Phagocytic Activity Of Peritoneal Macrophages Research Articles

Milk Fat Globule Epidermal Growth Factor-Factor VIII Is Down-Regulated in Sepsis via the Lipopolysaccharide-CD14 Pathway

Phagocytosis prevents the release of potentially harmful or immunogenic materials from dying cells. Milk fat globule epidermal growth factor (EGF)-factor VIII (MFG-E8) mediates the clearance of apoptotic cells. We have previously shown that the administration of MFG-E8-rich exosomes from immature dendritic cells promotes the phagocytosis of apoptotic cells and improves survival in sepsis. Because endotoxin is elevated in polymicrobial sepsis, we hypothesized that down-regulation of MFG-E8 is mediated via the LPS-CD14 pathway, eventually leading to the accruement of apoptotic cells. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP) in CD14-deficient (CD14(-/-)), TLR4-mutated and wild-type (WT) mice. In addition, endotoxemia was elicited by i.p. injection of LPS. LPS was also neutralized by pretreating CLP-induced WT mice with polymyxin B. Splenic MFG-E8 expression, phagocytic activity, and apoptosis were assessed 5 and 20 h after CLP or 5 h after LPS administration. In septic WT mice, MFG-E8 mRNA and protein levels were suppressed by 49 and 33%, respectively. Endotoxemia reduced MFG-E8 mRNA expression in a dose dependent manner and the down-regulation of MFG-E8 mRNA expression in CLP-induced sepsis was attenuated by polymyxin B. This CLP-induced suppression was not observed in both CD14(-/-) and TLR4-mutated mice. CLP significantly decreased phagocytic activity of peritoneal macrophages in WT (by 30%), but not in CD14(-/-) mice. CLP also induced significant apoptosis in the spleen of WT (by 61%), but less in CD14(-/-) mice. Thus, MFG-E8 production is down-regulated in sepsis by LPS-CD14 dependent fashion, leading to a reduction of phagocytosis of apoptotic cells.

Stimulation of Innate Immunity by Oral Administration of Dahi Containing ProbioticLactobacillus caseiin Mice

Immunomodulatory effects of a dahi (strained yogurt) containing probiotic Lactobacillus casei, designated "probiotic dahi," was evaluated in Swiss albino mice during 8 days of feeding and compared with control dahi-, nonfermented milk-, and no milk product diet-fed (control) groups. Lysosomal enzymes (beta-galactosidase and beta-glucuronidase) and phagocytic activities were estimated in peritoneal macrophages of animals fed with different experimental diets on days 2, 5, and 8. The oral administration of probiotic dahi increased (by 84%) beta-galactosidase activity in supernatant of cultured macrophages and achieved the highest values on day 2 and thereafter decreased up to day 8, at which no effect on beta-glucuronidase activities was observed; it was the same as the control group. Moreover, phagocytic activity also increased in probiotic dahi-fed mice after days 2 and 5 and then decreased after 8 days, but was still higher than in nonfermented milk and control dahi-fed groups. The counts of total lactobacilli significantly increased after feeding of probiotic dahi as compared to the other groups. However, no significant changes were observed in beta-galactosidase and beta-glucuronidase activities and phagocytic activity of peritoneal macrophages isolated from nonfermented milk- and normal diet-fed groups. The results of the present study reveal that nonspecific immune response markers were stimulated in mice by feeding of probiotic dahi containing probiotic L. casei instead of milk alone and that the effect was greater than in control dahi.

The effect of preoperative corticosteroids on peritoneal macrophage function after laparoscopic and open abdominal surgery in a rat model

