Phagocytic Activity Of Granulocytes Research Articles

Phagocytic Activity, Oxygen Metabolism and Serum Amyloid a Concentration in Peripheral Blood of Mink with Subclinical Aleutian Virus Infection.

Aleutian disease (AD) is a chronic disease of mink caused by the Aleutian Mink Disease Virus (AMDV) that results in dysfunction of the immune system. The prevalence of asymptomatic AMDV infections suggests a necessity to explore their effects on the cellular mechanisms of non-specific immunity in farmed mink. The study evaluated the phagocytic activity and oxygen metabolism of peripheral blood granulocytes and monocytes in mink with chronic subclinical AMDV infection. Moreover, the intensity of inflammatory processes was assessed based on the serum amyloid A (SAA) concentration. The analyses involved 24 brown mink females aged 12-24 months. The experimental group (group I) consisted of mink with chronic subclinical AMDV infections, and the control group (group II) included healthy animals. The statistical analysis was performed using the Mann-Whitney U rank test. Phagocytic activity of granulocytes and monocytes was carried out using flow cytometry, and SAA concentration was determined with enzyme-linked immunosorbent assay (ELISA). Compared with the control group, there was a significant decrease in the phagocytic activity and oxygen metabolism of granulocytes and monocytes in the AMDV-infected mink (p < 0.05). Additionally, it was found that the mean SAA value was significantly higher in the group infected with AMDV than in the control group (p < 0.05). The obtained data indicate that monitoring the serum SAA levels in mink with asymptomatic inflammation may help assess the health of mink and detect asymptomatic inflammation caused by AMDV infection.

PHAGOCYTIC ACTIVITY OF NEUTROPHILIC GRANULOCYTES OF ORAL FLUID IN CHILDREN WITH ACUTE FORMS OF LEUKEMIA

Relevance. In acute leukemia, the phagocytic activity of leukocytes changes. But the extend and details of these changes are still insufficiently studied.
 Objective: to assess the state of phagocytic activity of phagocytic cells (neutrophils and macrophages) in terms of phagocytic index, phagocytic number and oxygen-dependent phagocytosis in children with acute forms of leukemia.
 Materials and methods. We examined 35 children aged 6 to 16 years, who were at different stages of treatment of the underlying disease. The children were divided into two groups depending on the form of leukemia: Group I – nineteen children with acute lymphoblastic leukemia (ALL), nine of them at the stage of the first acute period, four at the stage of clinical remission, six at the stage of relapse; Group II - sixteen children with acute myeloid leukemia (AML), seven of them - at the stage of the first acute period, four -in the period of the clinical remission, five - at the stage of relapse. Control Group – fifteen practically healthy children. In oral fluid, the phagocytic activity of granulocytes was determined: phagocytic number (PN) – the percentage of phagocytic neutrophils; phagocytic index (PI) – the number (in conditional units) of phagocytosed microorganisms by one neutrophil; oxygen-dependent phagocytosis according to the NBT test (Nitroblue Tetrazolium) – the percentage of the maximum activity of neutrophils.
 Results. PN in the control group - 70.0±5.1%. In children with acute lymphoblastic leukemia at the stage of the first acute period of PN - 85.7±5.8%, at the stage of remission - 73.8 ±6.1%, during the relapse period - 88.3% ±4.8. In children with acute myeloblastic leukemia at the stage of treatment of the first acute period, PN was 87.2±6.0%, at the stage of remission - 72.6±5.9%, at the stage of relapse - 89.1±5.1%.
 PI in the control group – 3.9±0.6 In children with acute myeloid leukemia at the stage of treatment of the first acute period, PI was 21.1±0.7, at the stage of relapse – 25.3±0.4 In children with acute myeloblastic leukemia at the stage of treatment of the first acute period, PI was 16.1±0.5, during remission – 10.1±0.4, during the relapse period – 18.5±0.2.
 The indicator of oxygen-dependent cell activity, according to the NBT test, in practically healthy children was 17.6±1.23%. In children with acute myeloblastic leukemia at the stage of treatment of the first acute period, the percentage of cell activity was 40.4±1.86%, at the stage of relapse - 46.4±2.0%, during remission - 23.7±1.56%. In children with acute myeloblastic leukemia at the stage of treatment of the first acute period, the percentage of cell activity was 41.6±1.34%, during the period of relapse - 48.5±1.05%, at the stage of remission - 27.9±1.86%.
 Conclusion. The dependence of phagocytic activity of neutrophils in the oral fluid on the stage of treatment of acute leukemia in children was revealed. The phagocytic number, phagocytic index and oxygen-dependent phagocytosis are significantly increased at the stage of treatment of the first acute period and at the stage of relapse. At the stage of remission, the phagocytic number was within the normal range, but the phagocytic index and oxygen-dependent phagocytosis did not return to normal.
 No difference was found between the phagocytic activity of neutrophils in various forms of acute leukemia – acute lymphoblastic leukemia and acute myeloblastic leukemia.

