A5016884436- SARS-CoV-2 and COVID-19 Research
- HIV Research and Treatment
- Immune Cell Function and Interaction
- Viral gastroenteritis research and epidemiology
- COVID-19 Clinical Research Studies
- T-cell and B-cell Immunology
- SARS-CoV-2 detection and testing
- Bacterial Genetics and Biotechnology
- Bacterial biofilms and quorum sensing
- HIV/AIDS drug development and treatment
- HIV-related health complications and treatments
- Cytomegalovirus and herpesvirus research
- Gut microbiota and health
- Animal Virus Infections Studies
- Monoclonal and Polyclonal Antibodies Research
- Mycobacterium research and diagnosis
- Bacillus and Francisella bacterial research
- Complement system in diseases
- CRISPR and Genetic Engineering
- Heparin-Induced Thrombocytopenia and Thrombosis
- Metabolism and Genetic Disorders
- Diet and metabolism studies
- Platelet Disorders and Treatments
- HIV/AIDS Research and Interventions
- Psoriasis: Treatment and Pathogenesis
Centre Hospitalier de l’Université de Montréal
2020-2024
Université de Montréal
2020-2024
McGill University
2021
Western University
2021
Hôpital du Sacré-Cœur de Montréal
2021
McGill University Health Centre
2021
Hôpital Maisonneuve-Rosemont
2021
Kettering University
2016-2017
Memorial Sloan Kettering Cancer Center
2016
Cornell University
2009-2014
Emerging evidence indicates that both neutralizing and Fc-mediated effector functions of antibodies contribute to protection against SARS-CoV-2. It is unclear whether Fc-effector alone can protect Here, we isolated CV3-13, a non-neutralizing antibody, from convalescent individual with potent functions. The cryoelectron microscopy structure CV3-13 in complex the SARS-CoV-2 spike reveals antibody binds distinct angle approach an N-terminal domain (NTD) epitope only partially overlaps NTD...
X-ray crystallographic structural analyses of the bacterial transmembrane receptor LapD identify conserved molecular mechanisms that control biofilm formation in response to changes intracellular levels second messenger c-di-GMP.
Cholera toxin (CT) is the major virulence factor of pathogenic Vibrio cholerae. The present study demonstrates that a fraction CT associated with outer membrane vesicles (OMVs) released by V. Atomic force microscopy (AFM) and also transmission electron (TEM) purified OMVs from toxigenic cholerae O395 revealed spherical shaped size range 20–200 nm. Immunoblotting polyclonal anti-CT antibody GM1-ganglioside dependent ELISA suggest OMVs. CHO cell assay indicated OMV physiologically active....
RNase H enzymes sense the presence of ribonucleotides in genome and initiate their removal by incising ribonucleotide-containing strand an RNA:DNA hybrid. Mycobacterium smegmatis encodes four enzymes: RnhA, RnhB, RnhC RnhD. Here, we interrogate biochemical activity nucleic acid substrate specificity RnhA. We report that RnhA (like characterized previously) is H1-type magnesium-dependent endonuclease with stringent for hybrid duplexes. Whereas does not incise embedded mono-ribonucleotide, it...
Continuous emergence of SARS-CoV-2 variants concern (VOCs) is fueling the COVID-19 pandemic. Omicron (B.1.1.529) rapidly spread worldwide. The large number mutations in its Spike raise concerns about a major antigenic drift that could significantly decrease vaccine efficacy and infection-induced immunity. A long interval between BNT162b2 mRNA doses elicits antibodies efficiently recognize Spikes from different VOCs. Here, we evaluate recognition by plasma cohort naive previously infected...
Several severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariants have recently emerged, becoming the dominant circulating strains in many countries. These variants contain a large number of mutations their spike glycoprotein, raising concerns about vaccine efficacy. In this study, we evaluate ability plasma from cohort individuals that received three doses mRNA to recognize and neutralize these subvariant spikes. We observed BA.4/5 BQ.1.1 spikes are markedly less...
<h3>BACKGROUND:</h3> Patients receiving in-centre hemodialysis are at high risk of exposure to SARS-CoV-2 and death if infected. One dose the BNT162b2 vaccine is efficacious in general population, but responses patients uncertain. <h3>METHODS:</h3> We obtained serial plasma from health care worker controls before after vaccination with 1 mRNA vaccine, as well convalescent who survived COVID-19. measured anti–receptor binding domain (RBD) immunoglobulin G (IgG) levels stratified groups by...
SUMMARY HIV-1 envelope glycoprotein (Env) conformation substantially impacts antibody-dependent cellular cytotoxicity (ADCC). Envs from primary isolates adopt a prefusion “closed” conformation, which is targeted by broadly-neutralizing antibodies (bnAbs). CD4 binding drives Env into more “open” conformations, are recognized non-neutralizing Abs (nnAbs). To better understand Env-Ab and Env-CD4 interaction in CD4+ T cells infected with HIV-1, we simultaneously measured antibody mRNA expression...
ABSTRACT Biofilm formation by Pseudomonas fluorescens Pf0-1 requires the cell surface adhesin LapA. We previously reported that LapG, a periplasmic cysteine protease of P. , cleaves N terminus LapA, thus releasing this from and resulting in loss ability to make biofilm. The activity LapG is regulated inner membrane-localized cyclic-di-GMP receptor LapD via direct protein-protein interactions. Here we present chelation metal add-back studies demonstrating calcium availability regulates...