Background Peritoneal macrophages play an important role in the immune response after abdominal operations. The stress response after these operations has been associated with impaired phagocytosis by peritoneal macrophages. This study examined the influence of minimally invasive techniques and preoperative corticosteroid administration on postoperative peritoneal macrophage phagocytic activity. Methods After IACUC approval, 66 Sprague Dawley rats were randomly divided into 7 groups: baseline animals (B), anesthesia controls (AC), open cecectomy (OC), and laparoscopic cecectomy (LC). Within the AC, OC, and LC groups, half received intraperitoneal (IP) dexamethasone (10 mg/kg) 1 hour before surgery (+S), and the other half received an equal volume of normal saline IP (−S). Animals were observed postoperatively for 24 hours and were then euthanized. Peritoneal macrophages were harvested via intraperitoneal lavage. A phagocytosis assay was performed to calculate the net phagocytosis and percent response to the effector agent. Statistical analysis was performed using analysis of variance and a Student t test between groups. A P value of <.05 was considered significant. Results Significant differences were observed between groups. The B group had a response rate of 94.2% ± 56.7%, which was not different from the AC groups (−S, P = .28; +S, P = .16) or the LC-S group ( P = .9). The lowest phagocytic activity rate was in the OC-S group with a response rate of 33.8% ± 28.5%. The highest phagocytic response rates occurred in the AC +S (145.2% ± 60.2%) and LC +S (198.1% ± 103.5%). These were not significantly different from each other ( P = .3). The LC +S group had a significantly higher percent response than all of the other groups. The phagocytic response rate of the OC +S group was not different from either the AC-S group ( P = .07) or the LC-S group ( P = .8); however, it was less than the AC +S group ( P = .02) and the LC +S group ( P = .003). Conclusion Open cecectomy resulted in greater impairment of the phagocytic activity of peritoneal macrophages than laparoscopic cecectomy. The addition of preoperative corticosteroids improved phagocytic activity back to baseline function. The combination of minimally invasive surgical technique and preoperative corticosteroid administration resulted in the greatest postoperative phagocytic function of peritoneal macrophages in a rat model.

Chromium(III) Nanoparticles Affect Hormone and Immune Responses in Heat-Stressed Rats

This study was conducted to evaluate the effects of chromium nanoparticles (CrNano) on the hormone and immune responses of rats in heat stress condition. A total of 80 male Sprague-Dawley rats were randomly assigned to four dietary treatment groups (n = 20). The first group was offered a basal diet as a control. The second, third, and fourth groups received basal diet supplemented with 150, 300, and 450 microg/kg Cr, respectively, in the form of CrNano. At the end of the 8-week trial, growth performance, food utilization, and sera concentrations of hormones, immunoglobulins, and alexins were determined. Lymphocyte proliferation activity, antibody response to injected sheep red blood cells (SRBCs), and phagocytosis of peritoneal macrophages were determined by (3)H-thymidine uptake method, plaque-forming cells (PFC) assay, and ingesting chicken red blood cells test, respectively. The results indicated that rats that received CrNano exhibited no changes in growth rate and food efficiency compared to the control group. However, dietary supplementation of 150, 300, and 450 microg/kg Cr from CrNano significantly decreased serum concentrations of insulin and cortisol, increased sera levels of insulin-like growth factor I and immunoglobulin G, and enhanced the lymphoproliferative response, anti-SRBC PFC response, and phagocytic activity of peritoneal macrophages. These results suggest that dietary supplementation of Cr as CrNano affects hormone and immune status in heat-stressed rats.

Enzymatic preparation of immunomodulating hydrolysates from soy proteins

Soy protein hydrolysates with lower molecular weight were enzymatically prepared by several commercially available proteases (Alcalase 2.4 L, Flavourzyme, Trypsin, Papain, Protease A and Peptidase R) with protein recovery varied from 42.59% to 79.87%. Relative content of positively charged peptides was determined on SP Sephadex C-25 using gradient sodium chloride solution as eluents. Immunomodulating properties were evaluated by measuring their effect on in vitro proliferation of murine spleen lymphocytes and phagocytic activity of peritoneal macrophages. The results showed that soy protein hydrolysates (SPHs) prepared with Alcalase and insoluble soy protein (InSP), preferable to other enzymes and soy proteins, have the highest immunomodulating activity and the optimum conditions were determined as follows: E/ S = 2% (Alcalase), 60 °C, pH 8.0, InSP concentration 6% and 225 min. Positive correlations were obtained between the immunomodulating activity and content of positively charged peptides. The results suggested that lower molecular weight and positively charged peptides released from soy protein were effective in stimulating immunomodulating activity, thus provided insights into the preparation of potent immunomodulating products.