Влияние пептида GHK-D-Ala на механизмы врожденного иммунитета и процессы перекисного окисления липидов в условиях инфицированной раны

The objective is to study the effects of Gly-His-Lys-D-Ala (GHK-D-Ala) peptide on mechanisms of innate immunity and lipid peroxidation processes in infected wound. Materials and methods. The experiments were carried out on 80 Wistar male rats. The infected wound was modeled by applying a full-layer wound on the back and performing primary wound surgery with primary suturing 24 hours later. GHK-D-Ala peptide was injected at a dose of 0.5 µg/kg into the wound area every day for 30 days. The phagocytic activity of blood neutrophils was studied in spontaneous and stimulated nitroblue tetrazolium reduction test (NBT-test). The activity of lipid peroxidation (LPO) processes in rats’ blood serum was assessed by the content of malondialdehyde (MDA) and acylhydroperoxides (AHP). Results. GHK-D-Ala administration had a positive effect on both phagocytosis mechanisms and the level of LPO products in comparison with the control group. There was a significant increase in NST-positive neutrophils in the spontaneous test against peptide administration on days 3, 7, 10, and 30 (p˂0.001) and in the stimulated NST test on days 3, 7, and 10 (p < 0.001). The functional neutrophil reserve had been significantly increased by day 10 (p˂0.05) and had been significantly lower by day 30 (p < 0.05). Phagocytic index and phagocytic number were significantly higher on days 3 and 10 (p < 0.01). The phagocyte activity index significantly increased on days 3 and 10 (p < 0.05-0.001).A significant decrease in the MDA concentration was demonstrated on days 3, 7, 10, and 30 (p<0,001). There was a significant decrease in the content of AGP on days 3, 7, 10 and 30 (p < 0.001). Conclusion. The corrective effect of Gly-His-Lys-D-Ala peptide on the phagocytic activity of granulocytes and the processes of lipid peroxidation in infected skin wounds was established.

Balneotherapy in Stimulating Resistance to Infections – the Little-used Health Resort’s Potential During the COVID-19 Pandemic

To function properly, the human immune system must be adequately stimulated. Immune activity is stimulated as a result of the use of vaccines as well as the exposure of the body to infections. This type of stimulation only increases the specific humoral immunity, characterized by relatively short duration, and targeted at a well-defined antigen. In the case of the COVID-19 virus, immune memory cells persist for up to one year. In parallel with specific stimulation, it is necessary to develop non-specific immunity. It is the body’s first line of defense against infection, affects many microorganisms, and supports specific immunity. We can develop and strengthen this immunity using non-pharmacological methods, including balneotherapy, physical activity, and an appropriate diet. There is now much scientific evidence showing the effectiveness of balneotherapy in improving innate immunity. In in vitro and in vivo studies with high scientific credibility, the following effects of balneotherapy on the immune system were demonstrated: stimulation of the proliferation of T lymphocytes (especially CD4), normalization of the ratio between lymphocytes with different cytotoxic and anti-inflammatory effects, increased number of granulocytes and stimulation of the phagocytic activity of granulocytes and macrophages, lowering the concentration of proinflammatory cytokines and stimulating the secretion of anti-inflammatory cytokines, CRP, prostaglandins (PGE2), as well as antioxidant and neurohormonal activity. Among treatments with balneoimmunostimulatory effects, one should mention sulfide baths, peloid compresses, brine baths, radon treatments, and hot baths. These treatments are mainly used as part of health resort treatment. In Poland, health resort treatment represents excellent health potential. Unfortunately, it is very modestly used in activities aimed at improving the immunity of Polish society. This treatment would be best combined in patients after vaccination and in a certain period before vaccination, which would significantly increase the effectiveness of prophylactic vaccinations.

