Modulation of IgG and complement receptor expression of phagocytes in kidney cancer patients during treatment with interferon-alpha.

BACKGROUND: The mode of action of interferon involves both direct cytotoxic and antiproliferative effects on the tumour cell and indirect effects that facilitate immune detection by the host. Among the immunological effects of interferon-alpha is the activation of monocytes. As opsonin receptors are crucial in the function of phagocytes, e.g. monocytes and neutrophils, their modulation by interferon-alpha (INF-alpha) merit to be further clarified. We hypothesised that the role of phagocytes in defence against cancer is reflected in the expression of opsonin receptors for IgG and complement, which further could be modified by INF-alpha. PATIENTS AND METHODS: The expression of the receptors for IgG and complement was studied in neutrophils and monocytes from blood samples of 18 kidney cancer patients treated with INF-alpha and from 39 healthy individuals. Blood samples were collected prior/to and during treatment with INF-alpha, 4.5 to 13.5 MU t.d.w., subcutaneously. After lysing the red blood cells, the samples were incubated with fluorochrome conjugated monoclonal antibodies specific for IgG (Fc gammaRI, -RII and -RIII) and complement (CR1, CR3) receptors and then analysed in flow cytometry. The results were given as the mean log fluorescence intensity (a measure of receptor number) and as the proportion of receptor-positive cells. In the in vitro experiments, the direct effect of interferon-alpha on the receptors of neutrophils and monocytes was studied. RESULTS: In patients before any treatment, the expression of CR3 and Fc gammaRI receptors in neutrophils and all receptors except Fc gammaRIII in monocytes was significantly raised when compared to the controls. Treatment with INF-alpha, induced statistically significant; transient changes in CR1-receptor expression in neutrophils and Fc gammaRI expression in monocytes. Incubation of blood cells with INF-alpha in vitro confirmed the induction of CR1 receptors in neutrophils. CONCLUSION: Changes in receptor expression reflect the inflammatory activation of phagocytes in metastatic kidney cancer. The pattern of receptor expression differs from that observed in infectious diseases. Interferon-alpha both in vivo and in vitro modulates the expression of phagocytic receptors.

Colostral proteins from cows immunised with Streptococcus mutans/S. sobrinus support the phagocytosis and killing of mutans streptococci by human leucocytes.

Passive immunisation, based on bovine colostral preparations, is an area of active research. Specific bovine antibodies inhibit the virulence factors of target pathogens but the interactions between whey preparations and human immune defence cells are not well known. Bovine colostrum inhibits the phagocytic activity of bovine leucocytes and this may reflect the biological activity of immunoglobulins in it. Therefore, this study aimed to examine the effects of bovine whey protein preparations from the colostrum of Streptococcus mutans/S. sobrinus-immunised and sham-immunised cows on binding, ingestion and killing of these bacteria by human leucocytes. Binding and ingestion of FITC-labelled bacteria were estimated by flow cytometry and leukocyte activation was measured as chemiluminescence. Killing rate was estimated by plate counting and by measuring bioluminescence from S. mutans- containing the insect luciferase gene. Colostral whey protein preparation from hyperimmunised cows activated human leucocytes by opsonising specific bacteria. Neutrophils, eosinophils and monocytes weakly phagocytosed non-opsonised bacteria and bacteria opsonised with control product. On the contrary, binding and ingestion were efficient in the presence of the preparation from immunised cows. Thus, these results show that bovine colostral whey proteins are able to support the activation of human phagocytes against pathogenic microbes and that this property is related to specific antibodies in whey preparations. These whey proteins may also be clinically useful, especially in preventing the colonisation of newly erupted teeth by mutans streptococci.

Mode of delivery directs the phagocyte functions of infants for the first 6 months of life.

Factors that direct the immune responsiveness of the newborn beyond the immediate post-natal period are not known. We investigated the influence of mode of delivery and type of feeding on the phagocyte activity during the first 6 months of life. Sixty-four healthy infants (34 delivered vaginally and 30 by elective Caesarean section) were studied at birth and at the ages of 2 and 6 months. Phagocyte functions were studied by measuring the chemiluminescence (CL) activity of whole blood and isolated leucocytes and by investigating the expression of phagocyte receptors (FcgammaRI (CD64), FcgammaRII (CD32), FcgammaRIII (CD16), CR1 (CD35), CR3 (CD11b) and FcalphaR (CD89)) on neutrophils, monocytes and eosinophils by using receptor-specific MoAbs and immunofluorescence flow cytometry. Infants born by elective Caesarean section had significantly higher CL activity than those delivered vaginally during the entire 6-month follow up. In addition, infants who received formula feeds had significantly higher CL activity at 6 months of age and higher expression of FcgammaRI-, Fcalpha- and CR3-receptors on neutrophils than infants exclusively breast-fed. We suggest that stress reaction associated with labour influences the phagocytic activity measured in the cord blood but later during infancy the intraluminal antigens, gut microflora and diet, become important determinants in immune programming of human individuals.