Immunocorrecting properties of GB-115 dipeptide

We studied the effects of a new dipeptide with anxiolytic activity (GB-115, N-phenylhexanoyl-glycyl-L-tryptophan amide) on parameters of the immune in intact mice and in animals with secondary immunodeficiency caused by cyclophosphamide. GB-115 in doses of 0.1-10 mg/kg stimulated phagocytic activity of peritoneal macrophages and humoral immune response in intact mice. GB-115 exhibited immunocorrecting activity in animals with secondary immunodeficiency.

QS67. The Phagocytic Activity of Peritoneal Macrophages Is Enhanced by Exposure to Acidic Environments

QS67. The Phagocytic Activity of Peritoneal Macrophages Is Enhanced by Exposure to Acidic Environments

Feeding a Diet Containing a Fructooligosaccharide Mix Can Enhance Salmonella Vaccine Efficacy in Mice

Fructooligosaccharides (FOS) are considered prebiotics because of their ability to promote growth of specific beneficial gut bacteria, such as bifidobacteria. Some studies reported potential immune-modulating properties. The aim of this study was to investigate the effect of FOS:inulin mix on murine response to Salmonella vaccine and evaluate the relevance toward protection against Salmonella infection. Balb/c mice were fed a diet containing 5% FOS:inulin mix or a control diet 1 wk before oral immunization with a suboptimal dose of live attenuated Salmonella typhimurium vaccine. Four weeks after vaccination, mice were infected with LD100 of virulent S. typhimurium. Specific blood Salmonella immunoglobulin G and fecal immunoglobulin A significantly increased in mice fed the diet containing prebiotics compared with control mice 4 wk postimmunization. Peritoneal macrophage phagocytic activity also significantly increased in FOS:inulin-fed mice at 1 wk postimmunization compared with control mice. No detectable effects were observed on the percentage of lymphoid cell subsets in the spleen. However, production of cytokines, interferon-γ, interleukin-12, and tumor necrosis factor α, was numerically increased in spleen cell cultures stimulated with mitogens from FOS:inulin-fed mice 1 and 4 wk postimmunization. Salmonella translocation to lymphoid organs was not affected by feeding FOS:inulin. However, the improved response to Salmonella vaccine was concomitant with an increase in the survival rate of FOS:inulin-fed mice upon challenge with virulent Salmonella. No detectable effects were observed on the composition or the metabolic activity of the microbiota. Overall, the data suggest that a diet supplemented with FOS:inulin mix stimulates mucosal immunity and seems to improve efficacy of an oral vaccine.

Effect of long-term continuous consumption of fermented milk containing probiotic bacteria on mucosal immunity and the activity of peritoneal macrophages

The effect of the long-term administration of commercial fermented milk containing probiotic bacteria in the mucosal immune response and peritoneal macrophages was analyzed. BALB/c mice were fed with fermented milk for 98 consecutive days. Small and large intestines were removed for histology; IgA, CD4, CD8 cells and cytokines-producing cells were counted. The influence on the immune cells associated with bronchus and mammary glands as well as on peritoneal macrophages was also analyzed. Continuous oral administration of fermented milk increased IgA+ cells in both parts of the intestine (small and large intestine). IL-10, a regulatory cytokine, increased in the intestinal cells in most samples. TNF α, IFN γ and IL-2 producing cells were also enhanced. Values for CD4 and CD8 + cell populations in lamina propria of the intestine were increased in relation to the control throughout the assay. No modifications in the histology of intestines were observed. Long-term consumption of fermented milk enhanced intestinal mucosa immunity, mediated by IgA+ cells and by cytokine production. This improvement of gut immunity was maintained and down-regulated by cytokines such as IL-10, preventing gut inflammatory immune response. The effect of this fermented milk on mucosal sites distant to the gut, such as bronchus and mammary glands, showed that in both tissues the increase in IgA+ cells was only observed at the beginning of the continuous consumption and no modifications in the number of cytokine positive cells were found. Similar observations were found when phagocytic activity of peritoneal macrophages was measured. It was demonstrated that the most evident effect of long-term consumption of fermented milk was observed in the intestine. Immunodulatory effects and the maintenance of intestinal homeostasis without secondary effects after long-term administration of fermented milk were also observed.

