Secretion of TNF-alpha, IL-8 and nitric oxide by macrophages activated with polyanions, and involvement of interferon-gamma in the regulation of cytokine secretion

Infliximab Induction Lacks Efficacy and Increases BK Virus Infection in Deceased Donor Kidney Transplant Recipients: Results of the CTOT-19 Trial

BACKGROUND

Ischemia-reperfusion (IR) of a kidney transplant (KTx) upregulates TNF α production that amplifies allograft inflammation and may negatively affect transplant outcomes.

METHODS

We tested the effects of blocking TNF peri-KTx via a randomized, double-blind, placebo-controlled, 15-center, phase 2 clinical trial. A total of 225 primary transplant recipients of deceased-donor kidneys (KTx; 38.2% Black/African American, 44% White) were randomized to receive intravenous infliximab (IFX) 3 mg/kg or saline placebo (PLBO) initiated before kidney reperfusion. All patients received rabbit anti-thymocyte globulin induction and maintenance immunosuppression (IS) with tacrolimus, mycophenolate mofetil, and prednisone. The primary end point was the difference between groups in mean 24-month eGFR.

RESULTS

There was no difference in the primary end point of 24-month eGFR between IFX (52.45 ml/min per 1.73 m 2 ; 95% CI, 48.38 to 56.52) versus PLBO (57.35 ml/min per 1.73 m 2 ; 95% CI, 53.18 to 61.52; P =0.1). There were no significant differences between groups in rates of delayed graft function, biopsy-proven acute rejection (BPAR), development of de novo donor-specific antibodies, or graft loss/death. Immunosuppression did not differ, and day 7 post-KTx plasma analyses showed approximately ten-fold lower TNF ( P <0.001) in IFX versus PLBO. BK viremia requiring IS change occurred more frequently in IFX (28.9%) versus PLBO (13.4%; P =0.004), with a strong trend toward higher rates of BKV nephropathy in IFX (13.3%) versus PLBO (4.9%; P =0.06).

CONCLUSIONS

IFX induction therapy does not benefit recipients of kidney transplants from deceased donors on this IS regimen. Because the intervention unexpectedly increased rates of BK virus infections, our findings underscore the complexities of targeting peritransplant inflammation as a strategy to improve KTx outcomes.Clinical Trial registry name and registration number:clinicaltrials.gov (NCT02495077).

Gas chromatography (GC) fingerprinting and immunomodulatory activity of polysaccharide from the rhizome of Menispermum dauricum DC

This research aimed to establish the gas chromatography (GC) fingerprints and examine the immunomodulatory activity of the rhizome of Menispermum dauricum polysaccharides. In this study, the preparation conditions were optimized by the response surface method (RSM). GC is an effective and sensitive technique employed to measure the composition of monosaccharides; the GC fingerprints of total polysaccharides from 10 batches of the rhizome of M. dauricum (tMDP) were established, and chemometrics methods were adopted to examine the differences and similarities of tMDP from distinct regions. The similarity evaluation illustrated that the polysaccharides derived from the rhizome of M. dauricum from different origins were highly similar. The results of principal components analysis (PCA) illustrated that all the tMDPs may be integrated into one group within the 95% confidence interval, but the rhizome of M. dauricum from different origins could also be distinguished in the plot of PCA scores. Then, the major bioactive fraction MDP was purified and obtained by column chromatography. Our previous study showed that MDP exhibited significant immunomodulatory activity, but the mechanism of the in vitro immunomodulatory activity of MDP is unclear. The macrophage activation induced by MDP was abolished when Toll-like receptor 4 (TLR4) signaling was knocked down by the TLR4 inhibitor. Furthermore, western blot analysis illustrated that MDP activated RAW264.7 cells through MAPKs and NFκB pathways induced by TLR4. This research offers a theoretical foundation for quality control and additional study as a potential immunomodulator of MDP.

