Abnormal monocyte chemotactic response in cancer patients

Improved efficacy of a microencapsulated macrophage colony stimulating factor and methotrexate in melanoma

This study examines the effects of a combination therapy of both methotrexate (MTX) and albumin microspheres containing recombinant human macrophage colony-stimulating factor (rhM-CSF) in melanoma tumors. Melanoma tumors were induced in C57BL/6 male mice with subcutaneous injection of B-16 tumor cells. Therapy started once the tumor size reached 0.5 cm in diameter. Mice were divided into several groups, and dosing was carried out daily until death. Group I received MTX solution (2 mg/kg or 15 mg/kg), group II received rhM-CSF solution (100 micrograms), group III received albumin rhM-CSF microspheres (100 micrograms), and groups V-XV received different combinations of both agents daily. The weight, tumor size, and survival time (in days) were recorded. From the results, the control (no rhM-CSF administered) group survived for 11.8 +/- 1.92 days, and the group that received MTX solution survived for 19.4 +/- 5.03 days. However, the group that received both the MTX solution (15 mg/kg) and albumin rhM-CSF microspheres (100 micrograms/kg) demonstrated a significant increase (p < .05) in the survival time (30.4 +/- 3.27 days). The concentrations of cytokines (tumor necrosis factor alpha [TNF-alpha] and interleukin-1 beta [IL-1 beta]) in the different treatment groups were monitored to determine the effect of rhM-CSF on the immune system. The TNF-alpha concentration was significantly higher in the group that received the combination therapy (204 +/- 54.6 pg/ml) versus the control group (31.5 +/- 7.02 pg/ml). The IL-1 beta concentration was significantly higher (p < .05) in the rhM-CSF microsphere (100 micrograms/kg) treated group (62 +/- 17.2 pg/ml) versus the rhM-CSF solution (29.1 +/- 8.7 pg/cc).

Synergic in vitro effects of interleukin-2 and tau-interferon on the migration of blood monocytes from control subjects and patients with lung cancer

BACKGROUND

Macrophages can play a major role against cancer by exerting their cytotoxic activity against tumor cells. The presence of macrophages in tumor stroma is related to the recruitment of circulating blood monocytes through the release of chemotactic factors by cancer cells. However, fewer blood monocytes from patients with cancer, such as lung cancer, migrate from in vivo and in vitro, compared with blood monocytes control subjects.

METHODS

Two cytokines, interleukin-2 (IL-2) and tau-interferon (tau-INF), proposed in the treatment of cancer, were tested for their ability to modulate the migratory response in modified Boyden chemotactic chambers of blood monocytes obtained from control subjects and patients with lung cancer in the presence of two chemotactic factors: N-formylmethionyl-leucyl-phenylalanine and complement fraction C5a (C5a).

RESULTS

Incubation with IL-2 and tau-INF resulted in a dose-dependent depression of the migration of blood monocytes from control subjects and patients with lung cancer. IL-2 depression was induced by IL-2 concentrations of 10(5) units/ml, and tau-IFN effects were measured for concentrations of 100 mu/ml. Furthermore, when low concentrations of IL-2 were tested in combination with low concentrations of tau-IFN, dose-dependent depression of blood monocyte migration occurred.

CONCLUSIONS

Dose-dependent depression of blood monocyte migration may modulate the inflammatory component of tumor stroma in patients with lung cancer treated with these cytokines. It may also explain, in part, the high incidence of infections in patients treated with IL-2.

The presence of immunosuppressive 'p15E-like' factors in the serum and urine of patients suffering from malign and benign breast tumours

Certain types of tumours are capable of producing factors inhibiting mononuclear phagocyte chemotaxis which may contribute to defects in immunosurveillance. In head and neck cancer these factors are said to be related to the retroviral protein p15E. This study examines the presence of p15E-like factors in serum and urine of patients with malign and benign breast tumours. Thirty patients with breast cancer, 29 patients with benign breast masses, and 28 healthy controls were tested blindly with the monocyte polarization assay, using N-formyl-methionyl-leucylphenylalanine as chemo-attractant. The low molecular weight fractions prepared of sera of the malign tumour patients inhibited the monocyte polarization significantly (mean inhibition 34%, s.d. = 12) compared with those of benign tumour patients (15%, s.d. = 7) and of controls (14%, s.d. = 6). The observed inhibitory effects on the monocyte polarization could be compensated by MoAbs reactive to p15E-related antigens. The mean difference between the polarization inhibition with and without anti-p15E adsorption (the 'p15E-like factor-induced inhibition') was 25% (s.d. = 13) in the breast cancer group, compared with 7% (s.d. = 5) in the benign tumour patients and 5% (s.d. = 4) in the healthy control group. Surgical removal of the tumours resulted in a restoration of the monocyte polarization in 20/23 (87%) patients of the breast cancer group. Results testing preoperative urine samples correlated well with those of corresponding sera. These data give additional support to the concept that tumour-derived p15E-like factors are responsible for the inhibitory effect on monocyte chemotaxis in breast cancer patients, and that these factors can be found in serum as well as in urine.

