The effect of cytotoxic and anti-inflammatory drugs on the phagocytosis of neutrophil leucocytes

Neutrophils influx and proinflammatory cytokines inhibition by sodium salicylate, unlike aspirin, in Candida albicans-induced peritonitis model

Sodium salicylate (NaS) and aspirin (ASA) are known to have a variety of effects on microorganisms, such as fungus (C. albicans and C. neoformans), moreover, it have effects in leukocyte adhesion and migration in vitro. In this report, we investigated the effect of ASA and NaS in neutrophil migration and cytokine production in C. albicans-induced peritonitis murine model. For this, mice were treated intraperitoneally (i.p) or orally (po) with NaS or ASA; after they were stimulated i.p. with C. albicans, the cellular migration was evaluated 24 h after stimulation. NaS, in mice treated i.p., unlike ASA, was able to inhibit the neutrophil migration and proinflammatory cytokine production induced by C. albicans, such as TNF-α, IL-1, IFN-γ, IL-12, and IL-10, but did not alter the IL-4 levels in these animals. However, the po treatment with same the dose of NaS or ASA did not affect the influx of this cell for inflammatory site. These results suggest that the NaS inhibits cellular migration and proinflammatory cytokine by different anti-inflammatory mechanism compared to ASA.

Granulocyte function is stimulated by a novel hexapeptide, WKYMVm, in chemotherapy-treated cancer patients

Bacterial infections are major life-threatening complications in patients receiving cytotoxic drugs. These infections generally occur during periods of neutropenia. It has been suggested that the incidence of neutropenia correlates with the incidence of infections. A synthetic hexapeptide, WKYMVm, which stimulates phosphoinositide hydrolysis in leukocytes, has been shown to activate microbicidal activities of human polymorphonuclear neutrophils. In this study, we evaluate whether WKYMVm stimulates bactericidal activity in neutrophils obtained from patients who received chemotherapy for solid tumors when they were neutropenic. Eight patients and 11 healthy controls were recruited for the study. Patient neutrophils, on day 0 and at 2 weeks after chemotherapy, were collected. Expression of the WKYMVm peptide receptor, on leukocytes, was analyzed by fluorescein-activated cell sorting. Neutrophil bactericidal assays were performed using both reactive oxygen species generation and intracellular killing. Expression of the WKYMVm peptide receptor on leukocytes showed no difference in the treated patients compared to healthy controls. WKYMVm increased bactericidal activities, in a dose-dependent fashion, of control neutrophils compared to treated patient neutrophils obtained on day 0. WKYMVm markedly stimulated bactericidal activity of treated patient neutrophils obtained at 2 weeks after chemotherapy compared to treated patient neutrophils obtained on day 0. WKYMVm augmented neutrophil bactericidal activity was noted at low concentration but was suppressed at higher concentrations of 5-fluorouracil. WKYMVm augmented neutrophil bactericidal activity was not suppressed by cisplatin. WKYMVm has the potential for increasing neutrophil bactericidal activity in chemotherapy-treated cancer patients.

Effect of antipyretic therapy on the duration of illness in experimental influenza A, Shigella sonnei, and Rickettsia rickettsii infections

STUDY OBJECTIVES

To determine whether antipyretic therapy prolongs the course of experimental influenza A, Shigella sonnei, and Rickettsia rickettsii infections.

DESIGN

Retrospective observational study.

SETTING

University Center for Vaccine Development.

SUBJECTS

Fifty-four volunteers with experimentally induced influenza A, 45 with S. sonnei, and 21 with R. rickettsii infections participated.

INTERVENTIONS

Subjects from the six influenza A studies were challenged intranasally. If they met certain criteria, they were offered aspirin or acetaminophen for symptomatic relief. Subjects from the three Shigella studies were challenged with the bacteria and then given trimethoprimsulfamethoxazole. Acetaminophen also could be administered. In the one R. rickettsii trial, subjects were inoculated intradermally and treated with tetracycline. Again, acetaminophen was administered for symptomatic relief.

