Cytokine enhancement of in vitro antibody-dependent cellular cytotoxicity mediated by chimeric anti-GD3 monoclonal antibody KM871.
The chimeric KM871 monoclonal antibody targets the GD3 disialoganglioside antigen and is under investigation for its immunotherapeutic potential in melanoma. Preclinical and phase I studies have demonstrated the biodistribution and specific tumour targeting of KM871 to metastatic melanoma in vivo, with a long half-life and lack of immunogenicity making it an attractive candidate for further clinical trials. In vitro studies have demonstrated KM871 induces high levels of cytotoxicity in both antibody-dependent cellular-cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) assays. In order to investigate the potential for cytokine upregulation of KM871-mediated ADCC, freshly isolated healthy donor PBMC effector cells were cultured in the presence or absence of the cytokines interleukin-2, interleukin-12 and granulocyte/macrophage-colony stimulating factor and the ADCC determined over a 10-day period. In the absence of these cytokines, ADCC activity of 1 micro g/ml KM871 on (51) Cr-labeled SK-MEL-28 target cells could not be detected after 72 hrs of culture of PBMC effector cells in media. In contrast, ADCC mediated by KM871 was significantly enhanced and maintained for the 10-day study period upon culturing PBMCs with media containing IL-2 and/or IL-12, but not with GM-CSF. FACS analysis of the effector cell population indicated CD3-/CD16+56+ NK cells were primarily responsible for the KM871-mediated ADCC activity and a direct correlation was observed between the percentage of NK cells and the level of cytotoxicity mediated by the PBMCs. Furthermore, ADCC was significantly reduced using NK-depleted PBMCs. These results suggest combining IL-2 or IL-12 with KM871 may enhance KM871 immune-mediated cell killing in patients with metastatic melanoma.
Ludwig Institute for Cancer Research, Melbourne Tumour Biology Branch, Austin and Repatriation Medical Centre, Heidelberg, Victoria, 3084, Australia.
Zhanqi
Z
Liu
Fook-Thean
FT
Lee
Nobuo
N
Hanai
Fiona E
FE
Smyth
Antony W
AW
Burgess
Lloyd J
LJ
Old
Andrew M
AM
Scott
D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000920:Antibody-Dependent Cell Cytotoxicity / Q000187:drug effects*; D017252:CD3 Complex / Q000032:analysis; D019002:CD56 Antigen / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D016207:Cytokines / Q000494:pharmacology*; D005434:Flow Cytometry; D005732:Gangliosides / Q000276:immunology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D018664:Interleukin-12 / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D017452:Receptors, IgG / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D013997:Time Factors; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D019002:CD56 Antigen; D016827:CD8 Antigens; D016207:Cytokines; D005732:Gangliosides; D007376:Interleukin-2; D017452:Receptors, IgG; D011993:Recombinant Fusion Proteins; D018664:Interleukin-12; C026226:ganglioside, GD3; D016178:Granulocyte-Macrophage Colony-Stimulating Factor