Protective Role of NS1-Specific Antibodies in the Immune Response to Dengue Virus through Antibody-Dependent Cellular Cytotoxicity.

BACKGROUND: Dengue virus (DENV) non-structural protein 1 (NS1) has multiple functions within infected cells, on the cell surface, and in secreted form, and is highly immunogenic. Immunity from previous DENV infections is known to exert both positive and negative effects on subsequent DENV infections, but the contribution of NS1-specific antibodies to these effects is incompletely understood. METHODS: We investigated the functions of NS1-specific antibodies and their significance in DENV infection. We analyzed plasma samples collected in a prospective cohort study prior to symptomatic or subclinical secondary DENV infection. We measured binding to purified recombinant NS1 protein and to NS1-expressing CEM cells, antibody-mediated NK cell activation by plate-bound NS1 protein, and antibody-dependent cellular cytotoxicity (ADCC) of NS1-expressing target cells. RESULTS: We found that antibody responses to NS1 were highly serotype-cross-reactive and that subjects who experienced subclinical DENV infection had significantly higher antibody responses to NS1 in pre-infection plasma than subjects who experienced symptomatic infection. We observed strong positive correlations between antibody binding and NK activation. CONCLUSIONS: These findings demonstrate the involvement of NS1-specific antibodies in ADCC and provide evidence for a protective effect of NS1-specific antibodies in secondary DENV infection.

Celiac disease seroprevalence in patients with infertility. A case-control study.

BACKGROUND: Although most patients with celiac disease (CD) have digestive manifestations, in some of them they may be of extraintestinal (atypical) nature, such as chronic anemia, ataxia, and fertility disorders. OBJECTIVE: To determine the prevalence of CD-related antibodies in Mexican women with fertility disorders. MATERIAL AND METHODS: Case-control study of women who attended evaluation for fertility disorders in a specialized center. h-tTG-IgA, gliadin IgA II and gliadin IgG II were quantified; titers > 30 IU were considered positive. RESULTS: One-hundred and seventy-one cases and 171 controls were included; 137 patients (80.1%) had infertility, and 34 (19.9%), sterility. Eight patients (4.6%, 95% CI = 2.3-8.9) had at least one positive marker for CD in comparison with one woman in the control group (0.5%, 95% CI = 0.01-3, p = 0.04, odds ratio = 8.3). Six of the eight patients had unexplained infertility. CONCLUSIONS: Up to 4.6% of women with infertility had at least one positive marker for CD. As in other parts of the world, screening for CD could be recommended in women with infertility, especially in those with unexplained infertility.

ANTECEDENTES: Aunque los pacientes con enfermedad celiaca (EC) tienen en su mayoría manifestaciones digestivas, algunos pueden presentarlas de índole extraintestinal (atípicas), como anemia crónica, ataxia y trastornos de la fertilidad. OBJETIVO: Determinar la prevalencia de anticuerpos relacionados con EC en mujeres mexicanas con trastornos de la fertilidad. MATERIAL Y MÉTODOS: Estudio de casos y controles de mujeres que acudieron a valoración por trastornos de la fertilidad en un centro especializado. Se cuantificó h-tTG IgA, gliadina IgA II y gliadina IgG II; los títulos > 30 UI fueron considerados como positivos. RESULTADOS: Se incluyeron 171 casos y 171 controles; 137 pacientes (80.1 %) tuvieron infertilidad y 34 (19.9 %), esterilidad. Ocho pacientes (4.6 %, IC 95 % = 2.3-8.9) tuvieron al menos un marcador positivo para EC comparadas con una mujer del grupo control (0.5 %, IC 95 % = 0.01-3, p = 0.04, razón de momios = 8.3). Seis de las ocho pacientes presentaron infertilidad inexplicable. CONCLUSIONES: Hasta 4.6 % de las mujeres con infertilidad presentó al menos un marcador positivo para EC. Al igual que en otras partes del mundo, podría recomendarse el escrutinio para EC en mujeres con infertilidad, en especial en quienes padecen infertilidad inexplicable.

