Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 108
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Immunity ; 56(7): 1649-1663.e5, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37236188

RESUMO

Allogeneic hematopoietic stem cell transplantation (alloHSCT) from donors lacking C-C chemokine receptor 5 (CCR5Δ32/Δ32) can cure HIV, yet mechanisms remain speculative. To define how alloHSCT mediates HIV cure, we performed MHC-matched alloHSCT in SIV+, anti-retroviral therapy (ART)-suppressed Mauritian cynomolgus macaques (MCMs) and demonstrated that allogeneic immunity was the major driver of reservoir clearance, occurring first in peripheral blood, then peripheral lymph nodes, and finally in mesenteric lymph nodes draining the gastrointestinal tract. While allogeneic immunity could extirpate the latent viral reservoir and did so in two alloHSCT-recipient MCMs that remained aviremic >2.5 years after stopping ART, in other cases, it was insufficient without protection of engrafting cells afforded by CCR5-deficiency, as CCR5-tropic virus spread to donor CD4+ T cells despite full ART suppression. These data demonstrate the individual contributions of allogeneic immunity and CCR5 deficiency to HIV cure and support defining targets of alloimmunity for curative strategies independent of HSCT.


Assuntos
Infecções por HIV , Transplante de Células-Tronco Hematopoéticas , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Macaca fascicularis , Carga Viral
2.
Cereb Cortex ; 34(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38566509

RESUMO

Mixed feelings, the simultaneous presence of feelings with positive and negative valence, remain an understudied topic. They pose a specific set of challenges due to individual variation, and their investigation requires analtyic approaches focusing on individually self-reported states. We used functional magnetic resonance imaging (fMRI) to scan 27 subjects watching an animated short film chosen to induce bittersweet mixed feelings. The same subjects labeled when they had experienced positive, negative, and mixed feelings. Using hidden-Markov models, we found that various brain regions could predict the onsets of new feeling states as determined by self-report. The ability of the models to identify these transitions suggests that these states may exhibit unique and consistent neural signatures. We next used the subjects' self-reports to evaluate the spatiotemporal consistency of neural patterns for positive, negative, and mixed states. The insula had unique and consistent neural signatures for univalent states, but not for mixed valence states. The anterior cingulate and ventral medial prefrontal cortex had consistent neural signatures for both univalent and mixed states. This study is the first to demonstrate that subjectively reported changes in feelings induced by naturalistic stimuli can be predicted from fMRI and the first to show direct evidence for a neurally consistent representation of mixed feelings.


Assuntos
Afeto , Encéfalo , Humanos , Encéfalo/diagnóstico por imagem , Emoções , Mapeamento Encefálico/métodos , Córtex Pré-Frontal , Imageamento por Ressonância Magnética
3.
PLoS Pathog ; 18(3): e1010396, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35358290

RESUMO

The CCR5-specific antibody Leronlimab is being investigated as a novel immunotherapy that can suppress HIV replication with minimal side effects. Here we studied the virological and immunological consequences of Leronlimab in chronically CCR5-tropic HIV-1 infected humans (n = 5) on suppressive antiretroviral therapy (ART) and in ART-naïve acutely CCR5-tropic SHIV infected rhesus macaques (n = 4). All five human participants transitioned from daily combination ART to self-administered weekly subcutaneous (SC) injections of 350 mg or 700 mg Leronlimab and to date all participants have sustained virologic suppression for over seven years. In all participants, Leronlimab fully occupied CCR5 receptors on peripheral blood CD4+ T cells and monocytes. In ART-naïve rhesus macaques acutely infected with CCR5-tropic SHIV, weekly SC injections of 50 mg/kg Leronlimab fully suppressed plasma viremia in half of the macaques. CCR5 receptor occupancy by Leronlimab occurred concomitant with rebound of CD4+ CCR5+ T-cells in peripheral blood, and full CCR5 receptor occupancy was found in multiple anatomical compartments. Our results demonstrate that weekly, self-administered Leronlimab was safe, well-tolerated, and efficacious for long-term virologic suppression and should be included in the arsenal of safe, easily administered, longer-acting antiretroviral treatments for people living with HIV-1. Trial Registration: ClinicalTrials.gov Identifiers: NCT02175680 and NCT02355184.


