K cell mediated lysis of cultured colon carcinoma and urinary bladder carcinoma cells induced by monospecific antisera against carcinoembryonic antigen (CEA) and two CEA-related normal glycoproteins

The clinical value of immunohistochemically demonstrable CEA in breast cancer: a possible method of selecting patients for adjuvant chemotherapy

The production of carcinoembryonic antigen (CEA) by human breast cancer tissue has been studied in relation to the prognosis of patients with breast cancer. All of the patients were in a controlled trial of adjuvant chemotherapy for the treatment of operable breast cancer. CEA was studied in primary tumours and axillary node metastases from these patients using an immunoperoxidase (PAP) method. Sections of 290 primary carcinomas and 217 axillary metastases were examined for CEA. The CEA status of the primary tumours was of no value as a prognostic indicator nor in the selection of patients for chemotherapy. In contrast, patients could be divided into 3 groups on the basis of the CEA results in the axillary nodes. In one group, in which cases were strongly positive for CEA (24% of the total) the prognosis, as reflected by recurrence free survival, was relatively good and chemotherapy produced no further advantage. In another group in which cases were weakly positive for CEA (18% of the total) the prognosis was poor but chemotherapy produced significant improvement. In a third group, in which cases were negative for CEA (58% of the total) the prognosis was poor and was not improved by chemotherapy, at least in the short term. Thus, the CEA status of axillary metastases may be clinically useful.

Failure to detect killer cell activity in rabbits

Rabbit lymphoid cells from spleen, peripheral blood, and peritoneal cavity lacked killer (K)-cell activity against cell lines of rabbit and human origin, including virus-infected human tumor cells. This lack of activity was not affected by antibody concentration, source of antibodies, effector/target cell ratio, or length of assay. Rabbit leukocytes, however, were capable of lysing antibody-coated chicken erythrocytes. Hamster leukocytes, serving as a known source of K cells, mediated antibody-dependent cellular cytotoxicity against all targets. EA-rosette assays and mixed effector cell competition tests suggested a deficiency in rabbit K-cell activity which is not a result of an inherent lack of Fc receptor-positive cells or of some suppressor mechanism operating in the rabbit cell populations. Our data support the concept that antibody-dependent cellular cytotoxicity may not be a significant in vivo immune mechanism in certain species.

Membrane-associated antigens on tumor cells from transitional-cell carcinoma of the human urinary bladder. I. Immunological characterization by xenogeneic antisera

An antiserum was raised in rabbits by immunization with a human tumor cell line, T-24, derived from transitional cell carcinoma (TCC) of the urinary bladder. The specificity of the IgG fraction was assessed by antibody-dependent cellular cytotoxicity (ADCC), using purified blood lymphocytes from healthy human donors as effector cells and seven human cell lines as target cells (T-24 and two additional TCC-lines, two normal urothelial lines, one colon carcinoma and one malignant melanoma). The IgG induced strong lysis of all seven target cell types. However, lysis of the five urothelial lines was significantly stronger than that of the control tumors. Conversely, antisera to either of the control tumors induced a significantly stronger lysis of the homologous tumors than of the urothelial cells. All antisera contained antibodies to fetal bovine serum but removal of these by absorption did not change the specificity of the ADCC reactions. When the anti T-24 serum was exhaustively absorbed with glutaraldehyde-fixed spleen homogenate, the cytotoxicity to the control tumor targets was abolished. Although absorption reduced the antibody titer of the IgG preparation, ADCC to the TCC targets remained at a high level. There was no difference in the degree of lysis of the three TCC targets. Lysis of the two target lines from normal urothelium was slightly lower than that of the tumor cells. The results indicate that the anti-TCC serum contained antibodies to one or several antigens shared by five urothelial cell lines but not by the control tumors. Whether or not it also contained antibodies to TCC-associated antigens remains to be established. The molecular basis for these findings will be given in the accompanying paper.

Lymphocyte-mediated lysis of tumor cells in vitro (ADCC), induced by serum antibodies from patients with urinary bladder carcinoma or from controls

IgG fractions from serum of patients with transitional-cell carcinoma of the urinary bladder (TCC), patients with carcinoma of the prostate (CC) and healthy donors (HD) were tested for their capacity to induce antibody-dependent lymphocyte-mediated cytotoxicity (ADCC) to tumor cells in vitro. Lymphocytes from healthy donors were selected for low natural cytotoxicity to the target cells from established cell lines of TCC or other origins. IgG was prepared by adsorption of serum to Sepharose-bound protein A from Staphylococcus aureus and subsequent acid elution. When tested against a panel of six different target cells, most individual IgG preparations from all three donor groups contained antibodies inducing ADCC to some of the target cells. When IgG preparations from II untreated TCC patients were studied for ADCC induction to the TCC target T24 and the colon carcinoma HT29, cytotoxicity to T24 was, on an average, significantly higher than that to HT29. For IgG preparations from 18 TCC patients, treated with radiotherapy, a similar difference was seen but was not statistically significant. IgG preparations from II patients with carcinoma of the prostate and from 12 healthy donors did not show this differences. Moreover, while individual IgG preparations from untreated TCC patients were, on the average, significantly more cytotoxic to T24 than those from either of the two control groups, no such differences were seen when HT29 was the target. On the contrary, IgG preparations from patients with prostatic carcinoma were significantly more cytotoxic to HT29 than those from healthy donors. The results suggest that TCC patients develop a disease-related humoral immune response, superimposed on a "natural" immunity to a variety of antigens on the target cells used. The nature of the antigens involved in these reactions remains to be established. However, the results are compatible with previous findings, in these patients, of a bladder-tumor-related cellular cytotoxicity, to a large extent caused by the patients' own antibodies.