Convergence of the mammalian target of rapamycin complex 1- and glycogen synthase kinase 3-β-signaling pathways regulates the innate inflammatory response

The PI3K pathway and its regulation of mammalian target of rapamycin complex 1 (mTORC1) and glycogen synthase kinase 3 (GSK3) play pivotal roles in controlling inflammation. In this article, we show that mTORC1 and GSK3-β converge and that the capacity of mTORC1 to affect the inflammatory response is due to the inactivation of GSK3-β. Inhibition of mTORC1 attenuated GSK3 phosphorylation and increased its kinase activity. Immunoprecipitation and in vitro kinase assays demonstrated that GSK3-β associated with a downstream target of mTORC1, p85S6K, and phosphorylated GSK3-β. Inhibition of S6K1 abrogated the phosphorylation of GSK3-β while increasing and decreasing the levels of IL-12 and IL-10, respectively, in LPS-stimulated monocytes. In contrast, the direct inhibition of GSK3 attenuated the capacity of S6K1 inhibition to influence the levels of IL-10 and IL-12 produced by LPS-stimulated cells. At the transcriptional level, mTORC1 inhibition reduced the DNA binding of CREB and this effect was reversed by GSK3 inhibition. As a result, mTORC1 inhibition increased the levels of NF-κB p65 associated with CREB-binding protein. Inhibition of NF-κB p65 attenuated rapamycin's ability to influence the levels of pro- or anti-inflammatory cytokine production in monocytes stimulated with LPS. These studies identify the molecular mechanism by which mTORC1 affects GSK3 and show that mTORC1 inhibition regulates pro- and anti-inflammatory cytokine production via its capacity to inactivate GSK3.

The role of glycogen synthase kinase 3 in regulating IFN-β-mediated IL-10 production

The ability of IFN-β to induce IL-10 production from innate immune cells is important for its anti-inflammatory properties and is believed to contribute to its therapeutic value in treating multiple sclerosis patients. In this study, we identified that IFN-β stimulates IL-10 production by activating the JAK1- and PI3K-signaling pathways. JAK1 activity was required for IFN-β to activate PI3K and Akt1 that resulted in repression of glycogen synthase kinase 3 (GSK3)-β activity. IFN-β-mediated suppression of GSK3-β promoted IL-10, because IL-10 production by IFN-β-stimulated dendritic cells (DC) expressing an active GSK3-β knockin was severely reduced, whereas pharmacological or genetic inhibition of GSK3-β augmented IL-10 production. IFN-β increased the phosphorylated levels of CREB and STAT3 but only CREB levels were affected by PI3K. Also, a knockdown in CREB, but not STAT3, affected the capacity of IFN-β to induce IL-10 from DC. IL-10 production by IFN-β-stimulated DC was shown to suppress IFN-γ and IL-17 production by myelin oligodendrocyte glycoprotein-specific CD4(+) T cells, and this IL-10-dependent anti-inflammatory effect was enhanced by directly targeting GSK3 in DC. These findings highlight how IFN-β induces IL-10 production and the importance that IL-10 plays in its anti-inflammatory properties, as well as identify a therapeutic target that could be used to increase the IL-10-dependent anti-inflammatory properties of IFN-β.

Adjuvant activity of monophosphoryl lipid A for nasal and oral immunization with soluble or liposome-associated antigen

The effectiveness of monophosphoryl lipid A (MPL) as a mucosal adjuvant was investigated following oral or intranasal (i.n.) administration of an aqueous adjuvant formulation of MPL (MPL-AF) added to soluble antigen or liposomal antigen or incorporated into liposomal antigen membranes. Groups of BALB/c female mice were immunized with 50 to 100 microg of free or liposomal Streptococcus mutans crude glucosyltransferase (C-GTF) with or without MPL-AF added to the vaccine or incorporated into the liposomal membrane. Plasma, saliva, vaginal wash, and fecal extract samples were collected biweekly following immunization and assessed for antigen-specific antibody activity by enzyme-linked immunosorbent assay (ELISA). Mice immunized by the i.n. route had higher levels of salivary, plasma, and vaginal immunoglobulin A (IgA) anti-C-GTF responses and higher levels of plasma IgG anti-C-GTF than the orally immunized groups. A second administration of the vaccine 14 weeks after the initial immunization resulted in an anamnestic response to C-GTF resulting in 10- and 100-fold increases in saliva and plasma IgA and plasma IgG, respectively (in the i.n. immunized groups). Mice receiving a second i.n. immunization with liposomal antigen and MPL-AF had higher salivary IgA anti-C-GTF responses than mice immunized with antigen plus MPL-AF or liposomal antigen (P < 0.05). Plasma IgG anti-C-GTF activity was highest in mice immunized by the i.n. route with antigen formulations containing MPL-AF (P < 0.05). These results demonstrate the effectiveness of MPL-AF as an adjuvant for potentiating mucosal and systemic immune responses to liposomal C-GTF following i.n. immunization.