Assuntos
Vírus da Imunodeficiência Símia , Animais , Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Anti-HIV , Humanos , Macaca mulatta , Receptores CCR5
4.
Biochemistry ; 62(6): 1209-1218, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36857408

RESUMO

The physiological functions of the rhomboid-related protein 4 (RHBDL4) are emerging, but their molecular details remain unclear. Because increased expression of RHBDL4 has been clinically linked to poorer outcomes in cancer patients, this association urgently demands a better understanding of RHBDL4. To elucidate the molecular interactions and pathways that RHBDL4 may be involved in, we conducted proximity-dependent biotin identification (BioID) assays. Our analyses corroborated several of the expected protein interactors such as the transitional endoplasmic reticulum (ER) ATPase VCP/p97 (TERA), but they also described novel putative interactors including IRS4, PGAM5, and GORS2. Using proximity-ligation assays, we validated VCP/p97, COPB, and VRK2 as proteins that are in proximity to RHBDL4. Overall, our results support the emerging functions of RHBDL4 in ER quality control and also point toward putative RHBDL4 functions in protein membrane insertion and membrane organization and trafficking.


Assuntos
Proteínas de Membrana , Peptídeo Hidrolases , Humanos , Endopeptidases , Proteínas de Membrana/metabolismo
5.
Nat Methods ; 17(9): 928-936, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32747768

RESUMO

Chemically inducible dimerization (CID) uses a small molecule to induce binding of two different proteins. CID tools such as the FK506-binding protein-FKBP-rapamycin-binding- (FKBP-FRB)-rapamycin system have been widely used to probe molecular events inside and outside cells. While various CID tools are available, chemically inducible trimerization (CIT) does not exist, due to inherent challenges in designing a chemical that simultaneously binds three proteins with high affinity and specificity. Here, we developed CIT by rationally splitting FRB and FKBP. Cellular and structural datasets showed efficient trimerization of split pairs of FRB or FKBP with full-length FKBP or FRB, respectively, by rapamycin. CIT rapidly induced tri-organellar junctions and perturbed intended membrane lipids exclusively at select membrane contact sites. By conferring one additional condition to what is achievable with CID, CIT expands the types of manipulation in single live cells to address cell biology questions otherwise intractable and engineer cell functions for future synthetic biology applications.


Assuntos
Sirolimo/química , Serina-Treonina Quinases TOR/química , Proteínas de Ligação a Tacrolimo/química , Células HeLa , Humanos , Modelos Moleculares , Mutação , Conformação Proteica
6.
J Virol ; 96(16): e0072822, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-35924920

RESUMO

The 1918 H1N1 influenza pandemic was among the most severe in history, taking the lives of approximately 50 million people worldwide, and novel prophylactic vaccines are urgently needed to prevent another pandemic. Given that macaques are physiologically relevant preclinical models of human immunology that have advanced the clinical treatment of infectious diseases, a lethal pandemic influenza challenge model would provide a stringent platform for testing new influenza vaccine concepts. To this end, we infected rhesus macaques and Mauritian cynomolgus macaques with highly pathogenic 1918 H1N1 influenza virus and assessed pathogenesis and disease severity. Despite infection with a high dose of 1918 influenza delivered via multiple routes, rhesus macaques demonstrated minimal signs of disease, with only intermittent viral shedding. Cynomolgus macaques infected via intrabronchial instillation demonstrated mild symptoms, with disease severity depending on the infection dose. Cynomolgus macaques infected with a high dose of 1918 influenza delivered via multiple routes experienced moderate disease characterized by consistent viral shedding, pulmonary infiltrates, and elevated inflammatory cytokine levels. However, 1918 influenza was uniformly nonlethal in these two species, demonstrating that this isolate is insufficiently pathogenic in rhesus and Mauritian cynomolgus macaques to support testing novel prophylactic influenza approaches where protection from severe disease combined with a lethal outcome is desired as a highly stringent indication of vaccine efficacy. IMPORTANCE The world remains at risk of an influenza pandemic, and the development of new therapeutic and preventative modalities is critically important for minimizing human death and suffering during the next influenza pandemic. Animal models are central to the development of new therapies and vaccine approaches. In particular, nonhuman primates like rhesus and cynomolgus macaques are highly relevant preclinical models given their physiological and immunological similarities to humans. Unfortunately, there remains a scarcity of macaque models of pandemic influenza with which to test novel antiviral modalities. Here, we demonstrate that even at the highest doses tested, 1918 influenza was not lethal in these two macaque species, suggesting that they are not ideal for the development and testing of novel pandemic influenza-specific vaccines and therapies. Therefore, other physiologically relevant nonhuman primate models of pandemic influenza are needed.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Animais , Humanos , Macaca fascicularis , Macaca mulatta
7.
Cell Immunol ; 384: 104660, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36586393

