Phagocytic Activity Of Monocytes Research Articles

The effects of exercise and diurnal variation on monocyte subsets and monocyte‐platelet aggregates

Monocytes are important mediators in the pathophysiology of cardiovascular disease, but only scarce data are available on biological and methodological factors affecting their levels. Three monocyte subsets, CD14(++) CD16(-) CCR2+ (Mon1), CD14(++) CD16(+) CCR2(+) (Mon2), CD14(+) CD16(+) CCR2(-) (Mon3), and monocyte-platelet aggregates (MPAs) were analysed by flow cytometry. The effects of treadmill exercise were assessed on 12 healthy volunteers. Diurnal variation was evaluated in 16 healthy volunteers, and the effects of delayed blood processing were measured in 12 samples. Mon1 were increased when measured 15 min after exercise followed by a reduction at 1 h (P < 0·05 for both). MPAs were significantly reduced at 15 min and 1 h (P < 0·05 for both). There was significant diurnal variation in the numbers of Mon2, which were highest at 6 pm and lowest at 6 am. There were also significant diurnal variations in phagocytic activity of Mon1 and Mon2, which were highest at 12 pm and lowest at 12 am. Monocyte counts remained stable up to 2 h after venipuncture. MPAs were significantly increased at 2 h and increased further by 4 h after sampling. Monocyte subset Mon2 and monocyte phagocytic activity undergo significant diurnal variation. A single bout of exercise causes a temporal increase in monocytes and a reduction in MPAs. Monocyte subset counts should be analysed within 2 h of blood sampling, whereas measurement of MPAs and monocyte CD14 and CD16 expression should be performed within 1 h.

A novel extract from bovine colostrum whey supports innate immune functions. II. Rapid changes in cellular immune function in humans

ObjectiveTo evaluate acute effects of bovine colostrum low-molecular weight fraction (CLMWF) on selected aspects of innate immune function in healthy human subjects. MethodologyA placebo-controlled, double-blinded, randomized cross-over trial involving 12 healthy subjects, age 22–72, was conducted at NIS Labs during the year 2010. Placebo or 150mg CLMWF was given orally. Blood was drawn immediately before and at 1 and 2h after consumption. ResultsA single dose of CLMWF, when compared to placebo, resulted in rapid increase in phagocytic activity of monocytes at 1h (P<0.12) and polymorphonuclear cells at 1h (P<0.08) and 2h (P<0.03) after consumption. Observations included increased numbers of CD3+ T cells (P<0.05), and a transient reduction in circulating CD3−CD56+ natural killer (NK) cells at 1h (P<0.04), returning to normal levels at 2h after consumption (P<0.96). The relative increase of NK cells from 1 to 2h after consumption was not associated with an increase in CD69 or CD25 activation markers, suggesting that new NK cells were mobilized into circulation. ConclusionThe increased phagocytic activity and rapid transient changes in NK cell numbers suggest that upon consumption, interaction of CLMWF with immune cells in the gut mucosa triggers immediate events with systemic consequences.

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.

Phagocytic activity in blood and proliferation of peripheral blood lymphocytes during the perinatal period in primiparous sows

The objective of this study was to determine whether phagocytic activity in blood and proliferation of peripheral blood lymphocytes are impaired during perinatal period. The study comprised 18 primiparous sows (Landras × Large White) free from clinical signs of diseases. During the experiment blood samples were collected three times from each sow. Sampling was performed on three different dates, always from all sows at once. At the first date of sampling sows were 21 ± 3 days before parturition, at the second date ± 1 day around parturition time and at the third date 21 ± 3 days after parturition. Phagocytic activity of monocytes and granulocytes was assessed in heparinized whole blood with addition of fluorescein isothiocyanate (FITC)-labelled opsonized bacteria Escherichia coli and the percentage of phagocytes which have ingested bacteria was measured as fluorescence activity by flow cytometry. The percentage of phagocyting monocytes and granulocytes was lowest at parturition (72.6 ± 16.37, 52.4 ± 20.59) and significantly increased within the next 21 ± 3 days (86.5 ± 6.16, 69.89 ± 5.80). Similarly, the phytohemagglutinin (PHA) (10 μg/ml) stimulated in vitro lymphocyte response was suppressed by parturition in primiparous sows (p < 0.001).

