Skip to main content

Kevin O'Neil Saunders, PhD

Associate Professor in Surgery
Assistant Professor in the Department of Immunology
Assistant Professor in the Department of Molecular Genetics and Microbiology
Office: 2 Genome Court, 4074 Medical Science Research Building 2, Durham, NC 27710
Campus Mail: DUMC Box 3020 Med Ctr, Durham, NC 27710

The Saunders laboratory aims to understand the immunology of HIV-1 antibodies and the molecular biology of their interaction with HIV-1 envelope (Env) glycoprotein. Our overall goal is to develop protective antibody-based vaccines; therefore, the laboratory has two sections–antibody repertoire analysis and immunogen design. Our research premise is that vaccine-elicited antibodies will broadly neutralize HIV-1 if they can bind directly to the host glycans on Env. However, Env glycans are poorly immunogenic and require specific targeting by a vaccine immunogen to elicit an antibody response.

Anti-glycan HIV-1 antibody biology. The laboratory utilizes single B cell PCR to probe the antibody repertoire during natural infection and after vaccination. Using this technique we identified two monoclonal antibodies from HIV Env vaccinated macaques called DH501 and DH502 that bind directly to mannose glycans and to HIV-1 envelope (Env). We have characterized these antibodies using glycan immunoassays, antibody engineering, and x-ray crystallography to define the mechanisms of Env-glycan interaction by these antibodies. Glycan-reactive HIV antibodies are rarely elicited with HIV-1 vaccination; therefore we have studied the ontogeny of DH501 using longitudinal next generation sequencing and reversion of somatic mutations within the antibody variable regions. DH501 and DH502 antibodies are mostly found in the repertoire as IgG2 and IgM isotypes—similar to known natural glycan antibodies. Therefore we are examining whether vaccines mobilize antibodies from the natural glycan pool that affinity mature to interact with HIV-1 envelope. The results of these studies inform us about the similarities and differences between vaccine-induced glycan-reactive antibodies and known broadly neutralizing HIV-1 antibodies from human natural infection. These comparative studies define the molecular biology of glycan-reactive antibodies as well as determine how close current vaccines are to inducing glycan-dependent broadly neutralizing antibodies.

HIV-1 Env immunogen design. The discovery of lineages of broadly neutralizing antibodies in HIV-infected individuals has provided templates for vaccine design. With knowledge of the antibodies we desire to elicit we can engineer the HIV-1 Env to preferentially bind to those antibodies. We discovered that Man9GlcNAc2 is the glycan preferred by early precursors in broadly neutralizing antibody lineages. We translated this finding into a vaccine design strategy that we have termed “glycan learning.” This approach modifies the glycosylation of HIV-1 Env immunogens to be the optimal glycan type for engagement of the precursor antibody of glycan-reactive broadly neutralizing HIV-1 antibody lineages. The Env glycosylation sites and glycan type are then modified on subsequent Env immunogens to select antibodies that are maturing towards a broadly neutralizing phenotype. We have developed cell culture procedures and purification strategies combined with mass spectrometry analyses to create Env immunogens with specific glycosylation profiles. While the overall goal is to elicit protective neutralizing antibodies in vivo, we use these Env antigens in vitro to investigate the biology of B cell receptor engagement. More specifically, we investigate the effects of various immunogen delivery platforms, such as protein or gold nanoparticles, nucleic acid, or recombinant viral vectors on B cell activation.

Taken together, our research program is an interdisciplinary approach to understanding the molecular biology underlying antibody recognition of glycoproteins in order to produce protective vaccines.

Education and Training

  • Ph.D., Duke University, 2010

Publications

Edwards, Robert J., Katayoun Mansouri, Victoria Stalls, Kartik Manne, Brian Watts, Rob Parks, Katarzyna Janowska, et al. “Cold sensitivity of the SARS-CoV-2 spike ectodomain.” Nat Struct Mol Biol 28, no. 2 (February 2021): 128–31. https://doi.org/10.1038/s41594-020-00547-5.

