STAT6 controls the stability and suppressive function of regulatory T cells.

Signal transducer and activator of transcription 6 (STAT6) promotes tumorigenesis by decreasing the Forkhead box P3+ (Foxp3+) cell frequency allowing for the infiltration of inflammatory cells during the early stages of colitis-associated cancer (CAC). In this study, we dissected the role of STAT6 in the generation of inducible in vitro regulatory T cells (iTregs) and peripheral in vivo Tregs (pTregs) under inflammatory conditions. In in vitro assays, when STAT6 was lacking, iTregs preserved a stable phenotype and expressed high levels of Foxp3 and CD25 during long expansion periods, even in the presence of IL-6. This effect was associated with increased in vitro suppressive ability, over-expression of programmed death-1 (PD-1), CTLA-4, and Foxp3, and decreased IFN-γ expression. Furthermore, iTregs developed during STAT6 deficiency showed a higher demethylation status for the FOXP3 Treg-specific demethylated region (TSDR), coupled with lower DNA methyltransferase 1 (DNMT1) mRNA expression, suggesting that STAT6 may lead to Foxp3 silencing. Using a mouse model of CAC, the STAT6-/- pTregs expressed a more activated phenotype at the intestine, had higher suppressive capacity, and expressed more significant levels of PD-1 and latency-associated peptide of TGF-ß (LAP) associated with their ability to attenuate tumor development. These data suggest that STAT6 signaling impairs the induction, stability, and suppressive capacity of Tregs developed in vitro or in vivo during gut inflammation.

STAT1-Dependent Recruitment of Ly6ChiCCR2+ Inflammatory Monocytes and M2 Macrophages in a Helminth Infection.

Signal Transducer and Activator of Transcription (STAT) 1 signaling is critical for IFN-γ-mediated immune responses and resistance to protozoan and viral infections. However, its role in immunoregulation during helminth parasitic infections is not fully understood. Here, we used STAT1-/- mice to investigate the role of this transcription factor during a helminth infection caused by the cestode Taenia crassiceps and show that STAT1 is a central molecule favoring susceptibility to this infection. STAT1-/- mice displayed lower parasite burdens at 8 weeks post-infection compared to STAT1+/+ mice. STAT1 mediated the recruitment of inflammatory monocytes and the development of alternatively activated macrophages (M2) at the site of infection. The absence of STAT1 prevented the recruitment of CD11b+Ly6ChiLy6G- monocytic cells and therefore their suppressive activity. This failure was associated with the defective expression of CCR2 on CD11b+Ly6ChiLy6G- cells. Importantly, CD11b+Ly6ChiLy6G- cells highly expressed PDL-1 and suppressed T-cell proliferation elicited by anti-CD3 stimulation. PDL-1+ cells were mostly absent in STAT1-/- mice. Furthermore, only STAT1+/+ mice developed M2 macrophages at 8 weeks post-infection, although macrophages from both T. crassiceps-infected STAT1+/+ and STAT1-/- mice responded to IL-4 in vitro, and both groups of mice were able to produce the Th2 cytokine IL-13. This suggests that CD11b+CCR2+Ly6ChiLy6G- cells give rise to M2 macrophages in this infection. In summary, a lack of STAT1 resulted in impaired recruitment of CD11b+CCR2+Ly6ChiLy6G- cells, failure to develop M2 macrophages, and increased resistance against T. crassiceps infection.

STAT6 Is Critical for the Induction of Regulatory T Cells In Vivo Controlling the Initial Steps of Colitis-Associated Cancer.