植物多糖体C-UPⅢを投与した子豚の成長および単球の貪食能の活性化

植物多糖体C-UPⅢを投与した子豚の単球におけるラテックスビーズ貪食能（貪食数および貪食率）と成長について検討した． C-UPⅢを飼料中に0.05％，0.1％，0.2％および0.4％添加して，離乳直後の子豚に3日間連続で混餌投与した． その結果，単球貪食能はC-UPⅢを投与した全群で投与開始7日および14日後で増加が認められたが，対照群では逆に試験開始前よりも減少していた． 増体および飼料効率は，対照群と比較してC-UPⅢを添加した全群で高値となり，0.2％および0.4％添加群でより高値を示したことから，C-UPⅢが生体防御能が低下する離乳直後の子豚の免疫活性化に有効な手段の一つであると考えられた．

Changes of peripheral blood lymphocyte and leukocyte functions in Chronic Obstructive Pulmonary Disease

Introduction: Chronic obstructive pulmonary disease (COPD) is characterized by a chronic progressive inflammatory process predominantly in the small airways and lung parenchyma, with increased numbers of macrophages, neutrophils, and lymphocytes. The role of lymphocyte apoptosis as an important factor in regulation of systemic immune response in COPD patients is not yet certain. Methods: We studied 125 patients with COPD (stage I-IV) during acute exacerbation. The age range was 25 to 86 years. COPD was diagnosed according to the criteria recommended by the Global Initiative of Obstructive Lung Disease (GOLD, 2003). Blood samples of patients were collected after obtaining informed consent. All assays were conducted in vitro. Phagocytic activity of monocytes and neutrophils was investigated by latex bead ingestion method. T-cell surface antigens were studied by indirect immunofluorescence microscopy (IEF) using monoclonal antibodies against CD3, CD4, CD8, CD16, CD95 («Sorbent», Moscow). Apoptotic lymphocytes were quantified from blood samples stained with acridine orange and ethidium bromide in phosphate buffer. Results: Significant reduction of monocytes' and neutrophils' phagocytic activity was observed in the case of severe forms of COPD (stage III and IV). At all stages of the disease, the percentage of CD-lymphocytes (CD3, CD4, CD8, CD16) in blood was a significantly lower than in the control (healthy) group. Particularly, a decrease in T-cell subpopulations (CD4+, CD8+) was observed in COPD stages III and IV. The percentage of T-cells positive for CD95, necessary for Fas-dependent apoptosis, was decreased at all stages of COPD compared with controls. An accumulation of apoptotic cells in peripheral blood was revealed in COPD stage II-IV. Discussion: Our data suggest that apoptotic cells accumulate in the systemic circulation in COPD stage II-IV, which suggest that mechanisms to remove defective cells from the blood are disturbed. The increase in apoptotic lymphocytes in the systemic circulation was combined with a reduction of the phagocytic activity of monocytes and neutrophils.

Prognostic value of phagocytic activity of neutrophils and monocytes in sepsis. Correlation to CD64 and CD14 antigen expression

The role of the phagocytic function of monocytes and neutrophils in sepsis has been poorly investigated. The present study evaluated the impact of the phagocytic activity of neutrophils and monocytes on the outcome of patients with severe sepsis. Thirty-one patients and 30 healthy individuals were enrolled in the study. The phagocytic activity of monocytes and neutrophils was evaluated during 24 h after admission and the results were correlated to the expression of CD64 on neutrophils and monocytes, CD14 antigen on monocytes, the Simplified Acute Physiology Score II and the patients' survival. A reduced phagocytic activity of neutrophils during the first 24 h after admission was a negative predictor for survival. Increased expression of CD64 antigen on polymorphonuclear cells (PMNs) and monocytes was favourably correlated to the patients' survival. In multivariate analysis the phagocytic activity of PMNs was the only independent predictor factor for survival. Patients with PMN phagocytic activity <37% had lower expression of CD64 on monocytes and PMNs and worse outcome, while those with phagocytic activity >37% had higher expression of CD64 on monocytes and PMNs and better outcome. Reduced phagocytic activity of neutrophils may represent a state of neutrophil inactivation similar to that previously described for monocytes during the compensatory anti-inflammatory response.