MEASUREMENTS AND MAIN RESULTS

Data, excerpted from subjects' study records, were evaluated using Wilcoxon tests, Spearman's correlation coefficients, and multiple regression analysis. Two-tailed hypotheses with a p value of 0.05 were used for all of the analyses. There was a striking correlation between antipyretic therapy and duration of illness in subjects infected with influenza A and S. sonnei, but not R. rickettsii.

CONCLUSIONS

Multivariate analysis suggested that antipyretic therapy prolonged illness in subjects infected with influenza A, but its use was the result of prolonged illness in those infected with S. sonnei. The precise nature of these relationships requires a prospective, randomized, placebo-controlled trial.

Prolonged but reversible neutrophil dysfunctions differentially sensitive to granulocyte colony-stimulating factor in children with acute lymphoblastic leukaemia

Treatment of average-risk acute lymphoblastic leukaemia (ALL) in children consists of 6 months of intensive chemotherapy followed by 18 months of maintenance therapy. Polymorphonuclear leucocyte (PMN) functions from children with ALL were studied in order to evaluate and compare the toxicity of the initial intensive treatment with the toxicity of the subsequent less intensive maintenance treatment. H2O2 and O2- production, evaluated by chemiluminescence, were significantly decreased during the intensive period but returned to normal values when maintenance therapy began. In contrast, bactericidal activity against Gram-positive and Gram-negative microorganisms remained at low levels throughout the treatment but returned to normal values in patients off chemotherapy. PMN from patients on maintenance therapy exhibited an excess of morphological changes associated with apoptosis. This was confirmed by standard two-colour flow cytometry which revealed an increase in the number of hypodiploid cells, and increased expression of membrane phosphatidylserine together with a drastic reduction in the expression of the Fcgamma receptor IIIB (CD16). These defective PMN were differentially sensitive to the effects of granulocyte colony stimulating factor (G-CSF): G-CSF induced similar increase in chemiluminescence in control and patient PMN; GSF partially corrected the defective bactericidal activity; G-CSF did not affect the accelerated PMN apoptosis. These observations indicate that ALL children undergoing chemotherapy present PMN defective functions which are partially sensitive or even resistant to G-CSF.

Granulocyte functions in children with cancer are differentially sensitive to the toxic effect of chemotherapy

To analyze the toxicity associated to chemotherapy upon granulocytes, different functional assays were performed, within days of drug exposure and at time of bone marrow recovery, on polymorphonuclear neutrophils (PMN) from children with cancer. There were no significant postchemotherapy changes in the expression of the different receptors studied nor in the phagocytosis of Staphylococcus aureus 42D. By contrast, a significant decrease was observed in H2O2 production in PMN recently exposed to chemotherapy with both cytofluorometric and chemiluminescence assays. There was also a decrease in the production of O2- and in chemotaxis; finally, the intracellular killing of S. aureus 42D and Escherichia coli was reduced. In patients having recovered from drug-induced bone marrow aplasia, PMN functions were found to be normal except for bactericidal activity which was still defective. The observations indicate that, in patients exposed to chemotherapy, some PMN functions are transiently altered, whereas microorganism cell killing is continuously impaired.

Transient neutropenia after intravenous injection of vindesine in patients with lung cancer

