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1.
J Dev Biol ; 12(2)2024 May 01.
Article in English | MEDLINE | ID: mdl-38804433

ABSTRACT

BACKGROUND: Little is known about morphogenetic changes in the umbilical cord during the maturation process. Extracellular matrix remodeling, angiogenesis, progenitor activity, and immunomodulation are represented by specific markers; therefore, the aim of this study was to determine the expression of matrix metalloproteinase-2 (MMP2), tissue inhibitor of metalloproteinases-2 (TIMP2), CD34, vascular endothelial growth factor (VEGF), and human ß-defensin 2 (HBD2) in preterm and full-term human umbilical cord tissue. METHODS: Samples of umbilical cord tissue were obtained from 17 patients and divided into two groups: very preterm and moderate preterm birth umbilical cords; late preterm birth and full-term birth umbilical cords. Routine histology examination was conducted. Marker-positive cells were detected using the immunohistochemistry method. The number of positive structures was counted semi-quantitatively using microscopy. Statistical analysis was carried out using the SPSS Statistics 29 program. RESULTS: Extraembryonic mesenchyme cells are the most active cell producers, expressing MMP2, TIMP2, VEGF, and HBD2 at notable levels in preterm and full-term umbilical cord tissue. Statistically significant differences in the expression of CD34, MMP2, and TIMP2 between the two patient groups were found. The expression of VEGF was similar in both patient groups, with the highest number of VEGF-positive cells seen in the extraembryonic mesenchyme. The expression of HBD2 was the highest in the extraembryonic mesenchyme and the amniotic epithelium, where mostly moderate numbers of HBD2-positive cells were detected. CONCLUSIONS: Extracellular matrix remodeling in preterm and term umbilical cords is strongly regulated, and tissue factors MMP2 and TIMP2 take part in this process. The expression of VEGF is not affected by the umbilical cord's age; however, individual patient factors can affect the production of VEGF. Numerous CD34-positive cells in the endothelium of the umbilical arteries suggest a significant role of progenitor cells in very preterm and moderate preterm birth umbilical cords. Antimicrobial activity provided by HBD2 is essential and constant in preterm and full-term umbilical cords.

2.
Cell Rep Med ; 5(3): 101447, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38442713

ABSTRACT

There is an unmet clinical need for a non-invasive and cost-effective test for oral squamous cell carcinoma (OSCC) that informs clinicians when a biopsy is warranted. Human beta-defensin 3 (hBD-3), an epithelial cell-derived anti-microbial peptide, is pro-tumorigenic and overexpressed in early-stage OSCC compared to hBD-2. We validate this expression dichotomy in carcinoma in situ and OSCC lesions using immunofluorescence microscopy and flow cytometry. The proportion of hBD-3/hBD-2 levels in non-invasively collected lesional cells compared to contralateral normal cells, obtained by ELISA, generates the beta-defensin index (BDI). Proof-of-principle and blinded discovery studies demonstrate that BDI discriminates OSCC from benign lesions. A multi-center validation study shows sensitivity and specificity values of 98.2% (95% confidence interval [CI] 90.3-99.9) and 82.6% (95% CI 68.6-92.2), respectively. A proof-of-principle study shows that BDI is adaptable to a point-of-care assay using microfluidics. We propose that BDI may fulfill a major unmet need in low-socioeconomic countries where pathology services are lacking.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , beta-Defensins , Humans , Mouth Neoplasms/diagnosis , Mouth Neoplasms/pathology , beta-Defensins/analysis , beta-Defensins/metabolism , Carcinoma, Squamous Cell/diagnosis , Carcinoma, Squamous Cell/pathology , Biomarkers , Squamous Cell Carcinoma of Head and Neck
3.
Int J Mol Sci ; 24(18)2023 Sep 09.
Article in English | MEDLINE | ID: mdl-37762180

