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1.
Plant Genome ; : e20084, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33605090

RESUMO

Room-temperature shelf life is a key factor in fresh market apple (Malus domestica Borkh.) quality and commercial value. To investigate the genetic and molecular mechanism underlying apple shelf life, quantitative trait loci (QTL) were identified using bulked segregant analysis via sequencing (BSA-seq). Ethylene emission, flesh firmness, or crispness of apple fruit from 1,273 F1 plants of M. asiatica Nakai 'Zisai Pearl' × M. domestica 'Golden Delicious' were phenotyped prior to and during 6 wk of room-temperature storage. Segregation of ethylene emission and the flesh firmness or crispness traits was detected in the population. Thirteen QTL, including three major ones, were identified on chromosome 03, 08, and 16. A candidate gene encoding pectin acetylesterase, MdPAE10, from the QTL Z16.1 negatively affected fruit shelf life. A 379-bp deletion in the coding sequence of MdPAE10 disrupted its function. A single nucleotide polymorphism (SNP) in the MdPAE10 promoter region reduced its transcription activity. These findings provided insight into the genetic control of fruit shelf life and can be potentially used in apple marker-assisted selection.

2.
J Immunol ; 206(5): 1088-1101, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33495235

RESUMO

The skin of vertebrates is the outermost organ of the body and serves as the first line of defense against external aggressions. In contrast to mammalian skin, that of teleost fish lacks keratinization and has evolved to operate as a mucosal surface containing a skin-associated lymphoid tissue (SALT). Thus far, IgT representing the prevalent Ig in SALT have only been reported upon infection with a parasite. However, very little is known about the types of B cells and Igs responding to bacterial infection in the teleost skin mucosa, as well as the inductive or effector role of the SALT in such responses. To address these questions, in this study, we analyzed the immune response of trout skin upon infection with one of the most widespread fish skin bacterial pathogens, Flavobacterium columnare This pathogen induced strong skin innate immune and inflammatory responses at the initial phases of infection. More critically, we found that the skin mucus of fish having survived the infection contained significant IgT- but not IgM- or IgD-specific titers against the bacteria. Moreover, we demonstrate the local proliferation and production of IgT+ B cells and specific IgT titers, respectively, within the SALT upon bacterial infection. Thus, our findings represent the first demonstration that IgT is the main Ig isotype induced by the skin mucosa upon bacterial infection and that, because of the large surface of the skin, its SALT probably represents a prominent IgT-inductive site in fish.

3.
Int J Infect Dis ; 97: 278-282, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32502664

RESUMO

OBJECTIVES: Although COVID-19 is known to be caused by human-to-human transmission, it remains largely unclear whether ambient air pollutants and meteorological parameters could promote its transmission. METHODS: A retrospective study was conducted to study whether air quality index (AQI), four ambient air pollutants (PM2.5, PM10, NO2 and CO) and five meteorological variables (daily temperature, highest temperature, lowest temperature, temperature difference and sunshine duration) could increase COVID-19 incidence in Wuhan and XiaoGan between Jan 26th to Feb 29th in 2020. RESULTS: First, a significant correlation was found between COVID-19 incidence and AQI in both Wuhan (R2=0.13, p<0.05) and XiaoGan (R2=0.223, p<0.01). Specifically, among four pollutants, COVID-19 incidence was prominently correlated with PM2.5 and NO2 in both cities. In Wuhan, the tightest correlation was observed between NO2 and COVID-19 incidence (R2=0.329, p<0.01). In XiaoGan, in addition to the PM2.5 (R2=0.117, p<0.01) and NO2 (R2=0.015, p<0.05), a notable correlation was also observed between the PM10 and COVID-19 incidence (R2=0.105, p<0.05). Moreover, temperature is the only meteorological parameter that constantly correlated well with COVID-19 incidence in both Wuhan and XiaoGan, but in an inverse correlation (p<0.05). CONCLUSIONS: AQI, PM2.5, NO2, and temperature are four variables that could promote the sustained transmission of COVID-19.


