In Vitro Effects of Nitrogen Dioxide on the Release of Superoxide Anions, Tnf-α, and IL-8 by HL60-Macrophages and Bovine Alveolar Macrophages

Abstract

This study was designed to investigate the in vitro effect of nitrogen dioxide on some immunofunctions of immune-competent cells. , and bovine alveolar macrophages (BAM) were exposed to synthetic air or to NO, (1.5 and 3.0 ppm) for 1 or 2 h. Under the special conditions of exposure, which allow the cells to be kept in direct contact with the gases during the whole incubation period, the cells stay alive in synthetic air for more than 4 h. After a lag phase of about 1 h, the exposure to NO, results in a decrease of the viability, which is dependent both on the time and on the concentration. The morphology of the cell surface structures is obviously changed, even under conditions in which a loss of viability cannot yet be observed. Simultaneously, the capability of the cells to generate superoxide anions in response to a stimulation with zymosan, but not with TPA, is markedly reduced and, in ' addition, the spontaneous release of superoxide anions from nonstimulated cells is also diminished after their exposure to NO,. Like the superoxide anion production, the tumor necrosis factor OL VNF-a) and the interleukin 8 (IL-8) releases by both types of cell in ~ response to a stimulation with lipopolysaccharide ILP5) are significantly suppressed after NO, exposure. But whereas the exposure to NO, increases the liberation of TNF-o( and IL-8 by nonstimulated HL60-M, the TNF-OL release of resting BAMs is drastically suppressed. The results indicate that NO, has some distinct effects on immunologically relevant functions of HL60-M and BAMs.The effects concern mainly the capability of the cells to respond to external stimuli and only in a minor extent the functions of resting cells. These findings can help to explain the reported higher susceptibility to infections of animafs that have been exposed to NO,.

Modulation of IL-1?, IL-6, IL-8, TNF-?, and TGF-? secretions by alveolar macrophages under NO2 exposure

“…The comparison of these data with in vitro results from other authors is difficult, because a wide range of variations in cell susceptibility to NO2 has been reported [28]. This diversity is caused by species-specific differences as already described for hamsters compared with rats and by the conditions of the exposure [9,40].…”

“…This diversity is caused by species-specific differences as already described for hamsters compared with rats and by the conditions of the exposure [9,40]. Polzer et al observed also a decrease in TNF-oL release by bovine AM after NO2 exposure [28,29]. Ozone exposure was used in other studies investigating cytokine release by AM.…”

Modulation of cytokine production by interferential current in differentiated HL-60 cells

“…LPS binds to CD14, which is an opsonic cell surface receptor for LPS [Bhattacharya et al, 1997], stimulating many cellular processes such as the enhancement of cytosolic [Ca 2 ] i , production of reactive oxygen species, and the up-regulation of several in¯ammatory cytokines (TNFa, IL-1b, IL-6, and IL-8). This was observed in different cell types (human neutrophils, HL-60, THP-1 and U-937 cells) [Bhattacharya et al, 1997;Sironi et al, 1996;Welker et al, 1996;Polzer et al, 1994]. To ®nd optimal conditions for HL-60, these cells were treated with 0.1, 0.3, 1.0, 3.0, and 10 mg/ml LPS and the release of TNF at 3 h was determined.…”

Influence of Surfactant on Cytokine Release from Ozone-Exposed Human and Bovine Alveolar Macrophages in Vitro

“…The cells were exposed in Transwell culture plates (Costar, pore size 0.4 pm, polycarbonate). Seeding was with 3 x l o 6 BAM cells or 2 x lo6 HAM cells/ml RPMl 1640 medium; further information is contained in Polzer et al (1994b). Before exposure the medium below the polycarbonate membrane was removed.…”

“…The TNF-a was determined by a bioassay using WEHl 164 cells i n experiments with BAM (details see Polzer et al, 1994b) After ozone exposure, BAM release chemoattractants for other macrophages. This was quantified with a m icrochemotaxis chamber according to Falk et al (1980); details are given i n Polzer et al (1994b).…”