Chemiluminescence in a macrophage cell line modulated by biological response modifiers

Topical ALA-PDT modifies neutrophils' chemiluminescence, lymphocytes' interleukin-1beta secretion and serum level of transforming growth factor beta1 in patients with nonmelanoma skin malignancies A clinical study

BACKGROUND

Photodynamic therapy (PDT) has been recognized as a noninvasive therapeutic approach for the effective treatment of tumors. It has been shown in studies conducted on malignant cell lines and various animal tumor models, that the interaction of photosensitizing substances with light leads to the release of cytotoxic substances and stimulates the immune response.

PURPOSE

The aim of our study was to analyze the immune system response in patients undergoing photodynamic therapy due to basal cell carcinoma (BCC).

METHODS

Patients with skin malignancies have been treated by 10% delta-aminolevulinic acid (ALA) (Medac GmbH, Wedel, Germany) topically and light from a diode laser. Blood samples were obtained from each patient twice in the same day: before and 4h after photodynamic treatment procedure. In patients' serum the concentration of transforming growth factor beta1 (TGF-β1) was determined. Additionally the study has been conducted on lymphocytes and granulocytes from peripheral blood. In cell culture supernatants the concentration of interleukin 1beta (IL-1β), interleukin 2 (IL-2), interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα), the percentile composition of patients' lymphocytes and the chemiluminescence of neutrophils have been measured.

RESULTS

We have observed a significant increase (p=0.015) in the intensity of the neutrophil chemiluminescence and significant diminution (p=0.006) of IL-1β concentration in supernatants. Similarly the serum level of TGF-β1 has been significantly decreased (p<0.001).

CONCLUSION

It is very likely that human immune system activity is modified by topical ALA-PDT and may potentially contribute to its final outcome.

Characterization of influenza virus-induced death of J774.1 macrophages

The mechanism and role of influenza virus (IV)-induced pathogenesis of macrophages during respiratory infection are ill defined. Reported here are findings on IV-induced cytopathic effects (CPEs) for an in vitro experimental system using the murine macrophage cell line J774.1. CPE was elicited by 0.2 or greater multiplicity of infection (m.o.i.). CPEs showed a lag of 6-8 h postinfection and occurred most rapidly between 6 and 12 h. J774.1 cells did not support productive IV replication, but immunofluorescence demonstrated that IV protein synthesis occurred. Light microscopy and DNA staining showed that after death cells had very condensed cytoplasm and nuclei. Cell remnants were surrounded by intact plasma membrane (PM) as demonstrated by exclusion of a membrane-impermeant dye. Time-lapse video microscopy recordings between 6 and 10 h postinfection showed sequential structural changes, including previously undescribed events. Notable changes were a rapid cytokinesis (zeiosis; "cell boiling"), followed by nuclear shrinkage, and an unusual transient blebbing of the PM. DNA fragmentation occurred after 12 h, producing a wide size range. UV-inactivated virus failed to induce CPEs, and CPE was blocked by amantadine. N-Acetylcysteine and pyrrolidine dithiocarbamate, but not other inhibitors of reactive oxygen intermediates, reduced or blocked the CPE. Most changes observed are those attributed to apoptotic processes rather than necrotic cell death. The kinetics and inhibitor effects suggest that IV infection and replication must be initiated to activate CPEs.

Oldenlandia diffusa and Scutellaria barbata augment macrophage oxidative burst and inhibit tumor growth

Oldenlandia diffusa (OD) and Scutellaria barbata (SB) have been used in traditional Chinese medicine for treating liver, lung and rectal tumors. In this study we determined the effects of these phytochemicals on oxidative burst as an indicator of phagocytic function in a murine macrophage cell line J774 using an automated micro-fluorometric assay. A dose-dependent augmentation of oxidative burst was observed with OD as well as SB. The effect of OD and SB on the growth of a murine renal cell carcinoma (Renca) was also determined. Balb/c mice were transplanted subcutaneously with 1 x 10(5) Renca cells and were randomized into groups of 10 to receive oral feeding of OD (4 mg/day), SB (4 mg/day), or saline as control. Oral feeding with either OD or SB significantly inhibited the growth of Renca in mice. The data of this study show that OD and SB are capable of enhancing macrophage function in vitro and inhibiting tumor growth in vivo.