ABSTRACT

Obesity and metabolic comorbidities are associated with gut permeability. While high-fructose and Western-style diet (WSD) disrupt intestinal barrier function, oral administration of human α-defensin 5 (HD5) and ß-defensin 2 (hBD2) is believed to improve intestinal integrity and metabolic disorders. Eighty-four male C57BL/6J mice were fed a WSD or a control diet (CD) ± fructose (F) for 18 weeks. In week 13, mice were randomly divided into three intervention groups, receiving defensin fragment HD51-9, full-length hBD2, or bovine serum albumin (BSA)-control for six weeks. Subsequently, parameters of hepatic steatosis, glucose metabolism, and gut barrier function were assessed. WSDF increased body weight and hepatic steatosis (p < 0.01) compared to CD-fed mice, whereas peptide intervention decreased liver fat (p < 0.05) and number of hepatic lipid droplets (p < 0.01) compared to BSA-control. In addition, both peptides attenuated glucose intolerance by reducing blood glucose curves in WSDF-fed mice. Evaluation of gut barrier function revealed that HD51-9 and hBD2 improve intestinal integrity by upregulating tight junction and mucin expression. Moreover, peptide treatment restored ileal host defense peptides (HDP) expression, likely by modulating the Wnt, Myd88, p38, and Jak/STAT pathways. These findings strongly suggest that α- and ß-defensin treatment improve hepatic steatosis, glucose metabolism, and gut barrier function.

4.
Antioxidants (Basel) ; 12(8)2023 Aug 03.
Article in English | MEDLINE | ID: mdl-37627545

ABSTRACT

The innate immune system is the first line of defense of the body composed of anatomical barriers, such as skin and mucosa, as well as effector cells, antimicrobial peptides, soluble mediators, and cell receptors able to detect and destroy viruses and bacteria and to sense trauma and wounds to initiate repair. The human ß-defensins belong to a family of antimicrobial small cationic peptides produced by epithelial cells, and show immunomodulatory and pro-healing activities. Laser biostimulation is a therapy widely used to contrast microbial infection and to accelerate wound healing through biological mechanisms that include the creation of oxidative stress. In this paper, we explored laser biostimulation's ability to modulate the production of two ß-defensins, hBD-1 and hBD-2, in human keratinocytes and whether this modulation was, at least in part, oxidative-stress-dependent. Human spontaneously immortalized keratinocytes (HaCaT) were stimulated using laser irradiation at a 980 nm wavelength, setting the power output to 1 W (649.35 mW/cm2) in the continuous mode. Cells were irradiated for 0 (negative control), 5, 10, 25 and 50 s, corresponding to an energy stimulation of 0, 5, 10, 25 and 50 J. Positive control cells were treated with lipopolysaccharide (LPS, 200 ng/mL). After 6 and 24 h of treatment, the cell conditioned medium was collected and analyzed via ELISA assay for the production of hBD-1 and hBD-2. In another set of experiments, HaCaT were pre-incubated for 45 min with antioxidant drugs-vitamin C (Vit. C, 100 µM), sodium azide (NaN3, 1 mM); ω-nitro-L-arginine methyl ester (L-NAME, 10 mM) and sodium pyruvate (NaPyr, 100 µM)-and then biostimulated for 0 or 50 s. After 6 h, the conditioned medium was collected and used for the ELISA analysis. The hBD-1 and hBD-2 production by HaCaT was significantly increased by single laser biostimulation after 6 h in an energy-dependent fashion compared to basal levels, and both reached production levels induced by LPS. After 24 h, only hBD-2 production induced by laser biostimulation was further increased, while the basal and stimulated hBD-1 levels were comparable. Pre-incubation with antioxidative drugs was able to completely abrogate the laser-induced production of both hBD-1 and hBD-2 after 6 h, with the exception of hBD-1 production in samples stimulated after NaN3 pre-incubation. A single laser biostimulation induced the oxidative-stress-dependent production of both hBD-1 and hBD-2 in human keratinocytes. In particular, the pro-healing hBD-2 level was almost three times higher than the baseline level and lasted for 24 h. These findings increase our knowledge about the positive effects of laser biostimulation on wound healing.

5.
Diagnostics (Basel) ; 13(11)2023 May 28.
Article in English | MEDLINE | ID: mdl-37296737

ABSTRACT

BACKGROUND: Defensins are natural antimicrobial peptides that the human body secretes to protect itself from an infection. Thus, they are ideal molecules to serve as biomarkers for infection. This study was conducted to evaluate the levels of human ß-defensins in patients with inflammation. METHODS: CRP, hBD2 and procalcitonin were measured in 423 sera of 114 patients with inflammation and healthy individuals using nephelometry and commercial ELISA assays. RESULTS: Levels of hBD2 in the serum of patients with an infection were markedly elevated compared to those of hBD2 in patients with inflammation of non-infectious etiology (p < 0.0001, t = 10.17) and healthy individuals. ROC analysis demonstrated that hBD2 showed the highest detection performance for infection (AUC 0.897; p < 0.001) followed by PCT (AUC 0.576; p = ns) and CRP (AUC 0.517; p = ns). In addition, analysis of hBD2 and CRP in patients' sera collected at different time points showed that hBD2 levels could help differentiate inflammation of infectious and non-infectious etiology during the first 5 days of hospitalization, while CRP levels could not. CONCLUSIONS: hBD2 has the potential to serve as a diagnostic biomarker for infection. In addition, the levels of hBD2 may reflect the efficacy of antibiotic treatment.