Effect of 2‐hydroxyethyl‐methacrylate (HEMA) on the phagocytic and respiratory burst activity of human neutrophils and monocytes

Neutrophils and monocytes/macrophages (MØ), found in oral mucosa and gingival sulcus, phagocytose and kill bacteria using products produced during a respiratory burst. 2-Hydroxyethyl-methacrylate (HEMA) is a major component released from resin glass ionomer and dental adhesives. Hence, in pulp and gingiva, phagocytes can come into contact with unpolymerized HEMA monomers. The aim of this study was to examine the effects of exposure to HEMA on neutrophil and monocyte bactericidal function. Blood collected from five female volunteers was exposed in vitro to HEMA for 2 h and then phagocytosis, respiratory burst, and cellular integrity were measured using flow cytometry. Respiratory burst was quantified by measuring fluorescent rhodamine 123 generated via oxidation of dihydrorhodamine 123. Cellular membrane integrity was evaluated by staining with propidium iodide. The respiratory burst activity of the neutrophils was significantly decreased by exposure to 7.5 and 15 mM HEMA. No significant effect of HEMA was seen on the number of granulocytes or monocytes capable of performing respiratory burst. Furthermore, there was no significant effect of HEMA on the phagocytic activity of the monocytes or the granulocytes. In conclusion, HEMA did not affect the phagocytosis activity of neutrophils; however, the ability of the cells to kill internalized prey was significantly reduced.

Humoral and cellular immunity in cosmonauts after the ISS missions

Spaceflight effects on the immune system were studied in 30 cosmonauts flown onto the International Space Station (ISS) for long- (125–195 d, n = 15 ) and short-term (8–10 d, n = 15 ) missions. Immunological investigations before launch and after landing were performed by using methods for quantitative and functional evaluation of the immunologically competent cells. Specific assays include: peripheral leukocyte distribution, natural killer (NK) cell cytotoxic activity, phagocytic activity of monocytes and granulocytes, proliferation of T-cells in response to a mitogen, levels of immunoglobulins IgA, IgM, IgG, virus-specific antibody and cytokine in serum. It was noticed that after long-term spaceflights the percentage of NK ( CD 3 - / CD 16 + / CD 56 + ) cells was significantly reduced compared with pre-flight data ( p < 0.05 ) and NK activity was suppressed by 20–85% as compared with pre-flight data in 12 out of 15 cosmonauts. T-lymphocyte activity was decreased by 25–39% as compared with pre-flight data in 5 out of 13 cosmonauts. However, the relative number of CD 3 + , CD 4 + and CD 8 + T-cells did not change. The functional activity of NK and T-cells decreased in some of the cosmonauts after short-term missions. On the other hand, a moderate trend upward of NK cytotoxic activity and proliferative activity of T-cells was observed in some individuals. Concentrations immunoglobulins (IgA, IgM, IgG) and levels of M and G antibodies to herpes simplex virus (HSV), cytomegalovirus (CMV), Epstein–Barr virus (EBV) and herpes virus type 6 (HV6) in serum did not reveal significant changes after long- and short-term flights. Concentrations of cytokines (IL- 1 β , IL-2, IL-4 and TNF- α ) in serum changed in an apparently random manner as compared with values before long- and short-term missions. Despite the fact that many improvements have been made to the living conditions of aboard the ISS our investigations demonstrate the remarkable depression of the immunological function after the ISS missions. These results suggest that the clinical health risk (related to immune dysfunction) will occur during exploration class missions.

Cell-dependent influence on the phagocytosis induced by non-ionic contrast medium injection

Iodinated contrast media (CM) can inhibit phagocytosis. To better understand the importance of this effect upon the elementary defence mechanism, the aim of the study was to compare the in vivo effect of non-ionic CM on the engulfing ability of peripheral blood phagocytic cells from patients undergoing CM-enhanced CT. Neutrophil granulocytes and monocytes from patients' peripheral blood obtained before and 30 min after CM injection were incubated with fluorescent-labelled Escherichia coli bacteria. Both the percentage of cells that engulfed bacteria and the phagocytic activity per cell has been determined by flow cytometry. We found that phagocytosis was greater in neutrophils than in monocytes. CM decreased the percentage of monocytes phagocyting bacteria, both at 4 degrees C (20.3%+/-3.3% versus 16.1%+/-2.0%; p<0.03) and at 37 degrees C (51.6%+/-4.1% versus 47.5%+/-2.6%; p>0.05), and increased the percentage of neutrophils at 4 degrees C (11.8%+/-2.1% versus 14.3%+/-2.2%; p<0.002) and at 37 degrees C (83.1%+/-3.6% versus 85.1%+/-3.2%; p>0.05). The phagocytic activity decreased significantly at 37 degrees C in monocytes (p<0.02), and was not affected in neutrophils. CM injection has different effects on both the percentage of phagocytosing cells and the phagocytic activity in monocytes and neutrophils. The inhibitory effect on monocyte phagocytosis seems to be compensated by neutrophils.