Superoxide anion-generating activity of polymorphonuclear leukocytes and monocytes in patients with lung cancer

Superoxide anion (O2-) production by polymorphonuclear leukocytes (PMN) and monocytes (MN) was measured in the peripheral blood of 70 patients with lung cancer. The O2- production by these cells was decreased in many, but not all, patients. The incidence of patients with lower O2- production increased as the stage advanced. The correlation between O2- production by these cells and peripheral blood smears was evaluated in patients with cancer. Patients with 80% granulocytes and 40% monocytes or more in their peripheral blood had a significantly lower O2- production by PMN and MN compared with those with less than 80% granulocytes and 40% monocytes, respectively. These results indicate that an abnormally increased number of granulocytes and monocytes in the peripheral blood of patients with cancer may depress immunoregulatory function. In addition, decreased O2- production by these cells should be considered when assessing the defense mechanisms and susceptibility to infection of these patients.

Immunosuppressive retroviral-related factors in sera of patients with head and neck cancer

The chemotactic responsiveness of mononuclear phagocytes has often been found defective in patients with various malignancies. We have previously reported a defective chemotactic responsiveness in patients with head and neck cancer. Low-molecular-weight factors (LMWFs) have been isolated from tumors and can be held responsible for the inhibitory effect on monocyte chemotactic responsiveness. It is an intriguing new finding that these LMWFs can be neutralized by antibodies reactive to P15E, a structural envelope protein of murine leukemia retroviruses. In this report we describe a relatively easy and rapid method for the detection of immunosuppressive P15E-like factors in the sera of patients with head and neck cancer. The test is based on the monocyte polarization assay. Although only nine head and neck cancer patients were included in this study, the findings indicate that the test might be of value for clinical application. An early detection of a recurrence after treatment might be possible by the finding of a reappearance of the P15E-like factors in patients' sera during follow-up.

Immunohistochemical assessment of splenic lymphocyte and macrophage subpopulations in patients with gastric cancer

In order to assess the effects of malignant tumors on the immune system, 25 spleens from patients with gastric carcinoma were studied by in situ immunohistochemical methods for lymphocyte subsets and cells of the mononuclear phagocyte system. Highly significant reductions of CD4+ T cells (P less than 0.001), Ki M2+ and Ki M-3+ MPS cells (P less than 0.02 and P less than 0.05), and a stage-dependent reduction of Ki 67+ B cell proliferation activity (P less than 0.05) were seen in spleens of patients with gastric cancer. These results, which were obtained by morphologic methods in a noninvolved lymphatic organ, reflect the systemic immunosuppressive and immunodepleting effects of malignant tumors that are probably mediated by tumor-associated cytokines.

Chemotactic activity of chicken blood mononuclear leukocytes from 15I5-B-congenic lines to bacterially-derived chemoattractants

The chemotactic activity of chicken blood mononuclear leukocytes was examined in partially-developed 15I5-B-congenic chicken lines using Enterobacter cloacae culture supernatant and formyl-methionyl-leucyl-phenylanine (f-met-leu-phe) (10(-5)M). Cells from seven different coded B-congenic lines were used to study each chemoattractant in vitro. Mononuclear cells from lines .15I-B5,.C-B12 and the background line 15I5 (B15) exhibited a significantly greater directed migration to bacterial supernatant than did cells from four lines carrying the B2, B2, B13, and B19 haplotypes, respectively. Similarly response to f-met-leu-phe was greatest in lines .15I-B5,.C-B12 and .N-B21, with the same four lines exhibiting a significantly lower response. Since f-met-leu-phe was originally isolated from bacteria, the results indicate that these lines possess differential chemotactic responses to certain bacterially-derived chemoattractants. Major histocompatibility complex (MHC) differences between the lines may serve as a genetic basis for the differential responses. Extrapolation of these results to other chemotactic-receptor systems would require further examination.

Antiinflammatory proteins associated with human and murine neoplasms

The immune mechanisms by which a host recognizes and destroys a growing tumor are undoubtedly complex and, as yet, incompletely understood. It is apparent, however, that mononuclear phagocytes play an important role in the defense against neoplastic disease and that the ability of monocytes and macrophages to accumulate at and within a growing tumor is a strict requirement for them to effect that role. Studies from our laboratory as well as those of other investigators have demonstrated that patients with a variety of neoplastic diseases have a specific defect in monocyte chemotactic responsiveness and that this defect is associated with the presence of the tumor. Furthermore, we and others have shown that a similar defect occurs in tumor-bearing rodents, thus allowing model systems to be developed for the study of the mechanisms involved. We have demonstrated that transplanted, spontaneous or carcinogen-induced murine tumors produce low molecular weight proteins which inhibit the accumulation of macrophages to inflammatory foci and that a significant portion, if not all, of these proteins are physicochemically and antigenically related to the retroviral envelope protein p15E. We have shown that p15E itself can inhibit the inflammatory accumulation of macrophages in normal mice. Studies on a wide variety of cancer patients have revealed that the fluids of such patients contain proteins which inhibit the responses of normal monocytes to various chemotaxins and, as in tumor-bearing mice, that these antiinflammatory proteins are antigenically related to retroviral p15E. Recent studies have demonstrated that human tumor cells can simultaneously release factors which are chemotactic for monocytes with those which are p15E-related inhibitors of chemotactic responsiveness, suggesting that the mononuclear phagocyte response to a growing tumor may be, in part, dictated by the balance obtained between various proteins produced by that tumor. The isolation and characterization of endogenous retroviral sequences within the human genome and the observation that the envelope genes of these endogenous sequences are partially homologous to p15E provide potential candidates for the p15E-related inhibitors of chemotactic responses which have been identified from human cancer cells and fluids. Studies now under way in a number of laboratories should provide more definitive answers regarding the nature and source of these p15E-related inhibitors.(ABSTRACT TRUNCATED AT 400 WORDS)

