Induction of tumor-cell lysis by bi-specific monoclonal antibodies recognizing renal-cell carcinoma and cd3 antigen

✍ Scribed by J. Van Duk; S. O. Warnaar; J. D. H. Van Eendenburg; M. Thienpont; E. Braakman; J. H. A. Boot; G. J. Fleuren; R. L. H. Bolhuis

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: French
• Weight: 644 KB
• Volume: 43
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910430230

✦ Synopsis

Bi

-specific monoclonal antibodies (MAbs) were developed by somatic hybridization of 2 mouse hybridomas, one producing MAb against the G250 renal-cell carcinoma (RCC)-associated antigen and the other against the T-cell antigen CD3 (OKT3). The dual specificity of the hybrid MAb produced by these so-called quadromas was analyzed by immunohistochemistry on tissue sections and by cytotoxicity assays with relevant target and effector cells. The bi-specific MAb could induce TCRaflICD3 + and TCRyWCD3 + cloned lymphocytes to kill RCC cells. A noteworthy finding was that the TCRaB and y i lymphocyte clones showed different triggering abilities. The specificity of target-cell lysis by the cytotoxic T cells (CTL) was dictated by the specificity of the G250 MAb. Control bi-specific MAb, recognizing a cell-surface structure not involved in T-cell activation, did not induce lysis. Several IgG subclass switch variants of the G250 hybridoma, i.e., IgG,, h, 2b and IgE, were used for somatic hybridization with the OKT3 hybridoma (IgGd. Except for IgE, all IgG subclass combinations could equally induce cytolysis. Induction of cy- tolysis was inhibited only by excess OK13 MAb. Comparison of 2 bi-specific MAb preparations of the same combination (IgGwl), produced by 2 quadromas derived from the same parental hybridomas after identical purification procedures, produced different amounts of bispecific MAb.

ing concentrations of 8-azaguanine (Gibco, Grand Island, NY) starting from lop7 and rising to 2 X M. Thymidine kinase (TK)-deficient clones of G250 MAb switch variants were obtained by growing these G250 hybridomas in increasing concentrations of 5-bromodeoxyuridine (Sigma, St. Louis, MO) from up to 5.10-5 M, followed by exposure to daylight every 3 days. 5T0 whom reprint requests should be sent.