The Effects of β-Hydroxy-β-Methylbutyrate (HMB) on Chemotaxis, Phagocytosis, and Oxidative Burst of Peripheral Blood Granulocytes and Monocytes in Goats.

Simple SummaryThe main focus of industrial livestock production is to maximise production output without compromising the well-being of animals, which is why animal diets are supplemented with various feed additives. Feed additives boost immunity and protect animals against pathogens. The list of potential feed additives includes β-hydroxy-β-methylbutyrate (HMB) which occurs naturally in small quantities in citrus fruit, avocado, asparagus, cauliflower, selected fish species, red wine, milk, and alfalfa. However, its mechanism of action and effects on immune system cells have not been thoroughly investigated in animals, including goats. In the present study, the experimental goats whose diets were supplemented with HMB over a period of 60 days were characterised by higher levels of chemotactic and phagocytic activity and a higher rate of oxidative metabolism of peripheral blood granulocytes and monocytes than control group animals whose diets were not supplemented. Granulocytes and monocytes constitute the first line of defence against pathogens and protect animals against disease. They play a particularly important role in young animals which are more susceptible to viral and bacterial infections. Feed additives can deliver numerous benefits by boosting immunity and preventing the spread of infectious diseases in goats.The objective of this study was to determine the effect of β-hydroxy-β-methylbutyrate (HMB) on the chemotactic activity, phagocytic activity, and oxidative metabolism of peripheral blood granulocytes and monocytes in goats. Goat kids aged 30 ± 3 days were divided into two groups of 12 animals each: I—control, and II—experimental. Experimental group animals were fed a diet supplemented with HMB in the amount of 50 mg/Kg BW; whereas the diets of control goats were not supplemented. At the beginning of the experiment (day 0) and on experimental days 15, 30, and 60, blood was sampled from the jugular vein to determine and compare chemotactic activity (MIGRATEST® kit), phagocytic activity (PHAGOTEST® kit), and oxidative metabolism (BURSTTEST® kit) of peripheral blood granulocytes and monocytes by flow cytometry. The analyses of the chemotactic and phagocytic activity of granulocytes and monocytes revealed statistically higher levels of phagocytic activity in the experimental group than in the control group, as expressed by the percentage of phagocytic cells and mean fluorescence intensity. HMB also enhanced the oxidative metabolism of both granulocytes and monocytes, expressed by the rate of oxidative metabolism and mean fluorescence intensity after stimulation with Escherichia coli bacteria and PMA (4-phorbol-12-β-myristate-13-acetate).

Effect of dietary phosphorus deprivation on leukocyte function in transition cows

Phosphorus depletion and hypophosphatemia have been described to hamper immune function in different species, an effect barely studied in dairy cows commonly developing hypophosphatemia in early lactation. Dietary P deprivation in mid lactating dairy cows was associated with a decline of the number of granulocytes and impaired granulocyte survival, whereas the phagocytic activity remained unaffected. The objective of the study reported here was to determine the effect of P deprivation on the leukocyte function of periparturient dairy cows. Eighteen multiparous and late pregnant dairy cows were randomly assigned to either a treatment group that was offered a markedly P-deficient diet or a control group receiving the same ration with adequate P content. The study consisted of a 2-wk acclimation period that was followed by a P deprivation period extending from 4 wk before to 4 wk after parturition and a P repletion period of 2 wk thereafter. Blood samples for leukocyte counts and leukocyte function analysis were obtained at the end of the acclimation period, after 2 wk of P deprivation, within the first week of lactation, at the end of the P depletion period and after 2 wk of dietary P supplementation. Blood samples for biochemical analysis were obtained weekly. Immune function was assessed by means of a phagocytosis assay and a lymphocyte stimulation test. Dietary P deprivation resulted in pronounced and sustained hypophosphatemia. Time effects were observed on the counts of different leukocyte fractions, the relative number of phagocytic granulocytes, the degree of phagocytosis, and the lymphocyte proliferation. Differences between P-deprived and control cows were only identified for the degree of phagocytosis that was lower in P-deprived cows compared with control cows. The correlation and regression analyses, however, revealed positive associations of the plasma phosphate concentration and the granulocyte count, the relative number of phagocytic granulocytes, and the degree of phagocytosis at the end of the dietary P deprivation when P depletion was most severe. The results of the study reported here indicate a mild negative effect of pronounced and sustained hypophosphatemia on the granulocyte count and the phagocytic activity of granulocytes in transition dairy cows. The clinical relevance of this effect for health and productivity of dairy cows remains to be determined.

