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1.
J Clin Invest ; 134(7)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38557487

RESUMO

Endothelial function and integrity are compromised after allogeneic bone marrow transplantation (BMT), but how this affects immune responses broadly remains unknown. Using a preclinical model of CMV reactivation after BMT, we found compromised antiviral humoral responses induced by IL-6 signaling. IL-6 signaling in T cells maintained Th1 cells, resulting in sustained IFN-γ secretion, which promoted endothelial cell (EC) injury, loss of the neonatal Fc receptor (FcRn) responsible for IgG recycling, and rapid IgG loss. T cell-specific deletion of IL-6R led to persistence of recipient-derived, CMV-specific IgG and inhibited CMV reactivation. Deletion of IFN-γ in donor T cells also eliminated EC injury and FcRn loss. In a phase III clinical trial, blockade of IL-6R with tocilizumab promoted CMV-specific IgG persistence and significantly attenuated early HCMV reactivation. In sum, IL-6 invoked IFN-γ-dependent EC injury and consequent IgG loss, leading to CMV reactivation. Hence, cytokine inhibition represents a logical strategy to prevent endothelial injury, thereby preserving humoral immunity after immunotherapy.


Assuntos
Transplante de Medula Óssea , Infecções por Citomegalovirus , Imunidade Humoral , Interleucina-6 , Antivirais , Transplante de Medula Óssea/efeitos adversos , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/metabolismo , Imunoglobulina G , Interleucina-6/metabolismo , Animais , Camundongos
2.
J Pediatr Hematol Oncol Nurs ; : 27527530231214544, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38588659

RESUMO

Background: Few studies have examined biomarkers of stress and inflammation as underlying mechanisms of symptoms in adolescents and young adults with cancer. This study determined the feasibility of collecting blood and saliva samples across time, described the range and distribution of biomarkers, and explored the association of biomarkers with symptom adverse events (AEs). Method: This longitudinal, prospective repeated-measures single-site feasibility study recruited N = 10 children (M = 12.5 years) receiving treatment for advanced cancer. Symptom AE data and inflammation (cytokines and C-reactive protein) and physiologic response to stress (salivary cortisol and salivary alpha-amylase) biomarker levels were collected at three time points. Descriptive statistics were used to examine feasibility and acceptability and to summarize symptom AE, stress, and inflammatory biomarker data. A linear regression model was used to determine cortisol diurnal slopes. The relationship between symptom and inflammatory biomarker data was explored and Hedges's g statistic was used to determine its effect size. Results: Participants provided 83% of saliva samples (n = 199/240) and 185 samples were sufficient to be analyzed. Nurses collected 97% (n = 29/30) of blood samples. Participants reported the saliva collection instructions, kits, and reminders were clear and helpful. Insomnia, pain, fatigue, and anxiety demonstrated the most medium and large negative effects with inflammatory markers. Symptom AEs demonstrated the highest number of medium and large negative effects with interleukin-8 and tumor necrosis factor-alpha (-0.53 to -2.00). Discussion: The results indicate longitudinal concurrent collection of symptom and biomarker data is feasible and inflammatory and stress biomarkers merit consideration for inclusion in future studies.

3.
Ann Vasc Surg ; 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38582213

RESUMO

BACKGROUND: Numerous risk factors for lower limb amputations are known; however, this study aimed to identify risk factors for re-amputation in patients within 6 months from an initial lower limb amputation procedure. METHODS: This single-center retrospective cohort study was performed at the Hospital Regional Hans Dieter Schmidt in Brazil. The study included patients who were aged at least 18 years and had undergone lower limb amputation between 2013 and 2022. Patients who died while hospitalized and patients who were lost to follow-up after hospital discharge were excluded from the study. Patient age, sex, number of amputations, revision time, comorbidities, and potential risk factors were extracted from the physical therapy service database and electronic medical records of the hospital. Chi-squared test and student's t-test were used to identify statistical significance. RESULTS: A total of 652 patients were included, of which 35.2% (230) patients underwent re-amputation within 6 months of the first operation. We found that dialysis (P = 0.004; odds ratio [OR] 8.36, 95% confidence interval [CI] 3.09-20.5), smoking (P = 0.004; OR 1.67, 95% CI 1.18-2.35), and hypertension (P = 0.02; OR 1.55, 95% CI 1.09-2.19) were predictive factors for re-amputation within 6 months of lower limb amputation. CONCLUSIONS: Therefore, it is important to intervene early and provide additional support to patients undergoing lower limb amputation with these risk factors to reduce the potential for re-amputation in the future.

