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1.
Personnel Review ; 52(4):1071-1093, 2023.
Article in English | ProQuest Central | ID: covidwho-2320312

ABSTRACT

PurposeHow to manage outsourced employees in interorganizational teams with triangular relationships has not yet attracted enough attention. Based on relative deprivation theory, this study explores how relative deprivation affects outsourced employees' innovative behavior and investigates the complex moderating effects of dual organizational support.Design/methodology/approachThe authors tested their hypothesis by conducting a two-wave survey;responses to a questionnaire were collected from 283 outsourced employees and their managers among 52 client organizations.FindingsResults found that relative deprivation negatively influences the outsourced employees' innovative behavior by eliciting their perceptions of status conflict. Support from client (supplier) organization attenuates (aggravates) the positive impact of relative deprivation on innovative behavior throughout status conflict. The moderating effect of client organizational support was moderated by support from supplier organization.Research limitations/implicationsThe authors selected the outsourced employees in a Chinese context to conduct this study, and the results need to be generalized in future research.Practical implicationsClient organizational support can alleviate the negative effect of relative deprivation on outsourced employees, whereas supplier organization support aggravates the negative effect;managers should pay attention to the different effects of the two organizations' support and provide reasonable support for outsourced employees.Originality/valueThis study identified the mechanism of relative deprivation's effect on outsourced employees' innovative behavior from the perspective of interpersonal interaction and compared the effect of support from dual organizations. This study expands the research on triangular relationships, relative deprivation, status conflict and other field.

2.
Nat Aging ; 3(4): 418-435, 2023 04.
Article in English | MEDLINE | ID: covidwho-2287166

ABSTRACT

Aging is a critical risk factor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine efficacy. The immune responses to inactivated vaccine for older adults, and the underlying mechanisms of potential differences to young adults, are still unclear. Here we show that neutralizing antibody production by older adults took a longer time to reach similar levels in young adults after inactivated SARS-CoV-2 vaccination. We screened SARS-CoV-2 variant strains for epitopes that stimulate specific CD8 T cell response, and older adults exhibited weaker CD8 T-cell-mediated responses to these epitopes. Comparison of lymphocyte transcriptomes from pre-vaccinated and post-vaccinated donors suggested that the older adults had impaired antigen processing and presentation capability. Single-cell sequencing revealed that older adults had less T cell clone expansion specific to SARS-CoV-2, likely due to inadequate immune receptor repertoire size and diversity. Our study provides mechanistic insights for weaker response to inactivated vaccine by older adults and suggests the need for further vaccination optimization for the old population.


Subject(s)
COVID-19 , SARS-CoV-2 , Young Adult , Humans , Aged , COVID-19 Vaccines , COVID-19/prevention & control , Immunity, Cellular , Clone Cells , Epitopes , Vaccines, Inactivated
3.
Anal Chem ; 2022 Dec 01.
Article in English | MEDLINE | ID: covidwho-2133135

ABSTRACT

Unlike conventional surface plasmon resonance (SPR) using an antifouling film to anchor biomolecules and a reference channel for background subtraction, SPR microscopy for single-cell analysis uses a protein- or polypeptide-modified gold substrate to immobilize cells and a cell-free area as the reference. In this work, we show that such a substrate is prone to nonspecific adsorption (NSA) of species from the cell culture media, resulting in false background signals that cannot be correctly subtracted. To obtain accurate kinetic results, we patterned a dual-channel substrate using a microfluidic device, with one channel having poly-l-lysine deposited in situ onto a preformed polyethylene glycol (PEG) self-assembled monolayer for cell immobilization and the other channel remaining as PEG-covered for reference. The two 2.0 mm-wide channels are separated by a 75 µm barrier, and parts of the channels can be readily positioned into the field of view of an SPR microscope. The use of this dual-channel substrate for background subtraction is contrasted with the conventional approach through the following binding studies: (1) wheat germ agglutinin (WGA) attachment to the N-acetyl glucosamine and N-acetyl-neuraminic acid sites of glycans on HFF cells, and (2) the S1 protein of the COVID-19 virus conjugation with angiotensin-converting enzyme 2 (ACE2) on the HEK293 cells. Both studies revealed that interferences by NSA and the surface plasmon polariton wave diffracted by cells can be excluded with the dual-channel substrate, and the much smaller refractive index changes caused by the injected solutions can be correctly subtracted. Consequently, sensorgrams with higher signal-to-noise ratios and shapes predicted by the correct binding model can be obtained with accurate kinetic and affinity parameters that are more biologically relevant. The affinity between S1 protein and ACE2 is comparable to that measured with recombinant ACE2, yet the binding kinetics is different, suggesting that the cell membrane does impose a kinetic barrier to their interaction.