Inflammatory infiltrates of experimental mammary cancers

The purpose of this review was to summarize observations on the type and function of inflammatory infiltrates of mouse mammary tumors and to speculate on the underlying mechanisms and the significance of infiltrates to mammary tumor biology. Although the major conclusion is that much more work is needed, certain themes seem to be emerging. The number of infiltrating cells can be very high but is unrelated to biological behavior of the tumors. What seems to be important is the relative contributions of inflammatory cell subsets. In the case of T-cell subsets and NK cells, the infiltrates from tumors of long-term cell lines so far seem uninformative. The general characteristics are similar to those of infiltrates from rapidly proliferating, normal mammary tissues. These characteristics do not correlate with diverse biological behavior or malignant potential. A more informative model appears to be one in which the development of tumors from preneoplastic tissue can be observed. Here our attention is currently focused on NK cells. By contrast, the correlation between activated TAM and metastatic behavior suggests that our transplantable MMT lines may be biologically relevant in the study of infiltrating macrophages. We are especially interested in the role of TAM in the generation of tumor cell variability. Overall, our data indicate that the host infiltrate is another manifestation of both inter- and intra-tumor heterogeneity and, as such, is not simply a response to, but, rather, a part of the tumor ecosystem. Unraveling the cellular and molecular mechanisms that govern the inflammatory cell component of tumors should provide insight into the types of cellular interactions that result in tumor development and progression.

Defective T-lymphocyte chemotactic factor production in patients with established malignancy

Lymphocytes from 22 patients with established malignancy were stimulated with concanavalin A (Con A), and supernatants were tested for T-lymphocyte chemotactic factor (LCF). LCF activity was measured using a leading front chemotaxis assay with normal human T cells as responders. Fifteen of the 22 patients tested produced LCF at a level of less than 2 standard deviation below the mean of control cells. In 10 patients where mononuclear cells were stimulated with Con A for 24, 48, and 72 hr, LCF activity was significantly reduced at all three time points averaging 38, 14, and 43% of control levels, respectively. In 13 of the 31 patients, patient T-cell migration in response to casein was measured and compared to the production of LCF by mononuclear cells from these same patients. A significant correlation was observed indicating that both the response of T cells to a migration stimulus, and the production of T-cell-derived LCF was comparably suppressed. The reduction in LCF production by mononuclear cells from patients with established malignancy was not reversed by the addition of indomethacin to the culture system during Con A stimulation indicating that inhibition was not mediated by excessive prostaglandin production. The addition of patient mononuclear cells or T cells to normal mononuclear cells resulted in the inhibition of normal cell LCF by patient mononuclear cells or T cells. This could not be attributed to the production of a lymphocyte chemotactic inhibitor by patient cells, but appeared instead to be due to the direct inhibition of normal cell LCF synthesis or release by patient mononuclear cells or T cells. Separation of patient T cells into Leu 2 suppressor/cytotoxic or Leu 3 helper/inducer T cells showed that the inhibitory activity was associated with the Leu-2 T-cell subset. Heterologous normal Leu 2 T cells did not suppress normal mononuclear cell LCF production suggesting that patient Leu 2 T cells were functionally activated as compared to normal Leu 2 cells. The decreased production of LCF coupled with a depressed T-cell migratory activity in patients with established malignancy may in part be responsible for suppressed cellular immune reactions in these patients and possibly the impairment of tumor rejection.

Effects of tumor growth on host defenses

Monocytes and macrophages play an important role in host defense against neoplasia. Studies from our and other laboratories have demonstrated that patients with a variety of cancers have a defect in monocyte chemotactic responses. Tumor-bearing mice are also inhibited in their ability to accumulate macrophages to inflammatory foci. We have shown that extracts prepared from murine tumors, as well as the plasma and urine of tumor-bearing mice, contain anti-inflammatory proteins which are antigenically and physicochemically related to the immunosuppressive retroviral envelope protein p15E. Similarly, proteins capable of inhibiting monocyte chemotactic responses are present in human cancerous effusions and can be specifically absorbed by monoclonal antibodies to p15E. Furthermore, we have demonstrated that human malignant and mitogen-transformed cells contain p15E-related antigens. These findings led us to propose a two stage model of tumorigenesis: the first stage involves neoplastic transformation of a cell while the second stage involves activation of a gene coding for a p15E-like protein which allows the transformed cell to escape immune surveillance and go on to become a tumor. Support for this model has come from recent studies which have identified within the human genome an endogenous retrovirus sequence whose envelope gene is partially homologous to a highly conserved region of p15E. Using a synthetic peptide, termed CKS-17, we have shown that this region may be responsible for many of the biological activities of p15E and is capable of suppressing lymphocyte and natural killer cell immune functions as well as those of monocytes and macrophages. Thus tumors may be capable of evading host defense mechanisms by activation of a normal gene related to the immunosuppressive retroviral protein p15E.