We have found transient circulating neutropenia and pulmonary sequestration of neutrophils after the intravenous injection of vindesine, a microtubule disruptor. Experiment 1 Ten patients with lung cancer were given a bolus intravenous injection of 3 mg.m-2 vindesine (Fildesine(r)). In all patients, total leukocyte and neutrophil counts in the venous blood fell to 65% and 47% of baseline values respectively within 30 min, and returned to baseline values within 6 h. In contrast, the lymphocyte count was stable. Experiment 2 Male Wistar rats were given saline or 0.08 mg.kg-1 vindesine intravenously and were sacrificed after 30 min. Vindesine produced a 58% reduction in the neutrophil count in the systemic circulation and a threefold increase in the neutrophil/erythrocyte ratio in the pulmonary microvasculature. Experiment 3 We studied the effects of vindesine in vitro on neutrophils and lymphocytes isolated from the venous blood of healthy volunteers. Vindesine (10(-5)-10(-8) mol.l-1) reduced neutrophil deformability (filterability) and induced neutrophil polarization, with reversibility of both effects after washout. These effects of vindesine were completely inhibited by cytochalasin B, an actin filament disrupter. Vindesine did not stimulate the neutrophil functions of adherence to polystyrene tubes, chemotaxis, or superoxide anion generation. The filterability and morphology of lymphocytes were not altered by vindesine. Thus, we conclude that a bolus injection of vindesine produces pulmonary sequestration of neutrophils, which produces circulatory neutropenia, and that it is primarily mediated by a decrease in neutrophil deformability that occurs without activation of the cells.

Influence of chemotherapeutic agents on superoxide anion production by human polymorphonuclear leukocytes

The effects of 11 chemotherapeutic agents on superoxide anion (O2-) production were examined in human polymorphonuclear leukocytes (PMNL). All drugs, except predonine, were found to suppress O2- production in PMNL. Adriamycin (doxorubicin), mitomycin C, vindesine, cisplatin, etoposide, nimustine, and pepleomycin suppressed O2- production at relatively low drug concentrations, whereas methotrexate, 5-fluorouracil and vincristine suppressed O2- production at high drug concentrations. Time-dependent suppression of O2- production was evaluated in four drugs, namely Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), cisplatin, vindesine, and methotrexate. Only Adriamycin showed suppressive effect on PMNL-derived O2- production in a time-dependent manner. Production of O2- by PMNL is a fundamental element for its bactericidal activity. The authors' results showed suppression of O2- production in PMNL in the presence of chemotherapeutic agents. This indicates a relationship between chemotherapy drugs and susceptibility to infection. The influence of chemotherapeutic agents on O2- production by PMNL should thus be taken into consideration when assessing defense mechanisms and susceptibility to infection of patients treated with these drugs.

A review of mechanism of action of aspirin and its potential as an immunomodulating agent

The basic aspects of PG immune function interactions are presented and discussed herein. Specifically, the findings of many of the studies summarized suggest the possibility that pharmacologic actions of aspirin may play a role in enhancing the immune response to viral infections. Mechanisms proposed for ASA include: PG inhibition via the cyclooxygenase pathway, an interaction with cyclic nucleotides, altered cellular interactions with PG's, altered leukocyte migration, activation of complement components, stimulation of monocytopoiesis, and induction of interferon. Since dual effects for ASA have been observed for several of these mechanisms, it is clear that its role in modulating the immune response to viral infections is very complex. This delineation of a role for ASA, that would seem to constitute a defense against viral infections leads to an area worthy of study and surveillance.

Toxicological review of busulfan (Myleran)

Busulfan is a bifunctional alkylating agent that appears to be cytotoxic to slowly proliferating or non-proliferating stem cell compartments, although its specific molecular and cellular mechanisms are unknown. It is the drug of preference in treatment of chronic myelogenous or granulocytic leukemia because its cytotoxic activity results in primary damage or destruction of hematopoietic cells. Additional effects resulting from the cytotoxicity of busulfan in hematological and other tissues, as documented by both human and animal model studies, include lethality, sterility, teratogenicity, and alteration of immune function. Busulfan has been shown to be mutagenic to microorganisms, mammalian cells in culture, Drosophila, and rodents. This agent is also considered potentially carcinogenic to humans. Various tissue hyperplasia and preneoplastic cells have been observed in animal model studies with busulfan, and case reports on human patients implicate busulfan as the causative agent in induction of secondary malignancies. Reports from human and animal studies of busulfan's cytotoxicity, teratogenicity, carcinogenicity, and mutagenicity have been reviewed. This information may be useful in a quantitative assessment of the effects of this agent and the identification of significant deficiencies in the data base. Demonstration that busulfan induces mutations in both somatic and germ cells suggests the need to assess its risk to humans.

