The influence of carbon particles on the concentration of acid phosphatase and lysozyme enzymes within alveolar macrophages during the killing and degradation of Mycobacterium bovis

Immune response and protective efficacy of mannosylated polyethylenimine (PEI) as an antigen delivery vector, administered with a Streptococcus agalactiae DNA vaccine in Nile tilapia (Oreochromis niloticus)

This study examined the effectiveness of a DNA vaccine for S. agalactiae that was delivered by mannose-based polyethyleneimine (Man-PEI). The results showed that Man-PEI/pcDNA-Sip stimulated a higher serum antibody titer compared to control or other vaccine groups (p < 0.05). Additionally, it induced higher expression of immune-related genes, and increased activities of superoxide dismutase (SOD), acid phosphatase (ACP) and alkaline phosphatase (AKP). Furthermore, the Man-PEI/pcDNA-Sip group showed an improved relative percent survival (RPS) of 85.71%. These results demonstrate the potential value of Man-PEI as a vaccine delivery vehicle, and suggest that it can be effective in boosting the immune protective rate induced by pcDNA-Sip vaccines.

Antioxidant defence system based oxidative stress mitigation through dietary jamun tree leaf in experimentally infected snubnose pompano, Trachinotus blochii

A 45-day feeding trial was conducted to evaluate the effect of dietary jamun tree leaf (JL) on the antioxidant defence system-based disease resistance in juveniles of Trachinotus blochii. The juveniles of snubnose pompano were distributed into four treatment groups in triplicates. Each treatment was fed with a diet containing either 0 (0JL), 0.5 (0.5JL), 1 (1JL) and 1.5% JL (1.5JL) in the feed. After feeding trial, the fishes were experimentally infected with Vibrio parahaemolyticus. The activities of oxidative stress enzymes such as superoxide dismutase and catalase were found to be increasing with increasing level of dietary JL incorporation, and the lower value was witnessed in control group in pre- and post-challenge. After challenge, the alanine and aspartate aminotransferase activities in all the treatments were significantly increased (P < 0.05) than the pre-challenge condition and exhibited reverse trend with the antioxidant enzymes. The alkaline and acid phosphatase activities were found higher in 1.5JL group and showed significant difference (P < 0.05) among the treatments. The respiratory burst activity and liver glycogen content showed an increasing trend as the level of inclusion of JL increased in the diet. The acetylcholinesterase activity was significantly plunged (P < 0.05) after experimental infection, and JL diet fed groups showed better activity. After experimental infection with V. parahaemolyticus, the highest relative percentage of survival was observed in 1JL and 1.5JL groups. Hence, dietary supplementation of jamun tree leaf at the level of 1% is adequate to reduce the oxidative stress and improved the innate immune status through antioxidant defence system.

Effects of dietary vitamin D3 on growth performance, antioxidant capacities and innate immune responses in juvenile black carp Mylopharyngodon piceus

The aim of this experiment was used to investigate the effects of different contents of dietary vitamin D₃ on the growth performance and antioxidant and innate immune responses in juvenile black carp Mylopharyngodon piceus. Black carp juveniles were fed six levels of dietary vitamin D₃ (VD₃) (96, 220, 412, 840, 1480, and 3008 IU/Kg) for 9 weeks. Results showed that highest weight gain (WG) and special growth ratio (SGR) were obtained at 534.2 IU/Kg dietary VD₃ according to the second-order polynomial regression model. The protein efficiency ratio (PER) of black carp could be significantly increased by 412, 840, and 1480 IU/Kg dietary VD₃ (p < 0.05), while the feed conversion ratio (FCR) were reduced by 412, 840, and 1480 IU/Kg dietary VD₃ (p < 0.05). Adequate dietary VD₃ content (412, 840, and 1480 IU/Kg) could significantly upregulate expression levels of lipoxygenase 5 (LPO 5); increase the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GR); and improve GSH contents and total antioxidant capacities (T-AOC) in the liver of black carp. However, glutathione S-transferase (GST) activities and malondialdehyde (MDA) levels were significantly reduced by adequate dietary VD₃ content (412, 840, and 1480 IU/Kg) in the fish liver. In addition, 412, 840, and 1480 IU/Kg dietary VD₃ could significantly upregulate the mRNA expression levels of interferon-α (IFN-α), lysozyme (LYZ), hepcidin (HEPC), natural resistance-associated macrophage protein (NRAMP), and complement component 3 (C3) and C9 in the hemocytes and liver of black carp juveniles compared with the VD₃-deficient diet (96 IU/Kg). Meanwhile, higher contents of dietary VD₃ could increase serum LYZ and ACP activities and C3 and C4 contents in black carp juveniles compared with the groups fed VD₃-deficient diet. In conclusion, these results suggest that adequate dietary VD₃ could increase growth performances, improve antioxidant capacities, and then enhance innate immune parameters in black carp juveniles.

