Faculty, Staff and Student Publications
Publication Date
5-5-2022
Journal
Blood
Abstract
We observed that the immune checkpoint protein B7-H3 is overexpressed in acute myeloid leukemia (AML) patients with poor treatment outcomes. Inhibition of B7-H3 expression or blocking of its activity using a novel monoclonal antibody (T-1A5) in AML cells significantly enhanced natural killer (NK) cell-mediated cytotoxicity in AML cells in vitro and in vivo. Moreover, a human-mouse chimera of this antibody (ChT-1A5) induced antibody-dependent cell-mediated cytotoxicity (ADCC) in B7-H3+ primary AML cells, but not in normal hematopoietic cells, suggesting the specify of this antibody for AML cells. Epitope mapping studies identified that both T-1A5 and ChT-1A5 antibodies bind to the FG-loop region of B7-H3, which is known to regulate the immunosuppressive function of B7-H3. Furthermore, treatment with ChT-1A5 in combination with human NK cells significantly prolonged survival in AML patient-derived xenograft (PDX) models. Our results suggest that the ChT-1A5 antibody can inhibit the immunosuppressive function of B7-H3 protein as well as induce ADCC in B7-H3+ AML.
Keywords
Animals, B7 Antigens, Cell Line, Tumor, Humans, Immune Checkpoint Proteins, Killer Cells, Natural, Leukemia, Myeloid, Acute, Mice
DOI
10.1182/blood.2021014671
PMID
35231101
PMCID
PMC11022957
PubMedCentral® Posted Date
3-3-2022
PubMedCentral® Full Text Version
Post-print
Published Open-Access
yes
Included in
Bioinformatics Commons, Biomedical Informatics Commons, Hematology Commons, Hemic and Lymphatic Diseases Commons, Medical Sciences Commons, Oncology Commons
