivariate analysis, neurological involvement was the only predictor for plasma hBD-1 (ß, 0.274; p = .029). CONCLUSIONS: Findings suggest that hBD-1 and its encoding gene DEFB1 could modulate the risk for BD, especially for BD neurological involvement. Further work is needed for a better understanding of role of hBD-1 and its genetic variants in the pathogenesis of BD.

DEFB1 rs11362 Polymorphism and Risk of Chronic Periodontitis: A Meta-Analysis of Unadjusted and Adjusted Data.

Objective: Chronic periodontitis (CP) is a growing problem that affects the worldwide population, having significant impacts on people's daily lives and economic development. Genetics is an important component in the determination of individual susceptibility to periodontal diseases. Numerous studies have been performed to investigate the association between beta defensin 1 (DEFB1) rs11362 polymorphism and risk of CP, but the results are still inconclusive. Therefore, we conducted this meta-analysis to ascertain whether this variation in DEFB1 is associated with CP susceptibility. Methods: The relevant studies were searched in PubMed and Chinese National Knowledge Infrastructure (CNKI) databases up to January 9, 2018. Two independent authors selected citations and extracted the data from eligible studies. Odds ratios (ORs) with their 95% confidence intervals (95% CIs) were used to assess the strength of the association. Results: Seven case-control studies were included in this meta-analysis. Based on unadjusted data, there was no obvious association between DEFB1 rs11362 polymorphism and CP risk in all genetic models (A vs. G: OR = 0.86, 95%CI = 0.61-1.20; AA vs. GG: OR = 0.83, 95% CI = 00.50-1.39; AG vs. GG: OR = 1.01, 95%CI = 0.73-1.39; AG+AA vs. GG: OR = 0.91, 95% CI = 00.74-1.11; and AA vs. AG+GG: OR = 0.83, 95% CI = 00.57-1.21); the results of adjusted data also showed no significant relationship. Subgroup analyses based on ethnicity, participants' smoking status, HWE in controls and severity of CP all revealed similar results to that of the overall analysis. Sensitivity analysis indicated the results were robust and no evidence of publication bias was found. Conclusions: Our meta-analysis suggests that DEFB1 rs11362 polymorphism may not have an important effect on the risk of CP. Further large-scale and well-designed studies are necessary to validate our conclusion in the future.

Human beta defensin-1 is involved in the susceptibility to adeno-tonsillar hypertrophy.

INTRODUCTION: Innate immunity molecules are known to play a pivotal role in the homeostasis of the oral mucosa, permitting the presence of commensal microflora and, at the same time, providing a first line of defense against pathogens attempting to invade the oral cavity. Tonsils represent the local immune tissue in oral cavity, being able to provide a non-specific response to pathogens; however, in the presence of microbes or foreign materials present in the mouth tonsils could became infected and develop chronic inflammation, thus leading to hypertrophy. The etiology of the disease is multifactorial depending upon environmental and host factors, the latter including molecules of mucosal innate immunity. METHODS: Ninety-five children with adeno-tonsillar hypertrophy subjected to adeno-tonsillectomy were recruited at the pediatric otorhinolaryngology service of the Institute for Maternal and Child Health IRCCS Burlo Garofolo, Trieste (Italy). The specimen discarded from the surgery were used for genomic DNA extraction and genotyping, for mRNA extraction and gene expression analysis, finally the samples were cut and used to prepare slides to perform immunohistochemistry. RESULTS: Functional polymorphisms within DEFB1 gene, encoding the human beta defensin-1 (hBD-1), were analyzed finding association between DEFB1 rare haplotypes and susceptibility to adeno-tonsillar hypertrophy. DEFB1 mRNA expression was detected in the tonsils and the hBD-1 protein was localized at the epithelia of tonsils mainly in the proximity of the basal lamina. CONCLUSION: Our findings lead us to hypothesize an involvement of hBD-1 mediated innate immunity in the modulation of the susceptibility towards adeno-tonsillar hypertrophy development.

Human ß-defensin 1 update: Potential clinical applications of the restless warrior.