Tumor-derived chemotactic factor(s) from human ovarian carcinoma: evidence for a role in the regulation of macrophage content of neoplastic tissues

Supernatants from freshly disaggregated human ovarian carcinomas maintained in vitro for 24 hr, from primary ovarian carcinoma cultures (4-6 days in culture) and from established ovarian cancer cell lines were examined for chemotactic activity on blood monocytes in blind-well chemotaxis chambers. Tumor-cell culture supernatants induced migration of peripheral blood monocytes across polycarbonate filters with considerable heterogeneity among different tumors. Induction of migration occurred only in the presence of a gradient between the lower and upper compartments of the chamber. Chemotactic activity was characterized by means of supernatants from primary ovarian carcinoma cultures. Chemotactic factor(s) was (were) produced in serum-free conditions and the production was inhibited by emetine but not by mitomycin C. The activity was destroyed by exposure to proteolytic enzymes and by heating at 100 degrees C but was unaffected by RNase, DNase, lipase and exposure to extreme pH values or heating at 56 degrees C. Upon fractionation on Sephadex G 75, the activity eluted as a single peak in the cytochrome C region, corresponding to an apparent molecular weight of about 12 kd. The percentage of macrophages was assessed in 25 freshly disaggregated tumor specimens. Ovarian carcinomas were heterogeneous in their macrophage content with values ranging from 4 to 36%. A significant (r = 0.62; p = 0.00097), though far from absolute, correlation was found between chemotactic activity of culture supernatants and percentage of tumor-associated macrophages. Tumor-derived chemotactic factor(s) could be one of the mechanisms involved in the regulation of the macrophage content of human ovarian carcinomas.

Monocyte function in cervical carcinoma: plasma inhibitor of monocyte chemotaxis

Blood monocyte function was tested in 43 untreated patients with carcinoma of the cervix (stages Ib to IIIb) and 50 age-matched controls. Monocyte counts, adhesion to glass, spreading on glass, phagocytosis and killing of Candida albicans, and chemotaxis under agarose were not significantly different between the patient and control groups. In 65% of a further series of 17 patient/control pairs, the plasma of cervical carcinoma patients was shown to contain a cell-directed inhibitor of monocyte chemotaxis. The accumulated evidence indicates that production of such factors by malignant tumors is an important mechanism in counteracting mononuclear phagocyte defense.

Locomotion and chemotaxis of mononuclear phagocytes

The capacity for locomotion and for chemotaxis is probably very different in monocytes and macrophages from different sources. Numerous techniques have been established for studying the locomotion of these cells. Many of the factors are sparsely documented and the reports are scattered among various cell types. Heterogeneity of locomotion and chemotactic responsiveness is evident when established macrophage lines and mouse peritoneal macrophage are studied. The effects of mononuclear phagocytes and their released products on the locomotion of other cell types are reviewed.

Autochthonous murine tumors: effects of viral or ultraviolet induction, immunogenicity and transplantation on intratumoral macrophages and systemic inflammatory responses

Macrophage tumoricidal activity requires a constant influx of macrophages but many transplanted cancers inhibit macrophage inflammatory responses. In this paper we address the issue of whether or not autochthonous tumors induced by either mammary tumor virus (MTV) in C3H/He mice or ultraviolet (u.v.) radiation in C3H/He or BALB/c mice also depress macrophage responses. Anti-inflammatory activity was not observed either prior to or during growth of these autochthonous tumors. Rather, the opposite was observed: strongly immunogenic u.v.-induced tumors which were rejected upon transplantation to syngeneic hosts had enhanced macrophage responses and more intratumoral macrophages than those mice whose tumors were transplantable. Transplantation of MTV-induced tumors selected for more aggressive tumors which had fewer intratumoral macrophages. In both MTV- and u.v.-induced tumors inflammatory responses of mice bearing serially transplanted tumors often differed from mice with autochthonous tumors. Our results demonstrate that anti-inflammation is probably not required for emergence and growth of these autochthonous tumors, that strongly immunogenic tumors may actually enhance macrophage responses and that the effect of tumor bearing on macrophage inflammation is a characteristic of the tumor, including its site and host of origin, its immunogenicity and its transplant generation.

A study of certain functional parameters of monocytes from patients with multiple myeloma: comparison with monocytes from healthy individuals

Selected functions (i.e. phagocytosis and chemotaxis of circulating blood monocytes were studied on cells obtained from 20 patients with untreated multiple myeloma (MM) and the results were compared with those obtained on cells from 60 healthy persons. The mean number of circulating monocytes was only slightly increased over the normal value although a marked monocytosis was demonstrated in all of the 4 patients with M-components of the lambda light chain type. Plasma cells isolated from peripheral blood and from bone marrow of patients with MM were found to possess a strong alpha-naphthyl acetate esterase activity. No differences were observed in the phagocytic activity of monocytes from patients compared with those of the controls, whereas the chemotactic responsiveness of the monocytes from the patients was slightly increased.