Chinese medicinal herbs inhibit growth of murine renal cell carcinoma

Tumors are known to produce factors suppressing immune functions. We previously showed that a murine renal cell carcinoma (Renca) suppressed macrophage function in vitro and that this suppression was abolished by co-incubation with extracts of two Chinese medicinal herbs. We now report that these phytochemicals are capable of inhibiting growth of Renca in vivo. BALB/c mice were transplanted intraperitoneally (IP) with 1-2 x 10(5) Renca cells. One day after tumor transplant, mice were randomized into two groups. One group was treated IP, daily for 10 days, with 100 microliters of phytochemicals containing 500 micrograms each of Astragalus membranaceus and Ligustrum lucidum, while the other group received saline as controls. A cure rate of 57% was obtained with these phytochemicals when the initial tumor load was 2 x 10(5), and 100% when the initial tumor load was 1 x 10(5). Additional experiments were performed to investigate the mechanisms involved in this protection. Splenic macrophages from tumor-bearing mice were shown to have depressed chemiluminescent oxidative burst activity, and this depression was restored with phytochemical treatment. Splenocytes from mice transplanted with Renca responded less favorably to interleukin-2 (IL-2) in generating lymphokine-activated killer (LAK) cells; again this depression was restored with phytochemical treatment. Our data suggest that these phytochemicals may have exerted their antitumor effects via augmentation of phagocyte and LAK cell activities.

Modulation of chemiluminescence in a murine macrophage cell line by neuroendocrine hormones

This study determined the effects of neuropeptides and neuroendocrine hormones at the cellular level of the immune response using a murine macrophage cell line, J774, which exhibits a chemiluminescent oxidative burst upon acute stimulation with zymosan. We report that the zymosan-triggered oxidative burst of J774 cells can be modulated by the opioid peptides beta-endorphin (beta-END) and dynorphin A (DYN) in a naloxone-reversible fashion. Norepinephrine (NE) also modulated chemiluminescence (CL) emission of J774 cells, with dose-dependent suppression of CL dependent upon co-incubation with gamma-interferon (gamma-INF). Without gamma-INF co-incubation, NE shared with the opioid peptides beta-END and DYN the ability to modulate oxidative burst, producing an inverted-U dose response. These data indicate that J774 cells may be useful for explaining some mechanisms through which the neuroendocrine system interacts with the immune system.

An automated micro-fluorometric assay for monitoring oxidative burst activity of phagocytes

A micro-fluorometric assay using 2',7'-dichlorofluorescein diacetate (DCFH-DA) to monitor oxidative burst (OB) in phagocytes has been developed. This assay is based on the oxidation of nonfluorescent DCFH-DA to highly fluorescent 2',7'-dichlorofluorescein (DCF) both intracellularly and extracellularly. A murine macrophage cell line, J774, and a human monocytic cell line, Mono Mac 6, were used as models. The cells were harvested from tissue culture flasks, washed, counted and adjusted to desired concentrations. They were then dispensed into a 96-well flat-bottom tissue culture plate. After adding DCFH-DA and an agent eliciting OB, the plates were incubated in 5% CO2 at 37 degrees C for various periods. The intensity of fluorescence was measured directly in the wells of the tissue culture plate with the cells in situ using a computerized microplate fluorometer at 485 nm excitation and 530 nm emission. This assay provided a rapid measurement of oxidative burst of phagocytes. The automated micro-fluorometric assay may be suitable for screening the immunomodulating activities of various biological and pharmacological substances.