6.
Protein J ; 42(4): 399-407, 2023 08.
Article in English | MEDLINE | ID: mdl-37291459

ABSTRACT

COVID-19 is a disease that have affected the entire world, and it continues to spread with new variants. A patient's innate immune system plays a critical role in the mild and severe transition of COVID-19. Antimicrobial peptides (AMPs), which are important components of the innate immune system, are potential molecules to fight pathogenic bacteria, fungi, and viruses. Human ß-defensin 2 (hBD-2), a 41-amino-acid antimicrobial peptide, is one of the defensins inducibly expressed in the skin, lungs, and trachea in humans. In this study, it was aimed to investigate the interaction of hBD-2 produced recombinantly in Pichia pastoris with the human angiotensin-converting enzyme 2 (ACE-2) under in vitro conditions. First, hBD-2 was cloned in P. pastoris X-33 via the pPICZαA vector, a yeast expression platform, and its expression was confirmed by SDS-PAGE, western blotting, and qRT-PCR. Then, the interaction between recombinant hBD-2 and ACE-2 proteins was revealed by a pull-down assay. In light of these preliminary experiments, we suggest that the recombinantly produced hBD-2 may be protective against SARS-CoV-2 and be used as a supplement in treatment. However, current findings need to be supported by cell culture studies, toxicity analyses, and in vivo experiments.


Subject(s)
COVID-19 , beta-Defensins , Humans , beta-Defensins/genetics , beta-Defensins/pharmacology , beta-Defensins/metabolism , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/genetics , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Pichia/genetics , Pichia/metabolism
7.
BMC Pulm Med ; 23(1): 106, 2023 Mar 31.
Article in English | MEDLINE | ID: mdl-37003996

ABSTRACT

RATIONALE: Chronic obstructive pulmonary disease (COPD) is a complicated chronic inflammatory disease. It is important to investigate the characteristics of acute exacerbation of COPD to develop new therapeutic strategies. OBJECTIVE: This study aimed to determine the relationship between the human beta-defensin-2 (hBD-2) levels and aggravation of COPD. METHODS: We detected the sputum hBD-2 level of 254 patients from Guangzhou, China, for 2 years. The study participants were categorized into the COPD group (n = 203, GOLD 0-4) and the control group (n = 51, 40-79 years old). At baseline, 12th month, and 24th month, we detected the sputum hBD-2 level and levels of cytokines, such as CXCL10, CXCL11, and IFN. RESULTS: At baseline, there were no significant differences in the sputum and serum hBD-2 levels between the patients and the controls. However, the sputum hBD-2 levels of patients who had at least one symptom aggravation over the next 2 years were significantly lower than those of patients without any exacerbations (1130.9 ± 858.4 pg/mL vs. 2103.7 ± 1294.2 pg/mL, respectively; p = 0.001). Nevertheless, there were no statistically significant differences in the sputum hBD-2 levels between patients (no aggravation history) and controls (2084.9 ± 1317.6 pg/mL vs. 2152.5 ± 1251.6 pg/mL, respectively; p = 0.626). We used a logistic regression model to assess the relationship between aggravation and sputum hBD-2 levels. Interestingly, we found that low hBD-2 level (< 1000 pg/mL) was significantly associated with exacerbations. Specifically, patients with low hBD-2 levels were more likely to experience exacerbations in the next 12 months (0.333 vs. 0.117; p = 0.001). Moreover, we compared the hBD-2 levels between controls and patients with GOLD 3-4 and found that participants with bacteria (+) and/or viruses (+) had an association between hBD-2 level and disease severity (p = 0.02). CONCLUSION: Patients at risk of exacerbations are more likely to have lower sputum hBD-2 levels. These results have important implications for future therapies for COPD.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Viruses , beta-Defensins , Humans , Adult , Middle Aged , Aged , Sputum/microbiology , beta-Defensins/therapeutic use , Cytokines
8.
Front Immunol ; 13: 1008463, 2022.
Article in English | MEDLINE | ID: mdl-36569842