Immunization with a plasmid expressing pneumococcal surface protein A (PspA) can elicit protection against fatal infection with Streptococcus pneumoniae

Pneumococcal surface protein A (PspA) is a protectioneliciting protein of Streptococcus pneumoniae. We observed that immunization of BALB/c mice with a plasmid expressing PspA significantly protected the mice from lethal challenge with S. pneumoniae when compared to control mice that received injections of the plasmid vector alone. The plasmid construct expressing PspA has been designated pKSD2601. Mice immunized intramuscularly with pKSD2601 had a mean log of colony-forming units of 2.67 +/- 0.25 pneumococci circulating in their blood at 24 h after challenge as compared with control mice that had a mean log of colony-forming units of 4.95 +/- 0.59. Those mice with lower numbers of pneumococci subsequently survived the challenge. Given the quantitative nature and ultimate end point (ie live versus dead) our mouse model should be useful in working out optimum expression of bacterial genes for DNA immunization.

Intratracheal gene delivery with adenoviral vector induces elevated systemic IgG and mucosal IgA antibodies to adenovirus and beta-galactosidase

One major concern about using adenoviral vectors for repetitive gene delivery to lung epithelial cells is the induction of an immune response to the vector, thus, impeding effective gene transduction. To assess the immune response to the adenoviral vector, repetitive intratracheal (i.t.) gene dosing was performed in CD-1 mice using the replication-deficient adenovirus 5 (Ade5) vector carrying the lacZ gene, and compared to the antibody responses induced by conventional intranasal (i.n.) and intraperitoneal (i.p.) routes of immunization. Kinetics of serum IgG, IgA, and IgM antibody responses to the adenoviral vector and to beta-galactosidase (beta-Gal) were evaluated. Two or three adenoviral vector doses given by i.t., i.n., or i.p. routes resulted in serum IgG titers in excess of 1:200,000, whereas serum IgM and IgA were moderately induced. Analysis of the predominant murine IgG subclass was determined to be IgG2b and IgG2a. To determine the localization of this antibody response, the ELISPOT assay was employed. Lymphocytes were isolated from the lung, the lower respiratory lymph nodes (LRLN), the nasal passages (NP), and the spleen. For i.t- and i.n.-administered mice, the highest IgA spot-forming cell (SFC) response to Ade5 and beta-Gal was located in the NP and in the lung. Both the lung and the LRLN showed elevated numbers of IgG SFCs (4- to 12-fold greater than splenic IgG SFC response) for Ade5 and beta-Gal. This evidence suggests that the lung and associated lymphoid tissues were the source for serum antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of temperature on the immune system of channel catfish (Ictalurus punctatus)--I. Leucocyte distribution and phagocyte function in the anterior kidney at 10 degrees C

1. Temperatures of 18 degrees C for acclimation or assay had minimal or no effect on channel catfish phagocyte function. Significant suppression was observed at 10 degrees C acclimation and assay temperature. 2. According to the results of a multiple acclimation/assay temperature combination study, the primary impact of temperature on phagocyte function was due to the assay temperature. 3. The only functional change caused by acclimation temperature was the possible adaptation of the respiratory burst. However, 10 degrees C acclimation did cause a decline in the number of lymphocytes in the anterior kidney but not the number of neutrophils. In a temperature-kinetic study, the suppressive effect of 10 degrees C assay temperature was confirmed. 4. Results of our study indicated that phagocytosis in channel catfish is temperature-mediated. However, phagocytes appeared to be more resistant to low temperature than lymphocytes, which implies the importance of phagocytosis in the defense mechanisms of channel catfish at low temperatures.

Characterization of monoclonal antibodies to channel catfish, Ictalurus punctatus, leucocytes

Four monoclonal antibodies (MAbs) were evaluated for specific reactions to various catfish peripheral blood leucocytes and anterior kidney cells. The MAb 9E1 served as a standard and positive control for all test reactions because of its defined reactivity with channel catfish immunoglobulin and immunoglobulin bearing cells. Of the four MAbs, two have been characterized as being specific for a non-immunoglobulin marker on lymphocytes, thus marking T lymphocytes and two were specific for catfish neutrophils. Morphological, flow cytometric and functional analysis of the reactive cells verified these findings.

