Monocyte-mediated antibody-dependent cell-mediated cytotoxicity and spontaneous cytotoxicity in normals and cancer patients as assayed by human erythrocyte lysis.

The monocyte-macrophage system has long been recognized as a necessary accessory to the immune response. Recently, however, monocyte-macrophages have been shown to be important effectors of cell-mediated cellular cytotoxicity (both antibody dependent and antibody independent). In this study, monocyte-mediated cellular cytotoxicity of both types was assessed on 51Cr-labeled human erythrocytes (type B+) using autologous and standardized AB serum, and monocytes from 57 normal controls, 16 women with benign breast disease, and 175 patients with cancers of the breast (44 patients), colorectum (46 patients), head and neck (33 patients), lung (13 patients), and melanoma (39 patients). Although results were variable, many of the patients had depressed antibody-dependent cellular cytotoxicity suggesting decreased ability of their monocyte-macrophage to lyse the sensitized erythrocytes. Enhanced antibody-dependent cellular cytotoxicity was observed in patients with localized colorectal cancer, but this effect was reversed in patients with advanced disease. Serum factors did not significantly affect responses in most cases. The clinical relevance of this assay remains to be determined.

Guinea pig line 10 hepatocarcinoma model: characterization of monoclonal antibody and in vivo effect of unconjugated antibody and antibody conjugated to diphtheria toxin A chain.

Monoclonal antibodies were raised against the guinea pig line 10 (L10) hepatocarcinoma, and an IgG1-producing hybridoma (D3) was selected for further study. D3 is a true monoclonal antibody as demonstrated by two-dimensional gel electrophoresis. Radioimmunoassays on live cells revealed no cross-reactivity with normal tissues or with the line 1 hepatocarcinoma which was used as a control. Membrane immunofluorescence assays demonstrated similar specificity. Immunoperoxidase staining of cryostat sections of tumor and normal tissues of both adult animals and fetuses showed that the D3 monoclonal antibody reacted primarily with the L10 tumor, but some cross-reactivity with smooth muscle, placenta, fetal skeletal muscle, and fetal liver was also demonstrated. Radioimmunoprecipitation of detergent extracts of iodinated L10 cells showed that the antigen is present on the cell surface as a dimer of Mr 290,000 (unit size, Mr 148,000). Therapy studies with unconjugated D3 antibody demonstrated a minor dose-dependent effect on tumor growth. D3 antibody conjugated to the A chain of diphtheria toxin (10(-7) M) was cytotoxic to 100% of L10 cells in vitro. Animals treated with a single 1-mg i.v. injection of this immunoconjugate on Day 7 following the intradermal injection of 10(5) tumor cells demonstrated a highly significant inhibition of tumor growth compared to control animals and those treated with unconjugated antibody.

Localization of 111In- and 125I-labeled monoclonal antibody in guinea pigs bearing line 10 hepatocarcinoma tumors.

A murine monoclonal antibody (D3) with demonstrated specificity for the guinea pig line 10 hepatocarcinoma (L10) was radiolabeled with either 125I or 111In and used to image dermal tumors in vivo. In one set of experiments, L10 tumors were established middorsally in one group of animals, and the similarly derived, antigenically distinct line 1 tumor was established in another group of animals. In spite of background imaging of liver, kidney, and spleen, L10 tumors were visualized clearly. Incorporation of radiolabel was demonstrated to predominate in the L10 tumor. In a separate set of experiments, L10 and line 1 tumors were established in contralateral thighs in the same animals. L10 tumors were visualized clearly, and tissue uptake of radiolabel was demonstrated to reside predominantly in the L10 tumor.

Monocyte dysfunction in human cancer.

General immunobiologic studies in cancer patients have stressed measurements of lymphocyte function and have commonly ignored the monocyte-macrophage system. A preliminary study of peripheral blood monocyte-macrophage function was undertaken in a group of 90 cancer patients (18 breast, 32 colon, 13 head and neck, 9 lung, and 18 melanoma) and 70 controls. Studies included enumeration of extractible monocytes (EM), quantitation of differentiation into macrophages (macrophage precursor test: MP), evaluation of antibody-dependent cellular cytotoxicity (ADCC), and spontaneous cellular cytotoxicity (SCC) as measured with human erythrocytes, and measurements of monocyte and serum lysozyme activity. Breast cancer patients had normal profiles. Colon cancer patients showed the most profound abnormalities with decreased EM and MP and increased ADCC and SCC. Patients with Stage I and Stage II melanoma had normal profiles, whereas those with advanced melanoma had significantly decreased MP. This defect was restored in two patients by BCG immunotherapy. Head and neck cancer and benign breast disease patients had decreased EM, whereas patients with lung cancer had increased EM. Monocyte lysozyme production was unchanged in the cancer patients compared to controls. Serum lysozyme levels, however, were significantly increased in patients with cancers of the colon, head and neck, and lung. Although patients with localized breast cancer and melanoma had normal levels, these were increased in both patient groups with advanced disease. It would appear that the source of the increased serum lysozyme is probably not the peripheral blood monocytes, but could have originated in the intra-tumoral or tissue-bound macrophages which were not examined. Selected assays of peripheral blood monocyte function were deranged in certain types of cancer patients but were fully normal in others, and did not show consistent correlations with tumor type or stage. Tissue-bound or intra-tumoral macrophages might provide a more fruitful area for study in these disease categories.

The influence of incubation time and mitogen concentration on lymphocyte blastogenic response: determination of conditions that maximize population differences.

The blastogenic responsiveness of peripheral blood lymphocytes is a commonly applied measure of immune response capability. This assay is generally run under conditions of maximum lymphocyte stimulation. The purpose of this study was to evaluate which conditions of lymphocyte culture were able to best discriminate normal from subnormal lymphocyte responses to mitogens and antigens. Mitogen or antigen concentrations and the length of incubation time were varied while other assay conditions (serum supplement, lymphocyte concentration, amount of label, and length of label pulse) were kept constant. A total of 24 cancer patients and 25 normal controls were studied. Under optimal assay conditions that provided for maximum lymphocyte stimulation, we were unable to distinguish differences in response between young and old individuals or cancer patients and normal controls. However, at suboptimal mitogen/antigen concentrations or suboptimal incubation times, significant differences were observed in these populations. It is suggested that in the evaluation of lymphocyte stimulation responses in various clinical groups, suboptimal lymphocyte culture conditions may provide for maximum discrimination among the groups.

The safety and activity of polymerized ragweed: a double-blind, placebo-controlled trial in 81 patients with ragweed rhinitis.

Eighty-one patients with ragweed pollinosis were recruited for a double-blind, histamine placebo-controlled study of the safety, immunogenicity, and efficacy of 15 weekly injections of polymerized ragweed (PRW) immunotherapy totaling 1359 allergy units. Patients were paired on the basis of cutaneous end point titration to RAST standardized extracts of giant and short ragweed. One patient of each pair was randomized to receive PRW, and the other patient, a caramelized glucose histamine placebo. Symptom and medication score diaries were completed by 68 patients. All 68 patients received the full maintenance dose. No patient dropped out because of adverse reactions, and there were no systemic reactions. Except for one patient receiving placebo who developed mildly elevated liver function tests, there were no clinically significant changes in routine laboratory tests associated with injections. By Student's test on log-transformed values, blocking antibody rose significantly in the patients receiving PRW but was unchanged in those receiving placebo. By Wilcoxon paired signed-rank test, the symptom and medication scores in the patients receiving PRW were significantly lower than scores in the patients receiving placebo. This study demonstrates the safety, immunogenicity, and activity of PRW in the treatment of ragweed pollinosis.