4.
ACS Chem Biol ; 19(1): 101-109, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38069818

RESUMO

Protein-protein interactions (PPIs) are intriguing targets in drug discovery and development. Peptides are well suited to target PPIs, which typically present with large surface areas lacking distinct features and deep binding pockets. To improve binding interactions with these topologies and advance the development of PPI-focused therapeutics, potential ligands can be equipped with electrophilic groups to enable binding through covalent mechanisms of action. We report a strategy termed electrophile scanning to identify reactivity hotspots in a known peptide ligand and demonstrate its application in a model PPI. Cysteine mutants of a known ligand are used to install protein-reactive modifiers via a palladium oxidative addition complex (Pd-OAC). Reactivity hotspots are revealed by cross-linking reactions with the target protein under physiological conditions. In a model PPI with the 9-mer peptide antigen VL9 and major histocompatibility complex (MHC) class I protein HLA-E, we identify two reactivity hotspots that afford up to 87% conversion to the protein-peptide conjugate within 4 h. The reactions are specific to the target protein in vitro and dependent on the peptide sequence. Moreover, the cross-linked peptide successfully inhibits molecular recognition of HLA-E by CD94-NKG2A possibly due to structural changes enacted at the PPI interface. The results illustrate the potential application of electrophile scanning as a tool for rapid discovery and development of covalent peptide binders.


Assuntos
Antígenos HLA-E , Antígenos de Histocompatibilidade Classe I , Ligantes , Antígenos de Histocompatibilidade Classe I/metabolismo , Peptídeos/química , Ligação Proteica
5.
Cornea ; 43(3): 349-355, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37433174

RESUMO

PURPOSE: Residing in rural locations can be a barrier to health care access. This study investigated the impact of residing in rural and small town (RST) areas on Descemet stripping automated endothelial keratoplasty (DSAEK) indications and outcomes in Atlantic Canada. METHODS: A retrospective cohort analysis examined consecutive DSAEKs performed in Nova Scotia between 2017 and 2020. Patient rurality was determined by the Statistical Area Classification system developed by Statistics Canada. Univariate and multivariate logistic regression models were used to assess for factors associated with DSAEK indication, including repeat keratoplasty, RST residence status, and travel time. RESULTS: Of 271 DSAEKs during the study period, 87 (32.1%) were performed on the eyes of RST residents. The median postoperative follow-up time was 1.6 years. Undergoing DSAEK for a previous failed keratoplasty was not associated with a higher odds of RST residency (odds ratio [OR], 0.50; 95% confidence interval [CI], 0.19-1.16; P = 0.13) but was associated with travel time (OR, 0.78 for each increasing hour of travel; 95% CI, 0.61-0.99; P = 0.044). RST residency was not associated with the occurrence of graft failure (OR, 0.48; 95% CI, 0.17-1.17; P = 0.13). CONCLUSIONS: Residing in a rural area in Atlantic Canada was not associated with DSAEK graft failure. Repeat endothelial keratoplasty was associated with shorter travel time for corneal surgery but not rural residency status. Further research in this field could inform regional health strategies aimed at improving equity and accessibility to ophthalmology subspecialist care.