RESUMO

Phosphatidylserine (PS) is an anionic phospholipid exposed on the surface of apoptotic cells. The exposure of PS typically recruits and signals phagocytes to engulf and silently clear these dying cells to maintain tolerance via immunological ignorance. However, recent and emerging evidence has demonstrated that PS converts an "immunogen" into a "tolerogen", and PS exposure on the surface of cells or vesicles actively promotes a tolerogenic environment. This tolerogenic property depends on the biophysical characteristics of PS-containing vesicles, including PS density on the particle surface to effectively engage tolerogenic receptors, such as TIM-4, which is exclusively expressed on the surface of antigen-presenting cells. We harnessed the cellular and molecular mechanistic insight of PS-mediated immune regulation to design an effective oral tolerance approach. This immunotherapy has been shown to prevent/reduce immune response against life-saving protein-based therapies, food allergens, autoantigens, and the antigenic viral capsid peptide commonly used in gene therapy, suggesting a broad spectrum of potential clinical applications. Given the good safety profile of PS together with the ease of administration, oral tolerance achieved with PS-based nanoparticles has a very promising therapeutic impact.


Assuntos
Imunoterapia , Fosfatidilserinas , Células Apresentadoras de Antígenos , Autoantígenos , Tolerância Imunológica , Apoptose
8.
J Immunol ; 207(12): 2913-2921, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34810222

RESUMO

CD8+ T cells are key mediators of antiviral and antitumor immunity. The isolation and study of Ag-specific CD8+ T cells, as well as mapping of their MHC restriction, has practical importance to the study of disease and the development of therapeutics. Unfortunately, most experimental approaches are cumbersome, owing to the highly variable and donor-specific nature of MHC-bound peptide/TCR interactions. Here we present a novel system for rapid identification and characterization of Ag-specific CD8+ T cells, particularly well suited for samples with limited primary cells. Cells are stimulated ex vivo with Ag of interest, followed by live cell sorting based on surface-trapped TNF-α. We take advantage of major advances in single-cell sequencing to generate full-length sequence data from the paired TCR α- and ß-chains from these Ag-specific cells. The paired TCR chains are cloned into retroviral vectors and used to transduce donor CD8+ T cells. These TCR transductants provide a virtually unlimited experimental reagent, which can be used for further characterization, such as minimal epitope mapping or identification of MHC restriction, without depleting primary cells. We validated this system using CMV-specific CD8+ T cells from rhesus macaques, characterizing an immunodominant Mamu-A1*002:01-restricted epitope. We further demonstrated the utility of this system by mapping a novel HLA-A*68:02-restricted HIV Gag epitope from an HIV-infected donor. Collectively, these data validate a new strategy to rapidly identify novel Ags and characterize Ag-specific CD8+ T cells, with applications ranging from the study of infectious disease to immunotherapeutics and precision medicine.


Assuntos
Linfócitos T CD8-Positivos , Infecções por HIV , Animais , Epitopos , Epitopos de Linfócito T , Macaca mulatta , Receptores de Antígenos de Linfócitos T , Fator de Necrose Tumoral alfa
9.
PLoS Pathog ; 16(3): e1008339, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32163523