Human ß-defensin 1 (hBD-1) is a multifaceted antimicrobial peptide being a tumour suppressor and, depending on call of duty, capable of inducing self-nets and neutrophil extracellular traps (NETs) to capture and/or kill bacteria, participates in inflammatory responses in chronic diseases including hBD-3 upregulation and also capable of up/downregulation in the presence of certain species of Lactobacillus sp. Thus, is regulated by host microbiota. Alleles, genotypes and/or altered gene expression of its coding gene, DEFB1, have been associated with several human diseases/conditions ranging from metabolic/chronic (e.g. cancer), infectious (e.g. tuberculosis, HIV/AIDS), inflammatory (gastrointestinal diseases), male infertility and more recently, neurologic (e.g. depression and Alzheimer) and autoimmune diseases (e.g. vitiligo and systemic lupus erythematosus). The present update focuses on novel DEFB1/hBD-1 properties and biomarker features, its biological function and the pharmaceutical potential uses of antimicrobial peptide elicitors (APEs) or the engineered peptide in the treatment of hBD-1-related human diseases.

Distinct Histone Modifications Modulate DEFB1 Expression in Human Vaginal Keratinocytes in Response to Lactobacillus spp.

Vaginal commensal lactobacilli are considered to contribute significantly to the control of vaginal microbiota by competing with other microflora for adherence to the vaginal epithelium and by producing antimicrobial compounds. However, the molecular mechanisms of symbiotic prokaryotic-eukaryotic communication in the vaginal ecosystem remain poorly understood. Here, we showed that both DNA methylation and histone modifications were associated with expression of the DEFB1 gene, which encodes the antimicrobial peptide human ß-defensin-1, in vaginal keratinocyte VK2/E6E7 cells. We investigated whether exposure to Lactobacillus gasseri and Lactobacillus reuteri would trigger the epigenetic modulation of DEFB1 expression in VK2/E6E7 cells in a bacterial species-dependent manner. While enhanced expression of DEFB1 was observed when VK2/E6E7 cells were exposed to L. gasseri, treatment with L. reuteri resulted in reduced DEFB1 expression. Moreover, L. gasseri stimulated the recruitment of active histone marks and, in contrast, L. reuteri led to the decrease of active histone marks at the DEFB1 promoter. It was remarkable that distinct histone modifications within the same promoter region of DEFB1 were mediated by L. gasseri and L. reuteri. Therefore, our study suggested that one of the underlying mechanisms of DEFB1 expression in the vaginal ecosystem might be associated with the epigenetic crosstalk between individual Lactobacillus spp. and vaginal keratinocytes.

DEFB1 polymorphisms and salivary hBD-1 concentration in Oral Lichen Planus patients and healthy subjects.

OBJECTIVES: The aetiology of Oral Lichen Planus (OLP), a chronic inflammatory disease of oral mucosa, is not yet well understood. Since innate immunity may be hypothesized as involved in the susceptibility to OLP, we studied human beta defensin 1 (hBD-1) an antimicrobial peptide constitutively expressed in the saliva, looking at functional genetic variants possibly able to diminish hBD-1 production an consequently conferring major susceptibility to OLP. DESIGN: We analysed three DEFB1 polymorphisms at 5' UTR, -52G>A (rs1799946), -44C>G (rs1800972), -20G>A (rs11362) and two DEFB1 polymorphisms at 3'UTR, c*5G>A (rs1047031), c*87A>G (rs1800971), with the aim of correlating these genetic variants and hBD-1 salivary level in a group of OLP patients and in healthy subjects. We also evaluated hBD-1 salivary concentrations, using ELISA, in OLP and healthy controls. RESULTS: We compared hBD-1 concentrations in OLP and healthy subjects: hBD-1 concentration was significantly higher in OLP patients respect to control. When considering the correlation between DEFB1 polymorphisms genotypes and hBD-1 expression levels, significant results were obtained for SNPs -52G>A (p=0.03 both in OLP patients and healthy individuals) and -44C>G (p=0.02 in OLP patients). CONCLUSIONS: hBD-1 production was different between OLP and healthy subjects (not age-matched with OLP). DEFB1 gene polymorphisms, -52G>A and -44C>G, correlated with hBD-1 salivary concentrations.

Modulation of Human ß-Defensin-1 Production by Viruses.

While initially identified as a broad-spectrum antimicrobial peptide, constitutively expressed in epithelia, human ß-defensin (hBD)-1 is now recognized to have a more complex pattern of expression of its gene, DEFB1, as well as activities that extend beyond direct antimicrobial. These observations suggest a complex role for hBD-1 in the host defense against viral infections, as evidenced by its expression in cells involved in viral defense, and its gene regulation in response to viral challenge. This regulation is observed both in vitro and in vivo in humans, as well as with the murine homolog, mBD-1. While numerous reviews have summarized the existing literature on ß-defensin gene expression and activity, here we provide a focused review of relevant studies on the virus-mediated regulation of hBD-1 and how this regulation can provide a crucial aspect of the innate immune defense against viral infection.