Assuntos
Doenças da Córnea , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior , Distrofia Endotelial de Fuchs , Internato e Residência , Humanos , Doenças da Córnea/cirurgia , Estudos Retrospectivos , Ceratoplastia Penetrante , Acuidade Visual , Sobrevivência de Enxerto , Endotélio Corneano/cirurgia , Distrofia Endotelial de Fuchs/cirurgia
6.
J Pediatr Hematol Oncol Nurs ; 41(1): 5-15, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37697734

RESUMO

Background: The presence of poorly controlled symptoms negatively impacts the quality of life (QoL) throughout cancer treatment. The purpose of this multisite study was to explore the relationship between QoL and symptom adverse events (AEs) in children with advanced cancer over 6 months. Method: A prospective and longitudinal descriptive study design was used to collect QoL and symptom AE data from children aged 2 to 18 with advanced cancer. QoL was measured using the Pediatric Quality of Life Inventory (PedsQLTM) Cancer Module 3.0 and symptom AEs were measured using the Pediatric Patient-Reported Outcome-Common Terminology Criteria for AEs (PRO-CTCAEs®). Descriptive statistics were used to describe QoL and symptom AE data. Correlational analyses and generalized linear mixed models were used to examine the relationship between symptom AEs and QoL. Results: Forty-nine children participated in the study. The mean total PedsQLTM score was 73.86 for the sample across all time points. Children diagnosed with a central nervous system (CNS) tumor reported poorer QoL compared to children diagnosed with a hematologic malignancy or non-CNS solid tumor. Symptom frequency AEs of anxiety, pain, nausea, insomnia, hot flashes, and fatigue severity demonstrated the strongest and most significant negative correlation with total QoL scores. Analyses of the relationship between QoL and symptom AEs over time revealed time-specific significant differences with children who experienced frequency AEs of nausea, and anxiety reporting poorer QoL at time point 4 (week 8). Discussion: The Ped PRO-CTCAE® and PedsQLTM can be used to evaluate the relationship between symptom AEs and QoL in practice and in future research.


Assuntos
Neoplasias , Qualidade de Vida , Humanos , Criança , Estudos Longitudinais , Estudos Prospectivos , Neoplasias/complicações , Medidas de Resultados Relatados pelo Paciente , Náusea/etiologia
7.
J Vitreoretin Dis ; 7(5): 397-403, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37706085

RESUMO

Purpose: To assess sound-level exposure during vitrectomy using 3 of the most common commercially available machines. Methods: This noninterventional cross-sectional study examined sound emission from the Constellation, Stellaris, and EVA vitrector systems. For each machine, a noise dosimeter was used to measure the sound-level exposure of the surgeon during 3 surgical cases in which vitrectomy was performed. Sound levels associated with progressively increasing cut rates and vacuum pressures were also measured. Finally, sound measurements were taken during the use of various additional functions of each machine, including diathermy, laser, and extrusion. Sound levels were compared with occupational health guidelines in Canada and the United States. Results: The maximum sound level recorded during vitrectomy surgery was 88.2 dBA. The mean sound level during vitrectomy surgical cases ranged from 58.5 to 66.8 dBA. A strong positive linear correlation was found between the cut rate and sound level (r = 0.88-0.98) and the vacuum pressure and sound level (r = 0.83-0.97). This relationship was consistent across the 3 vitrector systems (P < .001). Conclusions: Noise exposure during vitrectomy procedures was acceptable but may be sufficient for surgical team activity interference, as described by World Health Organization recommendations. A strong correlation was found between the cut rate and noise exposure. If cut rates continue to increase, attention should be given to ensure that the resulting noise exposure does not threaten the hearing of vitreoretinal surgeons and the operating room staff.

8.
Nature ; 620(7972): 128-136, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37468623

RESUMO

Studies have demonstrated that at least 20% of individuals infected with SARS-CoV-2 remain asymptomatic1-4. Although most global efforts have focused on severe illness in COVID-19, examining asymptomatic infection provides a unique opportunity to consider early immunological features that promote rapid viral clearance. Here, postulating that variation in the human leukocyte antigen (HLA) loci may underly processes mediating asymptomatic infection, we enrolled 29,947 individuals, for whom high-resolution HLA genotyping data were available, in a smartphone-based study designed to track COVID-19 symptoms and outcomes. Our discovery cohort (n = 1,428) comprised unvaccinated individuals who reported a positive test result for SARS-CoV-2. We tested for association of five HLA loci with disease course and identified a strong association between HLA-B*15:01 and asymptomatic infection, observed in two independent cohorts. Suggesting that this genetic association is due to pre-existing T cell immunity, we show that T cells from pre-pandemic samples from individuals carrying HLA-B*15:01 were reactive to the immunodominant SARS-CoV-2 S-derived peptide NQKLIANQF. The majority of the reactive T cells displayed a memory phenotype, were highly polyfunctional and were cross-reactive to a peptide derived from seasonal coronaviruses. The crystal structure of HLA-B*15:01-peptide complexes demonstrates that the peptides NQKLIANQF and NQKLIANAF (from OC43-CoV and HKU1-CoV) share a similar ability to be stabilized and presented by HLA-B*15:01. Finally, we show that the structural similarity of the peptides underpins T cell cross-reactivity of high-affinity public T cell receptors, providing the molecular basis for HLA-B*15:01-mediated pre-existing immunity.