The role of lysosomes in BDE 47-mediated activation of mitochondrial apoptotic pathway in HepG2 cells

Polybrominated diphenyl ethers (PBDEs) are a group of widely used flame retardants. The rising presence of PBDEs in human tissues has received considerable concerns with regard to potential health risks. While the mitochondrial-apoptotic pathway has been suggested in PBDEs-induced apoptosis, the role of lysosomes is yet to be understood. In the present study, HepG2 cells were exposed to BDE 47 at various concentrations and durations to establish the causal and temporal relationships among various cellular events, such as cell viability, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis, and expression of cytochrome C and caspase 3. The involvement of lysosomes was simultaneously studied by evaluating lysosomal membrane permeability (LMP) and changes in the expression of cathepsin B, a lysosome hydrolase. In addition, a cathepsin B inhibitor (10 μM CA-074) was used to determine the involvement of lysosomes and potential interactions between lysosomes and mitochondria. Our results showed that ROS production was an initial response of HepG2 to BDE 47 exposure, followed by a decreased MMP; a loss of MMP caused additional ROS generation which acted to induce LMP; an increased LMP resulted in a release of cathepsin B which aggravated the loss of MMP leading to release of cytochrome C and caspase 3 and subsequent apoptosis. Pretreatment with CA-074 did not abolish the initial ROS generation, however, all downstream events were dramatically alleviated. Taken together, our data indicate that lysosomes might be involved in BDE 47-mediated mitochondrial-apoptotic pathway in HepG2 cells, possibly through feedback interactions between mitochondria and lysosomes.

Influence of alginic acid and fucoidan on the immune responses of head kidney leukocytes in cod

The present study investigated the immunomodulatory activities of alginic acid and fucoidan, both derived from brown seaweeds, on selected cellular immune responses and antibacterial activity of head kidney (HK) leukocytes of cod, Gadus morhua. Primary cultures of HK leukocytes were incubated with either 10 or 100 μg ml⁻¹ of the substances and the effects on respiratory burst, cellular proliferation, acid and alkaline phosphatase activity and cellular myeloperoxidase were measured at 3- and 24-h post-incubation. The antibacterial activity of the supernatants collected from the cell cultures incubated with 100 μg ml⁻¹ of the substances were tested against Vibrio anguillarum and Aeromonas salmonicida. Respiratory burst was significantly elevated in cells incubated with either alginic acid or fucoidan in a dose-dependent manner. Incubation with a higher dose of alginic acid and fucoidan resulted in lower cellular proliferation at 3- and 24-h, respectively. Both acid and alkaline phosphatase activities of HK leukocytes were not significantly modulated, except for a slight elevation of acid phosphatase in cells incubated with 100 μg ml⁻¹ of alginic acid for 24-h. Fucoidan, but not alginic acid significantly increased cellular myeloperoxidase activity at a concentration of 100 μg ml⁻¹. The growth of the bacteria in both the treated and control supernatants was significantly lower than what was observed in the bacterial culture medium. However, the supernatants from the treated cells had significantly higher bacterial growth compared with supernatants of the control cells. Taken together, these results showed that at the tested concentrations, both alginic acid and fucoidan are able to differentially stimulate some cellular immune responses of cod HK leukocytes in vitro and the respiratory burst activity was significantly stimulated by these brown algal derivatives. These substances could be tested as potential immunostimulants in future in vivo studies.

