A5013020668- SARS-CoV-2 and COVID-19 Research
- COVID-19 Clinical Research Studies
- SARS-CoV-2 detection and testing
- Animal Virus Infections Studies
- Immunotherapy and Immune Responses
- Hematopoietic Stem Cell Transplantation
- Plant-Microbe Interactions and Immunity
- Long-Term Effects of COVID-19
- Vaccine Coverage and Hesitancy
- Herpesvirus Infections and Treatments
- Cytomegalovirus and herpesvirus research
- Viral gastroenteritis research and epidemiology
- Computational Drug Discovery Methods
- Plant Stress Responses and Tolerance
- Photosynthetic Processes and Mechanisms
- Legume Nitrogen Fixing Symbiosis
- Viral-associated cancers and disorders
- Transplantation: Methods and Outcomes
- Viral Infections and Immunology Research
- Influenza Virus Research Studies
- vaccines and immunoinformatics approaches
- Poxvirus research and outbreaks
- Chronic Lymphocytic Leukemia Research
- Polyomavirus and related diseases
- Bacillus and Francisella bacterial research
University Health Network
2019-2025
Toronto General Hospital
2025
Toronto General Hospital Research Institute
2025
Health Net
2021
University of Toronto
2016-2019
Abstract Seeds respond to multiple different environmental stimuli that regulate germination. Nitrate stimulates germination in many plants but how it does so remains unclear. Here we show the Arabidopsis NIN-like protein 8 (NLP8) is essential for nitrate-promoted seed Seed nlp8 loss-of-function mutants not nitrate. NLP8 functions even a nitrate reductase-deficient mutant background, and requirement conserved among accessions. reduces abscisic acid levels nitrate-dependent manner directly...
Solid organ transplant recipients are at high risk of severe disease from COVID-19. We assessed the immunogenicity mRNA-1273 vaccine using a combination antibody testing, surrogate neutralization assays, and T cell assays. Patients were immunized with two doses after each dose above tests. CD4+ CD8+ responses in subset flow-cytometry. A total 127 patients enrolled which 110 provided serum all time points. positive anti-RBD was seen 5.0% one 34.5% doses. Neutralizing present 26.9%. Of note,...
The SARS-CoV-2 virus Omicron variant has now supplanted wild-type as the dominant circulating strain globally. Three doses of mRNA COVID-19 vaccine are recommended for transplant recipients their primary series. However, immunogenicity vaccines they specifically relate to not well studied. We analyzed Omicron-specific neutralization in after three-doses mRNA-1273 vaccine. Neutralization was determined using a spike pseudotyped lentivirus assay with constructs and Delta variants. A total 60...
COVID-19 is more severe in transplant recipients. Variants of concern have supplanted wild-type virus. In recipients, data are limited on 2-dose or 3-dose vaccine immunogenicity against variant viruses.To assess neutralizing antibody responses SARS-CoV-2 variants recipients after 2 and 3 doses.Secondary analysis a randomized, double-blind, controlled trial third dose mRNA-1273 versus placebo. (ClinicalTrials.gov: NCT04885907).Single-center program.Organ recipients.Third placebo.Sera were...
In allogeneic stem cell transplant (Allo-SCT) recipients, the cell-mediated and humoral immunogenicity of 3-dose SARS-CoV-2 vaccination schedule has not been investigated in prospective studies. a cohort, we recruited 122 Allo-SCT recipients since August 2021, when Ontario began offering vaccine for recipients. We determined immunity adverse effects SARS-COV-2 analysis (n = 95), median (interquartile range [IQR]) antibody titer against receptor-binding domain (RBD) spike (S) protein after...
Identifying sets of genes that are specifically expressed in certain tissues or response to an environmental stimulus is useful for designing reporter constructs, generating gene expression markers, understanding regulatory networks. We have developed easy-to-use online tool defining a desired profile (a modification our Expression Angler program), which can then be used identify exhibiting patterns match this as closely possible. Further, we another tool, Cistome, predicting exploring...
Determining the complete Arabidopsis (Arabidopsis thaliana) protein-protein interaction network is essential for understanding functional organization of proteome. Numerous small-scale studies and a couple large-scale ones have elucidated fraction estimated 300,000 binary interactions in Arabidopsis. In this study, we provide evidence that docking algorithm has ability to identify real using both experimentally determined predicted protein structures. We ranked 0.91 million generated by all...
Immunization of varicella-zoster virus (VZV)-seronegative solid organ transplant (SOT) patients using the live-attenuated varicella vaccine is generally contraindicated, leaving no widely applicable immunization option. The recombinant subunit herpes zoster (RZV) indicated for VZV-seropositive persons to prevent shingles but could potentially also protect VZV-seronegative against varicella. We performed a safety and immunogenicity evaluation RZV in SOT recipients as an option...
