A spectrum of monoclonal antibodies reactive with human mammary tumor cells.

Abstract

Splenic lymphocytes of mice, immunized with membrane-enriched fractions ofmetastatic human mammary carcinoma tissues, were fused with the NS-1 non-immunoglobulinsecreting murine myeloma cell line. This resulted in the generation of hybridoma cultures secreting immunoglobulins reactive in solid-phase radioimmunoassays with extracts of metastatic mammary carcinoma cells from involved livers, but not with extracts ofapparently normal human liver. As a result offurther screening of immunoglobulin reactivities and double cloning of cultures, 11 monoclonal antibodies were chosen that demonstrated reactivities with human mammary tumor cells and not with apparently normal human tissues. These monoclonal antibodies could be placed into at least five major groups on the basis of their differential binding to the surface of various live human mammary tumor cells in culture, to extracts of mammary tumor tissues, or to tissue sections of mammary tumor cells studied by the immunoperoxidase technique. Whereas a spectrum of reactivities to mammary tumors was observed with the 11 monoclonal antibodies, no reactivity was observed to apparently normal cells of the following human tissues: breast, lymph node, lung, skin, testis, kidney, thymus, bone marrow, spleen, uterus, thyroid, intestine, liver, bladder, tonsils, stomach, prostate, and salivary gland. Several of the antibodies also demonstrated a "pancarcinoma" reactivity, showing binding to selected non-breast carcinomas. None of the monoclonal antibodies showed binding to purified ferritin or carcinoembryonic antigen. Monoclonal antibodies of all five major groups, however, demonstrated binding to human metastatic mammary carcinoma cells both in axillary lymph nodes and at distal sites.Numerous investigators have reported the existence ofantigens associated with human mammary tumors (1-9). These studies, all conducted with conventional hyperimmune polyclonal sera, however, were unfortunately hampered with regard to the heterogeneity of the antibody populations employed and the amount of specific immunoglobulin that could be generated. Since the advent ofhybridoma technology (10), monoclonal antibodies of predefined specificity and virtually unlimited quantity may now be generated against a variety of antigenic determinants present on normal or neoplastic cells. The rationale of the studies reported here was to utilize extracts ofhuman metastatic mammary tumor cells as immunogens in an attempt to generate and characterize monoclonal antibodies reactive with determinants that would be maintained on metastatic, as well as primary, human mammary carcinoma cells. Multiple assays using tumor cell extracts, tissue sections, and live cells in culture have been employed to reveal the diversity of the monoclonal antibodies generated.MATERIALS AND METHODS Immunizations. Membrane-enriched cell extracts were prepared from breast tumor metastases to the liver from two patients as well as from apparently normal liver as described (11) Hybridoma Methodology. Somatic cell hybrids wer...

Monoclonal antibodies to human colon and colorectal carcinoma

“…Monoclonal antibodies have been produced against a number of human tumours, including melanoma (Dippold et al, 1980;Koprowski et al, 1978;Yeh et al, 1979), lung carcinoma (Kasai et al, 1981;Sikora & Wright, 1981), mammary carcinoma (Colcher et al, 1981;Schlom et al, 1980, Thompson et al, 1983, colorectal carcinoma (Herlyn et al, 1979;Koprowski et al, 1979) as well as other tumours (Deng et al, 1981;Kennett & Gilbert, 1979;Nadler ct al., 1980;Ritz et al, 1980;Sikora & Phillips, 1981;Ueda et al, 1981). The majority of these antibodies recognise either polymorphic, monomorphic or tissue-specific determinants, whilst others may recognise tumour-specific antigens, although this is questionable.…”

Immunohistochemical techniques in the early screening of monoclonal antibodies to human colonic epithelium

“…In general, cultured malignant cell lines are being used to elicit and detect these antibodies. Although some of them appear to be tumour-specific at present (Colcher et al, 1981) many others have been found, on further study, to react with cells other than the tumour cell (Koprowski et al, 1978;Dippold et al, 1980;Brown et al, 1981). Clearly, testing the specificity of individual McAbs, particularly for crossreactions with normal tissue, is of the utmost importance prior to their use in clinical situations: e.g.…”

Effects of humanization and gene shuffling on immunogenicity and antigen binding of anti-tag-72 single-chain Fvs

“…33,34 The MAb B72.3 IgG was generated using a membrane-enriched fraction from a mammary carcinoma metastasis. 35 The MAbs CC49 and B72.3 were purified from ascitic fluid obtained from pristaneprimed BALB/c mice. The resulting ascitic fluid was diluted 1:1 with 20 mM sodium phosphate, pH 7.0 and loaded on a Protein G Sepharose 4 Fast Flow column (Pharmacia, Piscataway, NJ).…”