Seroprevalencia de enfermedad celiaca en pacientes con infertilidad. Un estudio de casos y controles / Celiac disease seroprevalence in patients with infertility. A case-control study

Resumen Antecedentes: Aunque los pacientes con enfermedad celiaca (EC) tienen en su mayoría manifestaciones digestivas, algunos pueden presentarlas de índole extraintestinal (atípicas), como anemia crónica, ataxia y trastornos de la fertilidad. Objetivo: Determinar la prevalencia de anticuerpos relacionados con EC en mujeres mexicanas con trastornos de la fertilidad. Material y métodos: Estudio de casos y controles de mujeres que acudieron a valoración por trastornos de la fertilidad en un centro especializado. Se cuantificó h-tTG IgA, gliadina IgA II y gliadina IgG II; los títulos > 30 UI fueron considerados como positivos. Resultados: Se incluyeron 171 casos y 171 controles; 137 pacientes (80.1 %) tuvieron infertilidad y 34 (19.9 %), esterilidad. Ocho pacientes (4.6 %, IC 95 % = 2.3-8.9) tuvieron al menos un marcador positivo para EC comparadas con una mujer del grupo control (0.5 %, IC 95 % = 0.01-3, p = 0.04, razón de momios = 8.3). Seis de las ocho pacientes presentaron infertilidad inexplicable. Conclusiones: Hasta 4.6 % de las mujeres con infertilidad presentó al menos un marcador positivo para EC. Al igual que en otras partes del mundo, podría recomendarse el escrutinio para EC en mujeres con infertilidad, en especial en quienes padecen infertilidad inexplicable.

Abstract Background: Although most patients with celiac disease (CD) have digestive manifestations, in some of them they may be of extraintestinal (atypical) nature, such as chronic anemia, ataxia, and fertility disorders. Objective: To determine the prevalence of CD-related antibodies in Mexican women with fertility disorders. Material and methods: Case-control study of women who attended evaluation for fertility disorders in a specialized center. h-tTG-IgA, gliadin IgA II and gliadin IgG II were quantified; titers > 30 IU were considered positive. Results: One-hundred and seventy-one cases and 171 controls were included; 137 patients (80.1%) had infertility, and 34 (19.9%), sterility. Eight patients (4.6%, 95% CI = 2.3-8.9) had at least one positive marker for CD in comparison with one woman in the control group (0.5%, 95% CI = 0.01-3, p = 0.04, odds ratio = 8.3). Six of the eight patients had unexplained infertility. Conclusions: Up to 4.6% of women with infertility had at least one positive marker for CD. As in other parts of the world, screening for CD could be recommended in women with infertility, especially in those with unexplained infertility.

Antibiofilm properties of silver nanoparticles incorporated into polymethyl methacrylate used for dental applications.

BACKGROUND: Acrylic resins used in dental and biomedical applications do not have antimicrobial properties, their surface is susceptible to colonization of microorganisms. OBJECTIVE: The aim of this study was to evaluate the antibiofilm properties of silver nanoparticles (AgNPs) deposited in a polymethyl methacrylate (PMMA) surface against a Staphylococcus aureus biofilm. METHODS: The PMMA was impregnated with AgNPs by using the in-situ polymerization method. To determine the solubility of the incorporated silver (Ag+) atomic absorption spectrophotometry was used (AAS) at 24 h, 48 h, 7 days, and 30 days. Thirty specimens of PMMA with AgNPs and without NP (control group) were assembled in the CDC Biofilm Bioreactor system with a cell suspension of S. aureus. The specimens were removed at 6, 12, 24, 48, and 72 h to determine the viability profile and quantify the Arbitrary Fluorescence Units (AFU). RESULTS: The AgNPs showed an irregular and quasispherical shape with an average size of 25 nm. AAS analysis demonstrated a low solubility of Ag+. The formation of the S. aureus biofilm increased as the evaluation periods continued up to 72 h. The experimental group showed poor growth, and a decrease in the intensity of the fluorescence demonstrated a statistically significant inhibition of the formation of the biofilm (P < 0.05) in relation to the control group at 6, 12, 24, 48, and 72 h. CONCLUSION: AgNPs incorporated into PMMA decreased the growth and maturation of S. aureus biofilm.

Effect of microwave polymerization on the thermomechanical and surface properties of ocular prosthetic acrylic resins.

