76 research outputs found
Discovery and Differential Processing of HLA Class II-Restricted Minor Histocompatibility Antigen LB-PIP4K2A-1S and Its Allelic Variant by Asparagine Endopeptidase
Minor histocompatibility antigens are the main targets of donor-derived T-cells after allogeneic stem cell transplantation. Identification of these antigens and understanding their biology are a key requisite for more insight into how graft vs. leukemia effect and graft vs. host disease could be separated. We here identified four new HLA class II-restricted minor histocompatibility antigens using whole genome association scanning. For one of the new antigens, i.e., LB-PIP4K2A-1S, we measured strong T-cell recognition of the donor variant PIP4K2A-1N when pulsed as exogenous peptide, while the endogenously expressed variant in donor EBV-B cells was not recognized. We showed that lack of T-cell recognition was caused by intracellular cleavage by a protease named asparagine endopeptidase (AEP). Furthermore, microarray gene expression analysis showed that PIP4K2A and AEP are both ubiquitously expressed in a wide variety of healthy tissues, but that expression levels of AEP were lower in primary acute myeloid leukemia (AML). In line with that, we confirmed low activity of AEP in AML cells and demonstrated that HLA-DRB1*03:01 positive primary AML expressing LB-PIP4K2A-1S or its donor variant PIP4K2A-1N were both recognized by specific T-cells. In conclusion, LB-PIP4K2A-1S not only represents a novel minor histocompatibility antigen but also provides evidence that donor T-cells after allogeneic stem cell transplantation can target the autologous allelic variant as leukemia-associated antigen. Furthermore, it demonstrates that endopeptidases can play a role in cell type-specific intracellular processing and presentation of HLA class II-restricted antigens, which may be explored in future immunotherapy of AML
Učinkovita mikropropagacija i zakorjenjivanje vrste Micromeria croatica (Pers.) Schott (Lamiaceae)
Micromeria croatica is an endangered species with a great potential for use as a medical as well as ornamental plant. For commercial use, an efficient propagation protocol is required. The aims of this study were to establish an efficient protocol for micropropagation and rooting of M. croatica. A number of factors were tested including the influence of 6-benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) at different concentrations as well as the effect of explant orientation and topophysis on shoot proliferation. Rooting was investigated in agar-based medium supplemented with indole-3-butyric acid (IBA) or indole-3-acetic acid (IAA) at various concentrations. Media with 1 and 2 mg/L of BAP produced the highest number of shoots/explant. However, the lower concentration of BAP should be recommended due to longer shoots without any sign of hyperhydration. Explant orientation and node position showed equal capability for shoot proliferation. Importantly, 100% efficiency of rooting was achieved in an agar-based rooting medium. Acclimatisation exceeded 90%. Taken together, an efficient protocol for micropropagation and rooting of M. croatica has been established for future production.Hrvatska je bresina (Micromeria croatica) ugrožena biljna vrsta, s velikim potencijalom uzgoja u medicinske svrhe i kao ukrasna biljka. Za komercijalnu primjenu, nužan je učinkovit protokol za propagaciju. Cilj ovoga rada bio je uspostavljanje učinkovitoga protokola za mikropropagaciju i zakorjenjivanje vrste M. croatica upotrebom odrasle biljke kao izvora početnoga materijala. Testiran je velik broj faktora, uključujući utjecaj 6-benzilaminopurina (BAP) i 1-naftalen octene kiseline (NAA) u različitim koncentracijama, kao i utjecaj orijentacije eksplantata i topofizis efekta na proliferaciju izdanaka. Zakorjenjivanje je ispitivano u mediju s agarom, uz dodatak indol-3-maslačne kiseline (IBA) ili indol-3-octene kiseline (IAA) u različitim koncentracijama. Mediji s 1 ili 2 mg/L BAP-a producirali su najveći broj izdanaka / eksplantatu, međutim preporuča se niža koncentracija BAP-a, na kojoj su dobiveni duži izdanci, bez znakova hiperhidracije. Orijentacija eksplantata i nodiji s različitih pozicija na izdanku pokazali su jednaku sposobnost proliferacije izdanaka. Na mediju s agarom postignuta je 100% uspješnost zakorjenjivanja. Uspješnost aklimatizacije bila je iznad 90%. Zaključno, razvijen je učinkovit protokol za mikropropagaciju i zakorjenjivanje vrste M. croatica za moguću buduću proizvodnju
PERCEPÇÃO DOS DISCENTES DE CIÊNCIAS CONTÁBEIS SOBRE O CURSO E A PROFISSÃO CONTÁBIL: IMAGEM E ESTEREÓTIPOS
O objetivo do estudo foi compreender como está constituída a imagem do curso e da profissão contábil perante discentes de ciências contábeis. Por meio dos pressupostos da Teoria das Representações Sociais e dos estereótipos da profissão contábil, realizou-se uma pesquisa qualitativa através de entrevistas, realizadas por meio de grupos de focos, com acadêmicos do curso de ciências contábeis de um município do oeste paranaense. Para análise de dados da pesquisa, empregou-se categorização por meio da utilização do software Atlas/Ti, e posteriormente realizado análise de conteúdo. Como resultados destaca-se, que os acadêmicos, antes de entrar no curso, possuíam ideias estereotipadas quanto a profissão e quanto as expectativas sobre a profissão, constatou-se satisfação principalmente quanto ao amplo campo de atuação profissional
Competências docentes e aprendizagem em controladoria em programas de mestrado: uma investigação da percepção discente
Objetivo: Compreender a percepção dos discentes sobre a relação entre competências docentes e aprendizado de controladoria em programas de mestrado em contabilidade no sul e sudeste do Brasil.