4.
ACS Sens ; 7(11): 3560-3570, 2022 Nov 25.
Article in English | MEDLINE | ID: covidwho-2115655

ABSTRACT

Current tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detect either the constituent nucleic acids/proteins of the viral particles or antibodies specific to the virus, but cannot provide information about viral neutralization by an antibody and the efficacy of an antibody. Such information is important about individuals' vulnerability to severe symptoms or their likelihood of showing no symptoms. We immobilized online SARS-CoV-2 spike (S1) protein and angiotensin-converting enzyme 2 (ACE2) into separate surface plasmon resonance (SPR) channels of a tris-nitrilotriacetic acid (tris-NTA) chip to simultaneously detect the anti-S1 antibody and viral particles in serum samples. In addition, with a high-molecular-weight-cutoff filter, we separated the neutralized viral particles from the free antibody molecules and used a sensing channel immobilized with Protein G to determine antibody-neutralized viral particles. The optimal density of probe molecules in each fluidic channel can be precisely controlled through the closure and opening of the specific ports. By utilizing the high surface density of ACE2, multiple assays can be carried out without regenerations. These three species can be determined with a short analysis time (<12 min per assay) and excellent sensor-to-sensor/cycle-to-cycle reproducibility (RSD < 5%). When coupled with an autosampler, continuous assays can be performed in an unattended manner at a single chip for up to 6 days. Such a sensor capable of assaying serum samples containing the three species at different levels provides additional insights into the disease status and immunity of persons being tested, which should be helpful for containing the SARS-CoV-2 spread during the era of incessant viral mutations.


Subject(s)
COVID-19 , SARS-CoV-2 , Surface Plasmon Resonance , Humans , Angiotensin-Converting Enzyme 2 , Antibodies, Viral , COVID-19/diagnosis , Reproducibility of Results , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus , Virion/isolation & purification
5.
Forests ; 13(5):734, 2022.
Article in English | ProQuest Central | ID: covidwho-1872006

ABSTRACT

The establishment of natural protected areas (NPAs) is an effective means to deal with the degradation of ecosystems caused by climate change and human activities. The area and number of NPAs in the world have shown an obvious growth trend, and their development has ushered in a new bottleneck. More importantly, the management quality of NPAs should be improved, and the key to improving management quality lies in human beings, but the stakeholder groups involved in NPAs are often overlooked by policymakers. In this study, a quantitative review of the global scientific literature on NPAs stakeholders was conducted using a bibliometric approach. The research hotspots and trends, number, time, and countries were analyzed based on data from published articles. The stakeholder types and internal relationships in NPAs were summarized and mapped. The common problems of resources and community resident management among stakeholders were discussed. A total of 5584 research articles selected from the Web of Science core collection database were used as data sources and were visualized using VOSviewer and the Biblioshiny program in the R language. The results of the study help to reveal the mutual influence mechanism between stakeholders during the development of nature reserves and contribute to the sustainable development of global protected areas and human well-being.

6.
Front Pharmacol ; 13: 879733, 2022.
Article in English | MEDLINE | ID: covidwho-1862647

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) is an alphacoronavirus (α-CoV) that causes high mortality in suckling piglets, leading to severe economic losses worldwide. No effective vaccine or commercial antiviral drug is readily available. Several replicative enzymes are responsible for coronavirus replication. In this study, the potential candidates targeting replicative enzymes (PLP2, 3CLpro, RdRp, NTPase, and NendoU) were screened from 187,119 compounds in ZINC natural products library, and seven compounds had high binding potential to NTPase and showed drug-like property. Among them, ZINC12899676 was identified to significantly inhibit the NTPase activity of PEDV by targeting its active pocket and causing its conformational change, and ZINC12899676 significantly inhibited PEDV replication in IPEC-J2 cells. It first demonstrated that ZINC12899676 inhibits PEDV replication by targeting NTPase, and then, NTPase may serve as a novel target for anti-PEDV.

