Expression of the ULBP ligands for NKG2D by B-NHL cells plays an important role in determining their susceptibility to rituximab-induced ADCC.
Antibody-dependent cellular cytotoxicity (ADCC) is a major antitumor mechanism of action of therapeutic monoclonal antibodies (mAbs). The aim of this study was to identify tumor-associated factors which determine susceptibility to rituximab-induced ADCC. Thirty different CD20+ non-Hodgkin lymphoma cell lines were phenotyped for characteristics such as level of expression of NKG2D ligands, and the influence thereof on susceptibility to rituximab-induced ADCC was established. The present study demonstrated that tumor cell susceptibility to rituximab-induced ADCC was determined by 3 major tumor-associated factors: (i) the amount of the target molecule, CD20; (ii) the amount of the ligands for inhibitory killer Ig-like receptors, major histocompatibility complex class I; and (iii) the amounts of some of the NKG2D ligands, especially UL16-binding protein (ULBP) 1-3. The importance of the ULBPs was confirmed using antibody blockade. In conclusion, this is the first report to show the importance for rituximab-induced ADCC of ULBPs expressed on tumor cells. The ULBPs could be valuable diagnostic biological markers and significant targets for immunotherapy to improve efficacy not only of rituximab but also of other therapeutic mAbs.
Department of Medical Oncology and Immunology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan.
Atsushi
A
Inagaki
Takashi
T
Ishida
Hiroki
H
Yano
Toshihiko
T
Ishii
Shigeru
S
Kusumoto
Asahi
A
Ito
Masaki
M
Ri
Fumiko
F
Mori
Jianmin
J
Ding
Hirokazu
H
Komatsu
Shinsuke
S
Iida
Ryuzo
R
Ueda
D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D058846:Antibodies, Monoclonal, Murine-Derived; D000920:Antibody-Dependent Cell Cytotoxicity / Q000187:drug effects* / Q000276:immunology; D018951:Antigens, CD20 / Q000276:immunology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002401:Cathepsin B / Q000378:metabolism; D005434:Flow Cytometry; D058851:GPI-Linked Proteins; D006680:HLA Antigens / Q000378:metabolism; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000235:genetics / Q000378:metabolism*; D000069283:Rituximab; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20; D000970:Antineoplastic Agents; D058851:GPI-Linked Proteins; D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; C527085:KLRK1 protein, human; D008565:Membrane Proteins; D055655:NK Cell Lectin-Like Receptor Subfamily K; C423231:ULBP1 protein, human; C423229:ULBP3 protein, human; D000069283:Rituximab; D002401:Cathepsin B