RESUMO

Despite the success of antiretroviral therapy (ART) to halt viral replication and slow disease progression, this treatment is not curative and there remains an urgent need to develop approaches to clear the latent HIV reservoir. The human IL-15 superagonist N-803 (formerly ALT-803) is a promising anti-cancer biologic with potent immunostimulatory properties that has been extended into the field of HIV as a potential "shock and kill" therapeutic for HIV cure. However, the ability of N-803 to reactivate latent virus and modulate anti-viral immunity in vivo under the cover of ART remains undefined. Here, we show that in ART-suppressed, simian-human immunodeficiency virus (SHIV)SF162P3-infected rhesus macaques, subcutaneous administration of N-803 activates and mobilizes both NK cells and SHIV-specific CD8+ T cells from the peripheral blood to lymph node B cell follicles, a sanctuary site for latent virus that normally excludes such effector cells. We observed minimal activation of memory CD4+ T cells and no increase in viral RNA content in lymph node resident CD4+ T cells post N-803 administration. Accordingly, we found no difference in the number or magnitude of plasma viremia timepoints between treated and untreated animals during the N-803 administration period, and no difference in the size of the viral DNA cell-associated reservoir post N-803 treatment. These results substantiate N-803 as a potent immunotherapeutic candidate capable of activating and directing effector CD8+ T and NK cells to the B cell follicle during full ART suppression, and suggest N-803 must be paired with a bona fide latency reversing agent in vivo to facilitate immune-mediated modulation of the latent viral reservoir.


Assuntos
Antirretrovirais/administração & dosagem , Linfócitos B/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Interleucina-15/antagonistas & inibidores , Células Matadoras Naturais/efeitos dos fármacos , Proteínas/administração & dosagem , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Movimento Celular/efeitos dos fármacos , Modelos Animais de Doenças , Infecções por HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/fisiopatologia , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Humanos , Interleucina-15/genética , Interleucina-15/imunologia , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Macaca mulatta , Proteínas Recombinantes de Fusão , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/fisiopatologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Vírus da Imunodeficiência Símia/fisiologia , Latência Viral/efeitos dos fármacos
10.
BMC Gastroenterol ; 22(1): 52, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35130860

RESUMO

BACKGROUND: Juxta-papillary duodenal diverticulum (JPDD) has been associated with obstructive jaundice and ascending cholangitis. Potential mechanisms include periampullary colonization of pathogenic bacteria and mechanical obstruction. However, the relation of JPDD with pyogenic liver abscess (PLA) has not been reported. Moreover, approximately one third of patients with PLA have no identifiable risk factors and are labelled as "cryptogenic". We hypothesized that JPDD is an unidentified risk factor for cryptogenic PLA and the aim of this study was to examine this association. METHODS: We conducted a retrospective chart review to identify cases of PLA (n = 66) and compare those to matched controls (n = 66). 66 patients met the study inclusion criteria of a diagnosis of PLA using computerized tomography (CT) imaging and either positive culture or confirmed resolution after antibiotic therapy. Patients with diagnoses of amebic liver abscess, traumatic liver abscess, post cholecystectomy liver abscess, concurrent acute cholecystitis, and hepatobiliary malignancy were excluded. Controls were identified from a radiology database and matched one-to-one with the cases by age and sex. Demographic and clinical data was extracted from electronic medical records. CT scan images of all cases and controls were reviewed by a single expert radiologist to identify the presence of JPDD. Statistical tests including Chi-square and t-test with multiple logistic regression were used to examine the group differences in JPDD and other factors. RESULTS: Among 132 study samples, 13.6% (9/66) of the cases were found to have JPDD, compared to 3.0% (2/66) among controls (p = 0.03). This corresponded to an odds ratio (OR) of 5.05 [OR 5.05; CI 1.05-24.4] on multiple logistic regression analysis. In addition, 1/3rd of PLA cases with JPDD had no other traditional risk factors (cryptogenic PLA). However, a statistically significant association of JPDD with cryptogenic PLA could not be established possibly because of a small number of cases. We found significantly high rate of diabetes mellitus (DM) (42.4%; n = 28/66) among cases compared to controls (21.2%; n = 14/66; p = 0.01). CONCLUSION: We found a significant association between JPDD and PLA. We need studies with larger sample sizes to confirm this relationship and to explore if JPDD could be related to cryptogenic liver abscesses.


