Identification and Characterization of Human Antibodies Targeting the Human NKG2D Receptor — ASN Events
  1. Schedule
  2. Poster Session Two
  3. Identification and Characterization of Human Antibodies Targeting the Human NKG2D Receptor

Identification and Characterization of Human Antibodies Targeting the Human NKG2D Receptor (#209)

Yutthana Rittavee 1 , Mateusz Putyrski 2 , Francisco Ylera 2 , Matthew S Parsons 1 3 4
  1. Walter Reed Army Institute of Research - Armed Forces Research Institute of Medical Sciences (WRAIR-AFRIMS), BANGKOK, Thailand
  2. Bio-Rad Laboratories, Inc., Neuried, Germany
  3. U.S. Military HIV Research Program, CIDR, Walter Reed Army Institute of Research, Silver Spring, MD, USA
  4. Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA

A key therapeutic strategy for infectious diseases and cancers is the generation of bispecific engagers consisting of antibody fragments capable of engaging the target antigen and an activating receptor on a cytotoxic lymphocyte. These engagers bridge effector cells, such as natural killer (NK) cells, with infected or malignant cells, facilitating target cell elimination. Designing bispecific engagers capable of triggering NK cell-mediated cytolysis via the activating NKG2D receptor has considerable potential utility, as many NK cells in both the periphery and tissues express this receptor. Ligation of NKG2D on primed NK cells by one of its ligands or via antibody-mediated cross-linking can trigger NK cell activation and cytolysis. Considering potential future clinical utility, we endeavored to identify human antibodies capable of engaging NKG2D by panning the Bio-Rad Pioneer Antibody Library. The phage display selection used an NKG2D-Fc fusion protein as an antigen and a human Fc protein control for blocking the library. Five hundred forty-nine antigen-binding fragments (Fabs) were positive in ELISA and flow cytometry screening. Next, we assessed 376 Fabs from the screening using bio-layer interferometry (BLI) to determine dissociation rates (koff). We sequenced 56 clones with the lowest koff to identify 30 unique Fabs. Twenty-five Fabs were produced and demonstrated to bind to human NKG2D overexpressed on the surface of HEK cells transfected with human NKG2D. Ongoing experiments will determine the ability of these human antibody components to trigger NK cell activation and cytolysis. These data illustrate the feasibility of identifying human antibodies capable of targeting the human NKG2D receptor, which we could leverage to design bispecific engagers with clinical utility.