7.
Digit Signal Process ; 127: 103577, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1819476

ABSTRACT

The outbreak of coronavirus disease (COVID-19) and its accompanying pandemic have created an unprecedented challenge worldwide. Parametric modeling and analyses of the COVID-19 play a critical role in providing vital information about the character and relevant guidance for controlling the pandemic. However, the epidemiological utility of the results obtained from the COVID-19 transmission model largely depends on accurately identifying parameters. This paper extends the susceptible-exposed-infectious-recovered (SEIR) model and proposes an improved quantum-behaved particle swarm optimization (QPSO) algorithm to estimate its parameters. A new strategy is developed to update the weighting factor of the mean best position by the reciprocal of multiplying the fitness of each best particle with the average fitness of all best particles, which can enhance the global search capacity. To increase the particle diversity, a probability function is designed to generate new particles in the updating iteration. When compared to the state-of-the-art estimation algorithms on the epidemic datasets of China, Italy and the US, the proposed method achieves good accuracy and convergence at a comparable computational complexity. The developed framework would be beneficial for experts to understand the characteristics of epidemic development and formulate epidemic prevention and control measures.

8.
Anal Chim Acta ; 1208: 339830, 2022 May 22.
Article in English | MEDLINE | ID: covidwho-1783112

ABSTRACT

Current serological antibody tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) require enzyme or fluorescent labels, and the titer well plates cannot be reused. By immobilizing histidine (His)-tagged SARS-CoV-2 spike (S1) protein onto tris‒nitrilotriacetic acid (tris-NTA) sensor and using the early association phase for mass-transfer-controlled concentration determination, we developed a rapid and regenerable surface plasmon resonance (SPR) method for quantifying anti-SARS-CoV-2 antibody. On a five-channel SPR instrument and with optimized S1 protein immobilization density, each of the four analytical channels is sequentially used for multiple measurements, and all four channels can be simultaneously regenerated once they have reached a threshold value. Coupled with a programmable autosampler, each sensor can be regenerated at least 20 times, enabling uninterrupted assays of more than 800 serum samples. The accuracy and speed of our method compare well with those of the enzyme-linked immunosorbent assay (ELISA), and the detection limit (0.057 µg mL-1) can easily meet the requirement for screening low antibody levels such as those in convalescent patients. In addition, our method exhibits excellent channel-to-channel (RSD = 1.9%) and sensor-to-sensor (RSD = 2.1%) reproducibility. Obviation of an enzyme label drastically reduced the assay cost, rending our method (<60 cents) much more cost effective than those of commercial ELISA kits ($4.4-11.4). Therefore, our method offers a cost-effective and high-throughput alternative to the existing methods for serological measurements of anti-SARS-CoV-2 antibody levels, holding great promise for rapid screening of clinical samples without elaborate sample pretreatments and special reagents.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19/diagnosis , Enzyme-Linked Immunosorbent Assay , Humans , Reproducibility of Results , Surface Plasmon Resonance
9.
iScience ; 25(3): 103934, 2022 Mar 18.
Article in English | MEDLINE | ID: covidwho-1693365

ABSTRACT

Here, we evaluated the immune properties of the HLA-A2 restricted CD8+ T cell epitopes containing mutations from B.1.1.7, and furthermore performed a comprehensive analysis of the SARS-CoV-2 specific CD8+ T cell responses from COVID-19 convalescent patients and SARS-CoV-2 vaccinees recognizing the ancestral Wuhan strain compared to B.1.1.7. First, most of the predicted CD8+ T cell epitopes showed proper binding with HLA-A2, whereas epitopes from B.1.1.7 had lower binding capability than those from the ancestral strain. In addition, these peptides could effectively induce the activation and cytotoxicity of CD8+ T cells. Our results further showed that at least two site mutations in B.1.1.7 resulted in a decrease in CD8+ T cell activation and a possible immune evasion, namely A1708D mutation in ORF1ab1707-1716 and I2230T mutation in ORF1ab2230-2238. Our current analysis provides information that contributes to the understanding of SARS-CoV-2-specific CD8+ T cell responses elicited by infection of mutated strains or vaccination.