BACKGROUND: Polymerization conditions affect the physical-mechanical properties of acrylic resins used for craniofacial prostheses. OBJECTIVE: The aim of this study was to evaluate the effect of microwave polymerization on the thermomechanical properties and surface morphology of ocular prostheses fabricated with polymethyl methacrylate (PMMA). METHODS: PMMA discs were polymerized with microwave energy and with conventional heat polymerization (CHP) method. Ocular prostheses were fabricated to determine whether there were changes according to the polymerization method. The surface morphology and roughness were observed under SEM and AFM. The Vickers Hardness number (VHN) and flexural strength were measured. Thermal properties were evaluated with TGA/DSC, and chemical composition with FTIR. RESULTS: The PMMA acrylic resin polymerized with microwave energy showed a smooth surface with some relief areas. In the internal surface of the ocular prosthesis with microwave energy the PMMA is more compact. The mean roughness values were higher and statistically significant with CHP (P < 0.05), while the surface hardness and flexural strength were higher with microwave energy (P < 0.05). CONCLUSION: There were no changes in the calorimetry with either method, TGA showed an exothermic peak around 120 °C with CHP method. PMMA polymerized with microwave energy improved the mechanical and surface properties of the ocular prostheses.

Punica granatum as Anticandidal and Anti-HIV Agent: An HIV Oral Cavity Potential Drug.

The oral cavity is crucial from diagnosis to adherence to HAART therapy in the HIV/AIDS population; consequently, drugs that can maintain healthy conditions in the oral cavity are necessary for patients with HIV/AIDS. Punica granatum (pomegranate) is a tree that has been employed extensively for centuries in the traditional medicine of ancient cultures for the treatment of a wide range of diseases, including oral and dental diseases. In recent decades, its potent anticandidal properties have been shown, especially on Candida albicans, the cause of the most common clinical manifestation in HIV patients. The present work contributes to the review of the anti-HIV and anticandidal properties of the plant species P. granatum as involved with the oral cavity. The literature reviewed revealed that crude extracts of pomegranate and its main isolated compounds possess inhibitory activity on different HIV targets, including binding viral proteins and the three replicative HIV enzymes. In addition, in the literature reviewed, pomegranate exhibited anticandidal effects on 10 different species. Thus, pomegranate appears to be an excellent candidate to explore and incorporate into the treatment of the oral cavity of HIV/AIDS patients, in that, in addition to its pharmacological effects such as antiviral and anticandidal, pomegranate represents an easily available, inexpensive, and safe natural source.

Green Route to Produce Silver Nanoparticles Using the Bioactive Flavonoid Quercetin as a Reducing Agent and Food Anti-Caking Agents as Stabilizers.

In previous work, the isolated polyphenolic compound (PPC) quercetin was used as a reducing agent in the formation of silver nanoparticles (AgNPs), testing two types of quercetin. This PPC is a bioactive molecule that provides the electrons for the reduction of silver ions to zerovalent silver. The results demonstrated that quercetin in dietary supplement presentation was better than reagent grade quercetin for the synthesis of AgNPs, and the difference between them was that the dietary supplement had microcrystalline cellulose (CM) in its formulation. Therefore, this dietary anti-caking agent was added to the reagent-grade quercetin to validate this previously found improvement. AgNPs were obtained at neutral pH by a green route using quercetin as a reducing agent and microcrystalline cellulose and maltodextrin as stabilizing agents. In addition, different ratios were evaluated to find the optimum ratio. Ultraviolet-Visible spectroscopy (UV-VIS), Atomic Force Microscope (AFM), Z-potential, Dynamic Light Scattering (DLS) and X-ray Powder Diffraction (XRD) were used for characterization. The antibacterial activity of the S. aureus and E. coli agent was tested by the disk diffusion and microdilution method. According to the results, this green synthesis needs the use of food stabilizer when working at pH 7 to maintain AgNPs in the long term. The ideal ratio of reducing the agent:stabilizing agent was 1:2, since with this system stable AgNPs are obtained for 2 months and with improved antimicrobial activity, validating this method was ecologically and economically viable.

Use and management of disinfectants by dentists in San Luis Potosi, Mexico, during the covid-19 pandemic / Uso y manejo de desinfectantes por odontólogos de San Luis Potosí, México durante la pandemia covid-19