Milk hypersensitivity--key to poorly defined gastrointestinal symptoms in adults.

Lactose intolerance is a common adverse reaction to milk in adults, while milk hypersensitivity is a disorder of infancy. We hypothesized that milk hypersensitivity may cause many unspecific gastrointestinal disorders in adults. Twenty adults were subjected to double-blind, placebo-controlled milk challenge. Phagocyte activity, and Fc gamma and complement receptor expression of phagocytes were assayed, and serum total IgE, milk-specific IgE, and serum reactivity to milk protein were determined. The challenge increased phagocyte activity and complement receptor expression of phagocytes in subjects designated milk-hypersensitive, who had gastrointestinal symptoms from milk ingestion but normal lactose tolerance. The increase was not detected in lactose-intolerant or control subjects. The milk-hypersensitive group was also distinguished from the lactose-intolerant group by enhanced serum reactivity to milk protein. Only two out of nine milk-hypersensitive subjects had detectable milk-specific serum IgE. It is concluded that milk hypersensitivity in adults, occurring as gastrointestinal reactions, may be more common than previously thought.

Determination of complement-mediated killing of bacteria by viability staining and bioluminescence.

Complement-mediated killing of bacteria was monitored by flow cytometric, luminometric, and conventional plate counting methods. A flow cytometric determination of bacterial viability was carried out by using dual staining with a LIVE/DEAD BacLight bacterial viability kit. In addition to the viable cell population, several other populations emerged in the fluorescence histogram, and there was a dramatic decrease in the total cell count in the light-scattering histogram in the course of the complement reaction. To permit luminometric measurements, Bacillus subtilis and Escherichia coli were made bioluminescent by expressing an insect luciferase gene. Addition of substrate after the complement reaction resulted in bioluminescence, the level of which was a measure of the viable cell population. All three methods gave essentially the same killing rate, suggesting that the bacteriolytic activity of serum complement can be measured rapidly and conveniently by using viability stains or bioluminescence. In principle, any bacterial strain can be used for viability staining and flow cytometric analysis. For the bioluminescence measurements genetically engineered bacteria are needed, but the advantage is that it is possible to screen automatically a large number of samples.

Probiotic bacteria down-regulate the milk-induced inflammatory response in milk-hypersensitive subjects but have an immunostimulatory effect in healthy subjects.

BACKGROUND: Probiotic bacteria can influence immune responses both specifically by stimulating antibody production and nonspecifically by enhancing phagocytosis of pathogens and modifying cytokine production. OBJECTIVE: The authors hypothesized that probiotic bacteria can alleviate hypersensitivity by influencing phagocytes. The modulation of phagocytes may be different in healthy subjects compared with hypersensitive subjects. SUBJECTS AND METHODS: In a double-blind, cross-over study, challenges with milk in milk-hypersensitive and healthy adults with or without an intestinal bacterial strain, Lactobacillus GG (ATCC 53103) were performed. The challenge-induced immunoinflammatory response was recorded by measuring the expression of phagocytosis receptors prior to and after the challenge using flow cytometry. RESULTS: In milk-hypersensitive subjects, milk challenge increased significantly the expression of CR1, FcgammaRI and FcalphaR in neutrophils and CR1, CR3 and FcalphaR in monocytes. Milk with Lactobacillus GG prevented the increase of the receptor expression. In healthy subjects, milk challenge did not influence receptor expression while milk with Lactobacillus GG increased significantly the expression of CR1, CR3, FcgammaRIII and FcalphaR in neutrophils. CONCLUSION: Probiotic bacteria appear to modulate the nonspecific immune response differently in healthy and hypersensitive subjects. This is seen as an immunostimulatory effect in healthy subjects, and as a down-regulation of immunoinflammatory response in milk-hypersensitive subjects.

Altered expression of IgG and complement receptors indicates a significant role of phagocytes in atopic dermatitis.

BACKGROUND: Strict dietary precautions against allergic sensitization may benefit a group of predisposed children. OBJECTIVE: To develop new strategies for identifying these children, a better understanding of the processes that initiate sensitization and regulate and perpetuate the inflammatory response is needed. METHODS: We measured the expression of the receptors for the constant (Fc) region of IgG (Fc gamma RI, Fc gamma RII, and Fc gamma RIII) and that for the complement fragments C3b and C3bi (CR1 and CR3) in neutrophils and monocytes from 39 children with atopic dermatitis, 17 disease control patients with acute infections, and 17 healthy control subjects. The capacity of phagocytes to produce reactive oxygen species was also determined. To find the best way of discriminating the patients with atopic dermatitis from control subjects, a stepwise logistic binary regression model was made. RESULTS: The stepwise logistic regression analysis was based on differences in individual receptor expression between the study groups. Because acute infections strongly affected receptor expression in both neutrophils and monocytes, to avoid diagnostic bias, children with acute infections were excluded from the analysis. The combination of the receptors CR1 in neutrophils and Fc gamma RI and Fc gamma RII in monocytes was the best indicator of atopic dermatitis. A significant correlation between the expression of CR1 in neutrophils and in monocytes, as well as reactive oxygen species production of phagocytes, and the severity of the eczema was detected. CONCLUSIONS: These results suggest that a distinct receptor profile of phagocytic cells can be characterized in patients with atopic dermatitis, providing a new direction to the search for early identification of children predisposed to allergic sensitization.