Effects of Dietary Arginine on Hematological Parameters and Innate Immune Function of Channel Catfish

The effects of elevated dietary arginine on the hematology and immune function of juvenile channel catfish Ictalurus punctatus were evaluated by means of in vivo and in vitro experiments. Healthy juvenile channel catfish (average weight, 34.8 g) were fed casein-gelatin-based diets containing 28% crude protein and supplemented with crystalline L-arginine (ARG) at 0.5, 1, 2, or 4% of diet. An intact-protein diet containing 1.3% arginine also was included to investigate the effects of amino acid form (crystalline-free amino acids versus intact protein). Each purified diet was fed to apparent satiation to triplicate groups of fish for 6 weeks. At the end of the experimental feeding period, the fish were injected intraperitoneally with two doses (3 d apart) of 2 mg lipopolysaccharide/kg body weight. Six days after the initial injection, the fish were anesthetized and tissue samples were obtained to evaluate hematological and humoral and cellular immune parameters, including phagocytic activity of peritoneal macrophages, hemoglobin, hematocrit, mean corpuscular volume (MCV), blood cell counts, plasma protein, and hepatic superoxide dismutase activity. High dietary levels (4% ARG) resulted in significantly higher levels of hemoglobin, hematocrit, and circulating erythrocytes. Dietary ARG did not significantly affect MCV and the number of circulating leukocytes, lymphocytes, eosinophils, and monocytes. In vitro, a moderate level (2 mM) of ARG in the culture media was found to be ideal in significantly enhancing phagocytosis. This study demonstrates that some aspects of the immune system of channel catfish are sensitive to changes in dietary ARG.

Influence of feeding fermented milk and non-fermented milk containing Lactobacillus casei on immune response in mice

The effect of feeding Lactobacillus casei in the form of fermented and non-fermented milk on non-specific as well as humoral immune response in mice was investigated. Feeding of L. casei fermented milk (LcF), its cell free supernatant (LcS), and L. casei non-fermented milk (LcNF) to mice for period of two, five and eight days resulted in increased activity of β-galactosidase and β-glucuronidase in peritoneal macrophages in comparison to skim milk (control). The phagocytic activity of peritoneal macrophages also increased significantly (p<0.01) in mice fed on LcF, LcS and LcNF compared to skim milk-fed mice. The maximum rise in β-galactosidase, β-glucuronidase and phagocytic activity was on day 5 post-feeding. In challenge studies with Shigella dysenteriae, it was observed that colonization of S. dysenteriae in the intestine, liver and spleen was significantly less in mice fed on LcNF and LcF in comparison to mice fed on skim milk for a period of seven days before challenge. Levels of secretory antibodies were higher in groups fed LcNF and LcF. The results suggest the immunomodulatory potential of L. casei.

Immunotoxicological Study of One of the Most Common Over-The-Counter Pyrethroid Insecticide Products in Egypt

A commonly available aerosolized pyrethroid insecticide containing deltamethrin and imiprothrin is widely used for hygienic control in Egypt. The immunotoxic effects after inhalation exposures to the preparation of each for 2, 10, and 30 days were investigated in rats. For each exposure, the insecticide (containing 0.2% imiprothrin and 2.5% deltamethrin) was sprayed in all directions in a room (using a special attachment located in the ceiling in the center of the room) for 30 s each minute for 15 min; the room was then kept closed for 15 min. After each spray interval, the rats were introduced for 30 min and then removed to a clean room. The exposure process was repeated a total of three times on each day of the respective regimens. The interval between the 15-min spray/15-min pause/30-min rat exposure cycles was 120 min. Twenty-four hours after the final exposure in each particular regimen, the cohort rats in the regimen (air and exposed) were weighed, sacrificed, and their tissues were removed for analyses. Immunological tests performed included assessments of potential changes in immunopathology (determined from body and splenic weights), humoral-mediated immunity (based on plaque-forming activity of spleen cells), cell-mediated immunity (determined from splenic lymphocyte responsiveness to stimulation with phytohemagglutinin and immune cell (sub)type profile analyses), and nonspecific immunity (based on phagocytic activity of peritoneal macrophages). The results indicated that of all the endpoints examined, among the rats exposed over a 2-day period to the imiprothrin- and deltamethrin-containing insecticide aerosol, the only significant change noted (relative to values from time-matched controls) was in the levels of splenic CD4+CD8− and CD4+ CD8+ cells. In contrast, exposures on each day of a 10-day period led to significant decreases in several endpoints; exceptions to this were values for body and spleen weight (unaffected), splenic OX12−OX19+ levels (significant increase), and CD4+CD8− levels (unaffected, relative to control). Rats exposed for 30 days displayed significant decreases in each test applied, except for increases in both splenic OX12−OX19+ and CD4+CD8− cell levels relative to corresponding control rat values. The present study findings indicate that repeated noncontinuous inhalation of a commonly utilized insecticide that contains imiprothrin and deltamethrin can cause a variety of immunotoxic effects in sites distal to the lungs.