Assuntos
Colangite , Divertículo , Abscesso Hepático Piogênico , Estudos de Casos e Controles , Colangite/complicações , Divertículo/complicações , Divertículo/diagnóstico por imagem , Humanos , Abscesso Hepático Piogênico/complicações , Estudos Retrospectivos
11.
J Immunol ; 204(8): 2169-2176, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32161099

RESUMO

Currently 247 million people are living with chronic hepatitis B virus infection (CHB), and the development of novel curative treatments is urgently needed. Immunotherapy is an attractive approach to treat CHB, yet therapeutic approaches to augment the endogenous hepatitis B virus (HBV)-specific T cell response in CHB patients have demonstrated little success. In this study, we show that strain 68-1 rhesus macaque (RM) CMV vaccine vectors expressing HBV Ags engender HBV-specific CD8+ T cells unconventionally restricted by MHC class II and the nonclassical MHC-E molecule in RM. Surface staining of human donor and RM primary hepatocytes (PH) ex vivo revealed the majority of PH expressed MHC-E but not MHC class II. HBV-specific, MHC-E-restricted CD8+ T cells from RM vaccinated with RM CMV vaccine vectors expressing HBV Ags recognized HBV-infected PH from both human donor and RM. These results provide proof-of-concept that MHC-E-restricted CD8+ T cells could be harnessed for the treatment of CHB, either through therapeutic vaccination or adoptive immunotherapy.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Vírus da Hepatite B/imunologia , Hepatite B Crônica/imunologia , Hepatócitos/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Animais , Hepatite B Crônica/virologia , Hepatócitos/virologia , Macaca mulatta
12.
Transpl Infect Dis ; 23(4): e13696, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34288294

RESUMO

BACKGROUND: Since phase III trials for the most prominent vaccines excluded immunocompromised or immunosuppressed patients, data on safety and efficacy of SARS-CoV-2 vaccines for recipients of solid organ transplantations are scarce. AIMS: Our study offers a synthesis of expert opinions aligned with available data addressing key questions of the clinical management of SARS-CoV-2 vaccinations for transplant patients. METHOD: An online research was performed retrieving available recommendations by national and international transplantation organizations and state institutions on SARS-CoV2 vaccination management for transplant recipients. RESULTS: Eleven key statements were identified from recommendations by 18 national and international societies, and consensus for the individual statements was evaluated by means of the Society Recommendation Consensus score. The highest consensus level (SRC A) was found for prioritized access to vaccination for transplant patients despite anticipation of a weakened immune response. All currently authorized vaccines can be considered safe for transplant patients (SRC A). The handling of immunosuppressive medication, the timely management of vaccines, and other aspects were aligned with available expert opinions. CONCLUSION: Expert consensus can be determined for crucial aspects of the implementation of SARS-CoV-2 vaccination programs. We hereby offer a tool for immediate decision-making until empirical data becomes available.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Consenso , Humanos , RNA Viral , SARS-CoV-2 , Vacinação
13.
J Clin Apher ; 36(1): 67-77, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32941672

RESUMO

Macaques are physiologically relevant animal models of human immunology and infectious disease that have provided key insights and advanced clinical treatment in transplantation, vaccinology, and HIV/AIDS. However, the small size of macaques is a stumbling block for studies requiring large numbers of cells, such as hematopoietic stem cells (HSCs) for transplantation, antigen-specific lymphocytes for in-depth immunological analysis, and latently-infected CD4+ T-cells for HIV cure studies. Here, we provide a detailed protocol for collection of large numbers of HSCs and T-cells from cynomolgus macaques as small as 3 kg using the Terumo Spectra Optia apheresis system, yielding an average of 5.0 × 109 total nucleated cells from mobilized animals and 1.2 × 109 total nucleated cells from nonmobilized animals per procedure. This report provides sufficient detail to adapt this apheresis technique at other institutions, which will facilitate more efficient and detailed analysis of HSCs and their progeny blood cells.