Assuntos
Alelos , Infecções Assintomáticas , COVID-19 , Antígenos HLA-B , Humanos , COVID-19/genética , COVID-19/imunologia , COVID-19/fisiopatologia , COVID-19/virologia , Epitopos de Linfócito T/imunologia , Peptídeos/imunologia , SARS-CoV-2/imunologia , Antígenos HLA-B/imunologia , Estudos de Coortes , Linfócitos T/imunologia , Epitopos Imunodominantes/imunologia , Reações Cruzadas/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia
9.
Nat Commun ; 14(1): 3680, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-37369668

RESUMO

In vitro, ACE2 translocates to the nucleus to induce SARS-CoV-2 replication. Here, using digital spatial profiling of lung tissues from SARS-CoV-2-infected golden Syrian hamsters, we show that a specific and selective peptide inhibitor of nuclear ACE2 (NACE2i) inhibits viral replication two days after SARS-CoV-2 infection. Moreover, the peptide also prevents inflammation and macrophage infiltration, and increases NK cell infiltration in bronchioles. NACE2i treatment increases the levels of the active histone mark, H3K27ac, restores host translation in infected hamster bronchiolar cells, and leads to an enrichment in methylated ACE2 in hamster bronchioles and lung macrophages, a signature associated with virus protection. In addition, ACE2 methylation is increased in myeloid cells from vaccinated patients and associated with reduced SARS-CoV-2 spike protein expression in monocytes from individuals who have recovered from infection. This protective epigenetic scarring of ACE2 is associated with a reduced latent viral reservoir in monocytes/macrophages and enhanced immune protection against SARS-CoV-2. Nuclear ACE2 may represent a therapeutic target independent of the variant and strain of viruses that use the ACE2 receptor for host cell entry.


Assuntos
COVID-19 , SARS-CoV-2 , Cricetinae , Animais , Humanos , SARS-CoV-2/fisiologia , Enzima de Conversão de Angiotensina 2/metabolismo , Pulmão/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Peptídeos/metabolismo , Epigênese Genética
10.
Angew Chem Int Ed Engl ; 62(19): e202300289, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-36894520

RESUMO

α-Klotho, an aging-related protein found in the kidney, parathyroid gland, and choroid plexus, acts as an essential co-receptor with the fibroblast growth factor 23 receptor complex to regulate serum phosphate and vitamin D levels. Decreased levels of α-Klotho are a hallmark of age-associated diseases. Detecting or labeling α-Klotho in biological milieu has long been a challenge, however, hampering the understanding of its role. Here, we developed branched peptides by single-shot parallel automated fast-flow synthesis that recognize α-Klotho with improved affinity relative to their monomeric versions. These peptides were further shown to selectively label Klotho for live imaging in kidney cells. Our results demonstrate that automated flow technology enables rapid synthesis of complex peptide architectures, showing promise for future detection of α-Klotho in physiological settings.


Assuntos
Glucuronidase , Proteínas Klotho , Glucuronidase/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Peptídeos/metabolismo , Rim/metabolismo
11.
Clin Transl Immunology ; 12(3): e1444, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36960148

RESUMO

Emergence of a definitive link between Epstein-Barr virus (EBV) and multiple sclerosis has provided an impetus to develop immune-based therapies to target EBV-infected B cells. Initial studies with autologous EBV-specific T-cell therapy demonstrated that this therapy is safe with minimal side effects and more importantly multiple patients showed both symptomatic and objective neurological improvements including improved quality of life, reduction of fatigue and reduced intrathecal IgG production. These observations have been successfully extended to an 'off-the-shelf' allogeneic EBV-specific T-cell therapy manufactured using peripheral blood lymphocytes of healthy seropositive individuals. This adoptive immunotherapy has also been shown to be safe with encouraging clinical responses. Allogeneic EBV T-cell therapy overcomes some of the limitations of autologous therapy and can be rapidly delivered to patients with improved therapeutic potential.

