Biology subjects

Dugan, H. L.

Publications and source records attributed to Dugan, H. L..

4 recordsLinked to original sources

bioRxiv2021

Librator, a platform for optimized sequence editing, design, and expression of influenza virus proteins

Artificial mutagenesis and chimeric/mosaic protein engineering have laid the foundation for antigenic characterization1 and universal vaccine design2-4 for influenza viruses. However, many methods used for influenza research and vaccine development require sequence editing and protein expression, limiting their applicability and the progress of related research to specialists. Rapid tools allowing even novice influenza researchers to properly analyze and visualize influenza protein sequences with accurate nomenclature are needed to expand the research field. To address this need, we developed Librator, a system for analyzing and designing protein sequences of influenza virus Hemagglutinin (HA) and Neuraminidase (NA). With Librators graphical user interface (GUI) and built-in sequence editing functions, biologists can easily analyze influenza sequences and phylogenies, automatically port sequences to visualize structures, then readily mutate target residues and design sequences for antigen probes and chimeric/mosaic proteins efficiently and accurately. This system provides optimized fragment design for Gibson Assembly5 of HA and NA expression constructs based on peptide conservation of all historical HA and NA sequences, ensuring fragments are reusable and compatible, allowing for significant reagent savings. Use of Librator will significantly facilitate influenza research and vaccine antigen design.

microbiology↗

bioRxiv2021

A public broadly neutralizing antibody class targets a membrane-proximal anchor epitope of influenza virus hemagglutinin

Broadly neutralizing antibodies against influenza virus hemagglutinin (HA) have the potential to provide universal protection against influenza virus infections. Here, we report a distinct class of broadly neutralizing antibodies targeting an epitope toward the bottom of the HA stalk domain where HA is "anchored" to the viral membrane. Antibodies targeting this membrane-proximal anchor epitope utilized a highly restricted repertoire, which encode for two conserved motifs responsible for HA binding. Anchor targeting B cells were common in the human memory B cell repertoire across subjects, indicating pre-existing immunity against this epitope. Antibodies against the anchor epitope at both the serological and monoclonal antibody levels were potently induced in humans by a chimeric HA vaccine, a potential universal influenza virus vaccine. Altogether, this study reveals an underappreciated class of broadly neutralizing antibodies against H1-expressing viruses that can be robustly recalled by a candidate universal influenza virus vaccine.

immunology↗

bioRxiv2020

Human antigen-specific memory natural killer cell responses develop against HIV-1 and influenza virus and are dependent on MHC-E restriction

For over a decade, multiple studies have disputed the notion of natural killer (NK) cells as purely innate lymphocytes by demonstrating that they are capable of putative antigen-specific immunological memory against multiple infectious agents including two critical global health priorities - HIV and influenza. However, the mechanisms underlying antigen specificity remain unknown. Herein, we demonstrate that antigen-specific human NK cell memory develops upon exposure to both HIV and influenza, unified by a conserved and epitope-specific targetable mechanism firmly dependent on the activating CD94/NKG2C receptor and its ligand HLA-E, and confirm these findings by three rigorous and novel assays. We validated the permanent acquisition of antigen-specificity by individual memory NK cells by single-cell cloning. We identified biomarkers of antigen-specific NK cell memory through RNA-Seq transcriptomic fingerprints and complex immunophenotyping by 30-parameter flow cytometry showing elevated expression of KLRG1, 4{beta}7 and NKG2C. Finally, we show individual HLA-E-restricted peptides that may constitute the dominant response in HIV-1- and influenza-infected persons in vivo. Our findings clarify the mechanisms behind formation of antigen-specific memory NK cells, and suggest they could be targeted for future vaccines, cure strategies, or other therapeutic interventions.

immunology↗

bioRxiv2020

SARS-CoV-2 infection severity is linked to superior humoral immunity against the spike

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently causing a global pandemic. The antigen specificity and kinetics of the antibody response mounted against this novel virus are not understood in detail. Here, we report that subjects with a more severe SARS-CoV-2 infection exhibit a larger antibody response against the spike and nucleocapsid protein and epitope spreading to subdominant viral antigens, such as open reading frame 8 and non-structural proteins. Subjects with a greater antibody response mounted a larger memory B cell response against the spike, but not the nucleocapsid protein. Additionally, we revealed that antibodies against the spike are still capable of binding the D614G spike mutant and cross-react with the SARS-CoV-1 receptor binding domain. Together, this study reveals that subjects with a more severe SARS-CoV-2 infection exhibit a greater overall antibody response to the spike and nucleocapsid protein and a larger memory B cell response against the spike.

immunology↗