Structure Characterization, Immunological Activity, and Mechanism of a Polysaccharide From the Rhizome of Menispermum dauricum DC

The purpose of this study was to investigate the structural characterization and immunological activity in vitro and in vivo of a polysaccharide from the rhizome of Menispermum dauricum. A new polysaccharide named MDP was isolated from the rhizome of Menispermum dauricum by hot water extraction, ethanol precipitation, anion-exchange, and gel-filtration chromatography. MDP was homogeneous and had a molecular weight of 6.16 ×103 Da, and it was an α-D-glucan containing a (1 → 6)-linked backbone, with a glucosyl residue at the C-3 position along the main chain. MDP exhibited immunological activity in vitro, which could significantly promote the proliferation and phagocytosis of RAW264.7 cells and the release of TNF-α and IL-6 factors. For immunological activity in vivo. MDP could significantly increase the thymus and spleen indices, enhance the macrophage function, increase the level of cytokine (IL-6 and TNF-α) and immunoglobulin IgM in the serum and regulate T lymphocyte subsets. Furthermore, MDP elevated the expression of the critical nodes in the TLR4-MyD88 signaling pathways in vivo. These results support the concept that MDP may exhibit immunological activity through TLR4-MyD88 signaling pathway in vivo.

T cell-derived tumor necrosis factor induces cytotoxicity by activating RIPK1-dependent target cell death

TNF ligation of TNF receptor 1 (TNFR1) promotes either inflammation and cell survival by (a) inhibiting RIPK1's death-signaling function and activating NF-κB or (b) causing RIPK1 to associate with the death-inducing signaling complex to initiate apoptosis or necroptosis. The cellular source of TNF that results in RIPK1-dependent cell death remains unclear. To address this, we employed in vitro systems and murine models of T cell-dependent transplant or tumor rejection in which target cell susceptibility to RIPK1-dependent cell death could be genetically altered. We show that TNF released by T cells is necessary and sufficient to activate RIPK1-dependent cell death in target cells and thereby mediate target cell cytolysis independently of T cell frequency. Activation of the RIPK1-dependent cell death program in target cells by T cell-derived TNF accelerates murine cardiac allograft rejection and synergizes with anti-PD1 administration to destroy checkpoint blockade-resistant murine melanoma. Together, the findings uncover a distinct immunological role for TNF released by cytotoxic effector T cells following cognate interactions with their antigenic targets. Manipulating T cell TNF and/or target cell susceptibility to RIPK1-dependent cell death can be exploited to either mitigate or augment T cell-dependent destruction of allografts and malignancies to improve outcomes.

Heat-killed Bacillus sp. SJ-10 probiotic acts as a growth and humoral innate immunity response enhancer in olive flounder (Paralichthys olivaceus)

Investigations were carried out to evaluate and quantify the effects of dietary supplementation with heat-killed (HK) Bacillus sp. SJ-10 (BSJ-10) probiotic (1 × 10⁸ CFU g^-1) on the growth and immunity of olive flounder (Paralichthys olivaceus). Flounder (averagely 9.64 g) were divided into two groups, and fed control and HK BSJ-10 (HKBSJ-10)-inoculated diets for 8 weeks. Investigations were carried out on growth and feed utilizations, innate immunity, serum biochemical parameters, microvilli length, and pro- and anti-inflammatory cytokine gene (tumor necrosis factor [TNF]-α, interleukin [IL]-1β, IL-6, and IL-10) transcriptions. Compared to control, HKBSJ-10 diet significantly (P < 0.05) enhanced weight gain and protein efficiency ratio, 1.17 and 1.11 folds respectively. Humoral innate immune parameters, lysozyme and superoxide dismutase in treatment group were also elevated by 1.34 and 1.16 folds. Similarly, an increased (P < 0.05) relative expressions of TNF-α, IL-1β, IL-6 were recorded in liver (2.71, 3.38, and 4.12 folds respectively), and gill (2.08, 1.98, and 1.81 folds respectively) than that of controls. Moreover, after challenge with Streptococcus iniae (1 × 10⁸ CFU mL^-1), the HKBSJ-10-fed group exhibited significantly higher protection (P < 0.05) against streptococcosis compared to controls, validating the observed changes in immune parameters and induction on the cytokine-encoding genes. Therefore, HKBSJ-10 increases growth, modulates innate immune parameters, and protects olive flounders against streptococcosis.

