技术资料

AbstractThe landscape of cancer treatment has been transformed by immune checkpoint inhibitors; however,the failure to benefit a large number of patients with cancer has underlined the need to identify promising targets for more effective interventions. In this study,we leverage 23andMe,Inc.’s large-scale human germline genetic and health database to uncover the previously unknown role of UL16-binding protein 6 (ULBP6),a high-affinity NK group 2D (NKG2D) ligand,in cancer and its promise as an immuno-oncology therapeutic target. We confirm ULBP6 expression in human tumors and demonstrate that soluble ULBP6 shed from tumors circumvents NKG2D activation provided by membrane-anchored NKG2D ligands to inhibit immune cell activation and tumor cell killing. Based on these findings,we developed 23ME-01473,a humanized Fc effector–enhanced antibody that binds to ULBP6 and its closely related family members,ULBP2 and ULBP5. 23ME-01473 effectively blocks soluble ULBP6-mediated immunosuppression to restore the NKG2D axis on NK and T cells to elicit tumor growth control. Moreover,the Fc effector–enhanced design of 23ME-01473 increases its binding affinity to fragment crystallizable gamma receptor IIIa,which,together with 23ME-01473’s binding to membrane-anchored ULBP6/2/5 on cancer cells,allows for augmented antibody-dependent cellular cytotoxicity induction,providing a second activation node for NK cells. Our studies demonstrate the therapeutic potential of an Fc effector–enhanced anti-ULBP6/2/5 antibody to reinvigorate NK cell and T-cell activation and cytotoxicity for the treatment of cancer.Significance:This study emphasizes the utility of population-based genome-wide assessments for discovering naturally occurring genetic variants associated with lifetime risks for cancer or immune diseases as novel drug targets. We identify ULBP6 as a potential keystone member of the NKG2D pathway,which is important for antitumor immunity. Targeting ULBP6 may hold therapeutic promise for patients with cancer. View Publication

Two types of acquired loss of heterozygosity are possible in cancer: deletions and copy-neutral uniparental disomy (UPD). Conventionally,copy number losses are identified using metaphase cytogenetics,whereas detection of UPD is accomplished by microsatellite and copy number analysis and as such,is not often used clinically. Recently,introduction of single nucleotide polymorphism (SNP) microarrays has allowed for the systematic and sensitive detection of UPD in hematologic malignancies and other cancers. In this study,we have applied 250K SNP array technology to detect previously cryptic chromosomal changes,particularly UPD,in a cohort of 301 patients with myelodysplastic syndromes (MDS),overlap MDS/myeloproliferative disorders (MPD),MPD,and acute myeloid leukemia. We show that UPD is a common chromosomal defect in myeloid malignancies,particularly in chronic myelomonocytic leukemia (CMML; 48%) and MDS/MPD-unclassifiable (38%). Furthermore,we show that mapping minimally overlapping segmental UPD regions can help target the search for both known and unknown pathogenic mutations,including newly identified missense mutations in the proto-oncogene c-Cbl in 7 of 12 patients with UPD11q. Acquired mutations of c-Cbl E3 ubiquitin ligase may explain the pathogenesis of a clonal process in a subset of MDS/MPD,including CMML. View Publication