Controlled field trial on the anthelmintic effectiveness of the morantel sustained-release bolus in grazing calves

The direct and indirect anthelmintic efficacies of the morantel sustained-release bolus given to calves were assessed in a 154-day controlled field trial. A permanent calf pasture (divided into 2 lots) and naturally parasitized calves were used. The medicated calves were given the bolus at the time they were placed on the pastures. Control calves did not receive anthelmintic therapy. The effectiveness of the bolus to control parasitic gastroenteritis was determined by monitoring various parasitologic determinants. The treated calves had significantly (P less than 0.01) reduced numbers of fecal nematode eggs for every posttreatment sampling period when compared with the control calves. Tracer calves, used periodically during the study to indicate pasture larval infectivities, had equivalent worm burdens at the beginning of the trial (treated vs control pasture). Tracer calves, added later in the study to the lot with treated calves, harbored 83% to 94% fewer nematodes than did their counterparts in the lot with the controls. Plasma pepsinogen concentrations, reflective of abomasal worm burden size and/or activity, were significantly higher (P less than 0.01) in the control than in the treated calves from day 54 until trial termination. At trial termination, the treated calves weighed an average of 27.8 kg more and harbored 80.9% fewer nematodes than the control calves. The morantel sustained-release bolus is an anthelmintic delivery device that has therapeutic and prophylactic antinematode activities. To achieve its optimum performance, the bolus must be used so that the epizootiologic patterns of the predominate parasitic nematodes are effectively disrupted. Generally, internal nematode parasitisms in the calf flourish during the animal's first springtime grazing period.(ABSTRACT TRUNCATED AT 250 WORDS)

Antiparasitic efficacy of ivermectin in naturally parasitized sheep

Sixteen sheep harboring naturally acquired parasitisms were allocated to 1 of 2 treatment groups: (i) sheep given ivermectin in an oral solution at the dosage rate of 200 micrograms/kg of body weight, and (ii) those given the vehicle at a dosage rate of 0.25 ml/kg. All animals were necropsied at 2 weeks after treatment. Parasites and percentages of parasitic reductions, as demonstrated in this trial, were: Dictyocaulus filaria (99.4%), Oestrus ovis first stage instars (100%), Trichuris ovis (98.9%), Strongyloides papillosus (99.8%), Nematodirus spathiger (100%), arrested 4th stage Nematodirus spp (96.2%), Trichostrongylus colubriformis (100%), T axei (100%), Oster tagia circumcincta (100%), Haemonchus contortus (100%), and arrested Haemonchus spp 4th stage larvae (99.9%). The sheep showed no adverse effects due to ivermectin or vehicle administration.

Effectiveness of ivermectin in the treatment of equine Parascaris equorum and Oxyuris equi infections

Fifteen horses harboring naturally acquired, patent Parascaris equorum and Oxyuris equi infections were equally allotted to 3 treatment groups given (1) injectable vehicle; (2) injectable ivermectin at the dose rate of 200 microgram/kg of body weight; and (3) injectable ivermectin at the rate of 300 microgram/kg. All treatments were given IM in the neck. All animals were killed 14 days after treatment and examined for the targeted nematodes. Regardless of dose rate, ivermectin proved 100% effective in the removal of adult O equi and P equorum infections. Levels of immature P equorum were decreased by 98.5% in both ivermectin-treated groups. Oxyuris equi 4th-stage larval injections were decreased by 95.7% and 99.9% by the 200 and 300 microgram/kg ivermectin treatments, respectively. Adverse reactions to the injections of drug were not seen.

Antiparasitic effectiveness of ivermectin in the horse

By way of a controlled trial, the anthelmintic efficacies of the injectable and paste formulations of ivermectin were evaluated in the horse. Treatment was given at the rate of 200 microgram/kg of body weight. Regardless of formulation, 100% removals were demonstrated for Strongylus vulgaris (intestinal), S edentatus, 2nd and 3rd instars of Gastrophilus nasalis and G intestinalis, "small strongyles," Triodontophorus serratus and T tenuicollis. Adult Cylicocyclus insigne populations were eliminated at the rates of 99.9% and 96.3% by the injectable and paste formulations, respectively. Levels of 4th-stage Cylicocyclus spp larvae, as detected in the luminal contents of the colon, were reduced by 88.3% and 33.2% by the injectable and paste formulations, respectively. There were no adverse tissue or behavioral reactions induced by either preparation of ivermectin.

Anthelmintic activities of ivermectin against gastrointestinal nematodes of cattle

The anthelmintic efficacy of ivermectin, a combined solution of the B1a and B1b fractions of avermectin, was assessed in a controlled trial. Twenty-four yearling calves experiencing naturally acquired, clinical gastrointestinal helminthiasis were evenly divided on the basis of weight into two 12-animal groups. The medicated group was given (subcutaneously) ivermectin at the dose rate of 200 microgram/kg of body weight. The control animals were given the vehicle alone, at an equivalent rate. All animals were killed 14 days later. At necropsy of the calves, gastrointestinal helminth arithmetic means were 178,626 and 575 for the control and the treated groups, respectively, an overall reduction of 99.7%. Nematodes which were present at substantial levels were Ostertagia ostertagi, O lyrata, Trichostrongylus axei, Cooperia punctate, C oncophora, C mcmasteri, and Oesophagostomum radiatum. Anthelmintic activity of ivermectin was excellent regardless of nematode species, sex, or stage of development.