A heteropolysaccharide from Saccharina japonica with immunomodulatory effect on RAW 264.7 cells

A heteropolysaccharide (SHP) with a strong immunomodulatory effect on RAW 264.7 cells was prepared from Saccharina japonica. Chemical analysis demonstrated that SHP was primarily composed of mannose, glucuronic acid, glucose, fucose, galactose, xylose and rahmnose with a molar ratio of 1.00:0.85:0.84:0.58:0.30:0.37:0.15. ESI-MS showed that depolymerized SHP produced oligo-glucuronan, oligo-glucuronomannan, sulfated fuco-oligosaccharides and other hetero-oligosaccharides. The in vitro immunomodulatory results showed that SHP could increase NO production and up-regulate the expression of many immune effectors, including iNOS, COX-2 and TNF-α, displaying an apparent immune enhancement activities. Western blot analysis proved that SHP activated the expression levels of many key components involved in NF-κB, MAPK and Akt signaling pathways. Our results together indicated that SHP has the potential to be developed as a novel immunomodulator for activating immune system.

Sex-dependent aortic valve pathology in patients with rheumatic heart disease

Background

Rheumatic heart disease is an autoimmune disease caused by group A streptococci infection and frequently affects the aortic valve. Sex differences are common in the disease progression, treatment, and outcome. However, little is known about the sex differences in the pathology of aortic valves in rheumatic heart disease.

Design

We studied the end-stage calcific aortic valves from male versus female patients to reveal the sex-dependent pathology differences and molecular changes associated with requiring valve replacement.

Methods

Aortic valves from 39 patients with rheumatic heart disease (19 males and 20 females) were collected at the time of aortic valve replacement for comparative pathology, immunohistochemistry, and gene expression analyses. Clinical characteristics were also analyzed and compared between the two groups.

Results

Aortic valves from female patients exhibited increased expression of collagens, infiltration of monocytes/macrophages and neovascularization. Aortic valves from female patients also had increased expression of inflammatory genes involved in the NFKB pathway (phosphorylated NFKB p65 subunit, IL8, and NOS3) and Th1 cytokine genes (IFNA and IL12B). The severe valve pathology in female patients was correlated with a higher serum level of anti-streptolysin O antibodies.

Conclusion

Inflammation is more prominent in aortic valves of female patients with rheumatic heart disease. This sex difference may contribute to the severe valve pathology and worse outcome of female patients.

Complex role for the immune system in initiation and progression of pancreatic cancer

The immune system plays a complex role in the development and progression of pancreatic cancer. Inflammation can promote the formation of premalignant lesions and accelerate pancreatic cancer development. Conversely, pancreatic cancer is characterized by an immunosuppressive environment, which is thought to promote tumor progression and invasion. Here we review the current literature describing the role of the immune response in the progressive development of pancreatic cancer, with a focus on the mechanisms that drive recruitment and activation of immune cells at the tumor site, and our current understanding of the function of the immune cell types at the tumor. Recent clinical and preclinical data are reviewed, detailing the involvement of the immune response in pancreatitis and pancreatic cancer, including the role of specific cytokines and implications for disease outcome. Acute pancreatitis is characterized by a predominantly innate immune response, while chronic pancreatitis elicits an immune response that involves both innate and adaptive immune cells, and often results in profound systemic immune-suppression. Pancreatic adenocarcinoma is characterized by marked immune dysfunction driven by immunosuppressive cell types, tumor-promoting immune cells, and defective or absent inflammatory cells. Recent studies reveal that immune cells interact with cancer stem cells and tumor stromal cells, and these interactions have an impact on development and progression of pancreatic ductal adenocarcinoma (PDAC). Finally, current PDAC therapies are reviewed and the potential for harnessing the actions of the immune response to assist in targeting pancreatic cancer using immunotherapy is discussed.

HIV-1 infection inhibits cytokine production in human thymic macrophages

OBJECTIVE

The thymus serves as a critical site of T-lymphocyte ontogeny and selection. Thymic infection by HIV-1 is known to disrupt thymocyte maturation by both direct and indirect means; however, the mechanism behind these effects remains poorly defined. Macrophages represent one of the most important peripheral targets of HIV-1 infection, are resident in the thymic stroma, and play a central role in thymocyte maturation.

MATERIALS AND METHODS

Studies presented here define three primary features and outcomes of thymic macrophages (TM) and HIV-1 infection: (1) The distinctive TM phenotype (surface markers and cytokine production measured by immunofluorescence, fluorescence-activated cell sorting, and reverse transcriptase polymerase chain reaction) relative to macrophages from other sources (blood [monocyte-derived macrophages] and bone marrow); (2) infection of TM by different HIV-1 subtypes (X4, R5, and X4/R5) measured by enzyme-linked immunosorbent assay and polymerase chain reaction; and (3) consequences of HIV-1 infection on cytokine production by TM measured by reverse transcriptase polymerase chain reaction.

