Biology subjects

Zhan, W.

Publications and source records attributed to Zhan, W..

7 recordsLinked to original sources

bioRxiv2022

Combating the SARS-CoV-2 Omicron variant with non-Omicron neutralizing antibodies

The highly mutated and transmissible Omicron variant has provoked serious concerns over its decreased sensitivity to the current coronavirus disease 2019 (COVID-19) vaccines and evasion from most anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies (NAbs). In this study, we explored the possibility of combatting the Omicron variant by constructing bispecific antibodies based on non-Omicron NAbs. We engineered ten IgG-like bispecific antibodies with non-Omicron NAbs named GW01, 16L9, 4L12, and REGN10987 by fusing the single-chain variable fragments (scFvs) of two antibodies through a linker and then connecting them to the Fc region of IgG1. Surprisingly, eight out of ten bispecific antibodies showed high binding affinity to the Omicron receptor-binding domain (RBD) and exhibited extreme breadth and potency against pseudotyped SARS-CoV-2 variants of concern (VOCs) including Omicron, as well as authentic Omicron(+R346K) variants. Six bispecific antibodies containing the cross-NAb GW01 neutralized Omicron variant and retained their abilities to neutralize other sarbecoviruses. Bispecific antibodies inhibited Omicron infection by binding to the ACE2 binding site. A cryo-electron microscopy (cryo-EM) structure study of the representative bispecific antibody FD01 in complex with the Omicron spike (S) revealed 5 distinct trimers and one unique bi-trimer conformation. The structure and mapping analyses of 34 Omicron S variant single mutants elucidated that two scFvs of the bispecific antibody synergistically induced the RBD-down conformation into 3-RBD-up conformation, enlarged the interface area, accommodated the S371L mutation, improved the affinity between a single IgG and the Omicron RBD, and hindered ACE2 binding by forming bi-trimer conformation. Our study offers an important foundation for anti-Omicron NAb design. Engineering bispecific antibodies based on non-Omicron NAbs may provide an efficient solution to combat the Omicron variant.

microbiology↗

bioRxiv2022

Asymmetric Pendrin Homodimer Reveals its Molecular Mechanism as Anion Exchanger

Pendrin SLC26A4 is an anion exchanger expressed in apical membranes of selected epithelia. Pendrin ablation causes Pendred syndrome, a genetic disorder disease associated with sensorineural hearing loss, hypothyroid goiter, and reduced blood pressure. However, its molecular structure has remained unknown limiting our understanding. Here, we determined the structures of mouse pendrin with symmetric and characteristically asymmetric homodimer conformations by cryo-electron microscopy. The asymmetric homodimer consists of an inward-facing protomer and an intermediate-state protomer, representing the coincident uptake and secretion process, and exhibits the unique state of pendrin as an electroneutral exchanger. This previously unrevealed conformation, together with other conformations we captured, provides an inverted alternate-access mechanism for anion exchange. Furthermore, our structural and functional data disclosed the properties of anion exchange cleft and interpreted the important pathogenetic mutations. These investigations shed light on the pendrin exchange mechanism and extend our structure-guided understanding of pathogenetic mutations. One-Sentence SummaryCryo-EM asymmetric Pendrin homodimer cracks its exchange mechanism and guides our understanding for pathogenetic mutations.

biophysics↗

bioRxiv2021

Broad neutralization of SARS-CoV-2 variants by an inhalable bispecific single-domain antibody

The effectiveness of SARS-CoV-2 vaccines and therapeutic antibodies has been limited by the continuous emergence of viral variants, and by the restricted diffusion of antibodies from circulation into the sites of respiratory virus infection. Here, we report the identification of two highly conserved regions on Omicron variant RBD recognized by broadly neutralizing antibodies. Based on this finding, we generated a bispecific single-domain antibody that was able to simultaneously and synergistically bind these two regions on a single Omicron variant RBD as revealed by Cryo-EM structures. This inhalable antibody exhibited exquisite neutralization breadth and therapeutic efficacy in mouse models of SARS-CoV-2 infections. The structures also deciphered an uncommon cryptic epitope within the spike trimeric interface that may have implications for the design of broadly protective SARS-CoV-2 vaccines and therapeutics.

immunology↗

bioRxiv2021

Artemisinin-based hybrids produce intracellular proteasome inhibitors that overcome resistance in Plasmodium falciparum