Human recombinant GM-CSF selectively primes receptor mediated respiratory burst of neutrophils in vitro.

The influence of human recombinant granulocyte-macrophage colony-stimulating factor (rH GM-CSF) on respiratory burst response of isolated human neutrophils was examined. Preincubation of cells with rH GM-CSF significantly increased the respiratory burst in response to formyl-methionyl-leucyl-phenylalanine (FMLP), measured by luminol-dependent chemiluminescence (CL) assay. This priming effect of rH GM-CSF was independent of extracellular Ca2+ and Mg2+. On the other hand, the pretreatment of cells with rH GM-CSF could not enhance the neutrophil CL responses to unopsonized, serum complement-opsonized or immunoglobulin G (IgG)-opsonized zymosan particles. rH GM-CSF directly induced a weak CL signal in neutrophils. This signal, however, was abolished when extracellular Ca2+ and Mg2+ were removed. Exposure to rH GM-CSF caused a divalent cation-dependent up-regulation of complement receptors (CR1 and CR3) on neutrophil cell surface, while the expression of IgG Fc-receptors (FcRII and FcRIII) was not markedly changed by rH GM-CSF. The results indicate that rH GM-CSF primes FMLP-induced CL but not zymosan particle-induced respiratory burst in human neutrophils. It is hypothesized that the reason for the different sensitivity of FMLP-receptors and receptors to zymosan particles to rH GM-CSF priming may lie in differences in the signal-transduction pathways of these receptor types.

Potentiation of central effects of L-dopa by an inhibitor of catechol-O-methyltransferase.

The effects of a COMT-inhibitor, U-0521, and a MAO-B-inhibitor, 1-deprenyl, on L-dopa-induced circling behaviour were compared in 6-OHDA-lesioned rats. The actions of U-0521 and 1-deprenyl on the anti-cataleptic effect of L-dopa were also studied. Both U-0521 and 1-deprenyl were found to potentiate L-dopa-induced circling behaviour and anti-cataleptic effect of L-dopa. In both test systems the L-dopa potentiation of 1-deprenyl was longer-lasting than that caused by U-0521. Thus inhibition of COMT, like inhibition of MAO, is able to enhance the central effects of L-dopa. This principle might be beneficial in the treatment of Parkinson's disease especially if COMT-inhibitors with greater performance can be developed.

Comparison of a slow-release indomethacin tablet and naproxen in osteoarthrosis.

A double-blind, crossover study was performed in 21 out-patients with osteoarthrosis of the hip or knee to compare the efficacy and tolerability of a new slow-release formulation (multiple units dose preparation) of indomethacin (50 mg) with those of naproxen (250 mg). After a wash-out period of 1 week, the patients were randomized to receive 2 tablets daily of one or other preparation for 3 weeks. This was followed by another wash-out period of 1 week, whereafter the patients were crossed over to the alternative drug for another 3 weeks. Subjective assessments of pain and objective assessment of joint mobility and the use of acetylsalicylic acid as rescue analgesic were used to evaluate the efficacy of the treatment. Analysis of results from 19 patients showed that both drugs effectively alleviated pain, and there was no difference between indomethacin and naproxen in this respect. There were 2 withdrawals, 1 on naproxen due to inefficacy and 1 on indomethacin due to gastro-intestinal side-effects. Otherwise, the drugs were well tolerated and side-effects occurred to the same extent on both drugs. This study confirms the good efficacy and tolerability of the new slow-release indomethacin preparation.

Tiapride and chlordiazepoxide in acute alcohol withdrawal. A controlled clinical trial.

The efficacy of chlordiazepoxide and tiapride in the management of acute alcohol withdrawal syndrome was compared in a randomized, parallel-group, double-blind trial. The mean daily dose for both preparations on the first two days was four capsules, i.e., 200 mg for chlordiazepoxide and 400 mg for tiapride. Thereafter the patients were treated according to the relief of symptoms obtained. The treatment periods lasted 3-5 days. Both drugs effectively alleviated alcohol withdrawal symptoms, especially anxiety, fear, hallucinations, insomnia, sweating, tremor, abdominal pain and vertigo. Seventy percent of the patients in the chlordiazepoxide and 42% in the tiapride group considered the drug effective. The difference was statistically significant in favour of chlordiazepoxide (p less than 0.05). Tiapride is an alternative drug in the treatment of this condition, if benzodiazepines are to be avoided.