Mononuclear phagocyte function in head and neck cancer. Chemotactic responsiveness of blood monocytes in correlation between histologic grade of the tumor and infiltration of these cells into the tumor area

The chemotactic responsiveness of peripheral monocytes and the acid-phosphatase activity of tumor-infiltrating macrophages, as well as the ultrastructural appearance, were studied in 40 patients with squamous cell carcinoma of the head and neck. The chemotactic responsiveness was found to be decreased in carcinoma patients, and this value appeared to be positively correlated in individual patients with the number of tumor-infiltrating macrophages, as well as with the histologic grade of the tumor. Patients with poorly differentiated malignancies showed impaired monocyte chemotactic responsiveness and low numbers of tumor-infiltrating macrophages. Macrophages present in the parenchyma of the tumor showed a weak and diffuse pattern of acid phosphatase activity. The acid phosphatase activity of stromal macrophages was much stronger and distributed in foci. Electron microscopic examination of the parenchymal macrophages revealed low numbers of lysosomes and the presence of tumor cell debris in the cytoplasm of the cell, without any sign of a surrounding phagosomal membrane. Together with the weak cytochemical reactivity, this probably indicates the poor functional state of the phagocyte when infiltrated in the parenchyma of the tumor. Low molecular weight factors derived from the tumor are known to decrease chemotactic responsiveness of peripheral monocytes. The poor functional state of the macrophages infiltrated within tumor parenchyma might be explained by assuming that a high concentration of such factors in the near vicinity of malignant cells causes toxic effects in macrophages.

Alveolar macrophage dysfunction in malignant lung tumours

Alveolar macrophage chemotaxis was measured in 129 individuals--13 normal volunteers, 15 tumour free patients with recent bronchopulmonary infections, 10 patients with chronic bronchitis, 29 patients with endothoracic sarcoidosis, 48 patients with primary bronchial carcinoma and 14 patients with pulmonary metastases from various origins. Chemotaxis was tested in the presence of either zymosan activated autologous serum, N-formyl-methionine-leucyl-phenylalanine (F-Met-Leu-Phe), or zymosan activated human AB serum. Alveolar macrophage chemotaxis was significantly less in patients with bronchial carcinoma than in healthy volunteers (p less than 0.01). Chemotaxis was significantly more depressed in samples obtained from the neighbourhood of the tumour than in samples from the opposite lung. Defective chemotaxis was also found in patients with sarcoidosis. In contrast, the presence of lung metastases did not affect chemotaxis. A recent bronchopulmonary infection was associated with significantly increased (p less than 0.02) chemotaxis in tumour free patients but not in patients with a primary lung tumour. The findings suggest that an intrinsic functional defect of alveolar macrophages might favour the development of bronchogenic carcinoma.

Decreased T lymphocyte migration in patients with malignancy mediated by a suppressor cell population

The migration and concentration of lymphocytes at sites of antigenic challenge are an integral part of the expression of delayed cutaneous hypersensitivity, as well as of tumor and graft rejection. In this study, we have analyzed the migration of T lymphocytes from patients with malignancy. We used casein and concanavalin A (Con A)-stimulated mononuclear cell supernatants to stimulate T cell locomotion. Peripheral blood T lymphocytes from 30 patients with established malignancy, 10 patients with indolent malignancy or benign tumor, and 42 normal adult controls were tested. Data are expressed as a migration index (MI), which represents the difference in micrometers between the distance migrated in response to a stimulus and the distance migrated in response to media alone. We observed a marked depression in casein-stimulated T lymphocyte migration in patients with established malignancy (mean MI +/- 1 SD = 17.0 +/- 9 microns) as compared with normal adult controls (mean MI +/- 1 SD = 35.3 +/- 10 microns). Similar results were observed with migration in response to Con A supernatants. T cells from patients with established malignancy had a mean MI of 5.8 +/- 4 microns to Con A supernatants as compared with 24.5 +/- 5 for controls. This depressed migration was apparent both in the distance that cells migrated and in the number of cells that migrated into the membrane. Of 10 patients with indolent malignancy or benign tumor, T cell migration in 8 was not significantly decreased as compared with controls. When we mixed equal concentrations of normal control T lymphocytes with T lymphocytes from patients with cancer and added the mixture directly to the upper compartment of the chemotaxis chamber, the response of the normal T cells to casein was inhibited by an average of 48%. We observed inhibition of this migration of normal cells when we added as little as 10% of patient cells to normal cells. When we mixed normal control T lymphocytes from different donors and added them directly to the upper compartment of the chemotaxis chamber, T lymphocyte migration in response to casein was not significantly altered. If T cells from patients with cancer were cultured overnight, the suppressive effect on lymphocyte locomotion was lost. Our results indicate that there is a population of T lymphocytes in patients with cancer that suppress normal T lymphocyte migration. This suppressor activity may partially explain the subversion of immunosurveillance in established neoplastic states, as well as the defective inflammatory reaction to intradermal injection of antigen observed in many patients with malignancy.

Deficient superoxide-generating activity and its activation of blood monocytes in cancer patients

Superoxide (O2-)-generating activity of blood monocytes, the precursors of macrophages, from patients with advanced cancer and/or infection was studied. Monocytes from normal subjects generated 0.288 +/- 0.022 nmol O2-/min/10(5) cells (mean +/- S.E.M., n = 36) after sequential stimulation with cytochalasin E and wheat germ agglutinin. Monocytes from 69 non-infected adult patients with advanced malignancy of the stomach, esophagus and liver, and 7 pediatric patients with neoplastic disease released significantly less O2- than those from normal subjects (0.176 +/- 0.015, P less than 0.005). Infection increased the activity about 4-fold in patients with malignancy compared to non-infected cancer patients. These results suggest that monocytes of cancer patients are defective in secreting O2-, though the activity may be stimulated by infection.

Mononuclear phagocyte function in head and neck cancer: depression of murine macrophage accumulation by low molecular weight factors derived from head and neck carcinomas

In earlier experiments chemotactic responsiveness of peripheral blood monocytes obtained from patients with head and neck cancers was found to be markedly depressed. In an attempt to attribute this defect in migration to an influence excited by low molecular weight factors of less than 25,000 daltons, derived from the tumor, Amicon filtrates of head and neck cancer cells were administered subcutaneously to C3H mice 24 hrs. before the intraperitoneal injection of concanavalin A. Subsequent macrophage accumulation into the peritoneal cavity was quantified. A clear inhibition of macrophage infiltration was found, particularly when filtrates of poorly differentiated tumors were used. Injection of filtrates from healthy oral mucosa were negative, whereas mouse mammary carcinoma filtrates strongly inhibited accumulation.

Effects of isolated tumor lymphocytes alone and with adherent cells

The effect on the growth of gradient-isolated mouse mammary tumor cells of different populations of lymphoid cells were evaluated in microcytotoxicity assays. Variable effects were obtained with tumor-bearer lymph node and spleen cells: in some experiments growth stimulation occurred, whereas in others inhibition was observed. Mixed effector populations gave more regular results: adherent spleen cells added to lymph node or spleen lymphocytes inhibited tumor cell growth in six of nine experiments; inhibition occurred when either of the effector populations in the mixture was derived from the tumor-bearing mouse. Tumor-associated lymphoid cells (TAL) stimulated growth of the tumor cells in five of seven experiments. However, TAL inhibited tumor growth when combined with adherent spleen cells from tumor-bearing animals. In contrast with the peripheral lymphoid cells, admixture of control adherent cells from normal animals with TAL did not inhibit growth. No natural killer effect was seen in these growth inhibition assays. These data indicate that lymphoid populations capable of inhibiting tumor cell growth can be found in tumor-bearing animals, but such combination of active cells are not present in the tumor site.

Monocyte antibody-dependent cellular cytotoxicity in cancer patients

Antibody-dependent cellular cytotoxicity (ADCC) mediated by peripheral blood monocytes was determined in 120 patients who had gastrointestinal tract (GIT), lung and breast cancer, melanoma, or Hodgkin's and non-Hodgkin's lymphoma. Results were expressed in terms of maximum cytotoxicity and cytotoxicity at E:T = 1:10 and were compared with the results obtained in 63 normal subjects. There was a significant decrease in maximal cytotoxicity for both the GIT cancer and the melanoma patient groups, but not for any of the other groups. These differences were not confirmed when results were expressed at low effector: target cell ratios, e.g., cytotoxicity at E:T = 1:10. The relationship between monocyte ADCC and disease extent was examined in those groups with sufficient numbers. Monocyte ADCC was higher in patients with GIT cancer of limited extent than in patients with extensive GIT cancer and in the control group.

Enhancement of macrophage invasion of tumors by administration of chemotactic factor-antitumor antibody conjugates

The numbers of macrophages in peritoneal guinea pig hepatomas were significantly (P less than 0.005) elevated by the intraperitoneal injection of a covalent conjugate of the chemotactic peptide, formylmethionylleucylphenylalanine (fMLP), and IgG reactive with surface antigens on the hepatoma cells. These conjugates, which were previously shown to be chemotactic for guinea pig peritoneal exudate macrophages in vitro, increased the numbers of macrophages in the tumors approximately twofold when injected either in a single dose or in five doses. Although five injections of unconjugated fMLP were nearly as effective as the IgG-fMLP conjugates, free fMLP did not enhance the numbers of macrophages in tumors when injected as a single dose. Unconjugated IgG had no effect. The mean tumor weights were decreased in those groups of guinea pigs which received IgG-fMLP but statistical significance was not achieved due to tumor weight variability in all groups.