Assuntos
Poluição do Ar/efeitos adversos , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Temperatura , Betacoronavirus , Monóxido de Carbono/efeitos adversos , China/epidemiologia , Cidades , Infecções por Coronavirus/transmissão , Humanos , Incidência , Dióxido de Nitrogênio/efeitos adversos , Pandemias , Material Particulado/efeitos adversos , Pneumonia Viral/transmissão , Estudos Retrospectivos
4.
Ying Yong Sheng Tai Xue Bao ; 31(2): 483-492, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32476341

RESUMO

To evaluate the applicability of AHC (agro-hydrological chemical and crop systems simulator) model and explore the suitable irrigation amount for peanut (Arachis hypogaea) under mulched drip irrigation in the semi-arid areas of northwestern Liaoning Province, based on the two-year field experimental data of peanut in 2016 and 2017, the model parameters were firstly chosen for global sensitivity analysis. Then, module parameters of soil moisture and crop growth were calibrated and validated. Finally, AHC model was used to analyze the responses of peanut yield and water use efficiency (WUE) to different irrigation amounts. The results showed that the two extremely sensitive parameters of the model were saturated hydraulic conductivity in the first and second layers of soil. Root mean square error (RMSE) and mean relative error (MRE) between simulated and measured values of soil water content ranged from 0.02 to 0.03 cm3·cm-3 and 1.5% to 2.3%, respectively. The RMSE and MRE of leaf area index and plant height were 0.3-0.6, 4.2-4.5 cm, and 5.0%-8.9%, 5.2%-6.8%, respectively. The MRE of peanut yield and water consumption were both within 5%, indicating that the model was suitable for simulating soil moisture and peanut growth in the northwest Liaoning Province. With the increases of irrigation amounts, peanut yield increased and water use efficiency decreased. Considering both peanut yield and WUE, we recommend that the optimal mulched drip irrigation amounts for peanut in the semi-arid areas of Northwestern Liaoning in test year (normal year) was 80-97 mm.


Assuntos
Irrigação Agrícola , Arachis , Biomassa , China , Solo , Água
5.
Contraception ; 102(1): 1-6, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32135125

RESUMO

OBJECTIVES: To calculate the minimum fetal red blood cell concentration required to cause maternal Rh sensitization; validate the use of a flow cytometry protocol below that concentration; preliminarily assess the concentrations of fetal red blood cells in pregnant women before and after uterine aspiration. STUDY DESIGN: Using pre-existing literature, we calculated the lowest concentration of fetal red blood cells found to cause sensitization within adult female circulation. We validated a two-color flow cytometry protocol using fluorescently labeled antibodies to Hemoglobin F (expressed by fetal red blood cells and adult F cells) and Carbonic Anhydrase (expressed in red blood cells during the third trimester and postnatally) by titrating second trimester cord blood into non-pregnant adult blood. We applied this flow cytometry protocol in a prospective cohort study of 42 pregnant women at 5-12 weeks gestational age undergoing uterine aspiration for induced or spontaneous abortion. RESULTS: The calculated threshold for causing Rh sensitization was 250 fetal red blood cells per 10 million total red blood cells. We showed a linear relationship between observed and expected fetal red blood cell fractions in titrated samples. Fetal red blood cell counts were more reliable when samples acquired by flow cytometry contained at least 1 million red blood cells. All 37 subjects with evaluable paired samples demonstrated fetal red blood cell concentrations below the calculated threshold for Rh sensitization both pre- and post-procedure. The fetal RBC concentrations increased from a mean of 4.5 (median 0, range 0-57) fetal RBCS pre- to a mean of 8.6 (median 2, range 0-32) fetal RBCs post- per 10 million total RBCs (p < 0.001). CONCLUSIONS: Flow cytometry was capable of separately quantifying fetal red blood cells and maternal F cells to very dilute concentrations. Fetal red blood cell exposure in the first trimester was well below the calculated threshold for maternal Rh sensitization in our cohort. Larger studies are warranted to confirm our pilot study findings, fill this evidence gap and inform universal guidelines for administering Rh immunoglobulin after first trimester uterine aspiration. IMPLICATIONS: Fetal red blood cell exposure following first trimester uterine aspiration is well below the calculated threshold for maternal Rh sensitization in our cohort.