12.
J Craniofac Surg ; 34(4): 1343-1346, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36913619

RESUMO

OBJECTIVE: Manual contouring of cartilage for nasal reconstruction is tedious and time-consuming. The use of a robot could improve the speed and precision of the contouring process. This cadaveric study evaluates the efficiency and accuracy of a robot methodology for contouring the lower lateral cartilage of the nasal tip. METHODS: An augmented robot with a spherical burring tool attached was utilized to carve 11 cadaveric rib cartilage specimens. In phase 1, the right lower lateral cartilage was harvested from a cadaveric specimen and used to define a carving path for each rib specimen. In phase 2, the cartilage remained in situ during the scanning and 3-dimensional modeling. The final carved specimens were compared with the preoperative plans through topographical accuracy analysis. The contouring times of the specimens were compared with 14 retrospectively reviewed cases (2017-2020) by an experienced surgeon. RESULTS: Phase 1 root mean square error of 0.40±0.15 mm and mean absolute deviation of 0.33±0.13 mm. Phase 2 root mean square error of 0.43 mm and mean absolute deviation of 0.28 mm. The average carving time for the robot specimens was 14±3 minutes and 16 minutes for Phase 1 and Phase 2, respectively. The average manual carving by an experienced surgeon was 22±4 minutes. CONCLUSIONS: Robot-assisted nasal reconstruction is very precise and more efficient than manual contouring. This technique represents an exciting and innovative alternative for complex nasal reconstruction.


Assuntos
Rinoplastia , Robótica , Humanos , Rinoplastia/métodos , Estudos Retrospectivos , Nariz/cirurgia , Cadáver
13.
J Hand Surg Am ; 48(3): 309.e1-309.e6, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-34949481

RESUMO

PURPOSE: The motor branch of the ulnar nerve contains fascicles that innervate the intrinsic musculature of the hand. This cadaveric study aimed to describe the organization and consistency of the internal topography of the motor branch of the ulnar nerve. METHODS: Five fresh-frozen cadaveric specimens with an average age of 74 years (range, 65-88 years) were dissected. The ulnar nerve was exposed and transfixed to the underlying tissues to maintain its orientation throughout the dissection. The dorsal cutaneous branch (DCB) and the volar sensory branch were identified and reflected to expose the motor branch. The fascicles to the first dorsal interosseus (FDI), flexor pollicis brevis, and abductor digiti minimi (ADM) were identified. Internal neurolysis was performed distal to proximal to identify the interfascicular arrangement of these fascicles within the motor branch. The organization of these fascicles was noted, and the branch points of the DCB, FDI, and ADM were measured relative to the pisiform using a handheld electronic caliper. RESULTS: The internal topography of the motor branch was consistent among all specimens. Proximal to the pisiform, the arrangement from radial to ulnar was as follows: volar sensory branch, flexor pollicis brevis, FDI/intrinsic muscles, ADM, and DCB. The position of these branches remained consistent as the deep motor branch curved radially within the palm and traveled to the terminal musculature. The locations of the average branch points of the FDI, ADM, and DCB with respect to the pisiform were as follows: FDI, 4.6 cm distal (range, 4.1-4.9 cm), 4.5 cm radial (range, 4.1-4.9 cm); ADM, 0.65 cm distal (range, 0.3-1.1 cm), 0.7 cm radial (range, 0.3-1.1 cm), DCB, 7.7 cm proximal (range, 4.2-10.1 cm), and 0.4 cm ulnar (range, 0.3-0.8 cm). CONCLUSIONS: The internal topography of the ulnar nerve motor branch was consistent among the specimens studied. The topography of the motor branches was maintained as the motor branch turns radially within the palm. CLINICAL RELEVANCE: This study provides further understanding of the internal topography of the ulnar nerve motor branch at the wrist level.


