Strong antitumor activities of IgG3 antibodies to a human melanoma-associated ganglioside.

Abstract

Three mouse monoclonal IgG3 antibodies, 2B2, IF4, and MG-21, recognize a GD3 ganglioside antigen that is expressed at the cell surface of most human melanomas. All three antibodies mediate antibody-dependent cellular cytotoxicity (ADCC) in vitro when tested with human lymphocytes as effector cells in a 2-hr or 4-hr 51Cr-release test, and one antibody, MG-21, also gives strong complement-dependent cytotoxicity with human serum. Antibody 2B2, which gives ADCC also in the presence of mouse lymphocytes, inhibited the outgrowth of a human melanoma in nude mice, but antibody IF4, which showed no ADCC with mouse lymphocyte effectors, did not.There are many approaches to the therapeutic application of antitumor antibodies. One of the most straightforward of these is to use the antibodies alone, without further modification. However, this approach requires antibodies that have strong antitumor effects either by themselves or in the presence of complement or effector cells such as killer (K) cells or macrophages (1).We have produced mouse monoclonal antibodies to several cell surface antigens that are primarily expressed in human melanomas (1)(2)(3)(4). One of the most specific of these antigens is a GD3 ganglioside, which was first defined by Dippold and co-workers (5, 6), using their antibody R24, and subsequently by Yeh and co-workers (7,8), using an IgM antibody, 4.2. We have recently obtained three additional antibodies to this antigen, 2B2, IF4, and MG-21, which, in contrast to antibody 4.2, are of the IgG3 subclass. As described in this paper, they give strong antibody-dependent cellular cytotoxicity (ADCC) when tested against melanoma cells in the presence of human lymphocytes. Antibody MG-21, but not the others, is strongly cytotoxic to melanoma cells in the presence of human serum as a source of complement. One of the antibodies, 2B2, which gives ADCC also with mouse lymphocytes, inhibited the outgrowth of a human melanoma in nude mice. MATERIALS AND METHODSTumors. Five different human melanoma lines from metastatic melanoma were used. All except one, M-2634, express high levels of the GD3 antigen according to binding assays, which were carried out as previously described (7,8). Four of the lines, SK-MEL-28 (2), M-2669 clone 13, M-2634, and M-2765, were propagated in vitro. The fifth line, M-2586, failed to grow in vitro and so was serially transplanted in nude mice, where it grew better than any of the other lines.Human lung (bronchial) carcinoma line CH27 was used as a control for antibody specificity. It does not express detectable GD3 antigen.Antibodies. BALB/c mice were immunized with SK-MEL-28 cells, and their spleen cells subsequently were hybridized with NS-1 cells. Hybridoma supernatants were screened for binding to GD3 that had been isolated from melanoma tissue and attached to the surface of the wells of Falcon 3034 Microtest plates as previously described (7). Irrelevant gangliosides were included as controls. Hybridomas 2B2 and IF4 were derived from one hybridization, and hybridoma MG-21, fr...

Trifunctional Bispecific Antibodies Induce Tumor-Specific T Cells and Elicit a Vaccination Effect

“…We characterized this immune response by using the transplantable B16-derived B78-D14 mouse melanoma cell line and the trifunctional bsAb Surek. The latter is directed against GD2, a ganglioside that is expressed in human small cell lung cancer, glioma or melanoma and whose potential as target structure for tumor immunotherapy has been shown in vitro and in mouse tumor models (34)(35)(36). In particular, Ig-IL-2 fusion proteins (21,(37)(38)(39) and bsAbs (18) turned out to be effective reagents for initiating immune responses against tumor cells expressing this ganglioside.…”

Suppression of human prostate tumor growth by a unique prostate-specific monoclonal antibody F77 targeting a glycolipid marker

“…Some have been used in trials of antibody therapy for melanoma, colon cancer, and other cancers (24)(25)(26). Studies indicate that these glycolipid antigens are effective for complement lysis because of the short distance between the site of complement activation and the cell membrane (27)(28)(29).…”

Recombinant Human Hexamer-Dominant IgM Monoclonal Antibody to Ganglioside GM3 for Treatment of Melanoma

“…7) and/or antibody-dependent cell-mediated cytotoxicity (8). Under clinical evaluation is the chimeric monoclonal antibody against ganglioside GD3 (9).…”