6.
J Int Med Res ; 48(3): 300060519887847, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31771379

RESUMO

OBJECTIVES: To describe the epidemiological features of a school varicella outbreak in Dongguan City, China, to identify the reasons underlying persistent spread, and to assess the effectiveness of the varicella vaccine. METHODS: We identified all cases during the outbreak. We described the outbreak epidemic course and examined the influence of the following variables on the outbreak: sleeping in the dormitory, eating in school, taking school transportation, hand-washing habits, morning examinations, and effectiveness of case isolation. Logistic regression was used to estimate the odds ratio and 95% confidence interval (CI) of contracting varicella. RESULTS: A total of 92 varicella cases were reported, accounting for 5.53% (92/1663) of all students. Among cases, 64.13% (59/92) were vaccinated. The outbreak lasted for 93 days and occurred in six generations. Vaccination coverage was between 78.05% and 85.67%. The varicella vaccine was effective in 56.63% of recipients (95% CI: 35.49-70.84%). Vaccine effectiveness significantly decreased after 4-6 years. CONCLUSIONS: The varicella vaccine was unable to prevent virus spread even with high vaccination coverage. Delayed and inefficient isolation of cases was the primary cause of the persistent outbreak.

7.
J Immunol ; 203(11): 3054-3067, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31645417

RESUMO

The pharyngeal organ is located at the crossroad of the respiratory and digestive tracts in vertebrate, and it is continuously challenged by varying Ags during breathing and feeding. In mammals, the pharyngeal mucosa (PM) is a critical first line of defense. However, the evolutionary origins and ancient roles of immune defense and microbiota homeostasis of PM are still unknown. In this study, to our knowledge, we are the first to find that diffuse MALT is present in PM of rainbow trout, an early vertebrate. Importantly, following parasitic infection, we detect that strong parasite-specific mucosal IgT and dominant proliferation of IgT+ B cell immune responses occurs in trout PM, providing, to our knowledge, the first demonstration of local mucosal Ig responses against pathogens in pharyngeal organ of a nonmammal species. Moreover, we show that the trout PM microbiota is prevalently coated with secretory IgT and, to a much lesser degree, by IgM and IgD, suggesting the key role of mucosal Igs in the immune exclusion of teleost pharyngeal bacteria. Overall, to our knowledge, our findings provide the first evidence that pharyngeal mucosal immunity appear earlier than tetrapods.


Assuntos
Evolução Biológica , Homeostase/imunologia , Oncorhynchus mykiss/imunologia , Faringite/imunologia , Mucosa Respiratória/imunologia , Animais , Faringite/patologia , Mucosa Respiratória/patologia
8.
iScience ; 19: 821-835, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31499339

RESUMO

The buccal mucosa (BM) is a critical first line of defense in terrestrial animals. To gain further insights into the evolutionary origins and primordial roles of BM in teleosts here we show that rainbow trout, a teleost fish, contains a diffuse mucosal associated lymphoid tissue (MALT) within its buccal cavity. Upon parasite infection, a fish immunoglobulin specialized in mucosal immunity (sIgT) was induced to a high degree, and parasite-specific sIgT responses were mainly detected in the buccal mucus. Moreover, we show that the trout buccal microbiota is prevalently coated with sIgT. Overall our findings revealed that the MALT is present in the BM of a non-tetrapod species. As fish IgT and mucus-producing cells are evolutionarily unrelated to mammalian IgA and salivary glands, respectively, our findings indicate that mucosal immune responses in the BM of teleost fish and tetrapods evolved through a process of convergent evolution.