Assuntos
Nervo Ulnar , Punho , Humanos , Idoso , Nervo Ulnar/anatomia & histologia , Cadáver , Nervos Periféricos , Braço
15.
Nat Commun ; 13(1): 5500, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36127359

RESUMO

Insulin-like growth factor (IGF) signaling is highly conserved and tightly regulated by proteases including Pregnancy-Associated Plasma Protein A (PAPP-A). PAPP-A and its paralog PAPP-A2 are metalloproteases that mediate IGF bioavailability through cleavage of IGF binding proteins (IGFBPs). Here, we present single-particle cryo-EM structures of the catalytically inactive mutant PAPP-A (E483A) in complex with a peptide from its substrate IGFBP5 (PAPP-ABP5) and also in its substrate-free form, by leveraging the power of AlphaFold to generate a high quality predicted model as a starting template. We show that PAPP-A is a flexible trans-dimer that binds IGFBP5 via a 25-amino acid anchor peptide which extends into the metalloprotease active site. This unique IGFBP5 anchor peptide that mediates the specific PAPP-A-IGFBP5 interaction is not found in other PAPP-A substrates. Additionally, we illustrate the critical role of the PAPP-A central domain as it mediates both IGFBP5 recognition and trans-dimerization. We further demonstrate that PAPP-A trans-dimer formation and distal inter-domain interactions are both required for efficient proteolysis of IGFBP4, but dispensable for IGFBP5 cleavage. Together the structural and biochemical studies reveal the mechanism of PAPP-A substrate binding and selectivity.


Assuntos
Proteína Plasmática A Associada à Gravidez , Somatomedinas , Aminoácidos/metabolismo , Peptídeos/metabolismo , Proteína Plasmática A Associada à Gravidez/química , Proteína Plasmática A Associada à Gravidez/metabolismo , Ligação Proteica , Somatomedinas/metabolismo
16.
PLoS Pathog ; 18(2): e1010339, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35157735

RESUMO

Adoptive T-cell immunotherapy has provided promising results in the treatment of viral complications in humans, particularly in the context of immunocompromised patients who have exhausted all other clinical options. The capacity to expand T cells from healthy immune individuals is providing a new approach to anti-viral immunotherapy, offering rapid off-the-shelf treatment with tailor-made human leukocyte antigen (HLA)-matched T cells. While most of this research has focused on the treatment of latent viral infections, emerging evidence that SARS-CoV-2-specific T cells play an important role in protection against COVID-19 suggests that the transfer of HLA-matched allogeneic off-the-shelf virus-specific T cells could provide a treatment option for patients with active COVID-19 or at risk of developing COVID-19. We initially screened 60 convalescent individuals and based on HLA typing and T-cell response profile, 12 individuals were selected for the development of a SARS-CoV-2-specific T-cell bank. We demonstrate that these T cells are specific for up to four SARS-CoV-2 antigens presented by a broad range of both HLA class I and class II alleles. These T cells show consistent functional and phenotypic properties, display cytotoxic potential against HLA-matched targets and can recognize HLA-matched cells infected with different SARS-CoV-2 variants. These observations demonstrate a robust approach for the production of SARS-CoV-2-specific T cells and provide the impetus for the development of a T-cell repository for clinical assessment.


Assuntos
Antígenos HLA/imunologia , Imunoterapia Adotiva , SARS-CoV-2/imunologia , Linfócitos T/imunologia , Adulto , Epitopos de Linfócito T , Feminino , Células HEK293 , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Microbiol Spectr ; 10(1): e0278021, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35196796