10.
Front Immunol ; 12: 764949, 2021.
Article in English | MEDLINE | ID: covidwho-1674330

ABSTRACT

We identified SARS-CoV-2 specific antigen epitopes by HLA-A2 binding affinity analysis and characterized their ability to activate T cells. As the pandemic continues, variations in SARS-CoV-2 virus strains have been found in many countries. In this study, we directly assess the immune response to SARS-CoV-2 epitope variants. We first predicted potential HLA-A*02:01-restricted CD8+ T-cell epitopes of SARS-CoV-2. Using the T2 cell model, HLA-A*02:01-restricted T-cell epitopes were screened for their binding affinity and ability to activate T cells. Subsequently, we examined the identified epitope variations and analyzed their impact on immune response. Here, we identified specific HLA-A2-restricted T-cell epitopes in the spike protein of SARS-CoV-2. Seven epitope peptides were confirmed to bind with HLA-A*02:01 and potentially be presented by antigen-presenting cells to induce host immune responses. Tetramers containing these peptides could interact with specific CD8+ T cells from convalescent COVID-19 patients, and one dominant epitope (n-Sp1) was defined. These epitopes could activate and generate epitope-specific T cells in vitro, and those activated T cells showed cytolytic activity toward target cells. Meanwhile, n-Sp1 epitope variant 5L>F significantly decreased the proportion of specific T-cell activation; n-Sp1 epitope 8L>V variant showed significantly reduced binding to HLA-A*02:01 and decreased proportion of n-Sp1-specific CD8+ T cell, which potentially contributes to the immune escape of SARS-CoV-2. Our data indicate that the variation of a dominant epitope will cause the deficiency of HLA-A*02:01 binding and T-cell activation, which subsequently requires the formation of a new CD8+ T-cell immune response in COVID-19 patients.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Epitopes, T-Lymphocyte/immunology , HLA-A2 Antigen/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Amino Acid Sequence , Antigen Presentation , Antigenic Variation , COVID-19/immunology , Epitopes, T-Lymphocyte/chemistry , Epitopes, T-Lymphocyte/genetics , Female , Humans , Immune Evasion , Lymphocyte Activation , Male , Middle Aged , Molecular Docking Simulation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
11.
STAR Protoc ; 2(3): 100789, 2021 09 17.
Article in English | MEDLINE | ID: covidwho-1641729

ABSTRACT

Here, we describe the use of the artificial antigen-presenting cell (aAPC) system for the verification of T-cell epitopes. We purify and activate CD8+ T cells from blood samples from HLA-A2 that are negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). CD8+ T cells are combined with peptide-loaded T2-A2 cells, which are then stained with a SARS-CoV-2-specific MHC-1 tetramer to identify specific HLA-A2-restricted T-cell epitopes. The use of aAPC and healthy donors means that only BSL2 lab conditions are needed. For details of the use and implementation of this protocol, please refer to Deng et al. (2021).


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Epitopes, T-Lymphocyte/immunology , HLA-A2 Antigen/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Tumor Necrosis Factor Receptor Superfamily, Member 7/immunology , Humans , Lymphocyte Activation
12.
J Leukoc Biol ; 110(6): 1171-1180, 2021 12.
Article in English | MEDLINE | ID: covidwho-1298499

ABSTRACT

The outbreak of coronavirus disease 2019 (COVID-19) has now become a pandemic, and the etiologic agent is the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). T cell mediated immune responses play an important role in virus controlling; however, the understanding of the viral protein immunogenicity and the mechanisms of the induced responses are still limited. So, identification of specific epitopes and exploring their immunogenic properties would provide valuable information. In our study, we utilized the Immune Epitope Database and Analysis Resource and NetMHCpan to predict HLA-A2 restricted CD8+ T cell epitopes in structural proteins of SARS-CoV-2, and screened out 23 potential epitopes. Among them, 18 peptides showed strong or moderate binding with HLA-A2 with a T2A2 cell binding model. Next, the mixed peptides induced the increased expression of CD69 and highly expressed levels of IFN-γ and granzyme B in CD8+ T cells, indicating effective activation of specific CD8+ T cells. In addition, the peptide-activated CD8+ T cells showed significantly increased killing to the target cells. Furthermore, tetramer staining revealed that the activated CD8+ T cells mainly recognized seven epitopes. All together, we identified specific CD8+ T cell epitopes in SARS-CoV-2 structural proteins, which could induce the production of specific immune competent CD8+ T cells. Our work contributes to the understanding of specific immune responses and vaccine development for SARS-CoV-2.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Epitopes, T-Lymphocyte/immunology , HLA-A2 Antigen/immunology , SARS-CoV-2/immunology , Viral Structural Proteins/immunology , Adult , Female , Humans , Lymphocyte Activation/immunology , Male
13.
Signal Transduct Target Ther ; 6(1): 126, 2021 03 24.
Article in English | MEDLINE | ID: covidwho-1147832