Protective effect of gypenosides against oxidative stress in phagocytes, vascular endothelial cells and liver microsomes

The action of gypenosides (GP, saponins of Gynostemma pentaphyllum, a Chinese medicinal herb) as an antioxidant was studied using various models of oxidant stress in phagocytes, liver microsomes and vascular endothelial cells. The results show that GP decreased superoxide anion and hydrogen peroxide content in human neutrophils and diminished chemiluminescent oxidative burst triggered by zymosan in human monocytes and murine macrophages. An increase of lipid peroxidation induced by Fe2+/cysteine, ascorbate/NADPH or hydrogen peroxide in liver microsomes and vascular endothelial cells was inhibited by GP. It was also found that GP protected biomembranes from oxidative injury by reversing the decreased membrane fluidity of liver microsomes and mitochondria, increasing mitochondrial enzyme activity in vascular endothelial cells and decreasing intracellular lactate dehydrogenase leakage from these cells. The extensive antioxidant effect of GP may be valuable to the prevention and treatment of various diseases such as atherosclerosis, liver disease and inflammation.

Chinese medicinal herbs reverse macrophage suppression induced by urological tumors

Tumors are known to produce factors suppressing macrophage function. In this study we demonstrated in vitro suppression of macrophage chemiluminescent oxidative burst associated with viable cells and cell-free extracts of two urological neoplasms--murine renal cell carcinoma (Renca) and murine bladder tumor (MBT). Suppression was reversed by extracts of two Chinese medicinal herbs, Astragalus membranaceus (AM) and Ligustrum lucidum (LL). Murine macrophage cell line J774 was incubated with either the viable tumor cells or the cell-free tumor extract for 18 hours at 37C and 5% CO2. Chemiluminescent oxidative burst as an indicator of macrophage function was triggered by adding zymosan A suspension containing luminol and assayed in an automated luminometer. Photon emission over time was counted and the results were expressed as integrated photon emission. Significant dose-related depression of oxidative burst occurred with either the viable tumor cells or the cell-free tumor extracts. Depression was partially or completely reversed by the presence of 50-100 micrograms./ml. of either the AM or the LL extract. AM and LL have previously been shown to modulate immune response. Data from this study suggest that they may also exert their antitumor activity via abolition of tumor-associated macrophage suppression.

Phagocytic cell chemiluminescence using different zymosan preparations

This study compared the effectiveness of opsonized and unopsonized zymosan prepared in our laboratories with a commercially available opsonized preparation used for induction of luminol-dependent oxidative burst in phagocytic cells. The production of chemiluminescence (CL) by human whole blood, isolated human neutrophils, normal BALB c mouse splenocytes, and an immortal BALB c mouse macrophage cell line (J774A.1) was tested in an automated luminometer. Recombinant murine or human interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) were used as priming agents in some of the experiments. With human leukocytes and normal mouse spleen cells the laboratory-prepared zymosans (regardless of opsonization) induced equal or significantly greater CL than did the commercially prepared zymosan. In addition, greatly increased CL was evident with IFN-gamma- and LPS-primed neutrophils tested with our zymosans compared with the commercial preparation. These results suggest that effective zymosans capable of inducing strong, reproducible CL responses from several different phagocytic cell populations can be readily made in the laboratory.

Phagocytic response modifying reactivity of enzymatic cell wall digests of Nocardia opaca

Aqueous extracts (ENOCW) and enzymatic digests of purified Nocardia opaca cell wall fragments, virtually free of muramyl peptides, were monitored for their phagocytic response modifying reactivity on polymorphonuclear leucocytes, separated or unseparated in whole human blood. In the presence of ENOCW a 74% increased production of superoxide during the respiratory burst of TPA-activated polymorphonuclear leukocytes was observed, as compared to the unprimed control. Delipidation of this preparation resulted in a further increase in reactivity (144%). Even in the presence of whole human blood, as a model for competitive binding in biological fluids, an enhanced generation of superoxide by TPA activated blood phagocytes remained detectable. A 37-75% decreased phagocytic reactivity in samples of HIV-seropositive blood was considerably restored in the presence of ENOCW.