Assuntos
Remoção de Componentes Sanguíneos/métodos , Células-Tronco Hematopoéticas/citologia , Linfócitos T/citologia , Animais , Benzilaminas/farmacologia , Creatinina/sangue , Ciclamos/farmacologia , Feminino , Fator Estimulador de Colônias de Granulócitos/farmacologia , Mobilização de Células-Tronco Hematopoéticas/métodos , Macaca fascicularis , Masculino
14.
Am J Transplant ; 20(7): 1826-1836, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32323460

RESUMO

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has a drastic impact on national health care systems. Given the overwhelming demand on facility capacity, the impact on all health care sectors has to be addressed. Solid organ transplantation represents a field with a high demand on staff, intensive care units, and follow-up facilities. The great therapeutic value of organ transplantation has to be weighed against mandatory constraints of health care capacities. In addition, the management of immunosuppressed recipients has to be reassessed during the ongoing coronavirus disease 2019 (COVID-19) pandemic. In addressing these crucial questions, transplant physicians are facing a total lack of scientific evidence. Therefore, the aim of this study was to offer an approach of consensus-based guidance, derived from individual information of 22 transplant societies. Key recommendations were extracted and the degree of consensus among different organizations was calculated. A high degree of consensus was found for temporarily suspending nonurgent transplant procedures and living donation programs. Systematic polymerase chain reaction-based testing of donors and recipients was broadly recommended. Additionally, more specific aspects (eg, screening of surgical explant teams and restricted use of marginal donor organs) were included in our analysis. This study offers a novel approach to informed guidance for health care management when a priori no scientific evidence is available.


Assuntos
Técnicas de Laboratório Clínico , Infecções por Coronavirus/prevenção & controle , Transplante de Órgãos/normas , Transplante de Órgãos/tendências , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Betacoronavirus , COVID-19 , Teste para COVID-19 , Consenso , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Cuidados Críticos , Medicina Baseada em Evidências , Política de Saúde , Humanos , Hospedeiro Imunocomprometido , Internacionalidade , Doadores Vivos , Transplante de Órgãos/métodos , Equipamento de Proteção Individual , Pneumonia Viral/epidemiologia , Reação em Cadeia da Polimerase , Radiografia Torácica , Alocação de Recursos , SARS-CoV-2 , Sociedades Médicas , Doadores de Tecidos , Tomografia Computadorizada por Raios X , Transplantados
15.
J Virol ; 93(19)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31315990

RESUMO

Major histocompatibility complex E (MHC-E) is a highly conserved nonclassical MHC-Ib molecule that tightly binds peptides derived from leader sequences of classical MHC-Ia molecules for presentation to natural killer cells. However, MHC-E also binds diverse foreign and neoplastic self-peptide antigens for presentation to CD8+ T cells. Although the determinants of MHC-E-restricted T cell priming remain unknown, these cells are induced in humans infected with pathogens containing genes that inhibit the transporter associated with antigen processing (TAP). Indeed, mice vaccinated with TAP-inhibited autologous dendritic cells develop T cells restricted by the murine MHC-E homologue, Qa-1b. Here, we tested whether rhesus macaques (RM) vaccinated with viral constructs expressing a TAP inhibitor would develop insert-specific MHC-E-restricted CD8+ T cells. We generated viral constructs coexpressing SIVmac239 Gag in addition to one of three TAP inhibitors: herpes simplex virus 2 ICP47, bovine herpes virus 1 UL49.5, or rhesus cytomegalovirus Rh185. Each TAP inhibitor reduced surface expression of MHC-Ia molecules but did not reduce surface MHC-E expression. In agreement with modulation of surface MHC-Ia levels, TAP inhibition diminished presentation of MHC-Ia-restricted CD8+ T cell epitopes without impacting presentation of peptide antigen bound by MHC-E. Vaccination of macaques with vectors dually expressing SIVmac239 Gag with ICP47, UL49.5, or Rh185 generated Gag-specific CD8+ T cells classically restricted by MHC-Ia but not MHC-E. These data demonstrate that, in contrast to results in mice, TAP inhibition alone is insufficient for priming of MHC-E-restricted T cell responses in primates and suggest that additional unknown mechanisms govern the induction of CD8+ T cells recognizing MHC-E-bound antigen.IMPORTANCE Due to the near monomorphic nature of MHC-E in the human population and inability of many pathogens to inhibit MHC-E-mediated peptide presentation, MHC-E-restricted T cells have become an attractive vaccine target. However, little is known concerning how these cells are induced. Understanding the underlying mechanisms that induce these T cells would provide a powerful new vaccine strategy to an array of neoplasms and viral and bacterial pathogens. Recent studies have indicated a link between TAP inhibition and induction of MHC-E-restricted T cells. The significance of our research is in demonstrating that TAP inhibition alone does not prime MHC-E-restricted T cell generation and suggests that other, currently unknown mechanisms regulate their induction.