Phagocytic and oxidative burst activity of phagocytic cells in peripheral blood and uterine washings in cows with clinical endometritis before and after intrauterine use of cephapirin and methisoprinol.

The aim of the study was to evaluate phagocytic and killing activity of phagocytic cells in blood and uterine flush of cows with endometritis before and after intrauterine (i.u.) administration of cephapirin and methisoprinol. The research was carried out on 28 cows with clinical endometritis. Animals were divided into four groups, each composed of seven cows, depending on the i.u. treatment used: Group A-cephapirin; Group B-methisoprinol; Group C-cephapirin and methisoprinol at the same time; and a control group-without medication. Using flow cytometry technique, the phagocytic activity of granulocytes and monocytes was identified, as well as the oxidative burst activity of neutrophils in the peripheral blood and uterine washings. Summarizing the results of the research, i.u. infusion of cephapirin caused a reduction in the phagocytic and killing activity of phagocytes. The i.u. use of methisoprinol increased phagocytic and killing activity of phagocytes in the uterus. Administering both listed substances simultaneously showed a decrease in phagocytosis, presumably due to the dominating inhibitor effect of the antibiotic. However, also an increase of mean fluorescence intensity was observed, presumably caused by the methisoprinol. Intrauterine use of immunostimulatory substances, can improve the effectiveness of the treatment of endometritis in cows.

Phagocytic Activity and Oxygen Metabolism of Peripheral Blood Granulocytes from Rabbits Experimentally Infected with Trichophyton Mentagrophytes.

IntroductionPhagocytic activity and oxygen metabolism of peripheral blood granulocytes from rabbits with experimental trichophytosis were assessed by flow cytometry.Material and MethodsVirulent species of T. mentagrophytes var. granulosum (Tm-K) isolated from rabbits with natural trichophytosis was used for experimental infection. The phagocytic activity of granulocytes was measured in whole blood by flow cytometry using the commercial Phagotest kit. Oxidative burst was measured in whole blood by flow cytometry using the commercial Bursttest kit.ResultsIt was found that rabbits were susceptible to infection with Trichophyton mentagrophytes under experimental conditions. The analysis of the phagocytic activity indices and oxygen metabolism of granulocytes in peripheral blood of infected rabbits showed that changes of the indices were connected with the progression and regression of the disease. A significant decrease in phagocytic activity and oxygen metabolism was observed during development of fungal lesions and it remained similar throughout the progress of the disease. The highest means of the percentage of activated and ingesting phagocytes and a significant increase in the mean fluorescence intensity (representing the number of ingested bacteria) were observed during spontaneous recovery. Therefore, the decrease or increase in the indices of phagocytic activity and oxygen metabolism of granulocytes from rabbits experimentally infected with T. mentagrophytes is somehow related to the progress of infection and suppressive activity of the fungus, whose elimination during recovery caused significant increases in investigated indices of non-specific cellular immunity.ConclusionThe results of the present investigation confirm that the mechanism of oxygen-dependent killing is crucial in infections caused by T. mentagrophytes.

Phagocytic activity and oxygen metabolism of peripheral blood granulocytes from rabbits experimentally infected with Trichophyton mentagrophytes