Virulence Attenuation of Capsular Polysaccharide-deleted Mutants of Streptococcus iniae in Japanese Flounder Paralichthys olivaceus

Streptococcus iniae is known as an important bacterial pathogen causing serious damage in fish culture industry worldwide. Although the capsule of this pathogen is suggested to play a role in the disease process, it has not been verified yet. In this study we created isogenic uncapsulated mutants of S. iniae NUF631 by Tn916 transposon mutagenesis and investigated the role of capsule in the virulence and resistance to phagocytic activities of peritoneal macrophages of Japanese flounder Paralichthys olivaceus. Mutants transformed from K + phenotype to K - pheno- type were all uncapsulated. They exhibited neither K + type-specific precipitation line in an immun- odiffusion test nor ladder-like banding pattern characteristic for bacterial acidic polysaccharides in polyacrylamide gel electrophoresis. Their virulence to Japanese flounder was highly attenuated. In contrast to the mutant strains, the parent capsulated strain resisted phagocytic and bactericidal activities of the macrophages and prevented chemiluminescence reaction of the mac- rophages upon phagocytosis. From these results, it is verified that the S. iniae capsule is an im- portant factor for intramacrophage survival of the pathogen.

The immunopotentiator effects of nefopam

The effects of opiate analgesics and non-steroidal anti-inflammatory drugs on the immune functions have been reported. The effect of the non-opiate analgesic nefopam on the immune functions has not yet been investigated. Male Swiss albino mice were treated with either heat killed E. coli or saline. They were classified into 12 groups. The effects of subacute (15 mg/kg/12 h S.C. daily for one week) and chronic (10 mg/kg/12 h S.C. daily for one month) treatment with nefopam on the levels of interferon-gamma (IFN-γ) and total immunoglobulins were examined in both normal and immunized mice. Also, the effect of the chronic administration of nefopam on the phagocytic activity of peritoneal macrophage was evaluated in both normal and immunized mice. Subacute and chronic administration of nefopam induced no significant raise in the level of interferon-gamma (IFN-γ) or in the level of total immunoglobulins in non-immunized animals, while subacute and chronic treatment with nefopam augmented markedly the immunization induced increase of level of interferon-gamma (IFN-γ). Furthermore, chronic treatment with nefopam potentiated significantly the production of total immunoglobulin induced by heat killed E. coli. Chronic treatment with nefopam also was associated with significant enhancement of innate immune response reflected in the pronounced increase in the phagocytic activity of macrophages in non-immunized and immunized animals. The enhancement of phagocytic activity of macrophages by nefopam in immunized animals was significantly higher than that of non-immunized animals. These findings revealed that nefopam has the ability to trigger the immune response for bacterial antigen. The mechanism behind the immunostimulatory effect of nefopam requires further investigation, but it may be due, at least in part, to the inhibitory effect of nefopam on the serotonin and norepinephrine reuptake at nerve endings. In conclusion, our findings postulated that nefopam stimulated the immune functions and improved the defence mechanism. This information may be of future therapeutic value in diseases that need immunologic enhancement.