10.
PLoS One ; 14(1): e0207258, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30615626

RESUMO

BACKGROUND: It has been widely understood that well-trained doctors are crucial for a high-quality public health system and safe patient care. Thus, in 2011, China initiated its first national residency training program, called the China Standardized Training for Resident Doctor (C-STRD), for medical graduates to prepare qualified doctors for the medical care system with increasing demands. So far, no studies have specifically address the prevalence of stress and its determinants among residents enrolled in the C-STRD. PARTICIPANTS AND METHODS: The research is performed in two stages. In stage I, the authors conducted a pilot study and met 112 C-STRD residents in person. Based on the preliminary data, a revised questionnaire was adopted in stage II, during which the authors conducted a multi-institutional, cross-sectional survey of 340 participants from 11 hospitals in Shanghai in a self-administered manner. RESULTS: The results showed that C-STRD residents were overall under severe stress as their mean PSS score was 27.5 ± 4.9, which was higher than the threshold of high stress (PSS = 20). Specifically, the PSS score for the residents with Bachelor (MB), Master (MM) and Doctoral of Medicine (MD) educational degree were 26.6 ± 4.1, 27.8 ± 3.5 and 27.1 ± 5.2, respectively (P>0.05). Their stress was mainly associated with their financial income status and workload, as these two factors caused more severe burden than other listed stressors (P<0.05). Specially, the residents indicated that their montly payroll amout were as low as $590.2 ± 127 while no benefit package and allowance were given. Surprisingly, wage arrears up to 5.3 month were reported by 36 (10%) participants. Workload survey showed the residents has high work intensity and inadequate rest. Since no stress management program was provided, the majority of residents tended to cope their stress with unhealthy strategies, such as mesmerizing in TV/computer (88.2%) and overeating (59.7%). CONCLUSION: The C-STRD residents are at high risk of perceived stress. Although there was a difference in perception of stress for workload and career future among different educational degree owners, low financial income is the major stressor among all C-STRD residents. Unhealthy stress management strategies were adopted by all residents due to lack of appropriate stress-relieving intervention.

11.
PLoS Pathog ; 14(11): e1007251, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30395648

RESUMO

The olfactory organ of vertebrates receives chemical cues present in the air or water and, at the same time, they are exposed to invading pathogens. Nasal-associated lymphoid tissue (NALT), which serves as a mucosal inductive site for humoral immune responses against antigen stimulation in mammals, is present also in teleosts. IgT in teleosts is responsible for similar functions to those carried out by IgA in mammals. Moreover, teleost NALT is known to contain B-cells and teleost nasal mucus contains immunoglobulins (Igs). Yet, whether nasal B cells and Igs respond to infection remains unknown. We hypothesized that water-borne parasites can invade the nasal cavity of fish and elicit local specific immune responses. To address this hypothesis, we developed a model of bath infection with the Ichthyophthirius multifiliis (Ich) parasite in rainbow trout, Oncorhynchus mykiss, an ancient bony fish, and investigated the nasal adaptive immune response against this parasite. Critically, we found that Ich parasites in water could reach the nasal cavity and successfully invade the nasal mucosa. Moreover, strong parasite-specific IgT responses were detected in the nasal mucus, and the accumulation of IgT+ B-cells was noted in the nasal epidermis after Ich infection. Strikingly, local IgT+ B-cell proliferation and parasite-specific IgT generation were found in the trout olfactory organ, providing new evidence that nasal-specific immune responses were induced locally by a parasitic challenge. Overall, our findings suggest that nasal mucosal adaptive immune responses are similar to those reported in other fish mucosal sites and that an antibody system with a dedicated mucosal Ig performs evolutionary conserved functions across vertebrate mucosal surfaces.


Assuntos
Imunidade nas Mucosas/imunologia , Cavidade Nasal/imunologia , Oncorhynchus mykiss/imunologia , Imunidade Adaptativa/imunologia , Animais , Linfócitos B/imunologia , Doenças Transmissíveis , Doenças dos Peixes/imunologia , Peixes/imunologia , Imunidade Humoral , Imunoglobulinas/imunologia , Tecido Linfoide/imunologia , Mucosa Nasal/imunologia , Doenças Parasitárias/imunologia , Doenças Parasitárias/prevenção & controle
12.
Zhonghua Nan Ke Xue ; 24(6): 558-561, 2018 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-30173464

RESUMO

Nanos2, a member of the Nanos2 gene family, is a specific gene in male germ cells and encodes an evolutionarily conserved RNA binding protein expressed in male primordial germ cells (PGCs) during the embryonic period as well as in the spermatogonial stem cells (SSCs) of the testis. In the embryonic period, Nanos2 promotes the development of male PGCs and inhibits them from meiosis. In the process of spermatogenesis, Nanos2 suppresses the differentiation of SSCs in the testis and maintains the stability of the SSC pool. The knockout of Nanos2 may cause the disappearance of germ cells and sterility in male mice while its overexpression in the testis may lead to accumulation of SSCs in seminiferous tubules. Besides, Nanos2 is involved in the degradation of specific RNAs and possibly associated with some diseases of the male reproductive system. This review focuses on the recent progress in the studies of Nanos2 in the male reproductive system.