Abstract Introduction Phagocytic activity and oxygen metabolism of peripheral blood granulocytes from rabbits with experimental trichophytosis were assessed by flow cytometry. Material and Methods Virulent species of T. mentagrophytes var. granulosum (Tm-K) isolated from rabbits with natural trichophytosis was used for experimental infection. The phagocytic activity of granulocytes was measured in whole blood by flow cytometry using the commercial Phagotest kit. Oxidative burst was measured in whole blood by flow cytometry using the commercial Bursttest kit. Results It was found that rabbits were susceptible to infection with Trichophyton mentagrophytes under experimental conditions. The analysis of the phagocytic activity indices and oxygen metabolism of granulocytes in peripheral blood of infected rabbits showed that changes of the indices were connected with the progression and regression of the disease. A significant decrease in phagocytic activity and oxygen metabolism was observed during development of fungal lesions and it remained similar throughout the progress of the disease. The highest means of the percentage of activated and ingesting phagocytes and a significant increase in the mean fluorescence intensity (representing the number of ingested bacteria) were observed during spontaneous recovery. Therefore, the decrease or increase in the indices of phagocytic activity and oxygen metabolism of granulocytes from rabbits experimentally infected with T. mentagrophytes is somehow related to the progress of infection and suppressive activity of the fungus, whose elimination during recovery caused significant increases in investigated indices of non-specific cellular immunity. Conclusion The results of the present investigation confirm that the mechanism of oxygen-dependent killing is crucial in infections caused by T. mentagrophytes.

СТРУКТУРА ИММУННЫХ ДИСФУНКЦИЙ У БОЛЬНЫХ С ХРОНИЧЕСКИМИ УРОГЕНИТАЛЬНЫМИ ИНФЕКЦИЯМИ

In recent years, the growth of urogenital infections, often transforming into chronic forms, is one of the most common causes of reproductive damage in women. The aim of the research was to study the structure of immune dysfunctions in patients with chronic urogenital infection. A one-stage observational study of 80 women of reproductive age with chronic urogenital infections was carried out. The control group consisted of 40 healthy women-donors. The main outcome of the study was the severity of the immunocomprometry of the female. The contents of different subpopulations of lymphocytes (CD3+, CD4+ and CD8+ T-lymphocytes, CD20+ B-), phagocytic activity of granulocytes and monocytes were determined, the migration index, the migration inhibition index, and the exponential function were calculated. The complex of immune dysfunctions established in such patients included a decrease in the number of T-cells and, primarily, CD4+ lymphocytes and their low mitogenic reactivity, an increase in the proportion of natural killer cells, a decrease in the number of actively phagocytic neutrophils and monocytes, the last hydrogen peroxide, an increase in the production of IgA and IgG. Typical were combinations of these violations. Conclusions: T-lymphocyte-monocyte immune deficitiency with the activation of the humoral link and the defectiveness of phagocytosis is a distinctive characteristic of chronic urogenital infection.

Effect of intravenous plasma transfusion on granulocyte and monocyte oxidative and phagocytic activity in dairy calves with failure of passive immunity

Plasma administration has been recommended in calves older than 48h with failure of passive immunity (FPI) to provide immunity consistent with adequate colostral ingestion. However, the protective serum immunoglobulin G (IgG) concentrations (≥1000mg/dL) of plasma derived IgG only lasts up to 12h. In addition to IgG, maternally derived colostral cells also confer immunity. The objective of the study was to determine the effect of intravenous plasma transfusion on granulocyte and monocyte oxidative and phagocytic activity in calves with FPI. Twenty-seven, one day-old, Jersey calves were assigned into 3 groups. The colostral (CL, N=9) group received 3L of colostrum once by oroesophageal tubing. Two other groups of calves received 1L of colostrum once by oroesophageal tubing and were assigned based on their health status (sick or non-sick) at 4days of age, as the sick-group (SG, N=7) or the non-sick (NG, N=11) groups. At 4days of age, the SG and NG groups were administered plasma intravenously at 30mL/kg. Granulocyte and monocyte oxidative and phagocytic activity was determined by flow cytometry. There was no significant difference in the granulocyte and monocyte oxidative or phagocytic activity among the 3 groups (P>0.05). Plasma administration had no significant effect on the oxidative or phagocytic activity of granulocytes or monocytes. In clinical practice, plasma administration for enhancing oxidative or phagocytic activity of granulocytes or monocytes, alone, might not be justified in calves with FPI.