Inflammation is the main driver of the tumor initiation and progression in colitis-associated colorectal cancer (CAC). Recent findings have indicated that the signal transducer and activator of transcription 6 (STAT6) plays a fundamental role in the early stages of CAC, and STAT6 knockout (STAT6-/-) mice are highly resistant to CAC development. Regulatory T (Treg) cells play a major role in coordinating immunomodulation in cancer; however, the role of STAT6 in the induction and function of Treg cells is poorly understood. To clarify the contribution of STAT6 to CAC, STAT6-/- and wild type (WT) mice were subjected to an AOM/DSS regimen, and the frequency of peripheral and local Treg cells was determined during the progression of CAC. When STAT6 was lacking, a remarkable reduction in tumor growth was observed, which was associated with decreased inflammation and an increased number of CD4+CD25+Foxp3+ cells in the colon, circulation, and spleen, including an over-expression of TGF-beta, IL-10, and Foxp3, compared to WT mice, during the early stages of CAC development. Conversely, WT mice showed an inverse frequency of Treg cells compared with STAT6-/- mice, which was followed by intestinal tumor formation. Increased mucosal inflammation, histological damage, and tumorigenesis were restored to levels observed in WT mice when an early inhibition/depletion of Treg cells was performed in STAT6-/- mice. Thus, with STAT6 deficiency, an increased number of Treg cells induce resistance against tumorigenesis, arresting tumor-promoting inflammation. We reported a direct role of STAT6 in the induction and function of Treg cells during CAC development and suggest that STAT6 is a potential target for the modulation of immune response in colitis and CAC.

Denitrase activity of Debaryomyces hansenii reduces the oxidized compound 3-nitrotyrosine in mice liver with colitis.

The oxidation of tyrosine to 3-nitrotyrosine is irreversible, and due to this characteristic, 3-nitrotyrosine is used as a marker for oxidative stress in a range of diverse chronic and degenerative diseases. It has been established that the yeast Debaryomyces hansenii (D. hansenii) can assimilate free 3-nitrotyrosine as unique source of nitrogen, and during saline stress, has a high denitrase activity to detoxify this compound in a reaction that involves the liberation of nitrogen dioxide from 3-nitrotyrosine. However, until now it has not been determined whether D. hansenii can detoxify protein-bound 3-nitrotyrosine such as nitrated proteins present in different chronic illnesses. TThe aim of the present study was to evaluate the denitrase activity of D. hansenii to reduce 3-nitrotyrosine from liver proteins of mice with colitis. Firstly, the levels of reactive oxygen species of liver tissue of colitic and control mice were measured by the reaction with the 2'7'-dichlorofluorescein diacetate. Denitrase activity of D. hansenii was evaluated by incubating cell extracts of the yeast with protein extracts from livers of mice with colitis. Following incubation, 3-nitrotyrosine was measured, and to corroborate that denitrase reaction had occurred, the production of nitrites was measured. In samples of liver tissue from mice with colitis, the maximum levels of reactive oxygen species were up to two times higher compared with the control livers. Following the incubation of colitic liver samples with cell extracts of D. hansenii, it was observed that 3-nitrotyrosine decreased to the basal concentration of control liver samples, and that the concentration of nitrites was increased. These results indicate that denitrase of D. hansenii extracts can effectively detoxify 3-nitrotyrosine bound to proteins and that the extracts could be used to decrease protein oxidation damage in chronic degenerative diseases.

Taenia solium glutathione transferase fraction activates macrophages and favors the development of Th1-type response.

Glutathione (GSH) transferase (GST) is an essential enzyme in cestodes for the detoxification of xenobiotics. In Taenia solium, two GSTs (Ts25GST and Ts26GST kDa) were isolated as a fraction (SGSTF) by GSH-Sepharose-4B. Both are located on the tegument. Immunization assays with SGSTF reduced up to 90% of the parasitic load in a murine model of cysticercosis. It prompted us to investigate how SGSTF induces this protective immune response. To test it, we exposed peritoneal macrophages to SGSTF for 24 h; such exposure favored the production of IL-12, TNF, and IL-10 as well as the expression of nitric oxide synthase 2 inducible (Nos2) and CD86, but did not induce the expression of chitinase-like 3 (Chil3). Confocal microscopy showed that the macrophages internalize the SGSTF which co-localized after 1 h with MHC-II in their plasma membranes. Macrophages exposed to SGSTF and co-cultured with anti-CD3 pre-activated T CD4+ cells, enhanced the proliferation of CD4+ cells, induced high interferon-γ (IFN-γ) secretion, and elevated the expression of CD25 and CD69, molecules associated with cell activation. Similar assay using T CD4+ cells from DO11.10 mice and ovalbumin (OVA) peptide+SGSTF as stimuli, showed enhanced cell proliferation and OVA-specific IFN-γ secretion. These data are in-line with those indicating that the P1, P5, and P6 peptides of Schistosoma japonicum 28GST highly promote T-cell proliferation and Th1 response in vitro We found that such peptides are also present on Ts25GST and Ts26GST. It suggests that SGSTF activates peritoneal macrophages to a classically activated-like phenotype, and that these macrophages induce the differentiation of T CD4+ cells toward a Th1-type response.