RESULTS

The results demonstrate that TM display a distinctive phenotype of HIV-1 receptors (CD4(lo), CXCR4(lo), CCR5(med), CCR3(hi)), chemokine production (macrophage inflammatory protein-1α(+); regulated on activation, normal T expressed and secreted(+); macrophage inflammatory protein-1b(-); stromal cell-derived factor -1(-)); and cytokine production (tumor necrosis factor-α(+), interleukin-8(+), macrophage colony-stimulating factor(+), interleukin-6(-)) relative to either monocyte-derived macrophages or bone marrow. TM were infected in vitro with R5 and X4/R5-tropic HIV-1 subtypes, and developed syncytia formation during long-term X4/R5 culture. In contrast, TM supported only transient replication of X4-tropic HIV-1. Lastly, infection of TM with HIV-1 abolished the production of all cytokines tested in long-term in vitro cultures.

CONCLUSIONS

Taken together, these results indicate that TM are a potential direct target of in situ HIV-1 infection, and that this infection may result in the disruption of macrophage functions that govern normal thymocyte maturation.

Mouririelliptica: validation of gastroprotective, healing and anti-Helicobacter pylori effects

ETHNOPHARMACOLOGICAL RELEVANCE

Mouriri elliptica Martius (Melastomataceae) is species reputed in folk medicine to heal gastric ulcer and gastritis.

AIM OF THE STUDY

Methanolic extract (ME) and ethyl acetate fraction (EAF) from leaves of Mouriri elliptica were evaluated for their gastroprotective, healing, immunological, toxicological and anti-Helicobacter pylori activities.

MATERIAL AND METHODS

The gastroprotective action of ME and EAF was evaluated in rodent experimental models and to elucidate mechanisms of action, the antisecretory action, involvements of NO, SH, PGE(2), anti-Helicobacter pylori action of ME was evaluated. We also used immunohistochemical (PCNA and COX-2) and immunomodulatory (murine peritoneal macrophages) assays to evaluate Mouriri elliptica effects.

RESULTS

ME present gastroprotective action without antisecretory effect. Otherwise, ME showed anti-Helicobacter pylori action (MIC=0.025mug/mL) and was able to inhibit NO production by macrophages. This species also accelerate the healing of ulcerated gastric mucosa by stimulating proliferation factors (PCNA), COX-2 and maintained basal PGE(2) level independent action of NSAID in gastric mucosa. The phytochemical investigation showed that this species possesses phenolic acid derivatives, acylglycoflavonoids and condensed tannins which probably influenced their pharmacological action.

CONCLUSION

All these results suggest the efficacy and safety of Mouriri elliptica in combating and healing gastric ulcer.

Interactions between immune and biotransformation systems in fish: a review

In animals biotransformation and immune system are not totally independent, there are numerous functional interrelationships between these two systems. They are both implicated in the capacity of organisms to resist to a wide variety of environmental components such as viruses, bacteria and xenobiotics. It is known for a long time that the immune system functions as a physiologic system and interacts with all the other components of the organism including nervous or endocrine ones. In the same manner, the biotransformation system (especially the cytochrome P450 monooxygenases) is involved in the regulation of numerous hormone productions. In this way, many studies in mammals have revealed the possible interaction between immune and biotransformation systems. Among these interactions, the capacity of the activation of host defense mechanisms to down-regulate microsomal cytochrome P450 and the role of biotransformation system in the xenobiotic-mediated immunotoxicity have been underlined. Advances in the basic knowledge of fish immune and biotransformation systems should lead to a better understanding of the possible interactions between both systems and should improve fish health monitoring which is a crucial ecotoxicological goal.