[Antioxidant enzymes and lipid peroxidation products in patients with pulmonary tuberculosis]

INTRODUCTION

A lot of studies have dealt with the oxidative stress in pulmonary diseases, and some of them with tuberculosis as well. The aim of this study was to examine the antioxidant enzyme level (superoxide dismutase, glutathione peroxidase, catalase) and the lipid peroxidation products in patients with tuberculosis.

MATERIAL AND METHODS

Forty patients with tuberculosis were included in the study. The examined parameters were measured before and three weeks after the beginning of the antituberculosis treatment (group I). The control group included 40 healthy persons (group II).

RESULTS

The superoxide dismutase level was significantly lower in group I in both measurements (p < 0.001 and p < 0.01) in relation to group II, but there were no significant changes in its level during the therapy. During the treatment, the glutation peroxidase level significantly increased (p < 0.05), and in relation to group II, its level was significantly lower in both measurements in group I (p < 0.001 and p < 0.001). The catalase level significantly increased during the treatment, but there was no significant difference in relation to group II level. There was no significant difference in relation to the lipid peroxidase products between the groups.

DISCUSSION

Our study group had reduced antioxidant enzyme level and some of them showed significant improvement during the treatment. The lipid peroxidase product level was stable.

CONCLUSION

In patients with tuberculosis the antioxidative status is lower and its level and possible development of the oxidative stress depend on the disease severity.

Responses of Atlantic cod Gadus morhua head kidney leukocytes to phytase produced by gastrointestinal-derived bacteria

This study identified phytase-producing bacteria that were previously isolated from the gastrointestinal tract of Atlantic cod, Gadus morhua and determined its effect on head kidney leukocytes. Out of the 216 bacterial strains tested, the two phytase producers were identified as Pseudomonas sp. and Psychrobacter sp. based on their 16S rDNA sequence. Crude phytase from these two bacterial strains was produced employing the shake flask method. Even though the total protein of the crude phytase was not significantly different for the two bacteria, the phytase activity of the crude enzyme produced by Pseudomonas sp. (97.1±16.7 U) was significantly higher than that of the enzyme from Psychrobacter sp. (75.9±2.4 U). When cod head kidney leukocytes were incubated with the crude phytase (50 μg ml(-1)), it resulted in enhanced cell proliferation, higher myeloperoxidase, and acid phosphatase activities. Extracellular responses-respiratory burst activity and hydrogen peroxide production were not enhanced by the crude enzyme. As a consequence, the growth of two pathogenic bacteria Aeromonas salmonicida and Vibrio anguillarum was not suppressed by the supernatants obtained from head kidney leukocytes incubated with the crude bacterial phytase. Thus, the enzyme from phytase-producing intestinal bacteria of Atlantic cod can stimulate intracellular head kidney leukocyte activities but not the production of extracellular substances that are involved in antibacterial response. These have implications on the potential use of bacterial phytase as feed supplement to boost cellular immune response of the fish and could be employed as a health management strategy in culture systems.

Lung cytotoxicity of combined exposure to refractory ceramic fibres and cigarette smoke