ABSTRACT

Background: A deep understanding of the causes of liability to SARS-CoV-2 is essential to develop new diagnostic tests and therapeutics against this serious virus in order to overcome this pandemic completely. In the light of the discovered role of antimicrobial peptides [such as human b-defensin-2 (hBD-2) and cathelicidin LL-37] in the defense against SARS-CoV-2, it became important to identify the damaging missense mutations in the genes of these molecules and study their role in the pathogenesis of COVID-19. Methods: We conducted a comprehensive analysis with multiple in silico approaches to identify the damaging missense SNPs for hBD-2 and LL-37; moreover, we applied docking methods and molecular dynamics analysis to study the impact of the filtered mutations. Results: The comprehensive analysis reveals the presence of three damaging SNPs in hBD-2; these SNPs were predicted to decrease the stability of hBD-2 with a damaging impact on hBD-2 structure as well. G51D and C53G mutations were located in highly conserved positions and were associated with differences in the secondary structures of hBD-2. Docking-coupled molecular dynamics simulation analysis revealed compromised binding affinity for hBD-2 SNPs towards the SARS-CoV-2 spike domain. Different protein-protein binding profiles for hBD-2 SNPs, in relation to their native form, were guided through residue-wise levels and differential adopted conformation/orientation. Conclusions: The presented model paves the way for identifying patients prone to COVID-19 in a way that would guide the personalization of both the diagnostic and management protocols for this serious disease.


Subject(s)
COVID-19 , beta-Defensins , Humans , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Antimicrobial Cationic Peptides/metabolism , beta-Defensins/genetics , beta-Defensins/metabolism , COVID-19/genetics , Cathelicidins
9.
Front Cell Infect Microbiol ; 12: 1009415, 2022.
Article in English | MEDLINE | ID: mdl-36310877

ABSTRACT

Escherichia coli is one of the commensal species most represented in the intestinal microbiota. However, there are some strains that can acquire new virulence factors that enable them to adapt to new intestinal niches. These include enteroinvasive E. coli (EIEC) that is responsible for the bacillary dysentery that causes severe diarrheal symptoms in both children and adults. Due to the increasing onset of antibiotic resistance phenomena, scientific research is focused on the study of other therapeutic approaches for the treatment of bacterial infections. A promising alternative could be represented by antimicrobial peptides (AMPs), that have received widespread attention due to their broad antimicrobial spectrum and low incidence of bacterial resistance. AMPs modulate the immune defenses of the host and regulate the composition of microbiota and the renewal of the intestinal epithelium. With the aim to investigate an alternative therapeutic approach, especially in the case of antibiotic resistance, in this work we created a line of intestinal epithelial cells able to express high concentrations of AMP human ß-defensin-2 (HBD-2) in order to test its ability to interfere with the pathogenicity mechanisms of EIEC. The results showed that HBD-2 is able to significantly reduce the expression of the proinflammatory cytokines by intestinal epithelial cells, the invasiveness ability of EIEC and the expression of invasion-associated genes.


Subject(s)
Escherichia coli , beta-Defensins , Child , Humans , Antimicrobial Peptides , beta-Defensins/pharmacology , Caco-2 Cells , Diarrhea/microbiology , Escherichia coli/genetics , Virulence Factors/genetics
10.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-940429