Assuntos
Diferenciação Celular , Proteínas de Ligação a RNA/genética , Espermatozoides , Animais , Técnicas de Inativação de Genes , Masculino , Meiose , Camundongos , RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo , Espermatogênese/fisiologia , Espermatogônias , Testículo/citologia
13.
Sci Rep ; 5: 17687, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26639056

RESUMO

During the past norovirus (NoV) epidemic season, a new GII.17 variant emerged as a predominant NoV strain, surpassed the GII.4 NoVs, causing outbreaks of acute gastroenteritis (AGE) in China. Here we report a study of an AGE outbreak in an elementary school in December 2014 caused by the new GII.17 NoV to explore the potential mechanism behind the sudden epidemics of the GII.17 NoV. A total of 276 individuals were sick with typical NoV infection symptoms of vomiting (93.4%), abdominal pain (90.4%), nausea (60.0%), and diarrhea (10.4%) at an attack rate of 5.7-16.9%. Genotyping of the symptomatic patients showed that individuals with a secretor positive status, including those with A, B, and O secretors and Lewis positive blood types, were sensitive to the virus, while the non-secretors and the Lewis negative individual were not. Accordingly, the recombinant capsid P protein of the GII.17 isolate showed a wide binding spectrum to saliva samples of all A, B, and O secretors. Thus, the broad binding spectrum of the new GII.17 variant could explain its widely spread nature in China and surrounding areas in the past two years.


Assuntos
Antígenos Virais/metabolismo , Infecções por Caliciviridae/virologia , Surtos de Doenças , Gastroenterite/epidemiologia , Gastroenterite/virologia , Norovirus/fisiologia , Sistema ABO de Grupos Sanguíneos/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , China/epidemiologia , Suscetibilidade a Doenças , Fezes/virologia , Humanos , Antígenos do Grupo Sanguíneo de Lewis/metabolismo , Dados de Sequência Molecular , Mutação/genética , Fenótipo , Estrutura Terciária de Proteína , Fatores de Risco , Saliva/virologia , Homologia Estrutural de Proteína , Estudantes
14.
J Virol ; 89(18): 9213-31, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26109729

RESUMO

UNLABELLED: Herpes simplex virus 1 (HSV-1) and HSV-2 infect many humans and establish a latent infection in sensory ganglia. Although some infected people suffer periodic recurrences, others do not. Infected people mount both cell-mediated and humoral responses, including the production of virus-neutralizing antibodies (Abs) directed at viral entry glycoproteins. Previously, we examined IgGs from 10 HSV-seropositive individuals; all neutralized virus and were directed primarily against gD or gD+gB. Here, we expand our studies and examine 32 additional sera from HSV-infected individuals, 23 of whom had no recurrent disease. Using an Octet RED96 system, we screened all 32 serum samples directly for both glycoprotein binding and competition with known neutralizing anti-gD and -gB monoclonal Abs (MAbs). On average, the recurrent cohort exhibited higher binding to gD and gB and had higher neutralization titers. There were similar trends in the blocking of MAbs to critical gD and gB epitopes. When we depleted six sera of Abs to specific glycoproteins, we found different types of responses, but always directed primarily at gD and/or gB. Interestingly, in one dual-infected person, the neutralizing response to HSV-2 was due to gD2 and gB2, whereas HSV-1 neutralization was due to gD1 and gB1. In another case, virus neutralization was HSV-1 specific, with the Ab response directed entirely at gB1, despite this serum blocking type-common anti-gD and -gB neutralizing MAbs. These data are pertinent in the design of future HSV vaccines since they demonstrate the importance of both serotypes of gD and gB as immunogens. IMPORTANCE: We previously showed that people infected with HSV produce neutralizing Abs directed against gD or a combination of gD+gB (and in one case, gD+gB+gC, which was HSV-1 specific). In this more extensive study, we again found that gD or gD+gB can account for the virus neutralizing response and critical epitopes of one or both of these proteins are represented in sera of naturally infected humans. However, we also found that some individuals produced a strong response against gB alone. In addition, we identified type-specific contributions to HSV neutralization from both gD and gB. Contributions from the other entry glycoproteins, gC and gH/gL, were minimal and limited to HSV-1 neutralization. Knowing the variations in how humans see and mount a response to HSV will be important to vaccine development.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Epitopos/imunologia , Herpesvirus Humano 1/imunologia , Herpesvirus Humano 2/imunologia , Imunoglobulina G/química , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/química , Anticorpos Antivirais/química , Especificidade de Anticorpos , Chlorocebus aethiops , Reações Cruzadas , Epitopos/química , Herpesvirus Humano 1/química , Herpesvirus Humano 2/química , Humanos , Imunoglobulina G/imunologia , Camundongos , Células Vero
15.
J Virol ; 88(21): 12612-22, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25142599