Helminth Products Potently Modulate Experimental Autoimmune Encephalomyelitis by Downregulating Neuroinflammation and Promoting a Suppressive Microenvironment.

A negative correlation between the geographical distribution of autoimmune diseases and helminth infections has been largely associated in the last few years with a possible role for such type of parasites in the regulation of inflammatory diseases, suggesting new pathways for drug development. However, few helminth-derived immunomodulators have been tested in experimental autoimmune encephalomyelitis (EAE), an animal model of the human disease multiple sclerosis (MS). The immunomodulatory activities of Taenia crassiceps excreted/secreted products (TcES) that may suppress EAE development were sought for. Interestingly, it was discovered that TcES was able to suppress EAE development with more potency than dexamethasone; moreover, TcES treatment was still effective even when inoculated at later stages after the onset of EAE. Importantly, the TcES treatment was able to induce a range of Th2-type cytokines, while suppressing Th1 and Th17 responses. Both the polyclonal and the antigen-specific proliferative responses of lymphocytes were also inhibited in EAE-ill mice receiving TcES in association with a potent recruitment of suppressor cell populations. Peritoneal inoculation of TcES was able to direct the normal inflammatory cell traffic to the site of injection, thus modulating CNS infiltration, which may work along with Th2 immune polarization and lymphocyte activation impairment to downregulate EAE development.

Lack of STAT6 Attenuates Inflammation and Drives Protection against Early Steps of Colitis-Associated Colon Cancer.

Colitis-associated colon cancer (CAC) is one of the most common malignant neoplasms and a leading cause of death. The immunologic factors associated with CAC development are not completely understood. Signal transducer and activator of transcription 6 (STAT6) is part of an important signaling pathway for modulating intestinal immune function and homeostasis. However, the role of STAT6 in colon cancer progression is unclear. Following CAC induction in wild-type (WT) and STAT6-deficient mice (STAT6-/-), we found that 70% of STAT6-/- mice were tumor-free after 8 weeks, whereas 100% of WT mice developed tumors. STAT6-/- mice displayed fewer and smaller colorectal tumors than WT mice; this reduced tumorigenicity was associated with decreased proliferation and increased apoptosis in the colonic mucosa in the early steps of tumor progression. STAT6-/- mice also exhibited reduced inflammation, diminished concentrations COX2 and nuclear ß-catenin protein in the colon, and decreased mRNA expression of IL17A and TNFα, but increased IL10 expression when compared with WT mice. Impaired mucosal expression of CCL9, CCL25, and CXCR2 was also observed. In addition, the number of circulating CD11b+Ly6ChiCCR2+ monocytes and CD11b+Ly6ClowLy6G+ granulocytes was both decreased in a STAT6-dependent manner. Finally, WT mice receiving a STAT6 inhibitor in vivo confirmed a significant reduction in tumor load as well as less intense signs of CAC. Our results demonstrate that STAT6 is critical in the early steps of CAC development for modulating inflammatory responses and controlling cell recruitment and proliferation. Thus, STAT6 may represent a promising target for CAC treatment. Cancer Immunol Res; 5(5); 385-96. ©2017 AACR.

Protective Effect of Amphipterygium adstringens Extract on Dextran Sulphate Sodium-Induced Ulcerative Colitis in Mice.

Amphipterygium adstringens is an endemic species in Mexico commonly known as "cuachalalate." Healers to treat gastritis, gastric ulcers, and gastrointestinal cancer have traditionally used the bark. We investigated the effects of alcoholic extract of A. adstringens (AaEE) in DSS-induced colitis in mice. The protective effect of AaEE was determined at 200 mg/kg by oral gavage for 10 days. We determine the effect of AaEE on clinical features (disease activity index), antioxidants, anti-inflammatory, and immunomodulatory activities in relation to the activity of SOD, CAT, and GPx, levels of proinflammatory cytokines, and changes both macroscopic and microscopic of the colonic mucosa. AaEE significantly reduced the inflammation of colon and significantly increased SOD and GPx activities. AaEE also significantly decreased TNF-α, IFN-γ, and IL-1ß cytokine levels compared to DSS-treated mice and reduced both infiltration of inflammatory cells and the mucosal damage in colon. The results suggested the protective potential of AaEE in DSS-induced colitis and this might be attributed to its phytochemicals compounds that have been found to induce a wide spectrum of activities such as reduction in oxidative stress, suppression of inflammation, modulating numerous signal transduction pathways, and induction of apoptosis. The findings of this study suggest that AaEE has substantial potential for the treatment of inflammatory colitis.