The Medicinal Mushroom Agaricus blazei Murrill: Review of Literature and Pharmaco-Toxicological Problems

Agaricus blazei Murrill (ABM) popularly known as 'Cogumelo do Sol' in Brazil, or 'Himematsutake' in Japan, is a mushroom native to Brazil, and widely cultivated in Japan for its medicinal uses, so it is now considered as one of the most important edible and culinary-medicinal biotechnological species. It was traditionally used to treat many common diseases like atherosclerosis, hepatitis, hyperlipidemia, diabetes, dermatitis and cancer. In vitro and in vivo ABM has shown immunomodulatory and antimutagenic properties, although the biological pathways and chemical substances involved in its pharmacological activities are still not clear. The polysaccharides phytocomplex is thought to be responsible for its immunostimulant and antitumor properties, probably through an opsonizing biochemical pathway. Clinical studies are positive confirmations, but we are still at the beginning, and there are perplexing concerns especially relative to the content of agaritine. Argantine is a well-known carcinogenic and toxic substance in animals, that must be completely and fully evaluated.

The preservation of phenotype and functionality of dendritic cells upon phagocytosis of polyelectrolyte-coated PLGA microparticles

Biodegradable microparticles (MP) represent a promising and efficient delivery system for parenteral vaccination. Recently, MP have also been explored as tool for the ex vivo antigen loading of professional antigen-presenting cells such as dendritic cells (DC) to be used as cellular vaccines. The purpose of this study was to investigate various polycationic coatings on poly(lactide-co-glycolide) (PLGA) MP, with regard to their effect on phenotypic and functional maturation of monocyte-derived DC (MoDC) that had previously been loaded with the MP in vitro. The preparation and concomitant coating of the PLGA was performed by means of a solvent extraction/evaporation method using a recently developed microextrusion-based technique. The polyelectrolytes tested for MP coating encompassed aminodextran, chitosan, poly(ethylene imine) (PEI), poly(L-lysine) and protamine. Uncoated and differently coated PLGA MP were fed to immature MoDC, which ingested efficiently the different MP types irrespective of their surface coating. The MP-loaded immature MoDC were then matured with the help of a cytokine/PGE-2 maturation cocktail. Here, the presence of the ingested MP did not affect the MoDC maturation in terms of expression of the surface markers CD80, CD83, CD86, HLA-DR and MMR, irrespective of the MP surface coating. Importantly, none of the PLGA MP types alone induced significant maturation of MoDC in the absence of the maturation cocktail. MP-loaded and subsequently matured MoDC expressed high levels of the chemokine receptor CCR7, whose functional activity was evidenced by the migration of MoDC towards CCL21, irrespective of the presence of ingested MP. Further, MP-loaded and subsequently matured MoDC also secreted comparable amounts of IL-10 and IL-12p70, irrespective of the presence of ingested MP except for PEI-coated PLGA MP, which enhanced significantly the secretion of IL-12p70 in mature MoDC. In conclusion, phenotypic and functional maturation of MoDC by means of a maturation cocktail remained unchanged irrespective of the presence of previously ingested differently coated PLGA MP. This offers interesting perspectives for using these particulate systems together with entrapped antigens for ex vivo loading of MoDC in view of cellular immunotherapy.

TNF-alpha gene 1031 T/C polymorphism in Turkish patients with Behçet's disease

BACKGROUND

Genetic factors that predispose individuals to Behçet's disease (BD) are considered to play an important role in development of the disease. The tumour necrosis factor (TNF)-alpha gene, which is closely linked to the HLA-B51 gene, is involved in susceptibility for BD. Recently, a polymorphism at position -1031 within the TNF-alpha promoter region was demonstrated to be responsible for susceptibility to BD in a British population. However, the functional effects of this polymorphism have not yet been determined.

OBJECTIVES

To investigate the possible relation of the TNF-alpha-1031 T/C polymorphism with susceptibility to BD in a Turkish population and to determine the functional importance of this polymorphism.

METHODS

Ninety-nine unrelated patients (47 women, 52 men; mean +/- SD age, 34.10 +/- 10.53 years) with BD and 103 ethnically matched healthy controls (52 males, 51 females; mean +/- SD age, 40.25 +/- 14.15) were enrolled in the study. For genotyping, polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) analysis was employed. The functional importance of TNF-alpha-1031 T/C polymorphism was determined with an enzyme-linked immunospot (ELISPOT) assay. For this purpose, mononuclear cells obtained from BD patients and controls were analysed for TNF-alpha and interferon (IFN)-gamma production.