ABSTRACT

ObjectiveTo observe the clinical efficacy of Maxingshigantang enema in the treatment of infant viral pneumonia by comparing related indicators, and comprehensively evaluate the effect of traditional Chinese medicine (TCM) enema on the intestinal microenvironment. MethodSixty infants with viral pneumonia were selected and randomly divided into 3 groups. The dosage of enema drugs in high- (0.117 g·mL-1) and low-concentration (0.07 g·mL-1) TCM enema groups was same (3.5 g per time), and the control group received normal saline enema, once a day for 7 days. Finally, the curative effect, total symptom score, salivary secretory immunoglobulin A (sIgA), human beta defensin 2 (hBD2) and fecal calprotectin (CALP) of each group were statistically analyzed by SPSS 21.0, and the clinical efficacy of TCM enema in treating children with pneumonia and asthma was comprehensively evaluated. ResultThe curative effect of high-concentration TCM enema group (total effective rate 100%, χ2=7.059) was equivalent to that of low-concentration TCM enema group (total effective rate 95%, χ2=4.329), higher than that of control group (total effective rate 70%) (P<0.017). After treatment, compared with control group and low-concentration TCM enema group, high-concentration TCM enema group had higher total symptom score of children (P<0.05, P<0.01). The proportion of coccobacillus was reduced in three groups, with high- and low-concentration TCM enema groups lower than control group (P<0.05). The salivary sIgA concentration was increased in three groups (P<0.05), with high-concentration TCM enema group higher than the other groups (P<0.01). The hBD2 concentration was decreased in three groups, with high- and low-concentration TCM enema groups lower than control group (P<0.05). The three groups reduced the fecal CALP concentration, and high-concentration TCM enema group had the highest reduction, followed by low-concentration TCM enema group (P<0.01). ConclusionTCM enema outweighs western medicine in improving clinical symptoms, intestinal flora, and mucosal immune function, and reducing inflammation in children, and the high-concentration TCM enema group has better curative effect. Therefore, with easiness to operate, high compliance, and significant therapeutic effect, TCM enema is worthy of clinical promotion.

11.
Cells ; 10(11)2021 11 03.
Article in English | MEDLINE | ID: mdl-34831214

ABSTRACT

Studies described so far suggest that human ß-defensin 2 is an important protein of innate immune response which provides protection for the human organism against invading pathogens of bacterial, viral, fungal, as well as parasitical origin. Its pivotal role in enhancing immunity was proved in infants. It may also be considered a marker of inflammation. Its therapeutic administration has been suggested for maintenance of the balance of systemic homeostasis based on the appropriate composition of the microbiota. It has been suggested that it may be an important therapeutic tool for modulating the response of the immune system in many inflammatory diseases, offering new treatment modalities. For this reason, its properties and role in the human body discussed in this review should be studied in more detail.


Subject(s)
Immunity , beta-Defensins/metabolism , Biomarkers/metabolism , Disease , Epithelium/metabolism , Humans , Organ Specificity , beta-Defensins/genetics
12.
Front Microbiol ; 12: 697232, 2021.
Article in English | MEDLINE | ID: mdl-34276631

ABSTRACT

Neisseria meningitidis is a gram-negative bacterium that often asymptomatically colonizes the human nasopharyngeal tract. These bacteria cross the epithelial barrier can cause life-threatening sepsis and/or meningitis. Antimicrobial peptides are one of the first lines of defense against invading bacterial pathogens. Human beta-defensin 2 (hBD2) is an antimicrobial peptide with broad antibacterial activity, although its mechanism of action is poorly understood. Here, we investigated the effect of hBD2 on N. meningitidis. We showed that hBD2 binds to and kills actively growing meningococcal cells. The lethal effect was evident after 2 h incubation with the peptide, which suggests a slow killing mechanism. Further, the membrane integrity was not changed during hBD2 treatment. Incubation with lethal doses of hBD2 decreased the presence of diplococci; the number and size of bacterial microcolonies/aggregates remained constant, indicating that planktonic bacteria may be more susceptible to the peptide. Meningococcal DNA bound hBD2 in mobility shift assays and inhibited the lethal effect of hBD2 in a dose-dependent manner both in suspension and biofilms, supporting the interaction between hBD2 and DNA. Taken together, the ability of meningococcal DNA to bind hBD2 opens the possibility that extracellular DNA due to bacterial lysis may be a means of N. meningitidis to evade immune defenses.

13.
ACS Infect Dis ; 7(8): 2068-2072, 2021 08 13.
Article in English | MEDLINE | ID: mdl-33779133

ABSTRACT

Antibacterial activity of silver nanoparticles is often associated with toxicity to the host. We here report that noncytotoxic doses of silver nanoparticles coated with zinc oxide, Ag@ZnO, can stimulate proliferation and migration of human keratinocytes, HaCaT, with increased expression of Ki67 and vinculin at the leading edge of wounds. Interestingly, Ag@ZnO stimulates keratinocytes to produce the antimicrobial peptides hBD2 and RNase7, promoting antibacterial activity against both extracellular and intracellular Staphylococcus aureus isolated from wounds. Overall, these results suggest that Ag@ZnO has the potential to significantly improve treatment outcomes in clearing wound infection.