Artemisinin resistant Plasmodium falciparum (Pf) is spreading despite combination chemotherapy (ACT). Here we report the design of artezomibs, single-molecule hybrids of an artemisinin and a Pf-selective proteasome inhibitor. Artezomibs exert a novel mode of action inside the malaria parasites. The artemisinin component covalently modifies parasite proteins, which become substrates of the Pf proteasome. The proteasomal degradation products that bear the proteasome inhibitor component of the hybrid then inhibit Pf proteasomes, including those with mutations that reduce binding affinity of the proteasome inhibitor component on its own. We demonstrated that artezomibs circumvent both artemisinin resistance conferred by Kelch13 polymorphism and resistance to the proteasome inhibitor associated with mutations in Pf proteasomes. This mode of action may enable the use of a single molecule with one pharmacokinetic profile to prevent the emergence of resistance.

microbiology↗

bioRxiv2021

The First High-Quality Reference Genome of Sika Deer Provides Insights for High-Tannin Adaptation

Sika deer are known to prefer oak leaves, which are rich in tannins and toxic to most mammals; however, the genetic mechanisms underlying their unique ability to adapt to living in the jungle are still unclear. In identifying the mechanism responsible for the tolerance of a highly toxic diet, we have made a major advancement in the elucidation of the genomics of sika deer. We generated the first high-quality, chromosome-level genome assembly of sika deer and measured the correlation between tannin intake and RNA expression in 15 tissues through 180 experiments. Comparative genome analyses showed that the UGT and CYP gene families are functionally involved in the adaptation of sika deer to high-tannin food, especially the expansion of UGT genes in a subfamily. The first chromosome-level assembly and genetic characterization of the tolerance toa highly toxic diet suggest that the sika deer genome will serve as an essential resource for understanding evolutionary events and tannin adaptation. Our study provides a paradigm of comparative expressive genomics that can be applied to the study of unique biological features in non-model animals.

genomics↗

bioRxiv2020

Regeneration of Functional Retinal Ganglion Cells by Neuronal Identity Reprogramming

Degeneration of retinal ganglion cells (RGCs) and their axons underlies vision loss in glaucoma and various optic neuropathies. There are currently no treatments available to restore lost vision in patients affected by these diseases. Regenerating RGCs and reconnecting the retina to the brain represent an ideal therapeutic strategy; however, mammals do not have a reservoir of retinal stem/progenitor cells poised to produce new neurons in adulthood. Here, we regenerated RGCs in adult mice by direct lineage reprogramming of retinal interneurons. We successfully converted amacrine and displaced amacrine interneurons into RGCs, and observed that regenerated RGCs projected axons into brain retinorecipient areas. They convey visual information to the brain in response to visual stimulation, and are able to transmit electrical signals to postsynaptic neurons, in both normal animals and in a diseased model. The generation of functional RGCs in adult mammals points to a therapeutic strategy for vision restoration in patients.

neuroscience↗

bioRxiv2019

Transcriptome analysis of the Larimichthys polyactis under heat and cold stress

The small yellow croaker (Larimichthys polyactis) is an important marine economic fish that is widely distributed in the East Sea, Yellow Sea and Bohai of China. However, the wild populations of small yellow croaker are severely depleted, and there is currently a developing large-scale artificial propagation of this fish for aquaculture. However, the current variety of small yellow croaker that is cultivated is not capable to coping with large fluctuations in temperature. Therefore, it is important to understand the molecular mechanisms that are activated in response to temperature stress in the small yellow croaker. Here, we conducted transcriptomic analysis of the liver of small yellow croaker under heat and cold stress. A total of 270,844,888, 265,727,006 and 259,666,218 clean reads were generated from heat temperature group, low temperature group and control group, respectively, and comparing expression of genes in these transcriptomes,10,878 unigenes that were differential expressed were identified. Sixteen of the differentially expressed unigenes were validated by qRT-PCR. Pathway enrichment analysis identified that the ER pathway, immune signaling pathway and metabolic response pathway were affected by temperature stress. The results of this study provide a comprehensive overview of temperature stress-induced transcriptional patterns in liver tissues of the small yellow croaker. In addition, these results can guide future molecular studies of heat and cold stress response in this species for improving the stock used for aquaculture.

physiology↗