Yngve Hansson

Monoclonal antibodies to antigens associated with transitional cell carcinoma of the human urinary bladder

SummarySpleen cells from BALB/c mice immunized with cells derived from transitional cell carcinomas (TCC) of the human urinary bladder were fused with mouse myeloma Sp 2/0 Ag14 cells. Monoclonal antibodies from six established hybridomas were investigated for specificity in a cell ELISA and in indirect immunofluorescence against a large panel of fixed intact cells. Three of the antibodies reacted with half or more of the eight bladder tumors and with a few unrelated tumors. They did not react at all with malignant or normal cells of hematopoietic origin. A fourth antibody reacted with seven of eight bladder tumors. It also reacted weakly with a prostatic carcinoma, with five of six malignant or transformed B cell lines, and with a subpopulation of normal lymphocytes, but not with any of the other cells on the test panel. These four antibodies did not react with cells derived from normal urothelium. The results suggest that these antibodies might recognize cell-type-restricted antigens associated with malignancy. Another antibody reacted with almost all urothelium-derived cells. It also reacted with three of three melanomas but not with any other cells on the panel. The sixth antibody reacted with 32 of the 37 cells tested. The spectrum of reactivities displayed by the antibody suggested that it recognizes HLA antigens.

A rapid method for detection of cellular proliferation using carboxyfluorescein Assay of growth factors (IL-2, IL-1) and growth inhibiting antibodies

The uptake of carboxyfluorescein diacetate (CFDA) into live cells was used as the basis for a simple, rapid and fully automated micromethod for determination of cell growth. The aim of the investigation was to adapt the CFDA method for detection of cell growth factors from cell culture supernatants. Thus, the biological activities of the growth factors IL-2 or IL-1 could be detected and quantitated at the same level of sensitivity as with the conventional [3H]thymidine incorporation. Similarly, the method was well suited to assay inhibition of IL-2-dependent lymphocyte growth by the monoclonal antibody anti-Tac, binding to the human lymphocyte membrane receptor for IL-2. The CFDA method proved to be rapid, reliable and well suited for several applications involving limiting numbers of cells and biological reagents.

Production of Antibodies to Cellular Antigens by EBV‐Transformed Lymphocytes from Patients with Urinary Bladder Carcinoma

Lymphocytes from patients with transitional‐cell carcinoma (TCC) of the urinary bladder were transformed by infection with Epstein‐Barr virus. To obtain B cells secreting antibodies reactive with TCC cells, the transformed cells were either adhered to irradiated monolayers of cultured allogeneic TCC cells or subcultured at limiting dilution. Supernatants from these cultures were tested in a modified enzyme‐linked immunosorbent assay against fixed cells, isolated plasma membranes, or lipid antigens or were tested by antibody‐dependent cellular cytotoxicity (ADCC), Reactions with antigens derived from the serum source were excluded by proper controls. By this approach a majority of the patients tested (7/12) gave rise to cultures producing antibodies recognizing various cellular antigens. The antibody‐containing supernatants from these cultures were usually of high titres and the reactive antibodies of IgM isotype. One culture, which had been selected by repeated adherence to TCC cells, produced antibodies reactive with such cells in ADCC. None of the antibodies investigated detected antigens exclusively present on TCC cells.

MHC nonrestricted cytotoxic T cell clones with selective specificity from patients with transitional cell carcinoma (TCC) of the urinary bladder

SummaryLymphocytes from patients with transitional cell carcinoma (TCC) of the urinary bladder are more cytotoxic to bladder tumor cells than to a variety of control cells. This disease-related cytotoxicity has previously been shown to involve several mechanisms and different types of effector cells. To analyze further the nature of the effector cells operative in this system, peripheral blood lymphocytes from eight TCC patients were stimulated in vitro with TCC extract and cultured in the presence of interleukin 2 and allogeneic feeder cells. When tested for cytotoxicity in vitro on a target cell panel including both adherent and nonadherent cell lines, the lymphocytes killed a broad spectrum of targets in a major histocompatibility complex (MHC)-unrestricted fashion. When cloned by limiting dilution, clones were obtained which displayed a more restricted pattern of target cell killing. Some of the clones were highly but not exclusively selective for TCC-derived target cells. Phenotypically, these cells resembled mature T cells of CTL-type (CD8+/CD4−). They also expressed the CD3/5 T cell antigen receptor complex but target cell killing was not MHC-restricted. The results of various inhibition experiments suggested that the CD3/TCR complex was involved in the cytotoxicity exhibited by these effector cells. However, its precise role in target cell recognition and the identification of the tumor cell structures recognised by the effector cells require further studies.

Humoral and Cellular Immune Response in Patients with Transitional Cell Carcinoma of the Urinary Bladder (TCC) Against Bladder Carcinoma Cells in Tissue Culture

Non-irradiated and irradiated patients with TCC of the urinary bladder as a group show disease related cytotoxicity. Moreover, our results strongly suggest that the effector cell(s) involved in these allogeneic reactions are of the K-cell type, ie. SIg- and FcR+ lymphocytes acting through antibodies. Furthermore, about 30% of the isolated IgG-fractions from patients sera had ADCC-inducing capacity. By means of using these antibodies in an insolubilised form we are presently trying to identify and characterise the tumour-associated antigens.