Subject(s)
Metal Nanoparticles , Zinc Oxide , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Humans , Keratinocytes , Pore Forming Cytotoxic Proteins , Silver
14.
Front Immunol ; 12: 636061, 2021.
Article in English | MEDLINE | ID: mdl-33717182

ABSTRACT

Asthma and allergies are complex, chronic inflammatory diseases in which genetic and environmental factors are crucial. Protection against asthma and allergy development in the context of farming environment is established by early animal contact, unpasteurized milk consumption and gut microbiota maturation. The human ß-defensin 2 (hBD-2) is a host defense peptide present almost exclusively in epithelial tissues, with pronounced immunomodulatory properties, which has recently been shown to ameliorate asthma and IBD in animal models. We hypothesized that adequate hBD-2 secretion plays a role in the protection against asthma and allergy development and that genetic variations in the complex gene locus coding for hBD-2 may be a risk factor for developing these diseases, if as a consequence, hBD-2 is insufficiently produced. We used MALDI-TOF MS genotyping, sequencing and a RFLP assay to study the genetic variation including mutations, polymorphisms and copy number variations in the locus harboring both genes coding for hBD-2 (DEFB4A and DEFB4B). We administered hBD-2 orally in a mouse model of house dust mite (HDM)-asthma before allergy challenge to explore its prophylactic potential, thereby mimicking a protective farm effect. Despite the high complexity of the region harboring DEFB4A and DEFB4B we identified numerous genetic variants to be associated with asthma and allergy in the GABRIELA Ulm population of 1,238 children living in rural areas, including rare mutations, polymorphisms and a lack of the DEFB4A. Furthermore, we found that prophylactic oral administration of hBD-2 significantly curbed lung resistance and pulmonary inflammation in our HDM mouse model. These data indicate that inadequate genetic capacity for hBD-2 is associated with increased asthma and allergy risk while adequate and early hBD-2 administration (in a mouse model) prevents atopic asthma. This suggests that hBD-2 could be involved in the protective farm effect and may be an excellent candidate to confer protection against asthma development.


Subject(s)
Anti-Asthmatic Agents/pharmacology , Asthma/genetics , Asthma/prevention & control , Hypersensitivity/genetics , Hypersensitivity/prevention & control , Lung/drug effects , Mutation , beta-Defensins/genetics , beta-Defensins/pharmacology , Animals , Asthma/immunology , Asthma/metabolism , Bronchoconstriction/drug effects , Case-Control Studies , Child , Cytokines/metabolism , DNA Copy Number Variations , Disease Models, Animal , Female , Gene Dosage , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Hypersensitivity/immunology , Hypersensitivity/metabolism , Inflammation Mediators/metabolism , Lung/immunology , Lung/metabolism , Lung/physiopathology , Male , Mice, Inbred BALB C , Phenotype , Polymorphism, Single Nucleotide
15.
bioRxiv ; 2021 Jan 07.
Article in English | MEDLINE | ID: mdl-33442698

ABSTRACT

New approaches to complement vaccination are needed to combat the spread of SARS-CoV-2 and stop COVID-19 related deaths and long-term medical complications. Human beta defensin 2 (hBD-2) is a naturally occurring epithelial cell derived host defense peptide that has antiviral properties. Our comprehensive in-silico studies demonstrate that hBD-2 binds the site on the CoV-2-RBD that docks with the ACE2 receptor. Biophysical and biochemical assays confirm that hBD-2 indeed binds to the CoV-2-receptor binding domain (RBD) (KD ~ 300 nM), preventing it from binding to ACE2 expressing cells. Importantly, hBD-2 shows specificity by blocking CoV-2/spike pseudoviral infection, but not VSV-G mediated infection, of ACE2 expressing human cells with an IC50 of 2.4± 0.1 µM. These promising findings offer opportunities to develop hBD-2 and/or its derivatives and mimetics to safely and effectively use as novel agents to prevent SARS-CoV-2 infection.