Effects of 21-kHz intermediate frequency magnetic fields on blood properties and immune systems of juvenile rats

Purpose: Due to a lack of science-based evidence, we explored the effects of exposure to intermediate frequency magnetic fields (IF-MF) on experimental animals. We assessed several immunological parameters to determine the effect of exposure of the whole body to IF-MF.Materials and methods: Male Sprague-Dawley rats (4–5 weeks old) were divided into three groups: Cage-control, sham, and 3.8-mT (rms) exposure groups. The animals were exposed to IF-MF at 21 kHz under fixed conditions in an acrylic holder. Exposure was performed for 1 h/day for 14 consecutive days. On the 15th day following the exposure, biochemical and hematological parameters in blood were analyzed. The effects of the exposure on immunological functions such as the cytotoxic activity of lymphocytes, chemotactic and phagocytic activity of granulocytes, and T (cluster of differentiation 4 [CD4] and cluster of differentiation 8 [CD8])-cell frequency were also examined.Results: Hematological parameters were not affected by IF-MF exposure. Other immune functions such as the cytotoxic activity and phagocytic activity were not affected. Populations of T cells after exposure also did not show any significant differences. In blood biochemistry, there was significant difference in inorganic phosphorus level between sham and exposure group. However, this will not induce any pathophysiological status, because they were still within physiological range. Overall, no significant effect by exposure of IF-MF was observed under our experimental conditions.Conclusions: Our results suggest that exposure to 21-kHz sinusoidal IF-MF at 3.8 mT for 1 h/day for 14 days did not affect immune function in juvenile rats.

Cytometric analysis of surface molecules of leucocytes and phagocytic activity of granulocytes and monocytes/macrophages in cows with pyometra.

Pyometra is a serious problem in dairy cow herds, causing large economic losses due to infertility. The development of pyometra depends mainly on the immunological status of the cow. The aim of the study was a comparative evaluation of selected indicators involving non-specific and specific immunity in cows with pyometra and in cows without inflammation of the uterus. The study was performed in 20 cows, which were divided into two groups: pyometra group and healthy group, each comprising 10 cows, based on the results of cytological and ultrasonographic tests. A flow cytometric analysis was performed for the surface molecules CD4, CD8, CD14, CD21, CD25 and CD4(+) CD25(+) on leucocytes, and the phagocytic activity was determined from granulocytes and monocytes/macrophages in the peripheral blood and uterine washings, respectively. It was demonstrated that the percentage of phagocytic granulocytes and monocytes/macrophages in both the peripheral blood and uterine washings was significantly lower in cows with pyometra compared with the healthy group (p<0.001). Significantly (p≤0.001) lower percentage of CD4(+) , CD14(+) , CD25(+) and CD4(+) CD25(+) phenotype leucocytes was also observed in the peripheral blood of cows from the pyometra group, along with a significantly higher (p<0.001) percentage of CD8(+) and CD21(+) lymphocytes as compared to the healthy group. The results of work indicate that disfunction of cell immunity coexisting with pyometra may be caused by a bacterial infection and the presence of blocking agents (IL-10), released by the increasing number of CD8(+) lymphocytes what leads to the advanced inflammation of uterus.

Determination of selected parameters for non-specific and specific immunity in cows with subclinical endometritis

Endometritis in dairy cow herds is a serious economic problem all over the world due to the large economic losses. The aim of the study was a comparative evaluation of selected indicators of non-specific and specific immunity in cows with subclinical endometritis and in cows without inflammation of the uterus. The study was performed on 40 cows on day 65 after delivery. Based on the results of cytological tests, the cows were divided into two groups: experimental (subclinical endometritis) and control (20 cows in each group). A flow cytometric analysis was performed for the leukocyte surface molecules CD4, CD8, CD14, CD21, CD25. Moreover the phagocytic activity of granulocytes and monocytes/macrophages in peripheral blood and uterine washings was determined. It has been demonstrated that the percentage of phagocytic granulocytes and monocytes/macrophages in both the peripheral blood and uterine washings was significantly lower for cows with subclinical endometritis when compared to cows undergoing a normal puerperal period (p<0.001). A significant (p≤0.001) decrease in the percentage of CD4+, CD14+, CD25+ and CD4+CD25+ leukocytes was also observed in peripheral blood of the cows from the experimental group. In uterine washings a significant decrease (p<0.001) in CD21+ and increase in CD8+ lymphocytes was detected. The results indicate that dysfunction of cell immunity coexisting with subclinical endometritis may be the main factor causing advanced inflammation of the uterus. Knowledge of immunological mechanisms observed in cows with subclinical endometritis could aid in choosing the right adjuvant therapy using immunomodulating agents.