Effect of ghrelin administration on phagocytic activity in acute cold-restraint stress exposed rats

Ghrelin, an endogenous ligand for growth hormone secretagogue receptor, was identified in the rat stomach. This peptide acts through nitric oxide (NO) by expressing endothelial nitric oxide synthase (eNOS) and down regulating inducible nitric oxide synthase (iNOS) at its gastroproprotective effect against restraint stress induced damage. Recently the ghrelin receptor has also been detected in peripheral systems including immune tissue. We have investigated the possible effect of ghrelin on phagocytic activity of peritoneal macrophages in acute cold-restraint stress (ACRS) exposed rats. The rats were divided into control, stress and ghrelin groups. In ghrelin groups, single dose and three days consecutive dose of ghrelin (20 μg/kg. i.p.) were applied to rats that were exposed to ACRS for 4 h. 1 ml of saline was injected i.p. after ACRS for 3 consecutive days to the rats of the stress groups. Ghrelin administration reduced the increased phagocytic activity induced by ACRS. We conclude that ghrelin exerts an important role at macrophage phagocytic activity in ACRS exposed rats.

Immunomodulatory activity of Sulforaphane, a naturally occurring isothiocyanate from broccoli (Brassica oleracea)

The effect of Sulforaphane on the immune system was studied using BALB/c mice. Intraperitoneal administration of five doses of Sulforaphane (500 microg/dose/animal/day) was found to enhance the total WBC count (12,950 cells/mm3) on 9th day. Bone marrow cellularity (23 x 10(6) cells/femur) and number of alpha-esterase positive cells (1346.66/4000 cells) were also increased by the administration of Sulforaphane. Treatment with Sulforaphane along with the antigen, sheep red blood cells (SRBC), produced an enhancement in the circulating antibody titre and the number of plaque forming cells (PFC) in the spleen. Maximum number of PFC (315.83 PFC/10(6) spleen cells) was obtained on the 6th day. Administration of Sulforaphane also showed an enhancement in the phagocytic activity of peritoneal macrophages. Moreover administration of Sulforaphane significantly reduced the elevated level of TNF-alpha production by LPS stimulated macrophages. These results indicate the immunomodulatory activity of Sulforaphane.

Immunomodulating capacity of commercial fish protein hydrolysate for diet supplementation

Dietary proteins harbour bioactive peptides that can be released by a fermentation process. Fish proteins are a valuable and little-exploited source of potentially active biopeptides. The aim of this research was to evaluate the effects of a commercially available fermented fish protein concentrate (Seacure ®) (FPC) derived from a fermentation process, on the mucosal immune response in a murine model. BALB/c mice received the FPC or the non-fermented powder at different concentrations (0.20, 0.25 or 0.30 mg/ml) for 2, 5 or 7 consecutive days. At the end of each feeding period, histological studies of the gut were carried out and the phagocytic activity of peritoneal macrophages, the number of IgA+ cells in the small intestine lamina propria and bronchial tissue and the number of IL-4+, IL-6+, IL-10+, IFN γ+ and TNF α+ cells in the small intestine lamina propria were determined. Different accumulative doses of FPC did not induce any inflammatory immune response and the normal morphology of the small intestine was not affected. Phagocytic activity of peritoneal macrophages was enhanced following FPC administration at 0.3 mg/ml for 7 consecutive days. The number of IgA+ cells increased in the small intestine lamina propria but not in the bronchial tissue. IL-4, IL-6 and IL-10 were all significantly increased in the lamina propria of the small intestine of animals that received FPC. At the same time, some pro-inflammatory cytokines such as IFN γ and TNF α also increased, but the intestinal homoeostasis was maintained and no tissue damage was observed. We conclude that FPC is an immunomodulating food with a demonstrated capacity to enhance non-specific host defense mechanisms.

