Butyrate modulates intestinal epithelial cell-mediated neutrophil migration

Butyrate, a short-chain fatty acid released by colonic bacteria and administered therapeutically in inflammatory bowel diseases, exerts immunomodulatory properties. The aim of the study was to determine the functional consequences of butyrate exposure on the proinflammatory responsiveness of human intestinal epithelial cells (IEC). IL-8 promoter activity in IEC pretreated with butyrate then exposed to proinflammatory stimuli was assayed by transfection of luciferase constructs. IL-8 secretion was determined by ELISA and neutrophil migration by flow cytometry. Receptor mRNA was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). Butyrate modulated proinflammatory IL-8 secretion differentially in Caco-2 and HT-29 cells on the transcriptional level. Pointing to the potentially underlying mechanism of increased IL-1 beta-stimulated IL-8 secretion in HT-29 cells, butyrate up-regulated IL-1RI mRNA but not IL-1RII. Butyrate pretreatment of IEC lines stimulated by IL-1 beta modulated neutrophil migration significantly: reduction towards Caco-2 and enhancement towards HT-29/p cells. Pharmacological inhibition of protein tyrosine phosphatases or treatment with mesalamine or sulphasalazine diminished IL-1 beta-stimulated IL-8 secretion by butyrate-exposed HT-29 cells substantially. Immunomodulatory effects of butyrate on IEC are functionally relevant for neutrophil migration. Pharmacological inhibition of enhanced IL-1 beta-mediated IL-8 secretion in a subpopulation of IEC may improve the clinical efficacy of butyrate.

Cellular immune response to autologous blood transfusion in hip arthroplasty: whole blood versus buffy coat-poor packed red cells and fresh-frozen plasma

BACKGROUND AND OBJECTIVES

Transfusion-induced immunomodulation by autologous blood is probably related to the buffy coat. Hence, in the present study, phagocytotic and oxidation activities of peripheral blood cells were investigated in hip arthroplasty patients exposed to autologous blood.

MATERIALS AND METHODS

Blood from 60 autologous donors was allocated at random to storage as whole blood (WB) or as buffy coat-poor packed red cells and fresh-frozen plasma (RCP). Phagocytotic and oxidation activities of neutrophils and monocytes, incidence of infections and length of hospital stay were compared among the groups of transfused (WB and RCP) and non-transfused (NT) patients.

RESULTS

Phagocytotic activities of neutrophils and monocytes were not significantly different among the WB, RCP and NT groups.

CONCLUSION

In the perioperative setting, a specific cellular immune response to autologous transfusion is not detectable.

Immune response to autologous transfusion in healthy volunteers: WB versus packed RBCs and FFP

BACKGROUND

Storage of blood as packed RBCs and FFP is standard practice in allogeneic transfusion. Separation into components has been proposed for autologous transfusion, as well, but beneficial effects have not yet been shown.

STUDY DESIGN AND METHODS

Twenty-four healthy male volunteers were randomly assigned to receive 1 unit of either autologous RBCs and FFP (RCP group) or WB (WB group) after 49 or 35 days of storage, respectively. The immune response was analyzed by ELISA for IL-6, C3a, terminal complement complex SC5b-9, TNF-alpha, and neopterin. Differential WBC counts and the phagocytosis of neutrophils and monocytes were measured by flow cytometry.

RESULTS

Cell counts of monocytes (0.85 x 10(3) ng/microL) [corrected] and neutrophils (6.9 x 10(3) ng/microL) [corrected] increased 30 minutes after WB transfusion and then returned to close to the baseline values seen in the RCP group (0.47 and 2.9 x 10(3) ng/microL [corrected], respectively) throughout the monitored period (p<0.05). C3a (169 vs. 116 ng/microL) [corrected] and IL-6 (29 vs. 6 pg/mL) reached higher plasma concentrations in the WB group (n = 11) than in the RCP group (n = 10). Phagocytosis of opsonized Escherichia coli was increased in neutrophils and monocytes and lasted up to 7 days after the transfusion of whole blood.

CONCLUSION

Autologous WB induces a modest immunomodulation, but this effect is not observed upon transfusion of autologous blood components.

N-acetylcysteine reduces respiratory burst but augments neutrophil phagocytosis in intensive care unit patients

OBJECTIVE

The antioxidant N-acetylcysteine (NAC) has been shown to attenuate septic tissue injury. To evaluate whether NAC affects host defense mechanisms in critically ill patients, thus predisposing to increased risk of infection, the current study focuses on neutrophil phagocytotic and burst activity after treatment with NAC.

DESIGN

Prospective, randomized, clinical trial.

SETTING

Twelve-bed operative intensive care unit in a university hospital.

PATIENTS

Thirty patients diagnosed with sepsis/systemic inflammatory response syndrome, or multiple trauma.

INTERVENTIONS

Patients were randomly assigned to receive either NAC (n = 15) for 4 days in increasing dosages (day 1: 6 g; day 2: 12 g; days 3 and 4: 18 g) or a mucolytic basis dosage of NAC (3 x 300 mg/day [control]; n = 15), respectively.

MEASUREMENTS AND MAIN RESULTS

Blood samples were taken before NAC high-dose infusion (day 1), after increasing doses of NAC (days 3 and 5) and 4 days after the last high-dose treatment (day 8). Neutrophil oxidative burst activity after stimulation with Escherichia coli and polymorphonuclear phagocytosis were determined in a flow cytometric assay. Baseline values of polymorphonuclear functions were comparable in both groups. NAC high-dose treatment resulted in a significantly improved phagocytosis activity compared with control patients. In contrast to this, polymorphonuclear burst activity was significantly reduced in the NAC high-dose treated group on day 3.

CONCLUSION

These findings suggest that infusion of NAC in high doses affects granulocyte functions in critically ill patients. Antimicrobial host defense requires the effective sequence of cell adhesion, phagocytosis, and bactericidal respiratory burst. The enhanced phagocytotic activity might be a compensatory mechanism in states of impaired respiratory burst to maintain tissue sterility. For certain mechanisms of disease, the effects observed might be favorable (e.g., ischemia/reperfusion, endothelial cell activation), for others (infection) this might be detrimental.

Endothelin-1 impairs neutrophil respiratory burst and elimination of Escherichia coli in rabbits

OBJECTIVE

During systemic inflammation, elevated levels of endothelin (ET)-1 have been reported. The aim of this study was to investigate the effects of ET-1 on neutrophil (PMN) respiratory burst, phagocytosis, and elimination of Escherichia coli from blood and tissues.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Experimental laboratory in a university hospital.

SUBJECTS

A total of 18 female chinchilla rabbits.

INTERVENTIONS

To quantify the clearance process, defined numbers (10(8) colony-forming units) of E. coli were injected intravenously into anesthetized rabbits, 60 mins after onset of continuous 0.2 microg/kg/min ET-1 administration (n = 9) and after saline infusion (control group, n = 9), respectively. To evaluate potential effects of ET-1 on bacterial elimination and killing, blood clearance of E. coli and colonization of different organs were investigated.

MEASUREMENTS

Variables monitored were neutrophil respiratory burst and phagocytosis activity, rates of bacterial elimination from the blood, arterial blood pressure, blood gases, serum lactate concentrations, and nitrite and nitrate levels. The animals were killed 3 hrs after bacterial injection and tissue samples of liver, kidney, spleen, and lung were collected for bacterial counts.

MAIN RESULTS

Compared with the control group, ET-1 significantly impaired PMN respiratory burst (p < .05) and prolonged elimination of injected E. coli from the blood (p < .01), whereas phagocytosis functions remained unaltered. The reduced PMN burst activity after ET-1 was associated with a higher bacterial colonization of all organs (lung, p < .01; spleen, p < .05). Endothelin-1 induced increases in mean arterial pressure (p < .01) and serum lactate concentrations, whereas nitrite and nitrate levels remained unaltered.

CONCLUSION

Endothelin-1 impairs respiratory burst and bacterial clearance from the blood and tissue. Thus, elevated levels of ET-1 during sepsis could induce organ hypoperfusion and cause disturbances in immune functions, increasing the risk of bacterial infections.

HLA-DR expression in acute pancreatitis

OBJECTIVE

To investigate the role of the monocyte/macrophage system in acute pancreatitis

DESIGN

Prospective clinical study

SETTING

University clinic, Germany

SUBJECT

37 consecutive patients who presented with acute pancreatitis.

MAIN OUTCOME MEASURE

Correlation between function of monocytes measured by HLA-DR expression and outcome

RESULTS

Patients were divided into three groups according to outcome: those with severe pancreatitis who died (n = 10), those with severe pancreatitis who survived (n = 15), and those with mild pancreatitis who survived (n = 12). There was a clear and significant difference between those with severe and those with mild disease. HLA-DR expression was initially depressed in both groups, but after the third day of treatment it started to recover significantly in those with mild disease (p < 0.05). The difference was also significant from day 7 onwards between those with severe disease who died and those with severe disease who survived (p < 0.05).

CONCLUSION

Monocyte function as measured by HLA-DR expression (CD14+DR+) is reduced in patients with acute pancreatitis and does not recover in patients who are going to die (median < 20 relative antigen density units; RU).

Chédiak-Higashi-Steinbrinck syndrome (CHS) in a 27-year-old woman--effects of G-CSF treatment

Chédiak-Higashi-Steinbrinck syndrome (CHS) is a rare autosomal recessive disorder which is usually lethal in early childhood. Diagnostic hallmark is the occurrence of giant inclusion bodies in peripheral leukocytes and their bone marrow precursors. We report on a 27-year-old female patient who was admitted for treatment of a skin abscess. She recovered after intravenous antibiotic treatment and surgical incision. Hematological investigation was initiated because of a persisting neutropenia of 15%, with a leukocyte count initially in the normal range but subsequent leukopenia. Case history revealed recurrent skin infections from childhood on, regularly requiring surgical intervention. One year prior to admission a neuropathy had been diagnosed, while a partial albinism had been known for years. Microscopic examinations of peripheral blood and bone marrow aspirate smears were diagnostic for CHS. Additionally, a secondary antibody deficiency was found. Normalization of the white blood cell count, including the differential count, was observed following initiation of G-CSF treatment. Functional assessment of phagocytosis and oxidative burst activity of granulocytes revealed normal results before and after stimulation with G-CSF, however, natural killer cell activity was only weak, with slight improvement after G-CSF treatment in vivo. Cytogenetic analysis showed a normal female karyotype. Although the haploidentical brother of the patient may serve as an allogeneic stem cell donor, transplantation has been postponed because of further deterioration of her already existing CHS-specific neurological impairment. Nevertheless, while receiving G-CSF maintenance treatment our patient experienced no further infectious episodes within 6 months after diagnosis of CHS.

Granulocyte colony-stimulating factor receptor expression on neutrophils of term and preterm neonates with and without signs of infection

Neutrophils are an essential component of the human host defence system against infection. Recombinant human granulocyte colony-stimulating factor induces neutrophilia and enhances effector functions of mature neutrophils. Since the biological effects of granulocyte colony-stimulating factor (G-CSF) are mediated by its receptor, we investigated the expression of G-CSF receptor on the surface of neutrophils of term and preterm neonates (n = 22) with and without signs of infection and of healthy adults (n = 13) by flow cytometry. In healthy adults, the percentage of neutrophils expressing G-CSF receptor was higher compared to cord blood of term and preterm neonates (87% vs 53%, P < 0.05). Between 2 and 32 h of life, neonates with signs of infection showed lower values of G-CSF receptor expression compared to neonates without signs of infection (32% vs 54%, P < 0.05). No correlation was detectable between expression of G-CSF receptor and gestational age.

CONCLUSION

Expression of granulocyte colony-stimulating factor receptor on neutrophils is lower than in adults. This may adversely affect granulopoiesis and neutrophil function during the neonatal period. Moreover, granulocyte colony-stimulating factor receptor expression seems to be down-regulated during neonatal infection.

Multidrug resistance in androgen-independent growing rat prostate carcinoma cells is mediated by P-glycoprotein

Prostate carcinomas are in general resistant against virtually all cytotoxic drugs. Up to now it has not been thoroughly evaluated whether specific resistance factors, such as the expression of the MDR1 gene, play a role in this multi-agent resistance and whether there is a link between drug resistance and hormone-independent growth. We investigated the resistance patterns of a hormone-sensitive and four hormone-independent Dunning rat carcinoma sublines against four drugs which are substrates of P-glycoprotein (vinblastine, taxol, doxorubicin, and etoposide) and two agents (methotrexate and cis-platinum) which are not transported by this efflux pump. All hormone-insensitive sublines, AT.1, AT. 3.1., MatLu and Mat LyLu, continuously showed a clearly enhanced resistance (3- to 26-fold) against the P-glycoprotein substrates, compared to the hormone-sensitive subline G. Only two of the androgen-independent sublines displayed enhanced resistance against methotrexate, whereas all of them were more sensitive against cisplatin than the androgen-sensitive G cells. By addition of verapamil the resistance against vinblastine (9- to 10-fold) and taxol (6.7- to 26.7-fold) in the hormone-insensitive cells could be almost totally reversed. Furthermore, the fluorescent P-glycoprotein substrate rhodamine-123 was effectively pumped out of the four tested hormone-independent cell lines, whereas the hormone-sensitive G cells were unable to extrude the dye. By reverse transcriptase polymerase chain reaction (RT-PCR) with primers specific for the rat mdr1b gene, the homologue to the human MDR1 gene, we could easily detect mdr1b expression in the androgen independent cell lines, but not in the G cells. Our results suggest that the product of the rat mdr1b gene is involved in the multidrug resistance of androgen-independent Dunning prostate carcinoma cells.

Neutrophil respiratory burst in term and preterm neonates without signs of infection and in those with increased levels of C-reactive protein

Developmental immaturities in neonatal host defense predispose the neonates to an increased mortality rate during bacterial infections. Early diagnosis is of great clinical importance, but, especially in neonates, is sometimes very difficult. The ability to generate reactive oxygen species, the so-called respiratory burst, is essential for neutrophils to kill infectious microorganisms. Therefore, changes of respiratory burst may reflect increased susceptibility of neonates to infections and may be useful for the early detection of infections. Superoxide anion production was determined by a flow cytometric method using dihydrorhodamine 123 (DHR) as an oxidative probe after priming of neutrophils with PBS buffer (spontaneous burst), with N-formyl-methionyl-leucyl-phenylalanine (fMLP), or with Escherichia coli. During the study period, the spontaneous percentage of activated cells in whole blood as well as the percentage of activated cells in stimulation with fMLP was lower in adults (n = 100; PBS, 1.0 +/- 0.1%; fMLP, 8.3 +/- 0.9%) compared with neonates without signs of infection (n = 143). Among the latter, the percentage of activated cells (PBS and fMLP assay) varied with respect to gestational age and hours of life: lowest values were measured in preterm newborns with gestational age less than 32 wk and between 25 and 120 h of life. The same correlation to gestational age was true for total neutrophil cell counts. In neonates with increased levels of C-reactive protein during the first 5 d of life (n = 43), the percentages of activated cells after PBS and fMLP incubation were higher than those of neonates without signs of infection. The relationship of neutrophil respiratory burst and neutrophil cell counts to gestational age might reflect at least in part a reason for the increased susceptibility of neonates to infections. Furthermore, determination of respiratory burst may prove to be a new laboratory parameter of neonatal infection.

A new side effect of inhaled nitric oxide in neonates and infants with pulmonary hypertension: functional impairment of the neutrophil respiratory burst

INTRODUCTION

Inhaled nitric oxide (NO) may be beneficial in the treatment of pulmonary hypertension, both of the newborn and in the adult respiratory distress syndrome. Up to now, serious systemic side effects have not been reported.

OBJECTIVE

The effect of inhaled NO on superoxide anion production by neutrophils.

DESIGN

Prospective study of a consecutive series of 15 neonates and infants.

SETTING

Neonatal and paediatric ICUs with a total of 17 beds (university hospital).

MEASUREMENTS AND RESULTS

Superoxide anion production was determined by a flow cytometric method using dihydrorhodamine 123 (DHR) as an oxidative probe after the priming of neutrophils with N-formyl-methionyl- leucylphenylalanine (fMLP) or with Escherichia coli. The generated fluorescence was expressed as relative fluorescence intensity (RFI). Inhalation of NO for more than 24 h reduced the superoxide anion production by neutrophils stimulated with E. coli to below baseline values before NO inhalation (mRFI = 158 +/- 25 vs 222 +/- 24; P = 0.03). This decrease was more pronounced after more than 72 h (mRFI = 133 +/- 17). At this time, superoxide anion production by fMLP-stimulated neutrophils was also decreased (mRFI = 40 +/- 3, vs 57 +/- 5; P = 0.03). The reduced capacity of superoxide production persisted throughout therapy with NO and lasted up to more than 4 days after the end of NO inhalation.

CONCLUSION

The results suggest that inhalation of NO in patients with pulmonary hypertension causes reduced superoxide anion production by neutrophils stimulated with E. coli or with fMLP. To determine the clinical importance of this systemic side effect with respect to bacterial infections, a randomized controlled study is necessary.

[Immune paralysis in acute pancreatitis--HLA-DR antigen expression on CD14+DR+ monocytes]

Determination of the prognosis in acute cases of pancreatitis, particularly in its serious and necrotizing form, still presents problems. Patients require intensive care and suffer from severe septic complications that do not correlate with pancreatic enzyme levels (amylase lipase).

METHOD

Thirty-one patients with acute pancreatitis were examined: group 1 -- necrotizing pancreatitis (lethal outcome n = 7); group 2 -- necrotizing pancreatitis (surviving n = 12); group 3 edematous pancreatitis (surviving n = 12). For 11 consecutive days after admission to a clinical ward, flow cytometric check-ups were carried out daily on all patients. The antigen-presenting system HLA-DR antigen expression on monocytes and C-reactive protein were examined.

RESULTS

When groups 1 and 2 were compared with group 3, HLA-DR values on monocytes were significantly different following the third day after admission (P < 0.01). Comparison of groups 1 and 2 were significant from the third day of observation (P < 0.001). During all 11 days of observation, patients in group 1 remained in immune paralysis (HLA-DR expression on monocytes CD14+DR+20% antigen density). All of these patients had infected necroses. Patients in group 2 overcame their immune paralysis. HLA-DR depression of monocytes and a long-standing high C-reactive protein level are almost certain predictors of a fatal outcome in cases with severe pancreatitis. A routine passage cytometric check/FACS to determine the activity of monocytes (HLA-DR) is of prognostic significance.

[Coping with illness/quality of life and immunologic parameters of patients with breast carcinoma and benign tumors]

OBJECTIVE

Maladaptive coping of the cancer illness leads to considerable psychosocial burden which can-as a chronic stress factor-impair various immune functions, e.g. cellular immunity.

PATIENTS AND METHODS

In a collective of 118 patients suffering from mammary carcinoma and 48 patients suffering from benign mammary tumors Coping was measured with the EORTC-MAC-scale and Quality of life with three questionnaires. Out of the immunologic variables the lymphocyte subpopulations were determined with flow cytometry. Immunglobulines, neopterin, C-reactive protein, and herpes serology were determined using standard methods.

RESULTS

At follow up a slight increase of the mean vales of sum-scores is observed for the adverse coping mechanisms, like helplessness/despair and fear. On the other hand, the values for the coping styles fatalism and denial decrease. Significant correlations are seen between anxious attitude and number of natural killer cells (CD16 and CD56). It must be pointed out that area of social contact show an inverse correlation in patients with mammary cancers: a strong improvement correlates with diminished natural killer cells as well as reduced activated killer cells.

CONCLUSIONS

The aim of this study is to determine whether a high risk group can be defined using these parameters and if these parameter can be influenced by psychotherapeutic interventions such as establishing "Coping-support-groups".