RESULTS

A significant difference was observed between BD patients and controls with respect to the allele frequency of TNF-alpha-1031C [P = 0.018, OR = 1.83, 95% confidence interval (CI) = 1.07-3.13]. When the allele frequencies were analysed according to the clinical features, the T allele in patients with positive skin pathergy test (SPT) was significantly increased when compared with those of patients without these findings (P = 0.004, OR = 2.75, 95% CI = 1.3-5.86). To demonstrate the frequency of TNF-alpha and IFN-gamma producing cells, mononuclear cells from four representative individuals of each genotype were used and the spontaneous and stimulated TNF-alpha and IFN-gamma values (spot numbers) were analysed. Compared with the control groups, a significant increase was observed in the number of cells producing TNF-alpha obtained from BD patients (P < 0.001). Moreover, the stimulation index for TNF-alpha [bacterial lipopolysaccharide (LPS) stimulated/unstimulated] was higher for the CC genotype (9 +/- 9.5) with respect to the other genotypes (TT; 1.3 +/- 0.3 and TC; 1.2 +/- 0.2). While the difference in the spontaneous IFN-gamma values between groups were not statistically significant, the stimulated IFN-gamma values were found to be significantly increased in the BD group when compared with the healthy control group (P = 0.004).

CONCLUSIONS

Our results showed that, in the Turkish population the TNF-alpha-1031C allele is associated with susceptibility to BD. On the other hand, carrying the T allele may render patients more prone to developing a positive skin pathergy test. In addition, ELISPOT assays revealed that BD patients exhibited a significantly higher number of mononuclear cells producing TNF-alpha, and cells obtained from patients with a CC genotype had a stronger response to LPS stimulation. The strong IFN-gamma response upon LPS stimulation in BD patients supports the previous findings that BD is a Th1 driven disease. These findings suggest that the TNF-alpha-1031 polymorphism may have a functional effect and could explain the reason for high levels of TNF-alpha production observed in BD patients.

Susceptibility of prostate epithelial cells to Chlamydia muridarum infection and their role in innate immunity by recruitment of intracellular Toll-like receptors 4 and 2 and MyD88 to the inclusion

Although Chlamydia infections are widespread throughout the world, data about immunopathogenesis of genitourinary tract infections in males are very limited. In the present work we present an in vitro model of male genital tract-derived epithelial cells, more precisely prostate epithelial cells (PEC), to analyze if they are susceptible and able to respond to Chlamydia muridarum infection. Our results demonstrate that rat PEC are susceptible to C. muridarum infection and respond to this pathogen by up-regulating different proinflammatory cytokine and chemokine genes that could participate in the recruitment and local activation of immune cells, therefore influencing innate and adaptive immune responses during Chlamydia infection. Moreover, we analyzed the expression of Toll-like receptor 4 (TLR4), TLR2, and related molecules on PEC and the effect of C. muridarum infection on their expression. Our results demonstrate that PEC express significant levels of TLR4, CD14, TLR2, and the adaptor molecule MyD88 and up-regulate these proteins in response to C. muridarum infection. Indeed, TLR4, CD14, TLR2, and the adaptor MyD88 are specifically recruited to the vicinity of the bacterial inclusion, suggesting that these TLRs are actively engaged in signaling from this intracellular location in these cells. This is, to our knowledge, the first time that an in vitro model of infection with Chlamydia of male tract-derived epithelial cells has been achieved, and it provides the opportunity to determine how these cells respond and participate in modulating innate and adaptive immune response during Chlamydia infections.

Possible implication of macrophages in the regulation of cytochrome P450 activities in carp (Cyprinus carpio)

Macrophages play a key role in the regulation of cytochrome P450 activity induced by immunostimulants in mammals. We investigated the effects of immunostimulants (LPS, dextran sulfate and tilorone) on biotransformation and macrophage activities in carp. The major effect of LPS was its capacity to inhibit 3-MC-induced cytochrome P450 activities in the liver and head kidney. Basal phase I activities were reduced by tilorone and dextran sulfate in immune organs. Tilorone and dextran sulfate differently modulated total cytochrome P450 contents and P4501A activities suggesting differential sensitivity for P450 classes. In immune organs, tilorone and dextran sulfate inhibited basal EROD activity. Tilorone inhibited 3-MC-induced EROD activity whereas dextran sulfate enhanced this activity. LPS and dextran sulfate increased ROS production by macrophages and all the immunostimulants induced macrophage activating factor (MAF) production. This study demonstrates for the first time in fish the capacity of CYP-regulated immunostimulants to activate macrophages and provides initial insight into the capacity of macrophages to regulate CYP activity induced by immunostimulants in fish.

