Complement and tumor immunology

Total hemolytic complement (CH50) and its fractions (C3 and C4) in the sera of patients with carcinoma of the oral cavity, uterine cervix, and breast

The total hemolytic complement activity of CH50 and its fractions C3 and C4 was determined in the sera of 196 patients with carcinoma of the oral cavity, 172 patients with carcinoma of the uterine cervix, and 166 patients with breast cancer. The values were compared with those of 18 patients with mammary dysplasia, 32 patients with mild to moderate dysplasia of the cervix, and 100 healthy, normal age- and sex-matched controls. No alterations in CH50, C3, and C4 were observed in the sera of patients with benign lesions, whereas a significant rise in the three factors was observed in all the cancer patients studied. The complement activity increased significantly with the progression of the disease up to stage III and remained persistently elevated thereafter. Patients who had a clinical cure had normal levels of CH50, C3, and C4, whereas the values remained elevated in patients who were still undergoing treatment for residual lesions.

Enhancement of phagocytosis by a calmodulin antagonist (W-7) in mice

W-7 [N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide], a well-known inhibitor of the calmodulin-dependent processes, strongly enhanced phagocytosis and ingestion of polystyrene latex beads into the peritoneal macrophages of BALB/c mice after the i.p. injection, whereas W-5 [N-(6-aminohexyl)-naphthalene sulfonamide], a less effective calmodulin antagonist, was much weaker than W-7. Binding of the third component of complement (C3) cleavage to the C3 receptor on macrophages after the i.p. injection of W-7 was enhanced as shown by the fluorescent antibody technique. These data suggest that calmodulin plays an important role in the phagocytosis of macrophages through the complement system.

Complement-dependent cellular cytotoxicity: lymphoblastoid lines that activate complement component 3 (C3) and express C3 receptors have increased sensitivity to lymphocyte-mediated lysis in the presence of fresh human serum

Lymphocyte-mediated lysis of cells of the Raji, Daudi, Jijoye, and Bjab lines was elevated when fresh human serum was added to the assay. A higher proportion of effector-target conjugates was observed in the presence of human serum. In similar experiments lysis of 1301, Rael, and P3HR-1 cells was unaltered. All cell lines activated the alternative pathway of complement but they varied in the expression of receptors for complement component 3 (C3) and in the ability to fix the C3 cleavage products on their membrane. The enhancement of lysis in the presence of human serum occurred only with those cells that bound C3. This characteristic was correlated to the expression of C3 receptors. Analysis of the nature of the deposited C3 was performed with Raji cells. Raji cells exposed to human serum bound C3b as indicated by the immunoadherence test. The C3b was further processed to C3bi, because the immunoadherence declined with time and conjugate formation increased with Daudi cells, which carry the C3 receptors CR2 and CR3. This suggests that in the lytic assay lymphocytes with C3bi receptors are recruited in the presence of human serum. We assume that the bridge of C3 molecules between targets and effectors increases the avidity of their interaction.

Effect of a protein-bound polysaccharide PS-K on the complement system

A protein-bound polysaccharide from mycelia of Coriolus versicolor PS-K, clinically used as an immunomodulator, has been shown to restore the decreased cellular immune response and to exhibit host-mediated antitumor activity. In this experiment, PS-K was found to increase serum complement level in guinea pig and in human without malignancy, when hemolytic assay of complement was performed using sensitized sheep erythrocytes for the classical pathway activity and unsensitized rabbit erythrocytes for the alternative pathway activity. Assay of complement components revealed increase in C3 level in guinea pig, but no significant changes in C1q, C4, C3, properdin, C3 activator, and C1-inhibitor in human, while C5 and C9 were depressed. Conversion of beta 1C to beta 1A was observed in the 7th day's plasma of these patients by crossed immunoelectrophoresis. Biosynthesis of guinea pig C3 was accelerated by administration of PS-K, but that of C4 was not affected. These evidences suggested that PS-K might potentiate immune response of the host by elevating serum complement level, in addition to the activation of the complement system.

Human melanoma associated antigens: a solid-phase assay for detection of specific antibody

A solid-phase radioimmunometric binding assay is described utilizing 125I-labeled protein A for the detection of antibody to human melanoma associated antigens. The novel aspect of this assay is the use of chemically defined spent culture medium of melanoma cells at target antigens previously depleted of fibronectin by affinity chromatography. This makes it possible to screen for antibody in unabsorbed antiserum. Sensitivity, reproducibility and ease of performance of the assay are optimized by conjugating target antigens to a background of bovine serum albumin dried onto polyvinyl 96-well microtiter plates and cross-linked with glutaraldehyde. The use of an immobilized soluble antigen target derived from a large pool of spent culture medium facilitates direct interassay comparisons and permits extensive absorption analysis of antisera. The assay has considerable potential in screening for alloantibody and both poly- and monoclonal xeonoantibody to human melanoma associated antigens.

Receptor sites for complement and for immune complexes on human nonhemopoietic tumor cells

Tumor cells in primary cultures derived from 11 untreated nonhemopoietic cancer patients were reacted with specifically coated sheep erythrocytes. Rosette formation between tumor and indicator cells was assessed, Eight of the primary cultures reacted positively with both IgG-coated (EAIgG) and with IgM-human complement coated (EAIgMC or EAIgMC 4,3) sheep erythrocytes. EAIgG rosette formation in positive cultures ranged from 25 to 85%, and for EAIgMC/EAIgMC 4,3 reactivity ranged between 22--95%. Rosette formation with E (uncoated) and EAIgM was negligible. These findings suggest that human nonhemopoietic tumor cells may carry on their surface receptor sites for an IgG component of immune complexes and for human complement. These receptor sites may be important in the host-tumor relationship.

Fluctuation of serum complement levels in children with neuroblastoma

Serum samples from eleven children with neuroblastoma were drawn at diagnosis and again every 15 days or a month after the beginning of treatment over the course of 17 months observation. Twenty healthy children of the same age with no appreciable clinical manifestation were also studied as controls. Investigations included quantitative serum complement levels (total complement hemolytic activity, C3 and C4), anticomplementary serum activity and urine catecholamine levels (VMA and HVA). Complement levels of tumor patients were significantly higher than those of healthy subjects, but fluctuations were seen at different stages of the disease; patients at admission with active tumors or tumor recurrence had higher complement levels than those of patients in remission. Temporary recurrences of the disease were usually accompanied by fluctuations of urinary catecholamines, serum complement levels (mainly C3) and anticomplementary serum activity. At the terminal phase of the disease a drop in complement levels was usually seen, while urinary catecholamines were progressively increasing.

The complement system in tumor immunity: significance of elevated levels of complement in tumor bearing hosts

The elevation of complement level in the sera and depressed state of tuberculin reaction were observed in lung cancer patients. A clinical follow-up study demonstrated negative conversion of tuberculin reaction while keeping the complement at an elevated level during the observation period. This phenomenon can be explained; the complement system is elevated to compensate the depressed cell-mediated system to prevent the immunological surveillance system from invading agents in tumor bearing hosts. The immunological states of the patients with various diseases are classified into six stages according to the tuberculin reactivity, positive or negative, and complement level: elevated, normal, or depressed. A healthy control group is composed of the group of complement normal and tuberculin positive (Stage I). Most of acute inflammation falls into the elevated level of both complement and positive tuberculin reaction (Stage II). Sarcoidosis, leprosy, and Wegener's granulomatosis are divided into the elevated level of complement and depressed tuberculin reaction (Stage III). Systemic lupus erythematosus is in Stage V with the depressed state of both tuberculin reaction and complement level. A follow-up study of lung cancer patients showed a possible chronological sequence starting from Stage I through III, and finally to V, similar to the progression-of-disease process. The biological and medical significance related to the phenomenon is discussed, standing upon immunochemical, phylogenical, and immunogenetical standpoints of complement research.

Cellular localization of immunoglobulin within human maglignant melanomata

The presence of antibody in patients with malignant melanoma is well established if one examines the serum. In this report we have attempted to identify antibody within solid tumours showing that they are rarely present in any appreciable quantity on the surface of tumour cells but can be seen frequently on a number of different types of host cell within the tumours. This is discussed in the light of the role of antibody in the circulation and the possibility of antibody behaving as a blocking factor in vivo.

Immunologic aspects of human thyroid cancer. Humoral and cell-mediated immunity, and a trial of immunotherapy

Immunologic studies were performed on 16 patients with thyroid cancer. Circulating leukocyte counts increased, parallel to development of the terminal stage of disease, but total lymphocytes decreased. Serum immunoglobulin and complement were high, even though almost all patients showed negative antithyroid antibodies. Delayed skin hypersensitivity to bacterial and viral antigens and lymphocyte responsivity to PHA were not impaired at the initial stage of disease, but were impaired in terminal illness. Cell-mediated immunity (CMI) to tumor antigens(s) was measured using the assays of lymphotoxin, migration inhibition factor, and peripheral leukocyte migration inhibition. A few patients showed significant response to tumor antigen, but not to homogenates of Graves' thyroid gland. Active immunotherapy was applied to three patients. Two patients, who were in the terminal stage of illness, could not develop generalized CMI; immunization did not alter the patients' rapid downhill course. One patient developed in vitro evidence of CMI against cancer tissue antigens, associated with decrease in tumor size. Four months after immunization, CMI was impaired in autologous plasma culture, but not in cultures in allogenic normal plasma.

Use of formalin-fixed melanoma cells for the detection of antibodies against surface antigens by a micro-immune adherence technique

Established malanoma cell lines were fixed in suspension with 4% formalin and tested for antigenic activity against sera from melanoma patients in a micro-immune adherence test. By incubation of formalin-fixed cells in serum-free medium the unspecific background rosette formation was substantially reduced to below 10%. As could be demonstrated in absorption experiments with viable and formalin-fixed tumor cells, surface antigens reacting with sera from melanoma patients are largely unaffected by formalin treatment.

Surface markers on human B and T lymphocytes. II. Presence of Epstein-Barr virus receptors on B lymphocytes

Human peripheral lymphocytes were investigated for receptors binding Epstein-Barr virus (EBV) because of the regular association of this virus with infectious mononucleosis and Burkitt's lymphoma. This was done by a cytoadherence technique where virus-producing cells, displaying fresh viral determinants in their cytoplasmatic membrane, were mixed with lymphocytes. Unfractionated lymphocytes were found to adhere to these cells in contrast to column-purified T lymphocytes. The specificity of the binding was confirmed by blocking experiments that showed that sera containing high titers of antibodies directed against the virus could partially inhibit the adherence in contrast to low-titer sera. It is concluded that B lymphocytes, in contrast to T lymphocytes, have receptors for EBV. In a second line of experiments it was found that established human lymphoblastoid lines that carry the EBV genome had receptors characteristic for B lymphocytes and did not form T-lymphocyte rosettes. In contrast, a line of known T-lymphocyte origin that did not carry the EBV genome had receptors characteristic for T lymphocytes. EBV-transformed simian lymphoblastoid lines had surface markers indicating a B-lymphocyte origin in contrast to HVS-transformed simian lines that lacked surface immunoglobulin but carried receptors for sheep red blood cells.

Two different complement receptors on human lymphocytes. One specific for C3b and one specific for C3b inactivator-cleaved C3b

IN THE PRESENT STUDY IT WAS SHOWN THAT NORMAL PERIPHERAL LYMPHOCYTES HAVE TWO DIFFERENT COMPLEMENT RECEPTORS: one for C3b (the immune adherence receptor) and one for C3b subsequent to its cleavage by C3b inactivator. The two receptors are not cross-reactive and were shown by tests with various antisera to be antigenically distinct. Both the immune adherence receptor and the receptor for C3b inactivator-cleaved C3b were found on normal peripheral lymphocytes and on cultured lymphoblastoid cells. In 15 out of 18 chronic lymphatic leukemia patients, the immune adherence receptor was either partially or completely missing from the peripheral lymphocytes, while the lymphocyte receptor for C3b inactivator-cleaved C3b was retained. Normal erythrocytes, on the other hand, were found to have only the immune adherence receptor. Granulocytes from normal peripheral blood appeared to have only a receptor for C3b and did not have a receptor for C3b inactivator-cleaved C3b.

Combined studies of complement receptor and surface immunoglobulin-bearing cells and sheep erythrocyte rosette-forming cells in normal and leukemic human lymphocytes

Human lymphocytes from normal peripheral blood, thymus, spleen, thoracic duct, and peripheral lymphocytes from patients with chronic lymphatic leukemia were studied for complement receptor sites (CRL), surface immunoglobulin (SIg), and for the ability to form rosettes with sheep erythrocytes (TRFC). The two B cell markers (CRL and SIg) were found to be in overlapping, but not totally identical populations, whereas cells that were able to form rosettes were found in a totally unrelated population of lymphocytes; TRFC is therefore probably a reliable marker for T cells. In peripheral blood 24% of lymphocytes had SIg, but only half of these were also CRL. Almost all of the non-SIg peripheral blood lymphocytes were TRFC. In the spleen and thoracic duct only a few lymphocytes were observed that had SIg and were not CRL. On the other hand, in two of three spleens studied 10-20% of cells were CRL that did not have SIg. In the thoracic duct all non-CRL that did not have SIg. In the thoracic duct all non-CRL, non-SIg cells were TRFC. In chronic lymphatic leukemia three findings were made: (a) The presence or absence of CRL was independent of the presence or absence of SIg so that in individuals whose cells were non-SIg. CRL were usually plentiful. (b) Leukemic cells were essentially negative for TRFC. (c) Leukemic cells reacted poorly with human C3 compared to mouse C3, EACmo detecting up to 20-fold more CRL than EAChu. This latter finding was in sharp contrast to normal CRL that reacted somewhat preferentially with EAChu. These data suggest that altered surface Ig receptors and complement receptors are present in chronic lymphatic leukemic cells. Since the cells obtained from all leukemic patients tested in this study had either the complement receptor or surface immunoglobulin in a high percentage of their cells and were essentially negative for TRFC, it is strongly suggested that leukemic lymphocytes are of B cell origin. The finding of lymphocytes with only one of the two B cell markers suggests that these markers are not uniformly present on all B cells and that depending on the source, one or the other may be deficient.

Receptors for complement and immunoglobulin on human leukemic cells and human lymphoblastoid cell lines

The bone marrow-derived (B) lymphocyte can be identified by the presence of easily detectable surface immunoglobulin and a receptor for antigen-antibody-complement complexes (EAC'). Monocytes and macrophages also bear a receptor for EAC' and in addition possess a receptor for red cell-IgG complexes (EA). Thymus-derived (T) lymphocytes bear neither of these receptors. The cells of 15 patients with leukemia and 19 human lymphoblastoid cell lines were examined for the presence of the EAC' and EA receptors. Of the human leukemias studied, only the cells from the patients with chronic lymphatic leukemia (CLL) possess the EAC' receptor. The EA receptor could not be demonstrated on CLL cells; hence, CLL cells bear the lymphocyte EAC' receptor and by this criteria represent B lymphocytes. 12/19 of the cell lines studied could be classified as B lymphocytes by the presence of the EAC' receptor and absence of the EA receptor. 2/19 cell lines possessed both the EAC' and EA receptors and thus resemble the monocyte. 5/19 cell lines had no detectable receptor for EAC' or EA. The approach presented in this study for the classification of leukemias and cell lines as to their B lymphocyte, T lymphocyte, or monocyte origin may have useful diagnostic and therapeutic implications.