PARENTERAL N-3 FATTY ACIDS MODULATE INFLAMMATORY AND IMMUNE RESPONSE IN RATS UNDERGOING TOTAL GASTRECTOMY

This study investigated the effect of n-3 fatty acid (FA)-containing parenteral nutrition on the circulatory lymphocyte subpopulation, intracellular cytokine and leukocyte adhesion molecule expression, and phagocytic activity in rats undergoing total gastrectomy. Normal rats with internal jugular catheters were assigned to normal control (NC) and two experimental groups and received total parenteral nutrition (TPN). At the same time, a total gastrectomy was performed in the experimental groups, whereas the NC group underwent a sham operation. The TPN solutions were isonitrogenous and identical in nutrient compositions except for differences in fat emulsion contents. The NC and one of the experimental groups received a soybean oil emulsion (SO), and the other experimental group received 50% soybean oil and 50% fish oil emulsion (FO). Half of the rats in each respective group were sacrificed 1 or 3 days after surgery or the sham operation to examine their immune response. The results showed that the FO group had a higher CD4 proportion and CD4/CD8 ratio than those of the SO and NC groups postoperatively. The phagocytic activity of peritoneal macrophages was higher in the FO group than in the NC group, but no difference was found between the SO and NC groups 3 days after surgery. The intracellular interferon (IFN)-gamma distribution in the FO group was higher than that of the SO group on postoperative days. Leukocyte adhesion molecule expressions and peritoneal monocyte chemotactic protein-1 levels were lower in the FO group than in the SO group on postoperative day 3. These results suggest that parenterally infused FO did not result in immunosuppression. In addition, FO administration promotes lymphocyte Th1 cytokine production, enhances peritoneal macrophage phagocytic activity, and reduces leukocyte adhesion molecule expression in rats with total gastrectomy.

Enhancement of peritoneal macrophage phagocytic activity against Leishmania major by garlic ( Allium Sativum) treatment

It has been shown that garlic ( Allium sativum) extract modulates immune responses. Macrophage activation is required to establish control of the intracellular infection and progressive disease of leishmaniasis. In this study, we consider the effect of a garlic extract and a fraction isolated from it on the engulfment and destruction of Leishmania major by resident peritoneal macrophages of Balb/ c mice. In regard to this study, the infiltration of macrophages in the peritoneal cavity after garlic treatment and the rate of amastigotes per macrophage were determined. The results show that a single dose of 20 mg/kg garlic extract intraperitoneally (i.p.) alters the number of peritoneal macrophages for at least 2 weeks. Intraperitoneal injection of garlic extract (20 mg/kg) or its protein fraction (0.04 mg/kg) augments parasite engulfment and destruction of intracellular amastigotes by macrophages.

Adaptation to the UV-induced suppression of phagocytic activity in murine peritoneal macrophages following chronic exposure to solar simulated radiation

Exposure of certain strains of mice to ultraviolet radiation (UVR) is known to suppress both local and systemic immune responses, including a reduction in the phagocytic activity of peritoneal macrophages. However, in many instances, the immunological effects have been observed following a single or a limited number of doses of UVR from sources containing a higher proportion of UVB than that emitted by the sun. The first aim of the present study was to establish whether a single exposure of C3H/HeN mice to solar simulated radiation (SSR) suppressed the ability of the peritoneal macrophages to phagocytose opsonised sheep red blood cells. The mice were irradiated with SSR from Cleo Natural lamps and a single dose of 31.9 J cm(-2) was found to be the minimal dose for significant suppression of macrophage phagocytic activity. Such a dose did not modulate the surface expression of I-A(k), CD11b, CD86 or FcgammaRII/III (CD32/16) on the macrophages. The second aim was to assess whether repeated SSR exposures with a dose below the minimal immunosuppressive dose affected macrophage activity and, if so, to test for photoadaptation by repeated exposures followed by a single, normally immunosuppressive dose of SSR, and then assaying the macrophage activity. Groups of mice were irradiated on each of 2, 10 and 30 days with 14.9 J cm(-2) SSR, followed in some instances by a single additional exposure of 31.9 J cm(-2) on the same day as the last irradiation. The phagocytic activity of the peritoneal macrophages was tested 24 h later. It was reduced by 32%, 18% and 4% respectively after 2, 10 and 30 repeated exposures to SSR, and by 39%, 21% and 7% respectively after 2, 10 and 30 repeated exposures plus the additional higher dose at the end. Thus, although the macrophage activity was initially suppressed by the SSR, photoadaptation of this immune parameter occurred following repeated exposures.