George Fu Gao’s research while affiliated with Zhejiang Medical University and other places

Background As SARS-CoV-2 continues to spread and evolve, new variants/sub-variants emerge, raising concerns about vaccine-induced immune escape. Here, we conducted a systematic analysis of the serology and immunogenicity of major circulating variants/sub-variants of SARS-CoV-2 since the outbreak. Methods We expressed and purified trimeric S proteins from 21 SARS-CoV-2 variants, with SARS-CoV included as an outgroup. Mice were immunized, and the resulting antisera were tested for binding antibodies after the third dose injection, and for neutralizing antibodies (NAbs) after both the second and third doses. Using pseudovirus neutralization assays, we evaluated cross-neutralization among major circulating variants. By integrating serological classification, antigenic mapping, and 3D landscape analysis, we explored the antigenic relationships among different SARS-CoV-2 variants and their impact on serological responses. Findings Based on the cross-neutralization activities of the sera from different S protein vaccinations and antigenicity analyses, we grouped the 21 lineages into six serotypes. Particularly, BA.2.86 and JN.1 had very weak cross-neutralization with all other SARS-CoV-2 sub-variants tested and were grouped into a separate serotype, Serotype VI. Interpretation This systematic study contributes to a better understanding of the evolution of SARS-CoV-2 and its antigenic characteristics and provides valuable insights for vaccine development. Funding This study was supported by the 10.13039/501100012166National Key R&D Program of China (2023YFC2307801, 2020YFA0509202 and 2021YFA1300803), the 10.13039/501100001809National Natural Science Foundation of China (82222040 and 82072289), CAS Project for Young Scientists in Basic Research (YSBR-083) and Beijing Nova Program of Science and Technology (20220484181).

Porcine deltacoronavirus (PDCoV) and transmissible gastroenteritis coronavirus (TGEV), the two causative agents of porcine diarrhea, have been reported to be at risk of cross-species transmission, including to humans. However, the potential host range in which these two CoVs interact remains unclear. We screened 16 animal counterparts for porcine aminopeptidase N (APN), the receptor of PDCoV and TGEV, and found that APNs from eight of 17 animals could bind to the receptor-binding domains (RBDs) of PDCoV and TGEV. Furthermore, the animal APNs that could bind to the RBDs could mediate cellular infection by both viruses. Dog APN (dAPN) has been identified as the animal receptor with the highest capability to mediate the virus infection. We further resolved the complex structures of dAPN bound to the PDCoV RBD/TGEV RBD, respectively, establishing its divergent receptor-binding modes. We identified R325 of dAPN as an important residue in the PDCoV RBD-dAPN interaction, and found the central role of Q746 and T749 in dAPN in the interaction with the TGEV RBD. These findings provide the molecular basis of the potential cross-species transmission of these two porcine CoVs and shed light on future surveillance of these CoVs.

The human body contains trillions of cells, classified into specific cell types, with diverse morphologies and functions. In addition, cells of the same type can assume different states within an individual's body during their lifetime. Understanding the complexities of the proteome in the context of a human organism and its many potential states is a necessary requirement to understanding human biology, but these complexities can neither be predicted from the genome, nor have they been systematically measurable with available technologies. Recent advances in proteomic technology and computational sciences now provide opportunities to investigate the intricate biology of the human body at unprecedented resolution and scale. Here we introduce a big-science endeavour called π-HuB (proteomic navigator of the human body). The aim of the π-HuB project is to (1) generate and harness multimodality proteomic datasets to enhance our understanding of human biology; (2) facilitate disease risk assessment and diagnosis; (3) uncover new drug targets; (4) optimize appropriate therapeutic strategies; and (5) enable intelligent healthcare, thereby ushering in a new era of proteomics-driven phronesis medicine. This ambitious mission will be implemented by an international collaborative force of multidisciplinary research teams worldwide across academic, industrial and government sectors.

Background Omicron sub-variants breakthrough infections (BTIs) have led to millions of coronavirus disease 2019 (COVID-19) cases worldwide. The acute-phase immune status is critical for prognosis, however, the dynamic immune profiling of COVID-19 during the first month after BTIs remains unclear. Methods In this study, we monitored the immune dynamics at various timepoints in a longitudinal cohort during the first month post-BTIs through clinical evaluation, single-cell RNA sequencing (scRNA-seq), T cell receptor (TCR)/B cell receptor (BCR) sequencing, and antibody mass spectrometry. Findings Serological analysis revealed limited impairment to functions of major organs, active cellular and humoral immunity at 2 weeks post-BTI, with significant increases in cytokines (CKs) and neutralizing antibody levels. However, 1 month post-BTI, organ function parameters and CK levels reverted to pre-infection levels, whereas neutralizing antibody levels remained high. Notably, scRNA-seq showed that lymphocytes maintained strong antiviral activity and cell depletion at 2 weeks and 1 month post-BTI, with genes CD81, ABHD17A, CXCR4, DUSP1, etc. upregulated, and genes PFDN5, DYNLRB1, CD52, etc. downregulated, indicating that lymphocytes status take longer to recover to normal levels than that routine blood tests revealed. Additionally, T cell-exhaustion associated genes, including LAG3, TIGIT, PDCD1, CTLA4, HAVCR2, and TOX, were upregulated after BTI. TCRs and BCRs exhibited higher clonotypes, mainly in CD8Tem or plasmablast cells, at 2 weeks post-BTI comparing 1 month. More IgG and IgA-type BCRs were found in the groups of 1 month post-BTI, with higher somatic hypermutation, indicating greater maturity. Verification of monoclonal antibodies corresponding to amplified BCRs highlighted the antigen-specific and broad-spectrum characteristics. Interpretation Our study elucidated the dynamic immune profiling of individuals after Omicron BA.5 sublineages BTI. Strong immune activation, antiviral response, antibody maturation and class transition at 2 weeks and 1 month after BTI may provide essential insights into pathogenicity, sequential immune status, recovery mechanisms of Omicron sublineage BTI. Funding This study was supported by the 10.13039/501100012166National Key R&D Program of China, the 10.13039/501100002858China Postdoctoral Science Foundation, 10.13039/501100021171Guangdong Basic and Applied Basic Research Foundation, the 10.13039/501100001809National Natural Science Foundation of China, CAS Project for Young Scientists in Basic Research, and the Air Force Special Medical Center Science and Technology Booster Program.

EfpA, the first major facilitator superfamily (MFS) protein identified in Mycobacterium tuberculosis (Mtb), is an essential efflux pump implicated in resistance to multiple drugs. EfpA-inhibitors have been developed to kill drug-tolerant Mtb. However, the biological function of EfpA has not yet been elucidated. Here, we present the cryo-EM structures of EfpA complexed with lipids or the inhibitor BRD-8000.3 at resolutions of 2.9 Å and 3.4 Å, respectively. Unexpectedly, EfpA forms an antiparallel dimer. Functional studies reveal that EfpA is a lipid transporter and BRD-8000.3 inhibits its lipid transport activity. Intriguingly, the mutation V319F, known to confer resistance to BRD-8000.3, alters the expression level and oligomeric state of EfpA. Based on our results and the observation of other antiparallel dimers in the MFS family, we propose an antiparallel-function model of EfpA. Collectively, our work provides structural and functional insights into EfpA’s role in lipid transport and drug resistance, which would accelerate the development of antibiotics against this promising drug target.