The bacterial dinucleotide second messenger c-di-GMP has emerged as a central molecule in regulating behavior, including motility and biofilm formation. Proteins for the synthesis degradation of effectors its signal transmission are widely used domain. Previous work established GGDEF-EAL domain-containing receptor LapD switch Pseudomonas fluorescens cell adhesion. senses inside cytosol relays this to outside by differential recruitment periplasmic protease LapG. Here we identify core...
Expression of fission yeast Pho1 acid phosphatase is repressed during growth in phosphate-rich medium. Repression mediated by transcription the prt locus upstream pho1 to produce a long noncoding (lnc) RNA. also governed RNA polymerase II CTD phosphorylation status, whereby inability place Ser7-PO4 mark (as S7A) derepresses expression, and Thr4-PO4 T4A) hyper-represses phosphate replete cells. Here we find that basal expression from prt-pho1 inversely correlated with activity promoter, which...
Among CD4+ T cells, helper 17 (Th17) cells are particularly susceptible to HIV-1 infection and depleted from mucosal sites, which causes damage the gut barrier, resulting in a microbial translocation-induced systemic inflammation, hallmark of disease progression. Furthermore, proportion latently infected Th17 persist long term gastrointestinal lymphatic tract where low-level transcription is observed. This residual viremia contributes chronic immune activation. Thus, key players HIV...
Due to the recrudescence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections worldwide, mainly caused by Omicron variant concern (VOC) and its sub-lineages, several jurisdictions are administering an mRNA vaccine boost. Here, we analyze humoral responses induced after second third doses in naive previously infected donors who received their dose with extended 16-week interval. We observe that interval elicits robust against VOCs, but this response is significantly...
Mannose-capped lipoarabinomannan (ManLAM) is a complex lipoglycan abundantly present in the Mycobacterium tuberculosis cell envelope. Many biological properties have been ascribed to ManLAM, from directly interacting with host and participating intracellular survival of M. tuberculosis, triggering innate adaptive immune responses, including activation CD1b-restricted T cells. Due its structural complexity, ManLAM considered heterogeneous population molecules which may explain different...
Stable surface adhesion of cells is one the early pivotal steps in bacterial biofilm formation, a prevalent adaptation strategy response to changing environments. In Pseudomonas fluorescens, this process regulated by Lap system and second messenger cyclic-di-GMP. High cytoplasmic levels cyclic-di-GMP activate transmembrane receptor LapD that turn recruits periplasmic protease LapG, preventing it from cleaving cell surface-bound adhesin, thereby promoting adhesion. study, we elucidate...
The aryl hydrocarbon receptor (AhR) regulates Th17-polarized CD4+ T cell functions, but its role in HIV-1 replication/outgrowth remains unknown. Genetic (CRISPR-Cas9) and pharmacological inhibition reveal AhR as a barrier to replication (TCR)-activated cells vitro. In single-round vesicular stomatitis virus (VSV)-G-pseudotyped infection, blockade increases the efficacy of early/late reverse transcription subsequently facilitated integration/translation. Moreover, boosts viral outgrowth...
ABSTRACT The majority of naturally elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs) because they unable to recognize Env trimer in its native “closed” conformation. Nevertheless, it has been shown that nnAbs have potential eliminate HIV-1-infected cells by antibody-dependent cellular cytotoxicity (ADCC) provided is present on cell surface “open” This most epitopes become accessible only after interaction with CD4 and exposure normally occluded...
ABSTRACT One characteristic of the HIV-1 CRF01_AE strain is that it contains a bulkier histidine residue at position 375 (H375) in its envelope glycoproteins (Env). This part Phe43 cavity, where 43 CD4 engages with gp120. It has been shown H375 contributes to resistance against small molecule inhibitors targeting Residue co-evolved few residues gp120 inner domain layers, and together they modulate susceptibility Env inhibitors. Since 629 within HR2 region gp41 also proposed have 375, we...
The majority of naturally-elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs), because they unable to recognize Env timer in its native "closed" conformation. Nevertheless, it has been shown that nnAbs have potential eliminate HIV-1-infected cells by Antibody-Dependent Cellular Cytotoxicity (ADCC) provided is present on cell surface "open" This most epitopes become accessible only after interaction with CD4 and exposure normally occluded closed...
ABSTRACT HIV-1 envelope glycoprotein (Env) conformation substantially impacts antibody-dependent cellular cytotoxicity (ADCC). Envs from primary isolates adopt a prefusion “closed” conformation, which is targeted by broadly neutralizing antibodies (bnAbs). CD4 binding drives Env into more “open” conformations, are recognized non-neutralizing Abs (nnAbs). To better understand Env–Ab and Env–CD4 interaction in CD4+ T cells infected with HIV-1, we simultaneously measured antibody mRNA...
ABSTRACT Fission yeast phosphate homeostasis entails transcriptional induction of genes encoding phosphate-mobilizing proteins under conditions starvation. Transcription factor Pho7, a member the Zn 2 Cys 6 family fungal transcription regulators, is central player in starvation response. The DNA binding sites promoters phosphate-responsive have not been defined, nor any structure-function relationships established for Pho7 protein. Here we narrow this knowledge gap by (i) delineating an...