The phagocytosis of yeast cells by blood monocytes. Effects of therapeutic concentrations of Vinca alkaloids

The role of cytoplasmic microtubules in the phagocytosis of yeast cells by blood monocytes was studied by means of therapeutic concentrations of the Vinca alkaloids vincristine, vinblastine, and vindesine. Phagocytosis was measured in a monolayer of glass-adherent monocytes fed with fluorescein-labelled yeast cells. Phagocytosis was composed of two sequential processes, yeast cell adherence to the monocyte and yeast cell engulfment by the monocyte. Monocyte phagocytosis was significantly inhibited by the Vinca alkaloids, mainly due to inhibition of engulfment but probably also due to inhibition of adherence. Since the Vinca alkaloids are microtubule antagonists it is reasonable to assume that monocyte phagocytosis, both adherence and engulfment, are partially microtubule-dependent processes. It is suggested that Vinca alkaloid inhibition of monocyte phagocytosis is of value in the treatment of type II-III autoimmune disorders, such as idiopathic thrombocytopenic purpura and autoimmune haemolytic anaemia.

Amelioration of hydroxyurea-induced suppression of phagocytosis in human granulocytes by free radical scavengers

The exposure of human circulatory white cells in vitro to 0.1-1-10 mol/l hydroxyurea (HU) for 20 h induced a progressive dose-dependent suppression of the phagocytic activity of granulocytes. The suppressing effect of 20 h exposure to 1 mol/l HU was used to examine the protection afforded by free radical scavengers against HU-induced cytotoxicity. It has been found that, in the suitable concentration of the protecting agent, a substantial protective effect of sodium benzoate, acetylosalicylic acid, alpha-tocopherol, ascorbic acid, catalase, peroxidase or superoxide dismutase can be achieved.

Evaluation of genotoxic potential of vincristine from multiple parameters

The genotoxic potential of vincristine is assessed by in vivo and in vitro cytogenetic assays on two test systems using multiple parameters. In in vivo experiments it was administered intraperitoneally to Swiss albino mice at doses computed on a surface area basis to lie within the therapeutic range. The parameters employed include screening of chromosome mutational activity in bone marrow and meiotic cells for periods covering one spermatogenetic cycle, in vivo SCE analysis and sperm head abnormality assay. In vitro studies included conventional scoring for chromosome mutations from human leucocyte cultures following administration of the drug at doses within the therapeutic range on the basis of blood volume. Strict controls were employed in both test systems. The data were treated by appropriate statistical tests to evaluate their validity. The results of in vivo experiments on somatic as well as meiotic test systems reveal a lack of clastogenic action of the compound. Both sexes respond in an identical fashion regarding this activity. The SCE analysis supports the in vivo nonclastogenic action of vincristine. Total univalents significantly seen with the highest dose after 1 and 2 weeks must be considered as being important as they can lead to aneuploidy. Evidence is adduced from sperm head abnormality assay that the drug induces point mutations. The results from in vitro test system indicate a positive chromosome mutational property. This is substantiated by results of in vitro SCE analysis. A comparison of data from in vivo and in vitro test systems suggests that a metabolic conversion of the compound in the former might render it innocuous for expressing the chromosome mutational activity. They also point out that vincristine evokes a differential clastogenic response in the two test systems despite bringing about an anaphase arrest commonly in both by acting on cytokinesis.

