Biology subjects

Beland, K.

Publications and source records attributed to Beland, K..

4 recordsLinked to original sources

bioRxiv2022

Molecular basis for antiviral activity of pediatric neutralizing antibodies targeting SARS-CoV-2 Spike receptor binding domain

Neutralizing antibodies (NAbs) hold great promise for clinical interventions against SARS-CoV- 2 variants of concern (VOCs). Understanding NAb epitope-dependent antiviral mechanisms is crucial for developing vaccines and therapeutics against VOCs. Here we characterized two potent NAbs, EH3 and EH8, isolated from an unvaccinated pediatric patient with exceptional plasma neutralization activity. EH3 and EH8 cross-neutralize the early VOCs and mediate strong Fc-dependent effector activity in vitro. Structural analyses of EH3 and EH8 in complex with the receptor-binding domain (RBD) revealed the molecular determinants of the epitope-driven protection and VOC-evasion. While EH3 represents the prevalent IGHV3-53 NAb whose epitope substantially overlaps with the ACE2 binding site, EH8 recognizes a narrow epitope exposed in both RBD-up and RBD-down conformations. When tested in vivo, a single-dose prophylactic administration of EH3 fully protected stringent K18-hACE2 mice from lethal challenge with Delta VOC. Our study demonstrates that protective NAbs responses converge in pediatric and adult SARS-CoV-2 patients.

microbiology↗

bioRxiv2022

Generation of Functional Human T Cell Development in NOD/SCID/IL2rγnull Humanized Mice Without Using Fetal Tissue: Application as a Model of HIV Infection and Persistence

Generating humanized mice with fully functional T cells currently relies on co-implantation of hematopoietic stem cells from fetal liver and autologous fetal thymic tissue (BLT mouse). However, access to such tissues has ethical and logistical challenges. Herein, we show that NOD/SCID/IL2r{gamma}null mice humanized with cord blood-derived CD34+ cells and implanted in quadriceps with pediatric thymic tissues excised during cardiac surgeries (CCST mice) are an alternative to BLT mice. Our data revealed a strong immune reconstitution in CCST mice, with T cells originating from CD34+ progenitor cells, proliferating efficiently in response to mitogenic stimulation ex vivo and capable of rejecting allogeneic human leukemic cells in vivo. Despite having less T cells than BLT mice, CCST mice were equally susceptible to mucosal or intraperitoneal HIV infection. Importantly, HIV-specific T cell responses were significantly higher in CCST-mice (median: 10.4% vs. 0.7%; p<0.0001 for CD8+cells and 3.9% vs. 0.7%; p<0.01 for CD4+ cells). As well, antiretroviral therapy (ART) robustly suppressed viremia and reduced the frequencies of cells carrying integrated HIV DNA by up to 2 logs in various CCST mouse tissues. As in BLT mice, we observed a complete viral rebound in 67% of the animals by 2-4 weeks following ART interruption, suggesting the presence of HIV reservoirs. In conclusion, CCST mice represent an ethical and practical alternative to BLT mice, broadening the feasibility of utilizing humanized mice for research on HIV and other human diseases. One Sentence SummaryWe herein report a new humanized mouse model implanted with human cord blood hematopoietic stem cells and allogenic pediatric thymic tissue that develops a functional T cell compartment and supports efficient HIV infection and persistence during antiretroviral therapy.

immunology↗

bioRxiv2022

Genome-wide CRISPR Screens Identify Ferroptosis as a Novel Therapeutic Vulnerability in Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is the most frequent cancer diagnosed in children. Despite the great progress achieved over the last 40 years, with cure rates now exceeding 85%, refractory or relapsed ALL still exhibit a dismal prognosis. This poor outcome reflects the lack of treatment options specifically targeting relapsed or refractory ALL. To address this gap, we have performed whole-genome CRISPR/Cas drop-out screens on a panel of seven B-ALL cell lines. Our results demonstrate that while there was a significant overlap in gene essentiality between ALL cell lines and other cancer types survival of ALL cell lines was dependent on several unique metabolic pathways, including an exquisite sensitivity to GPX4 depletion and ferroptosis induction and GPX4 KO. Detailed molecular analysis of B-ALL cells suggest that they are primed to undergo ferroptosis as they exhibit high steady-state oxidative stress potential, a low buffering capacity, and a disabled GPX-independent secondary lipid peroxidation detoxification pathway. Finally, we validated the sensitivity of B-ALL to ferroptosis induction using patient-derived B-ALL samples.

cancer biology↗

bioRxiv2019

Efficient and robust NK-Cell transduction with Baboon Envelope pseudotyped lentivector: a major tool for immunotherapy

NK-cell resistance to transduction is a major technical hurdle for developing NK-cell immunotherapy. By using Baboon envelope pseudotyped lentiviral vectors (BaEV-LVs) encoding eGFP, we obtained a transduction rate of 23.0{+/-}6.6% in freshly-isolated NK-cells (FI-NK) and 83.4{+/-}10.1% in NK-cells obtained from the NK-cell Activation and Expansion System (NKAES), even at low MOI, with a sustained transgene expression for at least 21 days. BaEV-LVs outperformed Vesicular Stomatitis Virus type-G (VSV-G)-, RD114-and Measles Virus (MV)-pseudotyped LVs (p<0.001). mRNA expression of both BaEV receptors, ASCT1 and ASCT2, was detected in FI-NK and NKAES, with much higher expression in NKAES. Transduction with BaEV-LVs encoding for CAR-CD22 resulted in robust CAR-expression on 44.2%{+/-}14.2% of NKAES cells, which allowed the specific killing of the NK-resistant pre-B-ALL-RS4;11 cell line. Using a larger vector, encoding a dual CD19/CD22-CAR separated by T2A, we were able to transduce and re-expand dual-CAR-expressing NKAES, even with low viral titer. These dual-CAR-NK efficiently and specifically killed both CD19KO-and CD22KO-RS4;11 cells, which may overcome antigen-loss escape in the clinical setting. Our results suggest that BaEV-LVs may efficiently enable NK-cell biological studies and translation of NK-cell-based immunotherapy to the clinic.

immunology↗