Six monoclonal antibodies (MAbs) (4 lgG3 and 2 IgM) were produced by hybridomas obtained from A/J mice immunized with EL4(C57BU6 derived-1 lymphoma). They were found to react with antigens expressed on both mouse and human Tlymphomas but not on B lymphomas or normal cells. All of these antibodies reacted with the disialoganglioside GD2, GalNAcPI -+4(NeuAccr2+8NeuAca2+3)Gal~l+4Glc-Cer, by 3 different assay systems including the immune adherence inhibition test, enzyme-linked immunosorbent assay, and enzyme immunostaining on thin-layer chromatography. The binding specificities of these MAbs to disialogangliosides differed. Four MAbs (Al-201, Al-287, AI-410, and Al-425) showed restricted specificities, detecting only GD2, whereas the other 2 (AI-245 and AI-267) had a broader specificity, recognizing GD2, GD3, and GDlb. No evidence was obtained for the presence of the antigenic epitope in glycoproteins of mouse and human tumor cells. The ganglioside content of EL4 was low in comparison with that of M 14 (a human melanoma cell line).
MATERIAL AND METHODS
Tissue culture lines
Cultures of cell lines were maintained in RPMI1640 supple-5T0 whom reprint requests should be sent, at the Tokyo Metropolitan