RESUMO

Understanding the immune response to severe acute respiratory syndrome coronavirus (SARS-CoV-2) is critical to overcome the current coronavirus disease (COVID-19) pandemic. Efforts are being made to understand the potential cross-protective immunity of memory T cells, induced by prior encounters with seasonal coronaviruses, in providing protection against severe COVID-19. In this study we assessed T-cell responses directed against highly conserved regions of SARS-CoV-2. Epitope mapping revealed 16 CD8+ T-cell epitopes across the nucleocapsid (N), spike (S), and open reading frame (ORF)3a proteins of SARS-CoV-2 and five CD8+ T-cell epitopes encoded within the highly conserved regions of the ORF1ab polyprotein of SARS-CoV-2. Comparative sequence analysis showed high conservation of SARS-CoV-2 ORF1ab T-cell epitopes in seasonal coronaviruses. Paradoxically, the immune responses directed against the conserved ORF1ab epitopes were infrequent and subdominant in both convalescent and unexposed participants. This subdominant immune response was consistent with a low abundance of ORF1ab encoded proteins in SARS-CoV-2 infected cells. Overall, these observations suggest that while cross-reactive CD8+ T cells likely exist in unexposed individuals, they are not common and therefore are unlikely to play a significant role in providing broad preexisting immunity in the community. IMPORTANCE T cells play a critical role in protection against SARS-CoV-2. Despite being highly topical, the protective role of preexisting memory CD8+ T cells, induced by prior exposure to circulating common coronavirus strains, remains less clear. In this study, we established a robust approach to specifically assess T cell responses to highly conserved regions within SARS-CoV-2. Consistent with recent observations we demonstrate that recognition of these highly conserved regions is associated with an increased likelihood of milder disease. However, extending these observations we observed that recognition of these conserved regions is rare in both exposed and unexposed volunteers, which we believe is associated with the low abundance of these proteins in SARS-CoV-2 infected cells. These observations have important implications for the likely role preexisting immunity plays in controlling severe disease, further emphasizing the importance of vaccination to generate the immunodominant T cells required for immune protection.


Assuntos
COVID-19/imunologia , Epitopos de Linfócito T/imunologia , SARS-CoV-2/imunologia , Sequência de Aminoácidos , Linfócitos T CD8-Positivos/imunologia , COVID-19/genética , COVID-19/virologia , Sequência Conservada , Coronavirus/química , Coronavirus/classificação , Coronavirus/genética , Coronavirus/imunologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Reações Cruzadas , Mapeamento de Epitopos , Epitopos de Linfócito T/química , Epitopos de Linfócito T/genética , Humanos , Células T de Memória/imunologia , SARS-CoV-2/química , SARS-CoV-2/genética , SARS-CoV-2/fisiologia , Alinhamento de Sequência , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
18.
BMC Infect Dis ; 22(1): 70, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35057745

RESUMO

BACKGROUND: Cancer is associated with excess morbidity and mortality from coronavirus disease 2019 (COVID-19) following infection by the novel pandemic coronavirus SARS-CoV-2. Vaccinations against SARS-CoV-2 have been rapidly developed and proved highly effective in reducing the incidence of severe COVID-19 in clinical trials of healthy populations. However, patients with cancer were excluded from pivotal clinical trials. Early data suggest that vaccine response is less robust in patients with immunosuppressive conditions or treatments, while toxicity and acceptability of COVID-19 vaccines in the cancer population is unknown. Unanswered questions remain about the impact of various cancer characteristics (such as treatment modality and degree of immunosuppression) on serological response to and safety of COVID-19 vaccinations. Furthermore, as the virus and disease manifestations evolve, ongoing data is required to address the impact of new variants. METHODS: SerOzNET is a prospective observational study of adults and children with cancer undergoing routine SARS-CoV-2 vaccination in Australia. Peripheral blood will be collected and processed at five timepoints (one pre-vaccination and four post-vaccination) for analysis of serologic responses to vaccine and exploration of T-cell immune correlates. Cohorts include: solid organ cancer (SOC) or haematological malignancy (HM) patients currently receiving (1) chemotherapy, (2) immune checkpoint inhibitors (3) hormonal or targeted therapy; (4) patients who completed chemotherapy within 6-12 months of vaccination; (5) HM patients with conditions associated with hypogammaglobulinaemia or immunocompromise; (6) SOC or HM patients with allergy to PEG or polysorbate 80. Data from healthy controls already enrolled on several parallel studies with comparable time points will be used for comparison. For children, patients with current or prior cancer who have not received recent systemic therapy will act as controls. Standardised scales for quality-of-life assessment, patient-reported toxicity and vaccine hesitancy will be obtained. DISCUSSION: The SerOzNET study was commenced in June 2021 to prospectively study immune correlates of vaccination in specific cancer cohorts. The high proportion of the Australian population naïve to COVID-19 infection and vaccination at study commencement has allowed a unique window of opportunity to study vaccine-related immunity. Quality of life and patient-reported adverse events have not yet been reported in detail post-vaccination for cancer patients. Trial registration This trial is registered on the Australia New Zealand Clinical Trials Registry (ANZCTR) ACTRN12621001004853. Submitted for registration 25 June 2021. Registered 30 July 2021 (Retrospectively registered). https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382281&isReview=true.