Prostate epithelial cells can act as early sensors of infection by up-regulating TLR4 expression and proinflammatory mediators upon LPS stimulation

Despite the prevalence of prostate disease, little is known about the immunobiology of the prostate and its contribution to disease. The main goal of this work was to investigate how prostate epithelial cells deal with inflammatory stimuli. To this aim, we stimulated a rat prostate epithelial cell line [metastasis-lung (MAT-LU)] or rat primary epithelial cells with lipopolysaccharide (LPS). Prostate epithelial cells constitutively express significant levels of Toll-like receptor 4 (TLR4) and CD14 mRNA. TLR2 transcription could also be demonstrated, suggesting that these cells could recognize a broader spectrum of microbial molecular patterns. TLR4, TLR2, and CD14 proteins were also detected, although not at the cell surface but intracellularly. Prostate epithelial cells not only express these receptors, but they are also able to respond to LPS, and LPS-stimulated MAT-LU cells activate nuclear factor-kappaB transcription factor, induce the expression of inducible nitric oxide (NO) synthase, and secrete NO. Even more, numerous chemokine genes are up-regulated or induced in this response. Our results clearly demonstrate that prostate epithelial cells are fully competent to respond. The fact that they express TLR4 and TLR2 intracellularly suggests the presence of regulatory mechanisms, which once overcome, could turn these cells into active players of the innate immunity, capable of initiating an inflammatory response.

Modulation of interleukin-8 and nitric oxide synthase mRNA levels by interferon-gamma in macrophages stimulated with lignin derivatives and lipopolysaccharides

It has been shown that interferon-gamma (IFN-gamma) plays a role in the regulation of interleukin-8 (IL-8), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) secretion by macrophages stimulated with lignin derivatives, such as EP3, and lipopolysaccharides (LPS) [Cytokine 11 (1999) 571]. To examine the mechanism by which IFN-gamma affects secretion of these factors, EP3- or LPS-stimulated macrophages were treated with different concentrations of IFN-gamma, and mRNA levels of IL-8, nitric oxide synthase (NOS) and TNF-alpha were determined by Northern blot analysis and reverse transcription-polymerase chain reaction (RT-PCR). As reported previously, stimulation of macrophages by EP3 or LPS dramatically induced the expression of IL-8, NOS, and TNF-alpha mRNAs. IFN-gamma clearly decreased the level of IL-8 mRNA in stimulated macrophages, although it did not affect the IL-8 mRNA level in unstimulated macrophages. In contrast, IFN-gamma appeared to increase the level of NOS mRNA both in unstimulated and stimulated macrophages. IFN-gamma, which increased the amount of TNF-alpha mRNA in unstimulated macrophages, showed no significant effect on the high level of TNF-alpha mRNA in stimulated macrophages. These results suggest that IFN-gamma causes changes in IL-8 and NO secretion by stimulated macrophages through its effects on the level of IL-8 and NO mRNA, respectively. Effects of IFN-gamma on TNF-alpha secretion by stimulated macrophages may be mediated by a different mechanism.

Secretion of TNF-alpha, IL-8 and nitric oxide by macrophages activated with Agaricus blazei Murill fractions in vitro

Water extracts of the mycelial culture and fruiting bodies of Agaricus blazei Murill were fractionated by ethanol precipitation using various ethanol concentrations. Original water extracts from mycelia (Fraction A-0) and fruiting bodies (Fraction B-0) induced TNF-alpha secretion by macrophages derived from rat bone marrow. Fractions B-4 and B-5 obtained from ethanol precipitation of fruiting bodies using 44% and 50% ethanol, respectively, and Fraction B-6 obtained from the supernatant at 50% ethanol markedly induced TNF-alpha secretion. Similar effects were observed in IL-8 secretion by macrophages. Regarding nitric oxide (NO), Fraction B-5 induced a significant increase in NO secretion and Fractions B-4 and B-6 induced slightly NO secretion. Northern blot analysis showed that the increases in cytokine- and NO secretion were due to an increase in cytokine mRNAs or NO synthase mRNA. Therefore, it is concluded that Agaricus blazei Murill components which activate macrophages result in the induction of cytokine- and NO secretion in vitro.