Vitamin D(3) availability and functional activity of peripheral blood phagocytes in experimental type 1 diabetes

The study was devoted to identifying the relation between vitamin D3 availability (assessed by the level of circulatory 25OHD3), content of vitamin D3 25-hydroxylase isozymes CYP27A1 and CYP2R1 in hepatic tissue and functional activity of peripheral blood phagocytes in mice with experimental type 1 diabetes. It has been shown that diabetes is accompanied by the development of vitamin D3-deficiency which is characterized by decreased 25OHD3 content in blood serum and determined by changes in tissue expression of the major isoforms of vitamin D3 25-hydroxylase. The level of hepatic CYP27A1 was revealed to be markedly reduced with a concurrent significant augmentation of CYP2R1. Cholecalciferol administration resulted in normalization of tissue levels of both isoforms of vitamin D3 25-hydroxylase and blood serum 25OHD3 content. Diabetes-associated vitamin D3 deficiency correlated with a decrease in phagocytic activity of granulocytes and monocytes, and their ability to produce antibacterial biooxidants such as reactive oxygen and nitrogen forms. Vitamin D3 efficacy to attenuate these abnormalities of immune function was established, indicating an important immunoregulatory role of cholecalciferol in the phagocytic mechanism of antigens elimination implemented by granulocytes and monocytes.

Phagocyte dysfunction in polymyalgia rheumatica and other age-related, chronic, inflammatory conditions

This study was conducted to evaluate phagocyte function in patients with age-related chronic inflammatory conditions. It included 95 patients with PMR, 17 with GCA, 40 with EORA, and 25 age-matched HCs. Serum IL-8 was determined with a bead array. The chemotactic capacity, phagocytic ability, and oxidative burst activity of circulating leukocytes were determined with flow cytometry kits. Patients with active chronic inflammatory diseases showed a significant increase in circulating levels of IL-8 that remained elevated in patients with PMR or EORA, despite treatment. No correlation was found between circulating IL-8 and the migratory capacity of neutrophils. Neutrophils from patients with active EORA without stimulus and after fMLP stimuli showed a higher capacity to migrate than those of the HCs (P=0.033). The phagocytic activity of granulocytes in the patients with GCA was significantly higher than in the HCs and the patients with PMR or EORA (P<0.05). The percentage and MFI of phagocytes that produce ROIs when stimulated with Escherichia coli was significantly reduced in neutrophils and monocytes from the patients with age-restricted inflammatory conditions. We concluded that the effector functions of phagocytes, determined to be chemotaxis, phagocytosis, and oxidative burst, are deregulated in age-restricted inflammatory disorders and may have a pathogenic role.

Immunotoxicity and genotoxicity testing of PLGA-PEO nanoparticles in human blood cell model

A human blood cell model for immunotoxicity and genotoxicity testing was used to measure the response to polylactic-co-glycolic acid (PLGA-PEO) nanoparticle (NP) (0.12, 3, 15 and 75 μg/cm2 exposure in fresh peripheral whole blood cultures/isolated peripheral blood mononuclear cell cultures from human volunteers (n = 9–13). PLGA-PEO NPs were not toxic up to dose 3 μg/cm2; dose of 75 μg/cm2 displays significant decrease in [3H]-thymidine incorporation into DNA of proliferating cells after 4 h (70% of control) and 48 h (84%) exposure to NPs. In non-cytotoxic concentrations, in vitro assessment of the immunotoxic effects displayed moderate but significant suppression of proliferative activity of T-lymphocytes and T-dependent B-cell response in cultures stimulated with PWM > CON A, and no changes in PHA cultures. Decrease in proliferative function was the most significant in T-cells stimulated with CD3 antigen (up to 84%). Cytotoxicity of natural killer cells was suppressed moderately (92%) but significantly in middle-dosed cultures (4 h exposure). On the other hand, in low PLGA-PEO NPs dosed cultures, significant stimulation of phagocytic activity of granulocytes (119%) > monocytes (117%) and respiratory burst of phagocytes (122%) was recorded. Genotoxicity assessment revealed no increase in the number of micronucleated binucleated cells and no induction of SBs or oxidised DNA bases in PLGA-PEO-treated cells. To conclude on immuno- and genotoxicity of PLGA-PEO NPs, more experiments with various particle size, charge and composition need to be done.