Abstract Immunocompromised patients are predisposed to severe COVID-19. Here we compare homotypic and heterotypic humoral cellular immune responses Omicron BA.1 in organ transplant across a diverse clinical spectrum. We perform variant-specific pseudovirus neutralization assays for D614G, Omicron-BA.1, -BA.2, Delta variants. also measure poly-and monofunctional T-cell ancestral SARS-CoV-2 peptide pools. identify that partially or fully-vaccinated recipients after infection with have the...
Solid organ transplant (SOT) recipients are at risk for severe coronavirus disease 2019 (COVID-19), despite vaccination. Our study aimed to elucidate COVID-19 vaccine immunogenicity and evaluate adverse events such as hospitalization, rejection, breakthrough infection in a SOT cohort.We performed prospective, observational on 539 adult (age ≥18 years old) recruited from 7 Canadian centers. Demographics including characteristics, types, immunosuppression infection, rejection were recorded....
Background. Ex vivo lung perfusion (EVLP) offers a novel platform for delivering targeted therapies directly to donor lungs before transplantation, potentially reducing systemic side effects. Our study evaluated the feasibility and safety of rituximab delivery from Epstein-Barr virus (EBV)-seropositive donors transplantation into EBV-seronegative recipients (D + /R – ) reduce risk EBV-associated posttransplant lymphoproliferative disorder (PTLD), which remains major obstacle in transplant...
Abstract Background In solid organ transplant (SOT) recipients, the primary vaccination series against Coronavirus Disease 2019 is 3 doses followed by boosters. We determined whether a fourth dose booster induced Omicron BA.4/5 neutralizing antibodies (nAbs) and T cells in large multicenter cohort study. Methods Serum was collected 4–6 weeks post-third post-fourth of messenger RNA vaccine 222 SOT recipients. nAbs were measured using pseudovirus neutralization assay that targeted spike...
Abstract Background In North America, both messenger RNA (mRNA) vaccines, Pfizer-BioNTech BNT162b2, and Moderna mRNA-1273, each utilizing a 2-dose regimen, have started to be administered individuals. Methods We evaluated the quantitative serologic antibody response following administration of either single dose or doses an mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in cohort 98 participants (88 healthcare workers [HCW] 10 solid organ transplant [SOT]...
Background. Several studies have described the clinical features of COVID-19 in solid-organ transplant recipients. However, many been retrospective or limited to more severe cases (hospitalized) and not routinely included serial virological sampling (especially outpatients) immunologic assessment. Methods. Transplant patients diagnosed with based on a respiratory sample PCR were prospectively followed up 90 d. Patients provided consent for convalescent serum samples nasopharyngeal swabs...
Health care workers (HCWs) are at higher risk for SARS-CoV-2 infection and may play a role in transmitting the to vulnerable patients members of community. This is particularly worrisome context asymptomatic infection. We performed cross-sectional study looking HCWs. screened HCWs via PCR. Complementary viral genome sequencing was on positive swab specimens. A seroprevalence analysis also using multiple assays. Asymptomatic health worker cohorts had combined positivity rate 29/5776 (0.50%,...
Allogeneic hematopoietic stem cell transplantation (HSCT) recipients are susceptible to severe outcomes of Coronavirus disease 2019 (COVID-19). Most guidelines recommend a fourth dose (ie, booster) COVID-19 vaccine reduce the infection risk, and observational studies needed determine immunogenicity safety booster in this population. The primary outcome was quantitative anti-receptor-binding domain (RBD) antibody titers after vaccine. secondary included adverse effects all-cause mortality....
T-cell immunity associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or vaccination in solid organ transplant recipients (SOTRs) is poorly understood. To address this, we measured responses 50 SOTRs prior SARS-CoV-2 infection. The majority of patients mounted SARS-CoV-2-specific CD4+ against spike (S), nucleocapsid, and membrane proteins; CD8+ were generated to a lesser extent. correlated antibody levels. Severity disease mycophenolate dose moderately lower...
Despite annual immunization, solid organ transplant (SOT) patients remain at increased risk for severe influenza infection because of suboptimal vaccine immunogenicity. We aimed to compare the CD4+ and CD8+ T-cell responses high-dose (HD) standard-dose (SD) trivalent inactivated vaccine.We collected peripheral blood mononuclear cells pre- postimmunization from 60 enrolled in a randomized trial HD versus SD (30 HD; 30 SD) during 2016-2017 season.The elicited significantly greater...
ABSTRACT We screened three separate cohorts of healthcare workers for SARS-CoV-2 via nasopharyngeal swab PCR. A seroprevalence analysis using multiple assays was performed in a subgroup. The asymptomatic health care worker had combined swap positivity rate 29/5776 (0.50%, 95%CI 0.32-0.75) compared to the symptomatic cohort 54/1597 (3.4%) (ratio 6.8:1). Sequencing demonstrated several variants. (n=996) 1.4-3.4% depending on assay. Protein microarray showed differing protein reactivities and...