Assuntos
Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Linfócitos T CD8-Positivos/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Vacinas contra a SAIDS/imunologia , Vírus da Imunodeficiência Símia/imunologia , Animais , Inibidores Enzimáticos/metabolismo , Macaca mulatta , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Vacinas contra a SAIDS/administração & dosagem , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
16.
Xenotransplantation ; 27(4): e12578, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31930750

RESUMO

Allogeneic hematopoietic stem cell transplantation (HSCT) and xenotransplantation are accompanied by viral reactivations and virus-associated complications resulting from immune deficiency. Here, in a Mauritian cynomolgus macaque model of fully MHC-matched allogeneic HSCT, we report reactivations of cynomolgus polyomavirus, lymphocryptovirus, and cytomegalovirus, macaque viruses analogous to HSCT-associated human counterparts BK virus, Epstein-Barr virus, and human cytomegalovirus. Viral replication in recipient macaques resulted in characteristic disease manifestations observed in HSCT patients, such as polyomavirus-associated hemorrhagic cystitis and tubulointerstitial nephritis or lymphocryptovirus-associated post-transplant lymphoproliferative disorder. However, in most cases, the reconstituted immune system, alone or in combination with short-term pharmacological intervention, exerted control over viral replication, suggesting engraftment of functional donor-derived immunity. Indeed, the donor-derived reconstituted immune systems of two long-term engrafted HSCT recipient macaques responded to live attenuated yellow fever 17D vaccine (YFV 17D) indistinguishably from untransplanted controls, mounting 17D-targeted neutralizing antibody responses and clearing YFV 17D within 14 days. Together, these data demonstrate that this macaque model of allogeneic HSCT recapitulates clinical situations of opportunistic viral infections in transplant patients and provides a pre-clinical model to test novel prophylactic and therapeutic modalities.


Assuntos
Modelos Animais de Doenças , Transplante de Células-Tronco Hematopoéticas , Infecções Oportunistas , Viroses , Aloenxertos , Animais , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Macaca fascicularis , Infecções Oportunistas/virologia
17.
J Immunol ; 200(1): 49-60, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29150562

RESUMO

MHC-E is a highly conserved nonclassical MHC class Ib molecule that predominantly binds and presents MHC class Ia leader sequence-derived peptides for NK cell regulation. However, MHC-E also binds pathogen-derived peptide Ags for presentation to CD8+ T cells. Given this role in adaptive immunity and its highly monomorphic nature in the human population, HLA-E is an attractive target for novel vaccine and immunotherapeutic modalities. Development of HLA-E-targeted therapies will require a physiologically relevant animal model that recapitulates HLA-E-restricted T cell biology. In this study, we investigated MHC-E immunobiology in two common nonhuman primate species, Indian-origin rhesus macaques (RM) and Mauritian-origin cynomolgus macaques (MCM). Compared to humans and MCM, RM expressed a greater number of MHC-E alleles at both the population and individual level. Despite this difference, human, RM, and MCM MHC-E molecules were expressed at similar levels across immune cell subsets, equivalently upregulated by viral pathogens, and bound and presented identical peptides to CD8+ T cells. Indeed, SIV-specific, Mamu-E-restricted CD8+ T cells from RM recognized antigenic peptides presented by all MHC-E molecules tested, including cross-species recognition of human and MCM SIV-infected CD4+ T cells. Thus, MHC-E is functionally conserved among humans, RM, and MCM, and both RM and MCM represent physiologically relevant animal models of HLA-E-restricted T cell immunobiology.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade/metabolismo , Células Matadoras Naturais/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Animais , Apresentação de Antígeno , Antígenos Virais/imunologia , Antígenos Virais/metabolismo , Células Cultivadas , Sequência Conservada/genética , Antígenos de Histocompatibilidade/genética , Antígenos de Histocompatibilidade/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Macaca fascicularis , Macaca mulatta , Modelos Animais , Peptídeos/imunologia , Peptídeos/metabolismo , Antígenos HLA-E
18.
Luminescence ; 35(6): 863-869, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32119755