Extraintestinal Helminth Infection Limits Pathology and Proinflammatory Cytokine Expression during DSS-Induced Ulcerative Colitis: A Role for Alternatively Activated Macrophages and Prostaglandins.

Chronic inflammation of the intestinal mucosa is characteristic of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. Helminth parasites have developed immunomodulatory strategies that may impact the outcome of several inflammatory diseases. Therefore, we investigated whether Taenia crassiceps infection is able to decrease the inflammatory effects of dextran sulfate sodium- (DSS-) induced ulcerative colitis in BALB/c and C57BL/6 mice. Preinfection significantly reduced the manifestations of DSS-induced colitis, as weight loss and shortened colon length, and decreased the disease activity index independently of the genetic background of the mice. Taenia infection decreased systemic levels of proinflammatory cytokines while increasing levels of IL-4 and IL-10, and the inflammatory infiltrate into the colon was also markedly reduced. RT-PCR assays from colon showed that T. crassiceps-infected mice displayed increased expression of Arginase-1 but decreased expression of iNOS compared to DSS-treated uninfected mice. The percentages of T regulatory cells were not increased. The adoptive transfer of alternatively activated macrophages (AAMФs) from infected mice into mice with DSS-induced colitis reduced the severity of colon inflammation. Administration of indomethacin abrogated the anticolitic effect of Taenia. Thus, T. crassiceps infection limits the pathology of ulcerative colitis by suppressing inflammatory responses mechanistically associated with AAMФs and prostaglandins.

The macrophage galactose-type lectin-1 (MGL1) recognizes Taenia crassiceps antigens, triggers intracellular signaling, and is critical for resistance to this infection.

C-type lectins are multifunctional sugar-binding molecules expressed on dendritic cells (DCs) and macrophages that internalize antigens for processing and presentation. Macrophage galactose-type lectin 1 (MGL1) recognizes glycoconjugates expressing Lewis X structures which contain galactose residues, and it is selectively expressed on immature DCs and macrophages. Helminth parasites contain large amounts of glycosylated components, which play a role in the immune regulation induced by such infections. Macrophages from MGL1(-/-) mice showed less binding ability toward parasite antigens than their wild-type (WT) counterparts. Exposure of WT macrophages to T. crassiceps antigens triggered tyrosine phosphorylation signaling activity, which was diminished in MGL1(-/-) macrophages. Following T. crassiceps infection, MGL1(-/-) mice failed to produce significant levels of inflammatory cytokines early in the infection compared to WT mice. In contrast, MGL1(-/-) mice developed a Th2-dominant immune response that was associated with significantly higher parasite loads, whereas WT mice were resistant. Flow cytometry and RT-PCR analyses showed overexpression of the mannose receptors, IL-4Rα, PDL2, arginase-1, Ym1, and RELM-α on MGL1(-/-) macrophages. These studies indicate that MGL1 is involved in T. crassiceps recognition and subsequent innate immune activation and resistance.

Extraintestinal helminth infection reduces the development of colitis-associated tumorigenesis.

Colitis-associated colorectal cancer (CAC) is one of the most common cancers and is closely related to chronic or deregulated inflammation. Helminthic infections can modulate inflammatory responses in some diseases, but their immunomodulatory role during cancer development remains completely unknown. We have analyzed the role of Taenia crassiceps-induced anti-inflammatory response in determining the outcome of CAC. We show that extraintestinal T. crassiceps infection in CAC mice inhibited colonic inflammatory responses and tumor formation and prevented goblet cell loss. There was also increased expression of IL-4 and alternatively activated macrophages markers in colonic tissue and negative immunomodulation of pro-inflammatory cytokine expression. In addition, T. crassiceps infection prevented the upregulation of ß-catenin and CXCR2 expression observed in the CAC mice, which are both markers associated with CAC-tumorigenesis, and reduced the numbers of circulating and colonic CD11b(+)Ly6C(hi)CCR2(+) monocytes. Thus, immunomodulatory activities induced by helminth infections may have a role in the progression of CAC.