ABSTRACT

The efficient induction and long-term persistence of pathogen-specific memory CD8 T cells are pivotal to rapidly curb the reinfection. Recent studies indicated that long-noncoding RNAs expression is highly cell- and stage-specific during T cell development and differentiation, suggesting their potential roles in T cell programs. However, the key lncRNAs playing crucial roles in memory CD8 T cell establishment remain to be clarified. Through CD8 T cell subsets profiling of lncRNAs, this study found a key lncRNA-Snhg1 with the conserved naivehi-effectorlo-memoryhi expression pattern in CD8 T cells of both mice and human, that can promote memory formation while impeding effector CD8 in acute viral infection. Further, Snhg1 was found interacting with the conserved vesicle trafficking protein Vps13D to promote IL-7Rα membrane location specifically. With the deep mechanism probing, the results show Snhg1-Vps13D regulated IL-7 signaling with its dual effects in memory CD8 generation, which not just because of the sustaining role of STAT5-BCL-2 axis for memory survival, but more through the STAT3-TCF1-Blimp1 axis for transcriptional launch program of memory differentiation. Moreover, we performed further study with finding a similar high-low-high expression pattern of human SNHG1/VPS13D/IL7R/TCF7 in CD8 T cell subsets from PBMC samples of the convalescent COVID-19 patients. The central role of Snhg1-Vps13D-IL-7R-TCF1 axis in memory CD8 establishment makes it a potential target for improving the vaccination effects to control the ongoing pandemic.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Interleukin-7/immunology , Proteins/immunology , RNA, Long Noncoding/immunology , SARS-CoV-2/immunology , Secretory Vesicles/immunology , Signal Transduction/immunology , Animals , Biological Transport, Active , CD8-Positive T-Lymphocytes/pathology , COVID-19/pathology , Humans , Immunologic Memory , Mice , Secretory Vesicles/pathology
14.
Comput Struct Biotechnol J ; 19: 1063-1071, 2021.
Article in English | MEDLINE | ID: covidwho-1056515

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which induced mainly the respiratory damage also caused ocular surface symptoms. However, the detailed description of ocular manifestations, severity fluctuations in confirmed COVID-19 adult patients still lacked. We analyzed onset clinical symptoms and duration, ocular symptoms, needs for medication, outcomes in 28 conjunctivitis patients who were extracted from 3198 COVID-19 patients hospitalized in Huoshenshan Hospital and Taikangtongji Hospital, Wuhan, China. The expression levels of ACE2, TMPRSS2, ANPEP, DPP4, NRP1 on fetal and adult ocular surface and mouse lacrimal glands were assessed by single cell seq analysis. Our results indicated that conjunctivitis was a rare and self-limited complication in adults with COVID-19 while the existence of coronavirus receptors on human ocular surface and mouse lacrimal glands indicated the risk of SARS-CoV-2 infection. Our research firstly examined SARS-CoV-2 receptors, including the new discovered one, NRP1, on the fetal ocular surface and in the mouse lacrimal glands.

15.
J Am Acad Orthop Surg ; 28(15): e679-e685, 2020 Aug 01.
Article in English | MEDLINE | ID: covidwho-526434

ABSTRACT

BACKGROUND: In response to COVID-19, American medical centers have enacted elective case restrictions, markedly affecting the training of orthopaedic residents. Residencies must develop new strategies to provide patient care while ensuring the health and continued education of trainees. We aimed to describe the evolving impact of COVID-19 on orthopaedic surgery residents. METHODS: We surveyed five Accreditation Council for Graduate Medical Education-accredited orthopaedic residency programs within cities highly affected by the COVID-19 pandemic about clinical and curricular changes. An online questionnaire surveyed individual resident experiences related to COVID-19. RESULTS: One hundred twenty-one resident survey responses were collected. Sixty-five percent of the respondents have cared for a COVID-19-positive patient. One in three reported being unable to obtain institutionally recommended personal protective equipment during routine clinical work. All programs have discontinued elective orthopaedic cases and restructured resident rotations. Most have shifted schedules to periods of active clinical duty followed by periods of remote work and self-isolation. Didactic education has continued via videoconferencing. DISCUSSION: COVID-19 has caused unprecedented changes to orthopaedic training; however, residents remain on the front lines of inpatient care. Exposures to COVID-19 are prevalent and residents have fallen ill. Programs currently use a variety of strategies to provide essential orthopaedic care. We recommend continued prioritization of resident safety and necessary training accommodations.


Subject(s)
Coronavirus Infections/epidemiology , Education, Medical, Graduate , Internship and Residency , Orthopedic Procedures/education , Pneumonia, Viral/epidemiology , Betacoronavirus , COVID-19 , Cities , Humans , Pandemics , SARS-CoV-2 , Surveys and Questionnaires , United States/epidemiology , Workload
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