Changes in some lung cytotoxic parameters after exposure to refractory ceramic fibres (RCF) or to cigarette smoke (S) and after combined exposure to RCF+S were studied in male Wistar rats in order to evaluate their potential adverse health effects. Four groups of rats were treated as follows : 1) intratracheally instilled by saline solution (0.4 ml); 2) intratracheally instilled by 4 mg of RCF; 3) exposed only to S (85 mg of total particulate matter/m(3) air ) for two hours daily; 4) exposed to RCF+S. After 6 months the animals were exsanguinated and the bronchoalveolar lavage (BAL) was perfomed. Viability and phagocytic activity of alveolar macrophages (AM), activity of lactate dehydrogenase (LDH) in cell-free BAL fluid (cf-BALF), acid phosphatase (ACP) and cathepsin D (CATD) in cfBALF, in BALF cells and in the lung tissue were estimated. Viability of AM was depressed by every type of exposure with RCF+S effect being at least additive. Phagocytic activity of AM increased in the presence of RCF. No significant changes in LDH activity were found. Activities of lysosomal enzymes measured in the lung tissue homogenates were not significantly changed, but those in the cfBALF increased especially after exposure to S with most expressive increase in BALF cells after exposure to S and RCF+S. In the case of CATD the effect of RCF+S was more than additive. The results point out to the persistence of the RCF exposure cytotoxic effects and their amplification by cigarette smoke.

Mycobacterium tuberculosis resides in nonacidified vacuoles in endocytically competent alveolar macrophages from patients with tuberculosis and HIV infection

Alveolar macrophages (AM) are the first professional phagocytes encountered by aerosols containing infections in the lungs, and their phagocytic capacity may be affected by these infections or environmental particles. The aim of this study was to evaluate the innate endocytic and phagocytic properties of human AM obtained from patients with pulmonary tuberculosis and to characterize the vacuoles in which Mycobacterium tuberculosis bacilli reside in vivo. AM were obtained by bronchoalveolar lavage from patients with suspected tuberculosis and from asymptomatic volunteers (controls). Clinical case definitions were based on mycobacterial culture of respiratory specimens and HIV serology. To assess phagocytosis, endocytosis, and acidification of the endosomal system, AM were cultured with IgG-coated polystyrene beads, dextran, and a pH-sensitive reporter (3-(2,4-dinitroanilino)-3-amino-N-methyldipropylamine) and were evaluated by light and immunoelectron microscopy. Cells from 89 patients and 10 controls were studied. We found no significant difference between the two groups in the ability of AM either to ingest beads and dextran or to deliver them to acidified lysosomes. In AM from patients with tuberculosis, the bacilli were located in vacuoles that failed to accumulate endocytosed material and were not acidified. We concluded that AM from patients with tuberculosis and HIV infections were competent to endocytose and phagocytose material and to deliver the material to functional, acidified lysosomes. M. tuberculosis residing in these AM arrests the progression of their phagosomes, which fail to fuse with acidified lysosomes. This confirms, for the first time in humans with tuberculosis and HIV, the conclusions from previous animal and in vitro studies.

Circulating antioxidants and lipid peroxidation products in untreated tuberculosis patients in Ethiopia

BACKGROUND

Knowledge of the antioxidant profile and its relation to lipid peroxidation in tuberculosis patients with or without accompanying HIV infection is scarce, particularly in developing countries.

OBJECTIVE

The objective was to further investigate the interaction between HIV, tuberculosis, and antioxidants and their relations with markers of oxidative stress in a large population of Ethiopians.

DESIGN

In a cross-sectional study, we evaluated antioxidants and markers of oxidative stress in Ethiopian tuberculosis patients with (n = 25) and without (n = 100) HIV infection and in Ethiopian (n = 45) and Norwegian (n = 25) healthy control subjects.

RESULTS

Concentrations of the antioxidant vitamins C and E and of vitamin A were significantly lower in tuberculosis patients than in healthy Ethiopians. Tuberculosis patients also had significantly lower thiol concentrations, particularly of the reduced forms. Tuberculosis patients, particularly those who were co-infected with HIV, had higher malondialdehyde concentrations than did control subjects. High malondialdehyde concentrations were associated with clinical severity as measured by the Karnofsky Performance Status Index and anthropometric scores. Ethiopian control subjects had lower concentrations of vitamin E and higher concentrations of malondialdehyde than did Norwegian control subjects.

CONCLUSIONS

Our findings further support a link between oxidative stress, tuberculosis, and HIV infection. However, whether antioxidant supplementation will improve tuberculosis outcome or is of importance for its prevention should be further examined in future prospective studies.