RESUMO

UNLABELLED: Relatively little is known about the extent of the polyclonal antibody (PAb) repertoire elicited by herpes simplex virus (HSV) glycoproteins during natural infection and how these antibodies affect virus neutralization. Here, we examined IgGs from 10 HSV-seropositive individuals originally classified as high or low virus shedders. All PAbs neutralized virus to various extents. We determined which HSV entry glycoproteins these PAbs were directed against: glycoproteins gB, gD, and gC were recognized by all sera, but fewer sera reacted against gH/gL. We previously characterized multiple mouse monoclonal antibodies (MAbs) and mapped those with high neutralizing activity to the crystal structures of gD, gB, and gH/gL. We used a biosensor competition assay to determine whether there were corresponding human antibodies to those epitopes. All 10 samples had neutralizing IgGs to gD epitopes, but there were variations in which epitopes were seen in individual samples. Surprisingly, only three samples contained neutralizing IgGs to gB epitopes. To further dissect the nature of these IgGs, we developed a method to select out gD- and gB-specific IgGs from four representative sera via affinity chromatography, allowing us to determine the contribution of antibodies against each glycoprotein to the overall neutralization capacity of the serum. In two cases, gD and gB accounted for all of the neutralizing activity against HSV-2, with a modest amount of HSV-1 neutralization directed against gC. In the other two samples, the dominant response was to gD. IMPORTANCE: Antibodies targeting functional epitopes on HSV entry glycoproteins mediate HSV neutralization. Virus-neutralizing epitopes have been defined and characterized using murine monoclonal antibodies. However, it is largely unknown whether these same epitopes are targeted by the humoral response to HSV infection in humans. We have shown that during natural infection, virus-neutralizing antibodies are principally directed against gD, gB, and, to a lesser extent, gC. While several key HSV-neutralizing epitopes within gD and gB are commonly targeted by human serum IgG, others fail to induce consistent responses. These data are particularly relevant to the design of future HSV vaccines.


Assuntos
Anticorpos Antivirais/sangue , Glicoproteínas/imunologia , Herpes Simples/imunologia , Simplexvirus/imunologia , Proteínas Estruturais Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Formação de Anticorpos , Humanos , Imunoglobulina G/sangue , Camundongos
16.
J Virol ; 88(14): 7786-95, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24789783