The immune system in healthy adults and patients with atopic dermatitis seems to be affected differently by a probiotic intervention

Probiotic bacteria are proposed to alleviate atopic dermatitis (AD) in infants. There are few indications about the effect of probiotics on AD in adults. The purpose of this study was to elucidate the influence of a probiotic drink containing a combination of the probiotics Lactobacillus paracasei Lpc-37, Lactobacillus acidophilus 74-2 and Bifidobacterium animalis subsp. lactis DGCC 420 (B. lactis 420) in healthy volunteers and in patients with AD on clinical and immunological parameters and their detection in feces. A double-blind, placebo-controlled, randomized cross-over study was conducted in 15 healthy adults and 15 patients with AD. The probiotic product or placebo was given over 8 weeks. A 2-week washout period was interconnected before the intervention was crossed. At the end of each period, blood and stool samples were collected. In patients, the severity of AD was evaluated using the Scoring of Atopic Dermatitis (SCORAD). L. paracasei and B. lactis were recovered in high numbers in feces after supplementation, whereas L. acidophilus marginally increased. In patients, the SCORAD tended to decrease by 15.5% (P=0.081). Major lymphocyte subsets were not affected by the probiotic intervention. However, CD57(+) increased significantly (P=0.034) in healthy subjects after probiotic intake and was not changed in patients, whereas CD4(+)CD54(+) decreased significantly (P=0.031) in patients with AD and remained uninfluenced in healthy subjects. The expression of CD4(+)CD25(+) T cells was similar in healthy subjects and AD patients. The phagocytic activity of monocytes and granulocytes was significantly increased in healthy subjects after probiotic intervention (P=0.014). L. paracasei Lpc-37 and B. lactis 420 are able to colonize the intestine transiently. This study reveals that the probiotics differently modulate peripheral immune parameters in healthy subjects and patients with AD.

Abstract 1046: The ApoA-I Mimetic Peptide, 4F, Inhibits LPS-induced Inflammatory Reactions Through Dysregulation Of The NFkB Activation Pathway.

Background: The apoA-I mimetic peptide 4F possesses potent anti-inflammatory properties. We previously reported that 4F inhibits lipopolysaccharide (LPS)-induced cytokine, chemokine and adhesion molecule expression in vivo and in vitro . Other data show that 4F reduces macrophage content in atheroma in susceptible mice. Objective: In this study, we explored anti-inflammatory mechanisms of 4F action under basal conditions and in the presence of LPS using THP1 monocytes/macrophages and primary human blood monocytes. Methods and Results: Blood monocytes isolated by Ficoll and CD14+ MACS separation were analyzed by FACS for CD14, TLR-4 and p-NFκB expression. Cytokines, chemokines and adhesion molecules were measured by the Searchlight multi-analyte analysis (Pierce, MA, USA). 4F treatment (3 days) of both THP-1 and blood monocytes enhanced the secretion of GM-CSF (25-fold), a potent inducer of monocyte to dendritic cell differentiation. 4F also inhibited (by 80%) the PMA-induced phagocytosis of FITC-labeled beads by THP-1 cells. In subsequent studies, effects of 4F on LPS-induced inflammatory responses in monocytes were tested. Pre-treatment with 4F significantly inhibited LPS-induced MCP-1 expression (by 50%) in both THP-1 cells and blood monocytes. Under these conditions, the expression of the anti-inflammatory cytokine IL-10 was increased by 200%. The effects of 4F on the activation of NFκB, a downstream mediator of LPS action, were studied using flow cytometry. 4F pre-treatment significantly inhibited LPS-induced NFκB phosphorylation (NFκBp65) compared to vehicle treatment. Protective effects of 4F in LPS-treated monocytes were associated with a 50% reduction in the expression of TLR-4 and CD14, cell surface receptors for LPS. Conclusions: These data provide evidence that 4F modulates functional properties of monocytes and show for the first time that 4F inhibits LPS-induced inflammatory responses by inhibiting the expression of CD14, TLR-4 and phosphorylation of NFκB. Enhanced GM-CSF expression and inhibition of monocyte phagocytic activity also suggest that 4F may favor the differentiation of monocytes to a dendritic cell rather than a macrophage phenotype.

Oxidative DNA damage in polymorphonuclear leukocytes of patients with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessively inherited disorder characterized by recurrent, inflammatory self-limited episodes of fever and other symptoms. This disease is caused by more than 25 mutations in the gene MEFV. During fever attacks, there is a substantial influx of polymorphonuclear leukocytes into the affected tissues. Attack-free periods are accompanied by the up-regulation of neutrophil and monocyte phagocytic activity and oxidative burst. These facts led us to hypothesize that oxidative damage by free radicals to DNA may accumulate in FMF patients. To test this hypothesis, we investigated oxidative DNA damage in polymorphonuclear leukocytes of FMF patients during the attack-free period in comparison with FMF-free control individuals. DNA was isolated from polymorphonuclear leukocytes of 17 FMF patients and 10 control individuals. DNA samples were analyzed by liquid chromatography/mass spectrometry and gas chromatography/mass spectrometry to measure the levels of various typical oxidatively induced products of DNA. We show, for the first time, that FMF patients accumulate statistically significant levels of these lesions in their DNA when compared to FMF-free control individuals. This work suggests that the persistent oxidative stress with excess production of free radicals in FMF patients may lead to accumulation of oxidative DNA damage. Defective DNA repair may also contribute to this phenomenon, perhaps due to mutations in the MEFV gene. The accumulation of mutagenic and cytotoxic DNA lesions may contribute to increased mutations and apoptosis in FMF patients, thus to worsening of the disease and well-being of the patients. Future research should deal with prevention of oxidative DNA damage and apoptosis in FMF patients, and also the elucidation of a possible role of DNA repair in this disease.

The Placental Barrier in Allogenic Immune Conflict in Spontaneous Early Abortions: Immunohistochemical and Morphological Study

Morphologic changes in the placental barrier in spontaneous early abortions under the maternal-embryonic immune conflict, and the role of maternal immunoglobulins (Igs) in these changes. We examined chorionic villi and other tissues obtained from 54 aborts between weeks 3.5 and 8 of pregnancy. Material was divided into two groups. Group 1 (control) contained 15 medically recommended and spontaneous early aborts with no signs of inflammations or pathologic immune processes. Group 2 contained 39 spontaneous early aborts with acute chorionic villitis. Immunohistochemical and morphometric methods were used to study the Igs, different types of immunocompetent cells, and apoptosis-related components of the placental barrier. Acute villitis was found to be characterized by the destruction of all components of the chorionic villi, thrombovasculitis with apoptosis of the endothelium of capillaries and erythroblasts, mucous swelling of the basal membrane, and coagulation of the blood proteins. Due to destruction of the capillaries, the number of avasculate villi increased, and the average number of capillaries per villus decreased. The extremely high number of phagolysosomes with IgG and IgA in the villous monocytes in the group 2 indicates an increase in the phagocytic activity of monocytes against maternal Igs and may reflect the presence of mother-embryo immune conflict. Apoptosis of monocytes and a high number of promonocytes were seen accompanied by a high concentration of p53 protein. A large disturbance in the trophoblast occurred with disappearance of bcl-2 and the appearance of Fas ligand. Massive destruction of maternal Igs in embryonic monocytes and acute villitis in the placental barrier are manifested during the mother-embryo immune conflict, and this may be one of the reasons of spontaneous early abortions.

Whole Blood Analysis of Phagocytosis, Apoptosis, Cytokine Production, and Leukocyte Subsets in Healthy Older Men and Women: The ZENITH Study

Few studies to date have examined age-related changes in markers of immune status in healthy older individuals. The immune status of 93 healthy individuals aged 55-70 years was assessed by two- and three-color flow cytometry and biochemical analysis. There were significant age effects (p <or=.05) on monocyte phagocytic activity and cluster of differentiation (CD) 3/human leukocyte antigen-D-related (HLA-DR) late-activated T lymphocytes (% expression). There was a significant (p <or= 0.1) Age x Sex interaction in absolute counts (x 10(9)/L) of CD3/CD8 total cytotoxic T lymphocytes (CTL), the CD4 T- helper to CD8 CTL ratio, the CD3/CD4/CD45RA naïve T helper to CD3/CD4/CD45RO memory T helper lymphocyte ratio, and interleukin (IL)-1beta (% expression) by activated monocytes. The study shows that alterations in markers of immune status occur between 55 and 70 years, and provides reference values for the lymphocyte measures in healthy men and postmenopausal women in this age group. The study further highlights the need for sex-specific reference ranges for such markers.

Impaired Endotoxin Tolerance Induction in Patients with Familial Mediterranean Fever

Objective: To investigate periodic disturbances in proinflammatory activation of neutrophils and monocytes in patients with familial Mediterranean fever (FMF) both during an attack and in remission. Methods: 20 FMF patients, who were naive to colchicine treatment and did not have amyloidosis, and 10 patients with Behçet’s disease (BD) were enrolled in this study. Phagocytosis, respiratory burst, CD11a/CD18 expression and intracellular cytokine synthesis were determined by flow cytometry. Endotoxin tolerance induction was defined by a reduced capacity of monocytes to respond to lipopolysaccharide (LPS) activation following a first exposure to LPS. Results:In FMF patients, we observed upregulation of neutrophil and monocyte phagocytic activity and oxidative burst during remission and downregulation of phagocytic activity and stimulus-dependent oxidative burst during an attack. A comparative analysis of oxidative burst has revealed that while the neutrophil population shows a certain periodicity in the increase (during remission) and decrease (during attacks) in the spontaneous and inducible respiratory burst, periodicity in the monocyte population is very poor. In addition, LPS-induced oxidative burst and CD11a/CD18 integrin surface expression is higher in patients during an attack compared to patients in remission. The induction of homologous tolerance of monocytes to the repeated action of LPS is observed in FMF patients during an attack, normal donors and patients with BD, whereas monocytes from patients in remission failed to induce LPS homologous tolerance and exhibited heightened sensitivity to bacterial endotoxin. We found that colchicine is able to restore impaired LPS homologous tolerance induction in FMF patients in remission upon increased synthesis of IL-4 in FMF patient monocytes. Conclusion: Chronic inflammation during FMF is characterized by periodic changes in monocyte and neutrophil activation and heightened sensitivity to endotoxin, which is associated with the episodic nature of FMF. Increased endotoxin sensitivity in the period of remission could result from a shift in the monocyte activation program from ‘alternatively’ into ‘classically’ activated monocytes, which may have important implications for the treatment of FMF.

植物多糖体C-UP IIIによる犬単球貪食能の活性化

The phagocytic activity of monocytes in the peripheral blood was examined in dogs administered with C-UP III, a mixture of plant polysaccharides. C-UP III was administered at doses of 0.01, 0.02 or 0.05g/kg/day for seven consecutive days, and phagocytic activity of monocytes was analyzed by the mean number of ingested latex beads (LB) and the percentage of monocytes that ingested LB. As a result, the phagocytic activities of monocytes were significantly elevated on day 7 after the start of administration in all groups. On day 21, the monocyte activity in dogs fed 0.02 and 0.05g/kg/day was still significantly higher than the initial levels; however, the 0.01g/kg/day group showed only an increased number of ingested LB, the percentage of LB ingested monocytes was not significantly higher. When C-UP III was administered at 8.3mg/kg twice a day for three days, the number of ingested LB was significantly elevated on days 3 and 7, while the percentage of monocytes that ingested LB was significantly elevated on days 2, 3 and 7. As a consequence phagocytic activity increased from day 3. There was no change in the body temperature of the dogs on days 0-2 before and 15, 30 and 45 min after C-UP III administration. The authors concluded that the enhanced phagocytic activity of monocytes was a result of C-UP III administration and not of elevated body temperature.

Circadian Dynamics of Monocyte Phagocytic Activity in Women during Lactation Complicated by Iron Deficiency

Biorhythms of phagocytic activity of peripheral blood monocytes were studied during lactation in healthy women and in women with iron deficiency. Circadian organization of monocyte function was characteristic of healthy nursing women. Strain in the system was associated with elevation of the mean circadian values for reserve potential of the absorption and digestive capacity of phagocytes. Circadian rhythms of the phagocytic and digestive capacity of peripheral blood monocytes were leveled during lactation complicated by iron deficiency. Decreased coefficient of the parameters activation is an early manifestation of latent iron deficiency. Decrease in the basic function parameters and reserve potential are directly related to the decrease in serum ferritin concentration.

Aflatoxin B1 albumin adduct levels and cellular immune status in Ghanaians

Although aflatoxins (AFs) have been shown to be immune-suppressive agents in animals, the potential role of AFs in modifying the distribution and function of leukocyte subsets in humans has never been assessed. We examined the cellular immune status of 64 Ghanaians in relation to levels of aflatoxin B1 (AFB1)-albumin adducts in plasma. The percentages of leukocyte immunophenotypes in peripheral blood, CD4+ T cell proliferative response, CD4+ T(h) and CD8+ T cell cytokine profiles and monocyte phagocytic activity were measured using flow cytometry. NK cell cytotoxic function was determined by perforin and tumor necrosis factor-alpha expression in CD3-CD56+ NK cells. AFB1-albumin adducts levels ranged from 0.3325 to 2.2703 (mean = 0.9972 +/- 0.40, median = 0.9068) pmol mg(-1) albumin. Study participants with high AFB1 levels had significantly lower percentages of CD3+ and CD19+ cells that showed the CD69+ activation marker (CD3+CD69+ and CD19+CD69+) than participants with low AFB1 levels (P = 0.002 for both). Also, the percentages of CD8+ T cells that contained perforin or both perforin and granzyme A were significantly lower in participants with high AFB1 levels compared with those with low AFB1 (P = 0.012 for both). Low levels of CD3+CD69+ (r = -0.32, P = 0.016) and CD19+CD69+ (r = -0.334, P = 0.010) cells were significantly associated with high AFB1 levels using correlation analysis. By multivariate analysis, there were strong negative correlations between the percentages of these cells (CD3+CD69+: b = -0.574, P = 0.001, and CD19+CD69+: b = -0.330, P = 0.032) and AFB1 levels. These alterations in immunological parameters in participants with high AFB1 levels could result in impairments in cellular immunity that could decrease host resistance to infections.

The Effect of IVIG on Fcγ Receptor-Dependent Monocyte Phagocytosis and FcγR Gene Expression.

BACKGROUNDThe mechanism(s) of intravenous immunoglobulin (IVIG) towards inhibition of monocyte phagocytic activity involves the function and/or the expression of inhibitory FcγRIIb in a murine model. To confirm these findings in human monocytes, we used a human monocyte phagocytic model in vitro to study the effects of IVIG on the phagocytic activity and the expression of FcγR genes.METHODSPart A: Monolayer Monocyte Phagocytosis AssayNormal volunteer's peripheral blood mononuclear cells (PBMC) were isolated from heparin anticoagulated blood by Ficoll-Hypaque (Pharmacia Biotech) density separation. The PBMCs were washed and the monocytes were purified using a magnetic bead-positive selection method with anti-CD14 antibody (Miltenyl Biotec). 105 monocytes were incubated in a microtiter plate at 37°C for 1 hour before exposed to IVIG 0.5 g/L. Anti-D (WinRho) sensitized Rh positive (R2R2) red cells were added to the monocytes at 0.5 hour and 18 hour post-IVIG treatment. After 1 hour incubation with sensitized RBC, monocytes phagocytic activity is measured by chemiluminescence detection with a LumiCount (Packard). The readings were normalized with maximal chemiluminescence signal achieved by the monocytes without prior exposure to IVIG (positive control). Part B: RT-PCR of FcγRIIa and FcγRIIbAfter 18 hours of exposure to two different concentrations of IVIG (0.5 and 5 gm/L), monocytes were collected and total RNA was isolated with TRIzol reagent (Invitrogen). 1 μg of RNA was used to generate first strand cDNA using Superscript II RT kit (Invitrogen). FcγRIIa and IIb were amplified with AmpliTaq Gold DNA polymerase system (Applied Biosystems). The PCR products were evaluated by polyacrylamide gel electrophoriesis.RESULTSPart A:Dose-response curves were generated by plotting normalized chemiluminescence against the concentration of anti-D used to sensitize the red cells. Anti-D sensitized red cells were phagocytosed by monocytes in a dose-dependent manner. There is a time-dependent inhibition of monocyte phagocytosis when monocytes were incubated with IVIG at 0.5 gm/L. (Fig. 1)Part B:There is no significant difference in the gene expression of FcRγIIb and FcγRIIa in the adherent monocytes after incubating with either low dose (0.5 gm/L) or high dose (5 gm/L) of IVIG for 18 hours. (Fig 2)CONCLUSIONDelayed inhibition of phagocytic activity with18-hour exposure to IVIG is not directly mediated via the modulation of FcγRIIb gene expression in human monocytes. Other mechanisms, such as intracellular signalling or receptor coupling, might be involved in the delayed inhibitory effects of IVIG. [Display omitted] [Display omitted]