Differential effect on cell-mediated immunity in human volunteers after intake of different lactobacilli

Probiotics are live microorganisms which have beneficial effects on the host when ingested in adequate amounts. Probiotic bacteria may stimulate immune effector functions in a strain-specific manner. In this blind placebo-controlled trial, we investigated the effects on the immune system following daily intake of six different strains of lactobacilli or the Gram-negative bacterium Pseudomonas lundensis for 2 or 5 weeks. Blood lymphocyte subsets were quantified by fluorescence activated cell sorter and the expression of activation and memory markers was determined. The bacterial strains were also examined for their capacity to adhere to human intestinal cells and to be phagocytosed by human peripheral blood mononuclear cells. Intake of Lactobacillus plantarum strain 299v increased the expression of the activation marker CD25 (P = 0·01) on CD8(+) T cells and the memory cell marker CD45RO on CD4(+) T cells (P = 0·03), whereas intake of L. paracasei tended to expand the natural killer T (NK T) cell population (P = 0·06). The phagocytic activity of granulocytes was increased following intake of L. plantarum 299v, L. plantarum HEAL, L. paracasei or L. fermentum. In contrast, ingestion of L. rhamnosus decreased the expression of CD25 and CD45RO significantly within the CD4(+) cell population. The observed immune effects after in-vivo administration of the probiotic bacteria could not be predicted by either their adherence capacity or the in-vitro-induced cytokine production. The stimulation of CD8(+) T cells and NK T cells suggests that intake of probiotic bacteria may enhance the immune defence against, e.g. viral infections or tumours.

Safety and tolerance of Bacteroides xylanisolvens DSM 23964 in healthy adults

We recently presented the strain Bacteroides xylanisolvens DSM 23964 to be safe for use in food. In order to confirm the tolerance of healthy humans to a regular oral intake of the strain B. xylanisolvens DSM 23964, we here report on the safety data of two successive human studies: a randomised and double-blind parallel group-controlled pilot study with 41 volunteers receiving a daily dose of a pasteurised fermented milk product containing up to 8.5×1011B. xylanisolvens DSM 23964 cells for 3 weeks, and a randomised and placebo-controlled double-blind major study with 140 volunteers receiving the same product but spray-dried and containing up to 1012 cells for 6 weeks. In both studies no persistent side effects of any kind were reported. The measured haematological parameters, and the serum concentrations of immunoglobulin and of inflammatory markers (IL-6, CRP, IFN-γ) were unaffected by the supplementation in both studies. A small decrease in the phagocytic activity of granulocytes and a small increase of TNF-α detected in the pilot study were both invalidated by the major study. This study further revealed that the supplementation induced no modification in natural killer cell activity and in liver enzyme values (gamma-glutamyl-transferase, glutamate-oxalacetate transaminase, glutamate-pyruvate transaminase). Our results definitively demonstrate that the pasteurised B. xylanisolvens DSM 23964 strain is safe and well tolerated by healthy human individuals.

Attenuated phagocytic activity of monocytes in type 2 diabetic Goto–Kakizaki rats

The aim of this study was to determine whether phagocytic activity of leukocytes is altered in type 2 diabetes. Goto–Kakizaki (G–K) rats, a genetic model for type 2 diabetes, and Wistar rats (control) were used to analyze the immunological status of phagocytes. Direct analysis of phagocytes was performed using peripheral whole blood. Phagocytic activity of monocytes induced by Escherichia coli BioParticles was significantly lower in G–K rats than in the control rats, whereas no significant differences in phagocytic activity of granulocytes and lymphocytes were found between G–K and control rats. Monocytes of G–K rats showed significantly lower CD11b/c expression compared with that in monocytes of control rats. However, lipopolysaccharide-stimulated activation of extracellular signal-regulated kinase and nuclear factor-κB in monocytes was not significantly different between G–K and control rats. Restriction of diet in G–K rats greatly improved their hyperglycemic status, but did not restore the levels of phagocytic activity and CD11b/c expression in monocytes of G–K rats to the levels observed in control rats. The results suggest that the phagocytic activity of monocytes is attenuated in G–K rats and that this attenuation is independent of blood glucose levels and is partly explained by a decrease in CD11b/c expression in G–K rats.