Full Text

Berendam, Stella J., Tiffany M. Styles, Papa K. Morgan-Asiedu, DeAnna Tenney, Amit Kumar, Veronica Obregon-Perko, Katharine J. Bar, et al. “Systematic Assessment of Antiviral Potency, Breadth, and Synergy of Triple Broadly Neutralizing Antibody Combinations against Simian-Human Immunodeficiency Viruses.” J Virol 95, no. 3 (January 13, 2021). https://doi.org/10.1128/JVI.01667-20.

Full Text

Roark, Ryan S., Hui Li, Wilton B. Williams, Hema Chug, Rosemarie D. Mason, Jason Gorman, Shuyi Wang, et al. “Recapitulation of HIV-1 Env-antibody coevolution in macaques leading to neutralization breadth.” Science 371, no. 6525 (January 8, 2021). https://doi.org/10.1126/science.abd2638.

Full Text

Pollara, Justin, Matthew Zirui Tay, R Whitney Edwards, Derrick Goodman, Andrew R. Crowley, Robert J. Edwards, David Easterhoff, et al. “Functional Homology for Antibody-Dependent Phagocytosis Across Humans and Rhesus Macaques.” Front Immunol 12 (2021): 678511. https://doi.org/10.3389/fimmu.2021.678511.

Full Text

Nyanhete, Tinashe E., Robert J. Edwards, Celia C. LaBranche, Katayoun Mansouri, Amanda Eaton, S Moses Dennison, Kevin O. Saunders, et al. “Polyclonal Broadly Neutralizing Antibody Activity Characterized by CD4 Binding Site and V3-Glycan Antibodies in a Subset of HIV-1 Virus Controllers.” Front Immunol 12 (2021): 670561. https://doi.org/10.3389/fimmu.2021.670561.

Full Text

Tolbert, William D., Dung N. Nguyen, Marina Tuyishime, Andrew R. Crowley, Yaozong Chen, Shalini Jha, Derrick Goodman, et al. “Structure and Fc-Effector Function of Rhesusized Variants of Human Anti-HIV-1 IgG1s.” Front Immunol 12 (2021): 787603. https://doi.org/10.3389/fimmu.2021.787603.

Full Text

Blasi, Maria, Donatella Negri, Kevin O. Saunders, Erich J. Baker, Hannah Stadtler, Celia LaBranche, Benjamin Mildenberg, et al. “Immunogenicity, safety, and efficacy of sequential immunizations with an SIV-based IDLV expressing CH505 Envs.” Npj Vaccines 5, no. 1 (November 18, 2020): 107. https://doi.org/10.1038/s41541-020-00252-w.

Full Text

Li, Dapeng, Todd Bradley, Derek W. Cain, Isabela Pedroza-Pacheco, Maria Aggelakopoulou, Robert Parks, Maggie Barr, et al. “RAB11FIP5-Deficient Mice Exhibit Cytokine-Related Transcriptomic Signatures.” Immunohorizons 4, no. 11 (November 10, 2020): 713–28. https://doi.org/10.4049/immunohorizons.2000088.

Full Text

Alam, S Munir, Kenneth Cronin, Robert Parks, Kara Anasti, Haitao Ding, Eden P. Go, Heather Desaire, et al. “Antigenicity and Immunogenicity of HIV-1 Envelope Trimers Complexed to a Small-Molecule Viral Entry Inhibitor.” J Virol 94, no. 21 (October 14, 2020). https://doi.org/10.1128/JVI.00958-20.

Full Text

Laczkó, Dorottya, Michael J. Hogan, Sushila A. Toulmin, Philip Hicks, Katlyn Lederer, Brian T. Gaudette, Diana Castaño, et al. “A Single Immunization with Nucleoside-Modified mRNA Vaccines Elicits Strong Cellular and Humoral Immune Responses against SARS-CoV-2 in Mice.” Immunity 53, no. 4 (October 13, 2020): 724-732.e7. https://doi.org/10.1016/j.immuni.2020.07.019.

Full Text

Pages