Metodologia: Estudo qualitativo com caráter descritivo-exploratório realizado por meio de entrevistas em profundidade. Foram entrevistados 19 alunos que concluíram a disciplina de controladoria em 9 programas de mestrado em contabilidade no sul e sudeste do Brasil. Empregou-se análise de conteúdo.
Resultados: Os alunos indicaram que a percepção sobre conhecimentos (domínio de conteúdo, experiência prática sobre organizações e experiência acadêmica), habilidades (prática pedagógica, incluindo comunicação, estratégias de ensino e método de avaliação) e atitudes (preparação das aulas; escolha dos materiais da disciplina; e relacionamento interpessoal) dos professores se relacionam com seu processo de aprendizagem. Esta diferenciação é apenas didática, pois tanto a teoria sobre competências quanto os resultados obtidos a partir das entrevistas demonstram que esses aspectos se inter-relacionam no processo de aprendizagem.
Contribuições do Estudo: Essa pesquisa pode trazer contribuições relevantes para professores e instituições avaliarem e promoverem mudanças no processo de ensino em controladoria nos programas de mestrado
Yeast pex1 cells contain peroxisomal ghosts that import matrix proteins upon reintroduction of Pex1
Pex1 and Pex6 are two AAA-ATPases that play a crucial role in peroxisome biogenesis. We have characterized the ultrastructure of the Saccharomyces cerevisiae peroxisome-deficient mutants pex1 and pex6 by various high-resolution electron microscopy techniques. We observed that the cells contained peroxisomal membrane remnants, which in ultrathin cross sections generally appeared as double membrane rings. Electron tomography revealed that these structures consisted of one continuous membrane, representing an empty, flattened vesicle, which folds into a cup shape. Immunocytochemistry revealed that these structures lack peroxisomal matrix proteins but are the sole sites of the major peroxisomal membrane proteins Pex2, Pex10, Pex11, Pex13, and Pex14. Upon reintroduction of Pex1 in Pex1-deficient cells, these peroxisomal membrane remnants (ghosts) rapidly incorporated peroxisomal matrix proteins and developed into peroxisomes. Our data support earlier views that Pex1 and Pex6 play a role in peroxisomal matrix protein import
Cellular and humoral immune responses to SARS-CoV-2 vaccination in patients after CD19.CAR-T cell therapy
Novel Mycobacterium tuberculosis Complex Pathogen, M. mungi
Seven outbreaks involving increasing numbers of banded mongoose troops and high death rates have been documented. We identified a Mycobacterium tuberculosis complex pathogen, M. mungi sp. nov., as the causative agent among banded mongooses that live near humans in Chobe District, Botswana. Host spectrum and transmission dynamics remain unknown
Declining mortality of cerebral venous sinus thrombosis with thrombocytopenia after SARS-CoV-2 vaccination
Publisher Copyright: © 2021 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.Background and purpose: High mortality rates have been reported in patients with cerebral venous sinus thrombosis (CVST) due to vaccine-induced immune thrombotic thrombocytopenia (VITT) after vaccination with adenoviral vector SARS-CoV-2 vaccines. The aim of this study was to evaluate whether the mortality of patients with CVST-VITT has decreased over time. Methods: The EudraVigilance database of the European Medicines Agency was used to identify cases of CVST with concomitant thrombocytopenia occurring within 28 days of SARS-CoV-2 vaccination. Vaccines were grouped based on vaccine type (adenoviral or mRNA). Cases with CVST onset until 28 March were compared to cases after 28 March 2021, which was the day when the first scientific paper on VITT was published. Results: In total, 270 cases of CVST with thrombocytopenia were identified, of which 266 (99%) occurred after adenoviral vector SARS-CoV-2 vaccination (ChAdOx1 nCoV-19, n = 243; Ad26.COV2.S, n = 23). The reported mortality amongst adenoviral cases with onset up to 28 March 2021 was 47/99 (47%, 95% confidence interval 37%–58%) compared to 36/167 (22%, 95% confidence interval 16%–29%) in cases with onset after 28 March (p < 0.001). None of the four cases of CVST with thrombocytopenia occurring after mRNA vaccination died. Conclusion: The reported mortality of CVST with thrombocytopenia after vaccination with adenoviral vector-based SARS-CoV-2 vaccines has significantly decreased over time, which may indicate a beneficial effect of earlier recognition and/or improved treatment on outcome after VITT.Peer reviewe
Cerebral venous thrombosis due to vaccine-induced immune thrombotic thrombocytopenia after a second ChAdOx1 nCoV-19 dose.
© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.Cerebral venous thrombosis (CVT) is the most common and severe manifestation of vaccine-induced immune thrombotic thrombocytopenia (VITT), which is a rare side effect of the SARS-CoV-2 vaccine ChAdOx1 nCoV-19 (Vaxzevria, AstraZeneca/Oxford). The absolute risk of VITT and VITT-related CVT is estimated at 20 and 8 per million first doses of ChAdOx1 nCoV-19, respectively.
So far, no definite VITT cases occurring after a second ChAdOx1 nCoV-19 vaccine dose have been reported, raising the question of whether VITT only occurs after a first dose. Two pharmacovigilance studies reported cases of thrombosis with thrombocytopenia after a second ChAdOx1 nCoV-19 dose, but because of lack of clinical data, none of these could be classified as VITT. Knowledge on whether VITT can occur after a second ChAdOx1 nCoV-19 dose is relevant for clinicians and policymakers, especially in low- and middle-income countries, which are currently the main users of adenovirus-based vaccines.
We used data from the “CVT after SARS-CoV-2 vaccination” registry to identify VITT-related CVT cases occurring after a second ChAdOx1 nCoV-19 dose.
Details of this registry have been published. Briefly, this ongoing study collects data on patients with CVT with symptom onset ≤28 days from SARS-CoV-2 vaccination, regardless of the type and dose of vaccine. The study is endorsed by the European Academy of Neurology and the European Stroke Organization. Investigators are instructed to report consecutive cases from their hospitals. The ethical review board of the Academic Medical Centre issued a waiver of formal approval for this observational study. Each center obtained local permission to carry out the study and acquired informed consent for the use of pseudonymized care data according to national law.
We used the case definition criteria of the United Kingdom expert hematology panel to classify cases as definite, probable, possible, or unlikely VITT after ChAdOx1 nCoV-19 administration among CVT cases reported until 1 December 2021.This work was supported by The Netherlands Organisation for Health Research and Development (ZonMw, grant number 10430072110005) (J.M.C.) and the Dr. C. J. Vaillant Foundation (J.M.C.).info:eu-repo/semantics/publishedVersio
Successful treatment of COVID-19 infection with convalescent plasma in B-cell-depleted patients may promote cellular immunity
Treatment with convalescent plasma has been shown to be safe in coronavirus disease in 2019 (COVID-19) infection, although efficacy reported in immunocompetent patients varies. Nevertheless, neutralizing antibodies are a key requisite in the fight against viral infections. Patients depleted of antibody-producing B cells, such as those treated with rituximab (anti-CD20) for hematological malignancies, lack a fundamental part of their adaptive immunity. Treatment with convalescent plasma appears to be of general benefit in this particularly vulnerable cohort. We analyzed clinical course and inflammation markers of three B-cell-depleted patients suffering from COVID-19 who were treated with convalescent plasma. In addition, we measured serum antibody levels as well as peripheral blood CD38/HLA-DR-positive T-cells ex vivo and CD137-positive T-cells after in vitro stimulation with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-derived peptides in these patients. We observed that therapy with convalescent plasma was effective in all three patients and analysis of CD137-positive T-cells after stimulation with SARS-CoV-2 peptides showed an increase in peptide-specific T-cells after application of convalescent plasma. In conclusion, we here demonstrate efficacy of convalescent plasma therapy in three B-cell-depleted patients and present data that suggest that while application of convalescent plasma elevates systemic antibody levels only transiently, it may also boost specific T-cell responses
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