Assuntos
COVID-19 , Neoplasias , Vacinas Virais , Austrália/epidemiologia , Vacinas contra COVID-19 , Humanos , Neoplasias/complicações , Estudos Observacionais como Assunto , Qualidade de Vida , SARS-CoV-2 , Vacinação , Hesitação Vacinal
19.
Nature ; 600(7888): 279-284, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34837071

RESUMO

Confocal microscopy1 remains a major workhorse in biomedical optical microscopy owing to its reliability and flexibility in imaging various samples, but suffers from substantial point spread function anisotropy, diffraction-limited resolution, depth-dependent degradation in scattering samples and volumetric bleaching2. Here we address these problems, enhancing confocal microscopy performance from the sub-micrometre to millimetre spatial scale and the millisecond to hour temporal scale, improving both lateral and axial resolution more than twofold while simultaneously reducing phototoxicity. We achieve these gains using an integrated, four-pronged approach: (1) developing compact line scanners that enable sensitive, rapid, diffraction-limited imaging over large areas; (2) combining line-scanning with multiview imaging, developing reconstruction algorithms that improve resolution isotropy and recover signal otherwise lost to scattering; (3) adapting techniques from structured illumination microscopy, achieving super-resolution imaging in densely labelled, thick samples; (4) synergizing deep learning with these advances, further improving imaging speed, resolution and duration. We demonstrate these capabilities on more than 20 distinct fixed and live samples, including protein distributions in single cells; nuclei and developing neurons in Caenorhabditis elegans embryos, larvae and adults; myoblasts in imaginal disks of Drosophila wings; and mouse renal, oesophageal, cardiac and brain tissues.


Assuntos
Aprendizado Profundo , Microscopia Confocal/métodos , Microscopia Confocal/normas , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/crescimento & desenvolvimento , Linhagem Celular Tumoral , Drosophila melanogaster/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Humanos , Discos Imaginais/citologia , Camundongos , Mioblastos/citologia , Especificidade de Órgãos , Análise de Célula Única , Fixação de Tecidos
20.
Cells ; 10(10)2021 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-34685626

RESUMO

The data currently available on how the immune system recognises the SARS-CoV-2 virus is growing rapidly. While there are structures of some SARS-CoV-2 proteins in complex with antibodies, which helps us understand how the immune system is able to recognise this new virus; however, we lack data on how T cells are able to recognise this virus. T cells, especially the cytotoxic CD8+ T cells, are critical for viral recognition and clearance. Here we report the X-ray crystallography structure of a T cell receptor, shared among unrelated individuals (public TCR) in complex with a dominant spike-derived CD8+ T cell epitope (YLQ peptide). We show that YLQ activates a polyfunctional CD8+ T cell response in COVID-19 recovered patients. We detail the molecular basis for the shared TCR gene usage observed in HLA-A*02:01+ individuals, providing an understanding of TCR recognition towards a SARS-CoV-2 epitope. Interestingly, the YLQ peptide conformation did not change upon TCR binding, facilitating the high-affinity interaction observed.


Assuntos
COVID-19/imunologia , COVID-19/virologia , Epitopos de Linfócito T/química , Antígeno HLA-A2/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Linfócitos T CD8-Positivos/citologia , Cristalografia por Raios X , Citocinas/metabolismo , Epitopos/química , Antígeno HLA-A2/química , Humanos , Mutação , Peptídeos/química , Ligação Proteica , Desnaturação Proteica , Dobramento de Proteína , Ressonância de Plasmônio de Superfície , Linfócitos T Citotóxicos/imunologia
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