Yeast cell phagocytosis by mononuclear leucocytes from peripheral blood: significance of the substrate

Lymphoprep-isolated mononuclear leucocytes (L-MNs) from peripheral blood of healthy donors were mixed with yeast cells and filmed by time-lapse microcinematography in glass chambers at +37 degrees C. The concentration of L-MNs and yeast cells was lowered so as to make directional L-MN movement (chemotaxis) a necessary condition of phagocytosis. 54 cases of phagocytosis were filmed. Only yeast cells lying immobile on the glass surface were engulfed. In addition, 11 collisions between free-floating yeast cells and glass-adherent L-MNs were noted. None of these collisions led to immediate engulfment. It is suggested that the process of phagocytosis requires prolonged leucocyte-prey contact, in the order of magnitude of 3 to 5 seconds.

Neutrophil Function during Cyclic Chemotherapy for Cancer Disease

A study of some aspects of granulocyte function was carried out before, during, and after cyclic chemotherapy in 9 patients surgically treated for carcinoma and in 6 patients with very advanced and inoperable cancer. In most patients, total leukocyte mobilization, Candida-stimulated nitroblue tetrazolium dye reduction, and phagocytosis increased after chemotherapy. Furthermore, delayed hypersensitivity skin reactions to PPD and above all to Varidase increased in the same cases. A significant correlation between accumulation of polymorphonuclear leukocytes into skin chambers and skin tests was found in both groups of patients (p < 0.001). In some instances, fluctuations in the levels of circulating immune complexes without a distinct correlation between these complexes and granulocyte function were found. The data support the hypothesis that depressed granulocyte function may contribute to an increased susceptibility to infections and may be considered an additional factor that favors tumor dissemination. Chemotherapy seems to restore polymorphonuclear function and delayed hypersensitivity skin reactions.

Effect of methotrexate on phagocytosis and killing of Staphylococcus aureus by human granulocytes

The effect of methotrexate on the phagocytosis and killing of Staphylococcus aureus by granulocytes from healthy blood donors was investigated in vitro. A concentration of methotrexate of 2.2 x 10(-4) mol/1 (100 micrograms/ml), which is readily obtained on high dose intravenous administration did not decrease the phagocytosis and intracellular killing of Staph. aureus. In addition, granulocytes isolated from patients after termination of 6 h and 24 h high-dose methotrexate infusions showed normal phagocytic activity.

Neutrophil function in cured cancer patients

Spontaneous and endotoxin-stimulated nitroblue tetrazolium (NBT) dye reduction was evaluated in 86 individuals cured of various types of solid malignancies and in 55 healthy adults. Oxygen consumption tests, at rest and during phagocytosis, were performed with polymorphonuclear leukocytes of 22 patients and 10 controls, chosen at random. The results revealed an impaired capacity of patients' neutrophils to reduce NBT. The decrease in the stimulated reduction values was more pronounced (p less than 0.0005) than in spontaneous values (p less than 0.01), and was also noticed in patients who had been treated by surgery alone and in those with a disease-free interval of 10 years or more. Oxygen consumption by patients' leukocytes was similar to that of controls. The present results, especially those of the endotoxin-stimulated NBT test, might reflect a neutrophil dysfunction in cured cancer patients. The nature of such an abnormality and its possible clinical implication are still obscure.

The effect of cytotoxic drugs on neutrophil phagocytosis in vitro and in patients with acute myelogenous leukaemia

The in vitro effects of a range of concentrations of cyclophosphamide, doxorubicin, actinomycin D, cytarabine and methotrexate on neutrophil phagocytosis of C. albicans was studied. The reduction in phagocytic index (PI) was inversely proportional to the dilution of the drug and there was some inhibition of phagocytosis at all dilutions of all drugs. In patients with acute myelogenous leukaemia (AML), in vivo experiments showed that remission chemotherapy of doxorubicin or daunorubicin together with cytosine arabinoside increasingly inhibited phagocytosis over the period studied. The importance of these findings in the chemotherapy of malignant disease and the possible mode of action of cytotoxic drugs are discussed.