16.
Article in English | MEDLINE | ID: mdl-33468461

ABSTRACT

Antimicrobial peptides (AMPs) play an important role in the defense against pathogens by targeting and killing invading microbes. Some pathogenic bacteria have been shown to negatively regulate AMP expression, while several commensals may induce AMP expression. The expression of certain AMPs, such as human beta-defensin 2 (hBD2), can be induced via nuclear factor NF-κB, which, in turn, is negatively controlled by tumor necrosis factor alpha-induced protein 3 (TNFAIP3, or A20). In this work, we examined the expression of hBD1 and hBD2 during coincubation of pharyngeal epithelial cells with pathogenic Neisseria meningitidis and commensal lactobacilli. The Lactobacillus strains induced hBD2 expression in human pharyngeal cells, while the pathogen N. meningitidis did not. In coincubation experiments, meningococci were able to dampen the AMP expression induced by lactobacilli. We found that N. meningitidis induced the NF-κB inhibitor A20. Further, RNA silencing of A20 resulted in increased hBD2 expression after meningococcal infection. Since it is known that induction of A20 reduces NF-κB activity and thus hBD2 levels, meningococcal-mediated A20 induction could be a way for the pathogen to dampen AMP expression. Finally, treatment of N. meningitidis and lactobacilli with synthetic hBD2 reduced N. meningitidis viability more efficiently than Lactobacillus reuteri, explaining why maintaining low AMP levels is important for the survival of the pathogen.


Subject(s)
Neisseria meningitidis , beta-Defensins , Epithelial Cells , Humans , Lactobacillus , NF-kappa B/genetics , Neisseria meningitidis/genetics , beta-Defensins/genetics
17.
Viral Immunol ; 34(2): 96-111, 2021 03.
Article in English | MEDLINE | ID: mdl-33370550

ABSTRACT

Immunization with hepatitis B vaccine is an effective measure for prevention and control of hepatitis B Virus (HBV) infection. Although lots of efforts to improve the effect of hepatitis B vaccine have been made, the function of human beta defensin 2 (hBD2) on hepatitis B vaccine keeps unclear. In this article, we report that hBD2 not only promoted the activation and maturation of immature dendritic cells (iDCs) by increasing MHC II and CD86 expression, but it also significantly upregulated the mRNA level of IL-6 and IL-12B in mouse bone marrow-derived dendritic cells. The serum concentrations of IFN-γ in mice stimulated with 300 ng hBD2 increased from 25.21 to 42.04 pg/mL, with a time extension from 4 to 12 h post-injection. During the process of three times immunization (1, 14, 28 days) with 3 µg hepatitis B vaccine combined with or without 300 ng hBD2 with a 2 week interval in BALB/c mice, the antibody against HBsAg (HBsAb) concentration in serum at every time point of observation in the combined group was statistically higher than the hepatitis B vaccine group. The serum concentration of IgG2a subclass HBsAb on the 14th day post last injection in the combined group was significantly higher than the hepatitis B vaccine group. Further, the splenic cells from the mice treated with both hBD2 and hepatitis B vaccine possessed a greater ability to produce a surface antigen of hepatitis B virus (HBsAg) specific IFN-γ than those treated with hepatitis B vaccine alone. The percentages of CD3+/CD4+ T cells and CD3+/CD8+ T lymphocytes in spleens from the mice treated with 300 ng hBD2 were statistically higher than the phosphate buffered saline group. These data suggest that hBD2 improves iDC maturation and the immune efficiency of hepatitis B vaccine in BALB/c mice.


Subject(s)
Hepatitis B , beta-Defensins , Animals , Hepatitis B/prevention & control , Hepatitis B Antibodies , Hepatitis B Surface Antigens/genetics , Hepatitis B Vaccines , Hepatitis B virus , Humans , Immunity , Mice , Mice, Inbred BALB C , Recombinant Proteins/immunology , Recombinant Proteins/therapeutic use , beta-Defensins/immunology , beta-Defensins/therapeutic use
18.
Article in English | MEDLINE | ID: mdl-32411614

ABSTRACT

Low body mass index (BMI) is a risk factor for progression from latent Mycobacterium tuberculosis infection to active tuberculosis (TB) disease. Anti-microbial peptides (AMPs) are multifunctional molecules that play a crucial role in the mammalian host innate defense mechanism. AMPs have been shown to have an important role in host immunity to TB infection. The association of antimicrobial peptides with low BMI-latent tuberculosis (LTBI) co-morbidity has not been explored. To study the association of AMPs with LTBI-BMI, we examined the systemic, baseline, and mycobacterial antigen stimulated levels of human neutrophil peptides 1-3, (HNP1-3), granulysin, human beta defensin-2 (HBD-2), and cathelicidin (LL-37) in individuals with LTBI and low BMI (LBMI) and compared them with individuals with LTBI and normal BMI (NBMI). LBMI was characterized by diminished systemic levels of HNP1-3, granulysin, HBD-2 and cathelicidin in comparison with NBMI. Similarly, LBMI was also characterized by diminished unstimulated levels of HNP1-3 and granulysin and diminished mycobacterial antigen stimulated levels of HNP1-3, granulysin, and HBD-2. In addition, certain AMPs exhibited a positive correlation with BMI. Our data, therefore, demonstrates that coexistent LBMI in LTBI is characterized by the diminished levels of HNP1-3, granulysin, HBD-2, and cathelicidin, thereby potentially increasing the risk of progression to active TB.