Taenia crassiceps infection does not influence the development of experimental rheumatoid arthritis.

It was previously reported by our group that infection with Taenia crassiceps reduces incidence and severity of inflammatory and autoimmune experimental diseases like type 1 diabetes and experimental autoimmune encephalomyelitis. In this research, we set out to study whether infection with T. crassiceps would affect the development of experimental rheumatoid arthritis (RA). We found that mice infected with the parasite and induced with experimental RA showed similar clinical scores as the noninfected experimental RA group; systemic cytokines were not affected while anti-CII Abs were higher in the infected group. Histological evaluation showed damage in both infected and noninfected experimental RA-induced groups and although some surface molecules such as PDL-2 and MR which are associated with immunomodulatory mechanisms were upregulated in the infected and RA-induced group as compared to the noninfected RA group, they did not exert any changes in the outcome of experimental RA. Thus, we determined that infection with T. crassiceps does not influence the outcome of experimental RA.

Signal transducer and activator of transcription factor 6 signaling contributes to control host lung pathology but favors susceptibility against Toxocara canis infection.

Using STAT6(-/-) BALB/c mice, we have analyzed the role of STAT6-induced Th2 response in determining the outcome of experimental toxocariasis caused by embryonated eggs of the helminth parasite Toxocara canis. Following T. canis infection wild-type BALB/c mice developed a strong Th2-like response, produced high levels of IgG1, IgE, and IL-4, recruited alternatively activated macrophages, and displayed a moderate pathology in the lungs; however, they harbored heavy parasite loads in different tissues. In contrast, similarly infected STAT6(-/-) BALB/c mice mounted a weak Th2-like response, did not recruit alternatively activated macrophages, displayed a severe pathology in the lungs, but efficiently controlled T. canis infection. These findings demonstrate that Th2-like response induced via STAT6-mediated signaling pathway mediates susceptibility to larval stage of T. canis. Furthermore, they also indicate that unlike most gastrointestinal helminths, immunity against larvae of T. canis is not mediated by a Th2-dominant response.

Helminth excreted/secreted antigens repress expression of LPS-induced Let-7i but not miR-146a and miR-155 in human dendritic cells.

MicroRNAs have emerged as key regulators of immune responses. They influence immune cells' function and probably the outcome of several infections. Currently, it is largely unknown if helminth parasites and their antigens modify host microRNAs expression. The aim of this study was to explore if excreted/secreted antigens of Taenia crassiceps regulate LPS-induced miRNAs expression in human dendritic cells. We found that these antigens repressed LPS-let-7i induction but not mir-146a or mir-155 and this correlates with a diminished inflammatory response. This let-7i downregulation in dendritic cells constitutes a novel feature of the modulatory activity that helminth-derived antigens exert on their host.

Increased levels of prolactin receptor expression correlate with the early onset of lupus symptoms and increased numbers of transitional-1 B cells after prolactin treatment.

BACKGROUND: Prolactin is secreted from the pituitary gland and other organs, as well as by cells such as lymphocytes. Prolactin has an immunostimulatory effect and is associated with autoimmune diseases that are characterised by abnormal B cell activation, such as systemic lupus erythematosus (SLE). Our aim was to determine if different splenic B cell subsets express the prolactin receptor and if the presence of prolactin influences these B cell subsets and correlates with development of lupus. RESULTS: Using real-time PCR and flow cytometry, we found that different subsets of immature (transitional) and mature (follicular, marginal zone) B cells express different levels of the prolactin receptor and are differentially affected by hyperprolactinaemia. We found that transitional B cells express the prolactin receptor at higher levels compared to mature B cells in C57BL/6 mice and the lupus-prone MRL/lpr and MRL mouse strains. Transitional-1 (T1) B cells showed a higher level of prolactin receptor expression in both MRL/lpr and MRL mice compared to C57BL/6 mice. Hyperprolactinaemia was induced using metoclopramide, which resulted in the development of early symptoms of SLE. We found that T1 B cells are the main targets of prolactin and that prolactin augments the absolute number of T1 B cells, which reflects the finding that this B cell subpopulation expresses the highest level of the prolactin receptor. CONCLUSIONS: We found that all B cell subsets express the prolactin receptor but that transitional B cells showed the highest prolactin receptor expression levels. Hyperprolactinaemia in mice susceptible to lupus accelerated the disease and increased the absolute numbers of T1 and T3 B cells but not of mature B cells, suggesting a primary effect of prolactin on the early stages of B cell maturation in the spleen and a role of prolactin in B cell differentiation, contributing to SLE onset.

TLR2 mediates immunity to experimental cysticercosis.

Information concerning TLR-mediated antigen recognition and regulation of immune responses during helminth infections is scarce. TLR2 is a key molecule required for innate immunity and is involved in the recognition of a wide range of viruses, bacteria, fungi and parasites. Here, we evaluated the role of TLR2 in a Taenia crassiceps cysticercosis model. We compared the course of T. crassiceps infection in C57BL/6 TLR2 knockout mice (TLR2⁻/⁻) with that in wild type C57BL/6 (TLR2⁺/⁺) mice. In addition, we assessed serum antibody and cytokine profiles, splenic cellular responses and cytokine profiles and the recruitment of alternatively activated macrophages (AAMφs) to the site of the infection. Unlike wild type mice, TLR2⁻/⁻ mice failed to produce significant levels of inflammatory cytokines in either the serum or the spleen during the first two weeks of Taenia infection. TLR2⁻/⁻ mice developed a Th2-dominant immune response, whereas TLR2⁺/⁺ mice developed a Th1-dominant immune response after Taenia infection. The insufficient production of inflammatory cytokines at early time points and the lack of Th1-dominant adaptive immunity in TLR2⁻/⁻ mice were associated with significantly elevated parasite burdens; in contrast, TLR2⁺/⁺ mice were resistant to infection. Furthermore, increased recruitment of AAMφs expressing PD-L1, PD-L2, OX40L and mannose receptor was observed in TLR2⁻/⁻ mice. Collectively, these findings indicate that TLR2-dependent signaling pathways are involved in the recognition of T. crassiceps and in the subsequent activation of the innate immune system and production of inflammatory cytokines, which appear to be essential to limit infection during experimental cysticercosis.

Consecutive low doses of cyclosporine A induce pro-inflammatory cytokines and accelerate allograft skin rejection.

Cyclosporine A (CsA) is a fungus-derived molecule with potent immunosuppressive activity that has been largely used to downregulate cell-mediated immune responses during transplantation. However, previous data have indicated that CsA shows immunomodulatory activity that relays on the antigen concentration and the dose of CsA used. To test the hypothesis that minimal doses of CsA may show different outcomes on grafts, we used an experimental model for skin transplants in mice. ICR outbred mice received skin allografts and were either treated daily with different doses of CsA or left untreated. Untreated mice showed allograft rejection within 14 days, with graft necrosis, infiltration of neutrophils and macrophages and displayed high percentages of CD8+ T cells in the spleens, which were associated with high serum levels of IL-12, IFN-g and TNF-α. As expected, mice treated with therapeutic doses of CsA (15 mg/kg) did not show allograft rejection within the follow-up period of 30 days and displayed the lowest levels of IL-12, IFN-g and TNF-α as well as a reduction in CD8+ lymphocytes. In contrast, mice treated with consecutive minimal doses of CsA (5×10(-55) mg/kg) displayed an acute graft rejection as early as one to five days after skin allograft; they also displayed necrosis and strong inflammatory infiltration that was associated with high levels of IL-12, IFN-g and TNF-α. Moreover, the CD4+ CD25hiFoxP3+ subpopulation of cells in the spleens of these mice was significantly inhibited compared with animals that received the therapeutic treatment of CsA and those treated with placebo. Our data suggest that consecutive, minimal doses of CsA may affect Treg cells and may stimulate innate immunity.

The activation of CD14, TLR4, and TLR2 by mmLDL induces IL-1ß, IL-6, and IL-10 secretion in human monocytes and macrophages.