Introduction: Chlorine, ethyl alcohol, and quaternary ammonium are disinfectants with antiviral activity against SARS-Cov2. However, there are no previous reports of their use and handling for cleaning and disinfection in dental offices. Objetive: To determine the use and management of disinfectants in critical and non-critical areas used by dentists in San Luis Potosí, Mexico, during the COVID-19 pandemic. Material and Methods: A validated cross-sectional survey was applied online to 100 dentists in San Luis Potosí between February and June 2021. Participants were informed about the handling of personal data according to the standard DOF regulations (DOF 07-05-2010). Results: A total of 100 dentists were included in the study, 63% female and 37% male, with a mean age of 26 years. The most widely used disinfectants during the pandemic in critical areas were Lysol® and 0.1% sodium hypochlorite in non-critical areas. Eighty-five percent of dentists know the adverse effects of inappropriate use of disinfectants, 72% did not have any sign or symptom associated with the use of disinfectants. The most used protection barrier was gloves (97%). Sixty-seven per cent of dentists disposed of disinfectant waste down the drain. Conclusion: Sodium hypochlorite and quaternary ammonium compounds and/or ethanol are used to clean non-critical and critical areas in dental offices. However, appropriate measures for their management are not adopted. It is necessary to implement educational strategies to improve the use and management of disinfectants in dental practice.

Introducción: Cloro, alcohol etílico y amonio cuaternario son desinfectantes que muestran actividad antiviral contra el SARS-Cov2, sin embargo, no existen reportes previos de su uso y manejo para la limpieza y desinfección en clínicas dentales. Objetivo: Determinar el uso y manejo de los desinfectantes en áreas críticas y no críticas empleados por los odontólogos en San Luis Potosí durante la COVID-19. Material y Métodos: Encuesta transversal validada y aplicada on-line a 100 odontólogos de San Luis Potosí durante febrero-junio 2021. Se informó a los participantes sobre el manejo de datos personales de acuerdo a la norma (DOF 05-07-2010). Resultados: Se incluyeron un total de 100 odontólogos, 63% del sexo femenino y 37% del sexo masculino, con una edad promedio de 26 años. Los desinfectantes más utilizados durante la pandemia en las áreas críticas fueron el Lysol® y el hipoclorito de sodio al 0.1% en áreas no críticas. El 85% de los odontólogos conocen los efectos adversos del uso inadecuado de los desinfectantes, 72% no tuvieron algún signo o síntoma asociado al uso de desinfectantes. La barrera de protección más utilizada fueron los guantes (97%). El 67% de los odontólogos eliminó los desechos de desinfectantes por la coladera. Conclusión: Para la limpieza de las áreas no críticas y críticas en las clínicas dentales se utilizan el hipoclorito de Sodio y compuestos de amonio cuaternario y/o etanol, sin embargo, no se utilizan las medidas adecuadas para su manejo. Es necesario implementar estrategias educativas para mejorar el uso y manejo de desinfectantes en la práctica dental.

Mucosal Vaccination: A Promising Alternative Against Flaviviruses.

The Flaviviridae are a family of positive-sense, single-stranded RNA enveloped viruses, and their members belong to a single genus, Flavivirus. Flaviviruses are found in mosquitoes and ticks; they are etiological agents of: dengue fever, Japanese encephalitis, West Nile virus infection, Zika virus infection, tick-borne encephalitis, and yellow fever, among others. Only a few flavivirus vaccines have been licensed for use in humans: yellow fever, dengue fever, Japanese encephalitis, tick-borne encephalitis, and Kyasanur forest disease. However, improvement is necessary in vaccination strategies and in understanding of the immunological mechanisms involved either in the infection or after vaccination. This is especially important in dengue, due to the immunological complexity of its four serotypes, cross-reactive responses, antibody-dependent enhancement, and immunological interference. In this context, mucosal vaccines represent a promising alternative against flaviviruses. Mucosal vaccination has several advantages, as inducing long-term protective immunity in both mucosal and parenteral tissues. It constitutes a friendly route of antigen administration because it is needle-free and allows for a variety of antigen delivery systems. This has promoted the development of several ways to stimulate immunity through the direct administration of antigens (e.g., inactivated virus, attenuated virus, subunits, and DNA), non-replicating vectors (e.g., nanoparticles, liposomes, bacterial ghosts, and defective-replication viral vectors), and replicating vectors (e.g., Salmonella enterica, Lactococcus lactis, Saccharomyces cerevisiae, and viral vectors). Because of these characteristics, mucosal vaccination has been explored for immunoprophylaxis against pathogens that enter the host through mucosae or parenteral areas. It is suitable against flaviviruses because this type of immunization can stimulate the parenteral responses required after bites from flavivirus-infected insects. This review focuses on the advantages of mucosal vaccine candidates against the most relevant flaviviruses in either humans or animals, providing supporting data on the feasibility of this administration route for future clinical trials.

Does microwave and hydrogen peroxide disinfection reduce Candida albicans biofilm on polymethyl methacrylate denture surfaces?

STATEMENT OF PROBLEM: Whether the disinfection of polymethyl methacrylate (PMMA) dentures eliminates Candida albicans biofilm is unclear. PURPOSE: The purpose of this in vitro study was to determine the antimicrobial effect of immersion in hydrogen peroxide (H2O2) and subsequent application of microwaves on the formation of C albicans biofilm on the surface of polished and unpolished PMMA disks. MATERIAL AND METHODS: Polished and unpolished PMMA disks (n=40) were mounted in a Center for Disease Control (CDC) biofilm reactor by adding yeast-dextrose-peptone (YPD) broth inoculated with C albicans in a cell suspension for 24 hours. After this period, the PMMA disks (n=8) were disinfected with 5 different solutions: saline solution, 1% sodium hypochlorite (NaOCl), H2O2, H2O2 microwaved at 650 W for 3 minutes (H2O2/µw), and distilled water microwaved at 650 W for 3 minutes (H2O/µw). On the polished and unpolished surface of each disk, arbitrary fluorescence units (AFU) were quantified with the live/dead bacterial viability kit (Invitrogen) by using confocal laser scanning microscopy (CLSM) to evaluate 10 different areas of each surface; these were counted as the colony-forming units (CFUs). The mean values were compared by using the Mann-Whitney U test (α=.05). RESULTS: Polished surfaces disinfected with H2O2/µw obtained the lowest viable cells (9.76 AFU) and nonviable cells (12.46 AFU) compared with H2O/µw and H2O2. In the unpolished surface the lowest mean values of viable cells (14.64 AFU) and nonviable cells (12.46 AFU) were obtained for the PMMA disks disinfected with H2O/µw compared with H2O2/µw and H2O2. Both polished and unpolished disks showed significant difference (P<.05) compared with the group of PMMA disks immersed in saline solution. No CFUs were detected in the polished or unpolished PMMA disks immersed in H2O2/µw or in NaOCl. CONCLUSIONS: H2O2 alone did not eliminate the formation of the biofilm of C albicans; however, in combination with the use of the microwave at 650 W for 3 minutes, the biofilm formation of C albicans on polished surfaces was reduced. The number of AFUs of viable-nonviable cells and CFUs depended on whether the surfaces are polished or unpolished.

Longitudinal Analysis of Dengue Virus-Specific Memory T Cell Responses and Their Association With Clinical Outcome in Subsequent DENV Infection.

Memory T cells resulting from primary dengue virus (DENV) infection are hypothesized to influence the clinical outcome of subsequent DENV infection. However, the few studies involving prospectively collected blood samples have found weak and inconsistent associations with outcome and variable temporal trends in DENV-specific memory T cell responses between subjects. This study used both ex-vivo and cultured ELISPOT assays to further evaluate the associations between DENV serotype-cross-reactive memory T cells and severity of secondary infection. Using ex-vivo ELISPOT assays, frequencies of memory T cells secreting IFN-γ in response to DENV structural and non-structural peptide pools were low in PBMC from multiple time points prior to symptomatic secondary DENV infection and showed a variable response to infection. There were no differences in responses between subjects who were not hospitalized (NH, n=6) and those who were hospitalized with dengue hemorrhagic fever (hDHF, n=4). In contrast, responses in cultured ELISPOT assays were more reliably detectable prior to secondary infection and showed more consistent increases after infection. Responses in cultured ELISPOT assays were higher in individuals with hDHF (n=8) compared to NH (n=9) individuals before the secondary infection, with no difference between these groups after infection. These data demonstrate an association of pre-existing DENV-specific memory responses with the severity of illness in subsequent DENV infection, and suggest that frequencies of DENV-reactive T cells measured after short-term culture may be of particular importance for assessing the risk for more severe dengue disease.

Dengue Virus Induces the Expression and Release of Endocan from Endothelial Cells by an NS1-TLR4-Dependent Mechanism.

A common hallmark of dengue infections is the dysfunction of the vascular endothelium induced by different biological mechanisms. In this paper, we studied the role of recombinant NS1 proteins representing the four dengue serotypes, and their role in promoting the expression and release of endocan, which is a highly specific biomarker of endothelial cell activation. We evaluated mRNA expression and the levels of endocan protein in vitro following the stimulation of HUVEC and HMEC-1 cell lines with recombinant NS1 proteins. NS1 proteins increase endocan mRNA expression 48 h post-activation in both endothelial cell lines. Endocan mRNA expression levels were higher in HUVEC and HMEC-1 cells stimulated with NS1 proteins than in non-stimulated cells (p < 0.05). A two-fold to three-fold increase in endocan protein release was observed after the stimulation of HUVECs or HMEC-1 cells with NS1 proteins compared with that in non-stimulated cells (p < 0.05). The blockade of Toll-like receptor 4 (TLR-4) signaling on HMEC-1 cells with an antagonistic antibody prevented NS1-dependent endocan production. Dengue-infected patients showed elevated serum endocan levels (≥30 ng/mL) during early dengue infection. High endocan serum levels were associated with laboratory abnormalities, such as lymphopenia and thrombocytopenia, and are associated with the presence of NS1 in the serum.

Anti-HIV and Anti-Candidal Effects of Methanolic Extract from Heteropterys brachiata.

Nowadays, the HIV pandemic is far from controlled. HIV+/AIDS patients show a serious risk of developing resistance to HIV antiretroviral drugs and to be orally colonized by albicans and non-albicans Candida strains resistant to antifungals. As a consequence, new drugs that possess anti-candidal and anti-HIV effects would represent an alternative in the comprehensive treatment of HIV+/AIDS patients. The present study evaluates the possible anti-HIV and anti-Candida effects of a methanolic extract from Heteropterys brachiata (Hb MeOH), an American tropical plant. The anti-HIV effect of Hb MeOH was tested using a non-radioactive colorimetric method (Lenti RT® Activity Assay; Cavidi Tech) that uses reverse transcriptase of HIV-1 enzyme as enzymatic target. The anti-candidal effect of HbMeOH extract was evaluated by following a standardized test protocol of microdilution for yeast using the Candida albicans strain ATCC® 90028. The Hb MeOH at 1 mg/mL concentration shows 38.5% RT-HIV inhibition, while Hb MeOH at 10 mg/mL concentration produced 98% C. albicans growth inhibition. Our findings show that the Hb MeOH possesses a strong anti-candidal activity and moderate anti-HIV effect and suggests that the plant extract could be considered as a potential candidate for HIV/AIDS treatment.

Frequency of Pathogenic Microorganisms in Removable Orthodontic Appliances and Oral Mucosa in Children.

OBJECTIVE: The aim of this study was to evaluate the frequency of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida species in removable orthodontic appliances (ROA) and the support oral mucosa in children. STUDY DESIGN: The study participants comprised 55 patients aged 6-12 years requiring ROA. The samples of biofilm colonization from the support oral mucosa and the ROA were taken prior to the use of the ROA (T0) and 4 weeks (T1) after ROA placement. The biofilm samples were seeded on chromogenic culture plates and incubated for 24-48 h. RESULTS: The microbial species evaluated were not present in either the support oral mucosa nor in the ROA at T0. After 4 weeks, P. aeruginosa was found in the support oral mucosa with a frequency of 60%, Candida spp. with 30.9% and S. aureus with 89.09%; in the ROA, P. aeruginosa with 67.7%, Candida spp. with 32.7%, while S. aureus with 90.9%. In the ROA were found C. glabrata in 15 cases, C. albicans in 14 cases, C. tropicalis in two cases, and C. krusei in one case. In the oral mucosa there were 10 cases of C. glabrata, 14 cases of C. albicans, one case of C. tropicalis, and 0 cases of C. krusei. CONCLUSIONS: The frequency of S. aureus, P. aeruginosa, and Candida spp. increased after the orthodontic treatment in either the ROA and or in the support oral mucosa. There is a direct relation between the use of the ROA and the increase of periodontal-pathogenic microorganisms.

Non-structural protein 1-specific antibodies directed against Zika virus in humans mediate antibody-dependent cellular cytotoxicity.

There is growing interest in understanding antibody (Ab) function beyond neutralization. The non-structural protein 1 (NS1) of Zika virus (ZIKV) is an attractive candidate for an effective vaccine as Abs against NS1, unlike the envelope or premembrane, do not carry the risk of mediating antibody-dependent enhancement. Our aim was to evaluate whether ZIKV NS1 Abs elicited following natural infection in humans can mediate antibody-dependent cellular cytotoxicity (ADCC). We evaluated the isotype specificity of ZIKV-specific Abs in immune sera and supernatants from stimulated immune PBMC and found that Abs against ZIKV NS1 and virus-like particles were predominantly of the IgG1 isotype. Using a recently developed FluoroSpot assay, we found robust frequencies of NS1-specific Ab-secreting cells in PBMC of individuals who were naturally infected with ZIKV. We developed assays to measure both natural killer cell activation by flow cytometry and target cell lysis of ZIKV NS1-expressing cells using an image cytometry assay in the presence of ZIKV NS1 Abs. Our data indicate efficient opsonization of ZIKV NS1-expressing CEM-NKR cell lines using ZIKV-immune but not ZIKV-naïve sera, a prerequisite of ADCC. Furthermore, sera from immune donors were able to induce both NK cell degranulation and lysis of ZIKV NS1 CEM-NKR cells in vitro. Our data suggest that ADCC is a possible mechanism for ZIKV NS1 Abs to eliminate virally infected target cells.

The Prevalence of Anti-Zein Antibodies: A Comparative Study between Celiac Disease and Irritable Bowel Syndrome.

Celiac disease (CD) is a chronic immune-mediated enteropathy triggered by exposure to dietary gluten in genetically predisposed individuals. In contrast, irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder affecting the large intestine, without an autoimmune component. Here, we evaluated the prevalence of IgA and IgG antibodies to maize zeins (AZA) in patients with CD and IBS. Using an in-house ELISA assay, the IgA and IgG anti-zein antibodies in the serum of 37 newly diagnosed CD (16 biopsy proved and 21 serological diagnosis) and 375 IBS patients or 302 healthy control (HC) subjects were measured. Elevated levels of IgA AZA were found in CD patients compared with IBS patients (p < 0.01) and HC (p < 0.05). CD patients had the highest prevalence (35.1%), followed by IBS (4.3%) and HCs (2.3%) (p < 0.0001). IgG AZA antibodies were not found in any CD patients, IBS patients, or HC subjects. A significant positive correlation was found between IgA AZA with IgA anti-gliadin (AGA, r = 0.34, p < 0.01) and IgA anti-deaminated gliadin peptides (DGP, r = 0.42, p < 0.001) in the celiac disease group. Taken together, our results show for the first time a higher prevalence of AZA IgA antibodies in newly diagnosed CD patients than in IBS patients, confirming a biased immune response to other gliadin-related prolamins such as maize zeins in genetically susceptible individuals.

Antimicrobial effect of gold nanoparticles in the formation of the Staphylococcus aureus biofilm on a polyethylene surface.

The main of this study was to evaluate the inhibitory effect on the in vitro formation of the Staphylococcus aureus biofilm formed on a polyethylene (PE) surface with a nanostructured Gold (Au) coating for medical devices. An experimental in vitro study was carried out using PE discs with an Au nanoparticle coating (AuNPs) on one side (experimental group) and without coating on the other (control group); the discs were mounted in the CDC biofilm reactor adding broth of yeast-dextrose-peptone (YPD) sterile culture inoculated with S. aureus in a cell suspension (5 × 108 cells/ml). The specimens were evaluated at different times (6, 12, 24, 48, 72 h) and stained with the Live/Dead Bacterial Viability Kit (Invitrogen) for observation, analysis, and quantification with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The results showed that as evaluation time passed an increasing of S. aureus biofilm formation was observed in the control group, in the experimental group, a statistically significant biofilm inhibition was observed with respect to the AuNPs uncoated specimens (p ≤ 0.05) and showed a ratio of almost 4:1 viable/nonviable in the biofilm of the uncoated surfaces, with a difference > 5 Log10 in the CFU counts. The PE with AuNP coating showed an inhibitory effect on the biofilm formation of S. aureus.

Characterization of the IL-17 and CD4+ Th17 Cells in the Clinical Course of Dengue Virus Infections.

The aims of this study were to determine the involvement of interleukin 17 (IL-17) and IL-17-producing cells in dengue pathogenesis. Blood samples from dengue virus (DENV)-infected patients were collected on different days after the onset of symptoms. Patients were classified according to 1997 World Health Organization guidelines. Our study examined 152 blood samples from dengue fever (DF, n = 109) and dengue hemorrhagic fever (DHF, n = 43) patients and 90 blood samples from healthy controls (HC). High serum concentrations of IL-17A and IL-22 were also associated with DHF (IL-17A [DHF vs. DF, p < 0.01; DHF vs. HC, p < 0.0001]; IL-22 [DHF vs. DF, p < 0.05; DHF vs. HC, p < 0.0001]). Moreover, there was a positive correlation between serum levels of IL-17A and IL-23, a key cytokine that promotes IL-17-based immune responses (r = 0.4089, p < 0.0001). Consistent with the IL-17-biased immune response in DHF patients, we performed ex vivo activation of peripheral blood mononuclear cells (PBMCs) from DHF patients and flow cytometry analysis showed a robust IL-17-biased immune response, characterized by a high frequency of CD4+IL-17+ producing cells. Our results suggests IL-17-producing cells and their related cytokines can play a prominent role in this viral disease.

Effect of Five Commercial Probiotic Formulations on Candida Albicans Growth: In Vitro Study.

PURPOSE: The objective was to evaluate the antagonistic effect of Lactobacillus and Bifidobacterium recovered from five commercial probiotics on the growth of C. albicans. STUDY DESIGN: The Lactobacillus and Bifidobacterium strains of five commercial probiotics were recovered and grown: Probio Hp+®, ProBiseis®, Lactipan®, Liolactil®, and Lacteol Fort®; 50 mg of each was hydrated and grown in Lactobacilli MRS (De Man, Rogosa and Sharpe) broth and incubated at 37°C with stirring (120 RPM) for 24 hours. Serial dilutions of 10-1 to 10-7 were made and viability was verified and quantified. For the antagonism tests, a suspension/inoculum of Lactobacillus strains recovered from each commercial preparation (4-30 × 109) and C. albicans ATCC 90028 (1.5-8 × 108) was prepared in MRS broth and incubated for 48 hours at 36°C, then plated on Dextrose Sabouraud Agar with Chloramphenicol and Rogosa Agar and the colony-forming units (CFU) were quantified. Additionally, viability was evaluated using the LIVE/DEAD® Yeast and Bacterial Viability kit. RESULTS: The probiotic that produced the highest acidity of the medium was Lactipan®, followed by Probiseis® and Liolactil®, while Probio Hp+® showed the least change. Probiseis® was determined to have the highest growth of probiotic bacteria and the highest inhibition on C. albicans, followed by Lactipan®; Liolactil® and ProbioHp+® showed the least effect. In fluorescence tests, ProBiseis® showed the best effect, followed by Liolactil® and Lactipan®; Probio Hp+® had less of an effect. CONCLUSIONS: Two commercial products (ProBiseis and Lactipan) whose formulations have L. acidophilus, L. casei, L. rhamnosus, L. plantarum, B. infantis, and S. thermophilus have a greater inhibitory effect on C. albicans ATCC 90028.

A few-layer graphene/chlorin e6 hybrid nanomaterial and its application in photodynamic therapy against Candida albicans.

The global emergence of multidrug resistance of fungal infections and the decline in the discovery of new antibiotics are increasingly prevalent causes of hospital-acquired infections, among other major challenges in the global health care sector. There is an urgent need to develop noninvasive, nontoxic, and new antinosocomial approaches that work more effectively and faster than current antibiotics. In this work, we report on a biocompatible hybrid nanomaterial composed of few-layer graphene and chlorin e6 (FLG-Ce6) for the photodynamic treatment (PDT) of Candida albicans. We show that the FLG-Ce6 hybrid nanomaterial displays enhanced reactive oxygen species (ROS) generation compared with Ce6. The enhancement is up to 5-fold when irradiated for 15 min at 632 nm with a red light-emitting diode (LED). The viability of C. albicans in the presence of FLG-Ce6 was measured 48 h after photoactivation. An antifungal effect was observed only when the culture/FLG-Ce6 hybrid was exposed to the light source. C. albicans is rendered completely unviable after exposure to ROS generated by the excited FLG-Ce6 hybrid nanomaterial. An increased PDT effect was observed with the FLG-Ce6 hybrid nanomaterial by a significant reduction in the viability of C. albicans, by up to 95%. This is a marked improvement compared to Ce6 without FLG, which reduces the viability of C. albicans to only 10%. The antifungal action of the hybrid nanomaterial can be activated by a synergistic mechanism of energy transfer of the absorbed light from Ce6 to FLG. The novel FLG-Ce6 hybrid nanomaterial in combination with the red LED light irradiation can be used in the development of a wide range of antinosocomial devices and coatings.