Subject(s)
Latent Tuberculosis , Mycobacterium tuberculosis , Tuberculosis , Body Mass Index , Humans , Morbidity , Tuberculosis/epidemiology
19.
Cureus ; 12(2): e6905, 2020 Feb 06.
Article in English | MEDLINE | ID: mdl-32064220

ABSTRACT

Introduction Sudharshan kriya pranayama (SKP) is a form of yoga that reduces inflammation and contributes to general health. Very few prior studies have examined the role of pranayama on oral health. We evaluated the clinical status and inflammatory biomarkers in patients with chronic periodontitis before and after SKP. Materials and methods Ninety male subjects were considered for the study and divided into three groups: subjects with a healthy periodontium (Group1), subjects with chronic gingivitis (Group2), and subjects with chronic periodontitis (Group3). The clinical parameters included plaque index (PI), gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL), and salivary markers human beta-defensin-2(HBD-2), peroxisome proliferator-activated receptor gamma (PPAR-γ), and nuclear factor-kappa B (NF-κB). These parameters and markers were evaluated before and after 90 days of SKP. The data obtained were statistically evaluated by McNemar's test, paired sample t-test, and one-way analysis of variance. Results There was a significant improvement in PI in all three groups. GI showed an improvement in Groups 2 and 3. PPD and CAL also showed an improvement in Group 3. HBD-2 and NF-κB decreased with SKP, whereas PPAR-γ expression increased after the intervention. In Groups 2 and 3 with the decrease in GI, there was a corresponding decrease in HBD-2. In Group 3 with an improvement in PPD and CAL, there was an improvement in PPAR-γ expression. Conclusions The results show that SKP can significantly decrease periodontal inflammation and improve periodontal status. It also effectively improves the expression of PPAR-γ, thereby decreasing salivary levels of HBD-2 and NF-κB, respectively. Based on our results, pranayama can be an effective adjunct in maintaining oral health.

20.
J Clin Periodontol ; 47(3): 309-318, 2020 03.
Article in English | MEDLINE | ID: mdl-31799742

ABSTRACT

AIM: To profile gingival tissue levels of human beta-defensin (hBD)-2 and hBD-3 in relation to gingival inflammation, Th17-related cytokine concentrations, Porphyromonas gingivalis counts, and gingipain and total protease activities. MATERIALS AND METHODS: Gingival tissue and subgingival plaque samples were collected from 21 periodontitis patients including 48 periodontal pocket sites with marginal, mild, or moderate to severe inflammation. hBD levels were determined by immunodetection, P. gingivalis counts with real-time polymerase chain reaction, protease activities with fluorogenic substrates, and cytokine concentrations with Luminex technique. Data were statistically analysed using Kruskal-Wallis and Mann-Whitney U tests and Spearman correlation coefficients. RESULTS: Subgingival plaque counts of P. gingivalis (p = .001) and gingipain activity (p < .001), as well as interleukin (IL)-1ß (p = .012), IL-10 (p = .024), IL-17A (p = .002), IL-17F (p = .006), and IL-23 (p = .036) concentrations were elevated in severely inflamed sites, whereas no change was observed in hBD-2 and hBD-3 levels. Negative correlations were found between protease activity and hBD-2 (p = .033) and hBD-3(p = .003) levels. CONCLUSIONS: Shift in gingival inflammation from marginal to mild stage is related to elevations in subgingival plaque P. gingivalis counts and gingipain activity, but not to tissue hBD levels. Negative correlations between hBDs and total protease activity suggest the degradation of these antimicrobial peptides in progressed inflammation.


Subject(s)
beta-Defensins , Gingiva , Humans , Inflammation , Periodontal Pocket , Porphyromonas gingivalis
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