RESUMO

The results of a clinical trial of a subunit vaccine against genital herpes were recently reported (R. B. Belshe, P. A. Leone, D. I. Bernstein, A. Wald, M. J. Levin, J. T. Stapleton, I. Gorfinkel, R. L. Morrow, M. G. Ewell, A. Stokes-Riner, G. Dubin, T. C. Heineman, J. M. Schulte, C. D. Deal, N. Engl. J. Med. 366: 34-43, 2012, doi:10.1056/NEJMoa1103151). The vaccine consisted of a soluble form of herpes simplex virus 2 (HSV-2) glycoprotein D (gD2) with adjuvant. The goal of the current study was to examine the composition of the humoral response to gD2 within a selected subset of vaccinated individuals. Serum samples from 30 vaccine recipients were selected based upon relative enzyme-linked immunosorbent assay (ELISA) titers against gD2; 10 samples had high titers, 10 had medium titers, and the remaining 10 had low ELISA titers. We employed a novel, biosensor-based monoclonal antibody (MAb)-blocking assay to determine whether gD2 vaccination elicited IgG responses against epitopes overlapping those of well-characterized MAbs. Importantly, IgGs from the majority of gD2-immunized subjects competed for gD binding with four antigenically distinct virus-neutralizing MAbs (MC2, MC5, MC23, and DL11). Screening of patient IgGs against overlapping peptides spanning the gD2 ectodomain revealed that about half of the samples contained antibodies against linear epitopes within the N and C termini of gD2. We found that the virus-neutralizing abilities of the 10 most potent samples correlated with overall gD-binding activity and to an even greater extent with the combined content of IgGs against the epitopes of MAbs MC2, MC5, MC23, and DL11. This suggests that optimal virus-neutralizing activity is achieved by strong and balanced responses to the four major discontinuous neutralizing epitopes of gD2. Importance: Several herpes simplex virus 2 (HSV-2) subunit vaccine studies have been conducted in human subjects using a recombinant form of HSV-2 glycoprotein D (gD2). Although several distinct, well-characterized virus-neutralizing epitopes on gD2 are targeted by murine monoclonal antibodies, it is not known whether the same epitopes are targeted by the humoral response to gD2 in humans. We have developed a novel, biosensor-based competition assay to directly address this important question. Using this approach, we identified epitopes that elicit strong humoral responses in humans, as well as other epitopes that elicit much weaker responses. These data provide new insight into the human response to known neutralizing gD2 epitopes and reveal characteristics of this response that may guide future vaccine development.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Epitopos/imunologia , Herpesvirus Humano 2/imunologia , Vacinas contra Herpesvirus/imunologia , Imunoglobulina G/sangue , Proteínas do Envelope Viral/imunologia , Anticorpos Antivirais/imunologia , Ensaio de Imunoadsorção Enzimática , Vacinas contra Herpesvirus/administração & dosagem , Humanos , Imunoglobulina G/imunologia , Testes de Neutralização , Ligação Proteica
17.
J Virol ; 88(5): 2677-89, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24352457

RESUMO

UNLABELLED: Glycoprotein B (gB), the fusogen of herpes simplex virus (HSV), is a class III fusion protein with a trimeric ectodomain of known structure for the postfusion state. Seen by negative-staining electron microscopy, it presents as a rod with three lobes (base, middle, and crown). gB has four functional regions (FR), defined by the physical location of epitopes recognized by anti-gB neutralizing monoclonal antibodies (MAbs). Located in the base, FR1 contains two internal fusion loops (FLs) and is the site of gB-lipid interaction (the fusion domain). Many of the MAbs to FR1 are neutralizing, block cell-cell fusion, and prevent the association of gB with lipid, suggesting that these MAbs affect FL function. Here we characterize FR1 epitopes by using electron microscopy to visualize purified Fab-gB ectodomain complexes, thus confirming the locations of several epitopes and localizing those of MAbs DL16 and SS63. We also generated MAb-resistant viruses in order to localize the SS55 epitope precisely. Because none of the epitopes of our anti-FR1 MAbs mapped to the FLs, we hyperimmunized rabbits with FL1 or FL2 peptides to generate polyclonal antibodies (PAbs). While the anti-FL1 PAb failed to bind gB, the anti-FL2 PAb had neutralizing activity, implying that the FLs become exposed during virus entry. Unexpectedly, the anti-FL2 PAb (and the anti-FR1 MAbs) bound to liposome-associated gB, suggesting that their epitopes are accessible even when the FLs engage lipid. These studies provide possible mechanisms of action for HSV neutralization and insight into how gB FR1 contributes to viral fusion. IMPORTANCE: For herpesviruses, such as HSV, entry into a target cell involves transfer of the capsid-encased genome of the virus to the target cell after fusion of the lipid envelope of the virus with a lipid membrane of the host. Virus-encoded glycoproteins in the envelope are responsible for fusion. Antibodies to these glycoproteins are important biological tools, providing a way of examining how fusion works. Here we used electron microscopy and other techniques to study a panel of anti-gB antibodies. Some, with virus-neutralizing activity, impair gB-lipid association. We also generated a peptide antibody against one of the gB fusion loops; its properties provide insight into the way the fusion loops function as gB transits from its prefusion form to an active fusogen.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Domínios e Motivos de Interação entre Proteínas/imunologia , Simplexvirus/imunologia , Proteínas Virais de Fusão/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Linhagem Celular , Chlorocebus aethiops , Mapeamento de Epitopos , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Lipossomos/química , Lipossomos/metabolismo , Modelos Moleculares , Mutação , Testes de Neutralização , Ligação Proteica , Conformação Proteica , Simplexvirus/genética , Células Vero , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/genética
18.
Mol Immunol ; 53(1-2): 52-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22796951