RESUMO

To precisely predict the life of optoelectronic displays over a short time, two life prediction models were established based on the three-parameter Weibull right approximation method (TPWRAM). In Model I, the acceleration life under each stress was obtained using TPWRAM, the data points formed by acceleration life and acceleration stress were, respectively, fitted by three extrapolation functions and the optimal extrapolation function was determined by comparing the fitting determination coefficient and root-mean-square error. In Model II, after introducing an acceleration parameter, the luminance attenuation data under conventional stress were calculated directly by combining the ones obtained using TPWRAM under each acceleration stress. The luminance attenuation test data from the vacuum fluorescent display (VFD) were collected through four groups of constant-stress accelerated degradation tests (ADT), and the two models were applied to the life prediction of VFD. The results indicated that the designed ADT scheme was feasible, Model I revealed the changing law of life with stress and simplified the process of life prediction, and Model II made it possible to obtain the luminance attenuation formula at conventional stress without conducting a conventional life test, overcoming the shortcomings of long time-consuming traditional life tests. It was verified by comparing the life prediction values that the two models had very high precision, and both of these not only achieve the accurate estimation of optoelectronic product life without resorting to conventional life test, but also improved the method of life prediction and perfect its theoretical system.


Assuntos
Vácuo
19.
Am J Gastroenterol ; 114(2): 352-354, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30333541

RESUMO

INTRODUCTION: Infliximab for inflammatory bowel disease (IBD) is FDA-approved to be administered 2 h or more. We adopted a new protocol to infuse infliximab over 1 h and in this study, we aimed to determine the safety of a 1-h infusion. METHODS: This retrospective cohort included adult IBD patients who received infliximab between June and December 2017 and compared reaction rates of 1-h maintenance infusions to that of 2-h maintenance infusions. RESULTS: A total of 551 infusions were administered to 179 patients. The infusion groups demonstrated no significant differences in reaction rates. CONCLUSIONS: Infliximab infusion over 1 h is well-tolerated.


Assuntos
Fármacos Gastrointestinais/administração & dosagem , Doenças Inflamatórias Intestinais/tratamento farmacológico , Infliximab/administração & dosagem , Infusões Intravenosas/métodos , Reação no Local da Injeção/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Quimioterapia de Manutenção , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
20.
BMC Bioinformatics ; 19(1): 32, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29402213

RESUMO

BACKGROUND: Genomic islands play an important role in microbial genome evolution, providing a mechanism for strains to adapt to new ecological conditions. A variety of computational methods, both genome-composition based and comparative, have been developed to identify them. Some of these methods are explicitly designed to work in single strains, while others make use of multiple strains. In general, existing methods do not identify islands in the context of the phylogeny in which they evolved. Even multiple strain approaches are best suited to identifying genomic islands that are present in one strain but absent in others. They do not automatically recognize islands which are shared between some strains in the clade or determine the branch on which these islands inserted within the phylogenetic tree. RESULTS: We have developed a software package, xenoGI, that identifies genomic islands and maps their origin within a clade of closely related bacteria, determining which branch they inserted on. It takes as input a set of sequenced genomes and a tree specifying their phylogenetic relationships. Making heavy use of synteny information, the package builds gene families in a species-tree-aware way, and then attempts to combine into islands those families whose members are adjacent and whose most recent common ancestor is shared. The package provides a variety of text-based analysis functions, as well as the ability to export genomic islands into formats suitable for viewing in a genome browser. We demonstrate the capabilities of the package with several examples from enteric bacteria, including an examination of the evolution of the acid fitness island in the genus Escherichia. In addition we use output from simulations and a set of known genomic islands from the literature to show that xenoGI can accurately identify genomic islands and place them on a phylogenetic tree. CONCLUSIONS: xenoGI is an effective tool for studying the history of genomic island insertions in a clade of microbes. It identifies genomic islands, and determines which branch they inserted on within the phylogenetic tree for the clade. Such information is valuable because it helps us understand the adaptive path that has produced living species.


Assuntos
Bactérias/genética , Ilhas Genômicas/genética , Filogenia , Software , Simulação por Computador , Evolução Molecular , Genoma Bacteriano , Reprodutibilidade dos Testes , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA