Cell-mediated cytotoxicity to human pulmonary neoplasms

Reactive antibodies in the bronchial washings of lung cancer patients

Lung-carcinoma-reactive antibodies have been previously isolated from tumor tissues and pleural effusions. To explore the immunoglobulin (Ig) content of bronchial secretions, bronchial washings of patients with inflammatory and neoplastic lung diseases were studied with respect to Ig levels and specificity. Expressed as Ig/potassium ratios, statistically significant increases in Ig levels were found in inflammatory diseases and even higher increases in lung carcinomas. The isolation of Ig from bronchial washings was achieved by dissociation of immune complexes at low pH, neutralization and subsequent purification by anion exchange chromatography. The isolated immunoglobulins were tested in indirect immunofluorescence against lung cancer cells of various histologic types in tissue cultures and fresh suspensions. Positive cytoplasmic fluorescence was obtained with cells of adeno carcinomas and squamous-cell carcinomas of the lung but not with cells of normal lung. The accessibility of bronchial washings makes the investigation of their lung-cancer-reactive immunoglobulins relatively easy and raises the possibility of its eventual conversion into a screening test.

Changes in tumor immunity during therapy determined by leukocyte adherence inhibition and dermal testing

Leukocyte adherence inhibition (LAI) is an easily carried out in vitro test for tumor reactivity which is based on the prevention of adherence of leukocytes incubated with antigen to which the donor is immune. In this study a comparison is made with dermal response to tumor antigen. A total of 234 patients were tested, 74 of whom had melanoma, 111 of whom had squamous cell carcinoma of the head and neck, 18 of whom had neuroblastoma and 31 of whom had other tumors. Forty-two persons without tumors acted as controls for the LAI test. A high degree of correlation was found between LAI and dermal response. Furthermore, LAI exhibited marked tumor specificity and showed a ten-fold greater sensitivity than dermal response. LAI may be used to monitor serial changes in tumor reactivity in cancer patients.

A plasma membrane antigen highly associated with oat-cell carcinoma of the lung and undetectable in normal adult tissue

The plasma membrane antigens of an oat-cell carcinoma of the lung were studied to determine if any antigens absent from normal adult tissue could be identified. Rabbit and monkey antisera were prepared to a highly purified plasma membrane fraction of an oat-cell carcinoma of the lung. The specificities of the antisera were studied by the indirect immunofluorescence method on frozen section substrate. The rabbit antiserum, after absorption with normal lung, liver, colon and peripheral nerve homogenates and extracts, failed to react with any detectable normal adult tissue. The absorbed anti-serum did react with 7 of 7 oat-cell carcinomas of the lung, but failed to react with any of 7 adeno-carcinomas of the lung, 6 epidermoid carcinomas of the lung, 7 colon carcinomas, 8 breast carcinomas, 4 kidney carcinomas, and 1 pancreatic carcinoma. The unabsorbed monkey antiserum failed to react with any detectable normal adult tissue, and had a tumor reactivity pattern nearly identical to that of the absorbed rabbit antiserum. Thus similar results were obtained with antisera from two different species. It is concluded that oat-cell carcinomas of the lung express a plasma membrane antigen(s) undetectable in normal adult tissue and highly associated with this tumor type.

Assessment of cell-mediated immunity to malignant mesothelioma by microcytotoxicity tests

Cell cultures were established from pleural effusions of patients with pleural mesothelioma, and peripheral mononuclear effector cells were tested for cytotoxicity against these cells by means of microcytotoxicity assay. Effector cells were obtained from normal healthy donors and from persons exposed occupationally to asbestos, including apparently healthy persons, patients with benign pleural conditions and patients with malignant mesothelioma. The overall incidence of cytotoxicity was low, and there was no evidence of increased cytotoxicity in mesothelioma patients or other asbestos-exposed donors. It is concluded that little or no tumour-directed cell-mediated immunity is detectable against malignant mesothelioma by microcytotoxicity methods.

Capillary tube leukocyte adherence inhibition: an assay for cell-mediated immunity in cancer patients

The leukocyte adherence inhibition (LAI) assay has been modified and automated in order to facilitate its clinical application. This new assay-the capillary tube LAI test-correlated with delayed cutaneous hypersensitivity using streptokinase-streptodornase antigen in 83% of the cases. When tested with a 3 M KC1 lung carcinoma antigen, lung carcinoma patients' leukocytes were more frequently inhibited (55%) than those of controls (normals 6%, other tumors 20%).

Detection of private and common tumor-associated antigens in murine sarcomas induced by different chemical carcinogens

Two fibrosarcomas of similar histological type, induced in C3Hf mice by either methylcholanthrene or 3,4-benz(a)pyrene, were shown to have individually unique tumor-rejection antigens in classical transplantation-type experiments. By contrast, sera of autochthonous mice, which resisted only transplants of the immunizing sarcoma, were found to contain complement-dependent cytotoxic antibodies, specific for both sarcomas, in vitro. The existence of individually unique as well as common tumor-associated antigens in chemically-induced murine sarcomas is suggested. The private "tumor transplantation-type" antigens elicited tumor rejection responses in vivo. The common tumor-associated antigens, although immunogenic in autochthonous hosts, inducing the production of tumor-specific antibodies, failed to induce transplantation cross-resistance in vivo. This study supports the contention that, in carcinogen-induced murine tumors, and perhaps in human neoplasms as well the evaluation of humoral (and cell-mediated) immune responses in vitro may not reflect tumor rejection-type immune responses in vivo.