UNLABELLED: Atherosclerosis is considered a chronic inflammatory disease in which monocytes and macrophages are critical. These cells express CD14, toll-like receptor (TLR) 2, and TLR4 on their surfaces, are activated by minimally modified low-density lipoprotein (mmLDL) and are capable of secreting pro-inflammatory cytokines. The aim of this research was thus to demonstrate that the activation of CD14, TLR2, and TLR4 by mmLDL induces the secretion of cytokines. METHODS: Human monocytes and macrophages were incubated with monoclonal antibodies specific for CD14, TLR4, and TLR2 prior to stimulation with mmLDL. Cytokine secretion was then compared to that observed upon mmLDL stimulation in untreated cells. RESULTS: Stimulation with mmLDL induced the secretion of pro-inflammatory cytokines. Blocking CD14 in monocytes inhibited secretion of interleukin (IL)-1ß (72%), IL-6 (58%) and IL-10 (63%), and blocking TLR4 inhibited secretion of IL-1ß by 67%, IL-6 by 63% and IL-10 by 60%. Blocking both receptors inhibited secretion of IL-1ß by 73%, IL-6 by 69% and IL-10 by 63%. Furthermore, blocking TLR2 inhibited secretion of IL-1ß by 65%, IL-6 by 62% and IL-10 by 75%. In macrophages, we found similar results: blocking CD14 inhibited secretion of IL-1ß by 59%, IL-6 by 52% and IL-10 by 65%; blocking TLR4 inhibited secretion of IL-1ß by 53%, IL-6 by 63% and IL-10 by 61%; and blocking both receptors inhibited secretion of IL-1ß by 69%, IL-6 by 67% and IL-10 by 65%. Blocking TLR2 in macrophages inhibited secretion of IL-1ß by 57%, IL-6 by 40% and IL-10 by 72%. CONCLUSION: Our study demonstrates that CD14, TLR4, and TLR2 participate in the immune response against mmLDL by inducing the production of pro-inflammatory cytokines in both monocytes and macrophages. These findings suggest that the activation of these receptors by mmLDL contributes to the inflammatory process of atherosclerosis.

[The role of eotaxins in bronchial asthma and nasal polyposis]. / Eotaxinas en asma bronquial y poliposis nasal.

Over the last few years, three specific eosinophil activating peptides, eotaxin-1, -2 and -3, members of the chemokine family have been identified. These cytokines exert a number of functions on eosinophils including chemotaxis, transendothelial migration and induction of the release of reactive oxygen species. Eosinophils are considered to play an important role in allergic disease by causing tissue damage through the release of toxic proteases, lipid mediators, cytokines and oxygen free radicals. This article reviews the role of eotaxins in asthma and nasal polyps. Discussion focuses on therapeutic guidelines, particularly as it has been shown that CCR3, the major chemokine receptor in eosinophils, serves as a eotaxin receptor.

Eotaxinas en asma bronquial y poliposis nasal / The role of eotaxins in bronchial asthma and nasal polyposis

Durante la última década se han descubierto tres péptidos con actividad quimotáctica específica para los eosinófilos y que son miembros de la familia de las quimocinas. Estas citocinas inducen a los eosinófilos a realizar diferentes funciones como quimotaxis, migración transendotelial e inducción de la liberación de radicales de oxígeno. Como los eosinófilos infiltran tanto las vías aéreas de pacientes asmáticos como los pólipos nasales, se ha postulado que las eotaxinas pueden ser responsables del reclutamiento de estas células. Los eosinófilos tienen la propiedad de inducir remodelamiento de la matriz extracelular y daño tisular a través de la liberación de proteasas tóxicas, mediadores inflamatorios, citocinas y radicales de oxígeno. Por lo cual, el desarrollo de estrategias terapéuticas que inhiban el reclutamiento de estas células constituye una esperanza en el tratamiento de las enfermedades alérgicas. Este artículo revisa la función de las eotaxinas en asma y poliposis nasal, además de discutir el posible uso de antagonistas de CCR3, receptor de las eotaxinas, como una nueva modalidad terapéutica de asma y poliposis nasal.

Over the last few years, three specific eosinophil activating peptides, eotaxin-1, -2 and -3, members of the chemokine family have been identified. These cytokines exert a number of functions on eosinophils including chemotaxis, transendothelial migration and induction of the release of reactive oxygen species. Eosinophils are considered to play an important role in allergic disease by causing tissue damage through the release of toxic proteases, lipid mediators, cytokines and oxygen free radicals. This article reviews the role of eotaxins in asthma and nasal polyps. Discussion focuses on therapeutic guidelines, particularly as it has been shown that CCR3, the major chemokine receptor in eosinophils, serves as a eotaxin receptor.