Characterization of a human blood monocyte subset with low peroxidase activity

Two human monocyte subsets from the peripheral blood of healthy donors have been isolated in greater than 90% purity by countercurrent centrifugal elutration and human serum albumin gradients and their functional capabilities have been assessed. We have demonstrated that one subset ("regular" monocytes, RM) showed intense cytoplasmic peroxidase staining and contained substantial peroxidase activity. In contrast, another subset ("intermediate" monocytes, IM) stained poorly for peroxidase and had low peroxidase activity. By electron microscopic analysis combined with peroxidase localization, it was found that IM had fewer peroxidase-positive granules per cell than did RM. IM coelutriated with some lymphocytes and by cell sizing analysis were shown to be slightly smaller than RM. Functional and cytochemical analysis of these subsets indicated that IM had less activity than RM in assays such as accessory cell function for mitogen-induced T lymphocyte proliferation and antibody-dependent cellular cytotoxicity, and that fewer IM expressed OKM1 antigen and pokeweed mitogen (PWM) receptors on their membranes than did RM. The subset of IM not bearing either the PWM receptor or the OKM1 antigen had very low peroxidase activity. IM also were found to have a greater sensitivity to polyriboinosinic and polyribocytidilic acid (100 micrograms/ml)-induced secretion of interferon. There was no significant difference in the phagocytic capability, the percentage of Fc receptor-positive cells, 5'-nucleotidase activity, DR antigen expression, or the responsiveness to migration inhibitory factor of IM as compared with RM. Furthermore, it was found that the ratio of IM to RM increased after prolonged cytapheresis, which suggests that IM are more mobilizable than RM from the extravascular reservoirs of human monocytes.

Depressed natural killer cell activity in tumor-bearing rats: effect of immunotherapy and cytoreductive chemotherapy

A single-cell cytotoxicity assay was used to determine the number of effector cells in the peripheral blood of normal and tumor-bearing Fischer 344 female rats which bound to and lysed K562 target cells. Of the blood leukocytes of normal rats 18.4 +/- 2.6% bound to K562 target cells; one-third of the conjugated target cells were killed as evidenced by trypan blue uptake. Cells isolated from the blood of rats bearing mammary adenocarcinoma R3230 or 13762 bound fewer target cells, 6.3 +/- 1.1 and 7.1 +/- 1.8%, respectively. The proportion of dead conjugated target cells was not different from that of normal rat leukocytes if the leukocytes were from rats bearing 13762 but was reduced by one-half if the leukocytes came from rats bearing R3230. Treatment of the tumor-bearing rats with cytoreductive chemotherapy returned the percentage conjugation to target cells to normal levels if the tumor growth was inhibited more than 70%. Treatment of the tumor-bearing rats with immunomodulating agents did not inhibit the growth of the tumors, but treatment with sodium ibuprofen or muramyl dipeptide increased the percentage conjugation significantly.

Inhibition of lymphocyte response by prostaglandin-producing suppressor cells in patients with melanoma

Peripheral blood mononuclear cells (PBMC) from 11 patients with metastatic melanoma (group II) had a significant decrease in blastogenesis to concanavalin A (Con A) (38.7 +/- 7.7 cpm X 10(3); mean +/- SE) compared to 21 patients who were disease free (70.6 +/- 6.7) or 16 healthy controls (83.6 +/- 10.3). If PBMC from patients were preincubated for 72 hr prior to exposure to mitogen, blastogenesis was restored to normal. In group II patients a similar improvement in reactivity of fresh PBMC occurred with indomethacin addition or following rigorous depletion of adherent monocytes. Supernatants from cells cultured with and without Con A in several group II patients contained very high levels of endogenous PGE2. Patients had a greater percentage of T lymphocytes bearing Fc receptors for ox erythrocytes (T gamma) than controls, which appeared to correlate with the increased sensitivity to suppression by exogenously added PGE2. These data suggest that the decreased blastogenesis in certain melanoma patients is due to an increase in PGE2 production by monocytes, along with an increase in lymphocyte sensitivity to its effects.

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.

Monocyte chemotaxis mediated by formyl-methionyl-leucyl-phenylalanine conjugated with monoclonal antibodies against human ovarian carcinoma

Availability of a chemically defined chemoattractant (fMLP) and of appropriate monoclonal antibodies may permit local manipulation of the inflammatory response to human tumors. fMLP has been conjugated with two monoclonal antibodies (OC125 and OC133) which react with human ovarian carcinomas. Conjugates retained the ability to bind to a human ovarian carcinoma line (OVCA433) judged by indirect immunofluorescence and by radioimmunoassay. The fMLP conjugate was maximally chemotactic for human blood monocytes and human peritoneal macrophages at protein concentrations of 300-900 micrograms/ml. Conjugates stimulated chemotaxis rather than chemokinesis. After incubation with an fMLP-antibody conjugate, antigen positive OVCA433 cells released chemotactic activity and attracted monocytes in vitro, whereas an antigen-negative ovarian cell line failed to do so. As monocytes can be important effectors of antibody dependent cell mediated cytoxicity, fMLP conjugates might increase monocyte concentrations at tumor sites and potentiate serotherapy for certain human neoplasms.

Effect of dichloromethylene diphosphonate (Cl2MDP) on immune function in breast cancer patients with bone metastases

Immune function was studied in normocalcemic breast cancer patients with bone metastases treated with either dichloromethylene diphosphonate (Cl2MDP) or placebo. The results showed no significant difference between the two patient groups. This suggests that Cl2MDP does not markedly impair the host's defense mechanisms, and in this respect can be safely used in the treatment of patients with resorptive bone disease.