RESUMO

New approaches for the treatment of inflammatory disorders such as rheumatic arthritis (RA) and inflammatory lung disease (asthma) are needed because a significant population of patients do not experience sustained relief with currently available therapies. The tyrosine kinase Syk plays a crucial role in inflammatory signaling pathways and has gained much attention as a potential target for treatment of inflammatory disorders. We have shown that our Syk siRNA injected directly into limb joints of arthritic mice, diminishes joint swelling and reduces levels of Syk kinase and inflammatory cytokines in joint tissue. Further, our Syk siRNA, administered via nasal instillation, inhibits recruitment of inflammatory cells to the bronchoalveolar fluid of allergen-sensitized mice. We propose that targeting Syk via localized application of Syk siRNA provides an opportunity for specific knockdown of Syk kinase with minimal potential for systemic effects.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Asma/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , RNA Interferente Pequeno/uso terapêutico , Alérgenos/imunologia , Animais , Artrite Experimental/tratamento farmacológico , Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Western Blotting , Feminino , Humanos , Hipersensibilidade/tratamento farmacológico , Hipersensibilidade/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pneumonia/tratamento farmacológico , Pneumonia/imunologia , Proteínas Tirosina Quinases/imunologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Quinase Syk , Transfecção
19.
J Biol Chem ; 286(1): 160-8, 2011 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-21044955

RESUMO

Phagocytosis of foreign pathogens by cells of the immune system is a vitally important function of innate immunity. The phagocytic response is initiated when ligands on the surface of invading microorganisms come in contact with receptors on the surface of phagocytic cells such as neutrophils, monocytes/macrophages, and dendritic cells. The complement receptor CR3 (CD11b/CD18, Mac-1) mediates the phagocytosis of complement protein (C3bi)-coated particles. Fcγ receptors (FcγRs) bind IgG-opsonized particles and provide a mechanism for immune clearance and phagocytosis of IgG-coated particles. We have observed that stimulation of FcγRs modulates CR3-mediated phagocytosis and that FcγRIIA and FcγRI exert opposite (stimulatory and inhibitory) effects. We have also determined that an intact FcγR immunoreceptor tyrosine-based activation motif is required for these effects, and we have investigated the involvement of downstream effectors. The ability to up-regulate or down-regulate CR3 signaling has important implications for therapeutics in disorders involving the host defense system.


Assuntos
Antígeno de Macrófago 1/imunologia , Fagocitose , Receptores de IgG/imunologia , Animais , Células COS , Chlorocebus aethiops , Feminino , Humanos , Antígeno de Macrófago 1/metabolismo , Masculino , Camundongos , Monócitos/imunologia , Monócitos/metabolismo , Fagocitose/imunologia , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas c-vav/metabolismo , Receptores de IgG/química , Receptores de IgG/metabolismo
20.
Mol Immunol ; 48(4): 691-6, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21168221

RESUMO

In addition to their primary role in hemostasis and wound healing, platelets play important roles in a multitude of physiological functions including immune and inflammatory responses. We present data that platelets, by virtue of their expression of the human specific FcγR, FcγRIIA, bind IgG complexes in vivo and that circulating phagocytes from healthy individuals internalize platelets in vivo. Human platelets, as a consequence of their expression of FcγRIIA, may thus, contribute to the clearance of IgG-containing complexes from the circulation.


Assuntos
Complexo Antígeno-Anticorpo/imunologia , Plaquetas/imunologia , Fagócitos/imunologia , Receptores de IgG/imunologia , Animais , Plaquetas/citologia , Plaquetas/ultraestrutura , Movimento Celular , Endocitose/imunologia , Citometria de Fluxo , Saúde , Humanos , Imunoglobulina G/imunologia , Camundongos , Monócitos/citologia , Monócitos/imunologia , Monócitos/ultraestrutura , Fagócitos/citologia , Fagocitose/imunologia , Ligação Proteica , Doadores de Tecidos
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