Quantitative studies of monocyte maturation in patients with malignant melanoma

Peripheral blood monocytes were cultured from normal volunteers and patients with malignant melanoma in a suspension culture containing 50% autologous plasma. The number of monocytes that matured into macrophages in the normal control population was 8.29 +/- 3.14 X 10(4) cells/ml blood, whereas in patients with malignant melanoma the number of matured monocytes was 3.15 +/- 2.80 X 10(4) cells/ml blood. The low macrophage maturation in patients with malignant melanoma was not found to be associated with any serum factors. Furthermore, from morphological studies done using scanning electron microscopy, there was no apparent difference between macrophages maturing from normal individuals or patients with malignant melanoma. From analysis of this adherent cell population there appears to be an intrinsic defeat in the maturation of monocytes in vitro in the case of patients with malignant melanoma.

Suppression of macrophage oxidative metabolism by products of malignant and nonmalignant cells

Each of 11 tumors tested produced a factor that markedly suppressed the ability of macrophages to release H2O2 or O.2- in response to phorbol myristate acetate or zymosan. Four of seven normal cell types produced a similar activity, which was 3.5-7 times lower in titer than that in tumor cell-conditioned medium (TCM), and which was much more rapidly reversible in its effects. TCM caused 50% inhibition of H2O2 release when it was present in the medium for 48 h at a concentration of 13%, or when 100% TCM was present in the medium for 18 h. The H2O2-releasing capacity of macrophages incubated in TCM only returned to control levels by 6 d after its removal. TCM prevented augmentation of H2O2-releasing capacity by lymphokines. The titer of suppressive activity in TCM depended on both the concentration of tumor cells and the duration of their incubation. TCM did not augment the activity of catalase, myeloperoxidase, glutathione peroxidase, or glutathione reductase or the content of glutathione within macrophages, suggesting that decreased synthesis rather than increased catabolism was responsible for reduced secretion of H2O2. Suppression of the release of H2O2 or O.2- by TCM appeared to be a relatively specific effect, in that TCM increased macrophage spreading and adherence to glass while exerting little influence on rates of phagocytosis, synthesis of protein, or secretion of lysozyme, plasminogen activator, or arachidonic acid and its metabolites. Thus, tumor cells and some normal cells can secrete a factor that selectively deactivates macrophage oxidative metabolism.

Chemotaxis of purified human monocytes in vitro: lack of accessory cell requirement

This study was undertaken to determine whether cell cooperation, either among monocytes or between monocytes and lymphocytes, is a prerequisite for monocyte chemotactic responsiveness. We compared Ficoll-Hypaque-separated mononuclear cells and a preparation of 99% pure monocytes obtained by chemotaxis in a newly designed separation chamber. Monocytes of both preparations migrated to chemoattractants without a lag phase, and no further increase in migrated cells was observed after 70 min. The cell dose-response was linear for both preparations over a wide range of cell concentrations in the cell input well of the chemotaxis chamber, suggesting that no monocyte-monocyte interaction was required. Since only 20 to 60% of the monocytes purified by chemotaxis migrated a second time, the possibility of a requirement for an accessory cell was tested. The addition to purified monocytes of several different mononuclear cell preparations comprising lymphocytes or nonmigrating monocytes had no effect on monocyte migration. These experiments show that normal human blood monocytes in vitro do not require stimuli from other cells to respond to chemoattractants. Their behavior is profoundly different from that of mouse peritoneal macrophages, which exhibit a time lag in vitro before migration toward an attractant and become more responsive with either increasing cell concentration or addition of purified lymphocytes.

In vitro monocyte maturation in squamous-cell carcinoma of the lung: influence of humoral factors

A previously described defect of in vitro monocyte maturation in patients with squamous-cell carcinoma of the lung (SCC) has been investigated further. The maturation of patients' monocytes in pooled normal human serum was significantly better than in autologous serum. Conversely, the maturation of normal control monocytes was significantly depressed in patients' serum. The defect has been shown to be due to the presence of an inhibitory factor, rather than the lack of a necessary component in the patients' serum. Artificially aggregated gamma-globulin inhibited monocyte maturation in vitro, but the presence of immune complexes in the serum of many patients with SCC did not correlate well with the depression of in vitro maturation of monocytes from the same patient. Similarly, pregnancy-associated alpha 2-glycoprotein, in increased amounts in the serum of patients with SCC, showed no correlation with monocyte maturation. The addition of soluble extracts of tumour, but not of surrounding normal lung tissue significantly inhibited monocyte maturation. The results suggest that the defective monocyte maturation in patients with SCC is at least in part due to serum inhibitory factors, which are likely to be a heterogeneous group.

Depressed mononuclear cell function in advanced neoplastic disease

The ascites fluids from 9 patients with invasive gynecologic neoplasms were examined to determine the immunocompetence of the mononuclear ascites cells and the immunoregulatory properties of the cell-free ascitic fluid. Blood mononuclear cells (from 5 patients) were also tested. The mononuclear cells from the cancer patients responded poorly to stimulation with polyclonal mitogens; only the blood mononuclear cell response to pokeweed mitogen was not significantly less than that of normal subjects. The addition of autologous serum or cell-free ascitic fluid to the cell cultures enhanced the response of the cells to phytohemagglutinin and pokeweed mitogen, had little effect on the response to concanavalin-A, and greatly depressed the response to succinyl-concanavalin-A. We found no evidence for the presence of suppressor cells in the ascites cell populations. The data are consistent with the thesis that the depressed immune responses are the result of malnutrition associated with advanced malignant disease.