IL-17-differentiated macrophages secrete pro-inflammatory cytokines in response to oxidized low-density lipoprotein.

BACKGROUND: Cytokines and macrophages play a central role in the development of atherosclerosis. Interleukin (IL)-17 is a pro-inflammatory cytokine with differential effects on innate immune cells. We investigated the effects of IL-17 on macrophage differentiation and foam cell formation and activation in response to oxidized low-density lipoprotein (oxLDL). METHODS: Human monocytes were treated with IL-17 to induce macrophage differentiation. As controls, human monocytes were differentiated into M1 macrophages (M1) or M2 macrophages (M2). Subsequently, we analyzed the expression levels of markers such as CD80, CD36 and Toll-like receptors (TLRs) as well as foam cell formation and cytokines in M1, M2 and macrophages differentiated with IL-17 with or without oxLDL. RESULTS: The expression of M1 or M2 markers or cytokines was not induced in macrophages differentiated with IL-17. Macrophages differentiated with IL-17 formed few foam cells, with an average proportion of 20%, and expressed 3 times as much TLR2 and 3.8 times as much TLR4 as M0 macrophages. Additionally, macrophages differentiated with IL-17 acquired inflammatory capacity in response to oxLDL through the expression of specific markers, such as CD80, which increased 18-times compared with macrophages differentiated with IL-17 alone, and secreted 1.3 times less tumor necrosis factor (TNF)-α than M1. Additionally, oxLDL increased the levels of CD80, CD86 and IL-6 by 5.7, 2.8 and 1.4 times in M1 compared with M1 in the absence of oxLDL. In M2, oxLDL induced increases in the secretion of IL-6 and TNF-α that were 1.9 times and 1.2 times smaller, respectively, than those observed in M1. CONCLUSION: Our study demonstrates that differentiation of macrophages with IL-17 does not induce the expression of markers or cytokines characteristic of M1 or M2 and these macrophages form few foam cells; however, the expression of TLR is increased. Moreover, these macrophages acquire the inflammatory capacity as evidenced by the expression of costimulatory molecules and secretion of pro-inflammatory cytokines in response to oxLDL. These findings suggest that the activation of macrophages differentiated with IL-17 by oxLDL contributes to the inflammatory process of atherosclerosis.

Beneficial Effects of Enteral Docosahexaenoic Acid on the Markers of Inflammation and Clinical Outcomes of Neonates Undergoing Cardiovascular Surgery: An Intervention Study.

BACKGROUND: Neonates undergoing surgery are at risk for uncontrolled inflammatory response and adverse clinical outcomes. Docosahexaenoic acid (DHA) ameliorates inflammation, improving clinical outcomes. However, its effect has not been evaluated in neonates undergoing surgery. We evaluated the effect of DHA on markers of inflammation and clinical outcomes in neonates undergoing surgery. METHODS: A double-blind clinical trial evaluated the effect of enteral DHA (DHA group) versus sunflower oil (SO group) perioperatively administered in neonates scheduled for cardiovascular surgery. Inflammation was evaluated by percentage of cells+ for cytokines and CD69 in mononuclear cells at baseline, 24 h and 7 days post surgery. Clinical outcomes measured were sepsis, organ dysfunctions (ODs), length of stay in intensive care and bleeding. Repeated measures analysis of variance and logistic regression were applied. RESULTS: Sixteen neonates received DHA and 18 received SO. Cells+ from neonates in the DHA group showed an early increase in receptor antagonist of interleukin (IL)-1+ (IL-1ra+) and IL-10+ and a late decrease in IL-6+. IL-1ß+ and IL-10+ changes were different between groups. After adjusting for confounders, less cells from DHA group were IL-1ß+, IL-6+, IL-1ra+ and IL-10+. DHA group presented less sepsis, ODs and shorter stay, but no difference in CD69+CD4+ cells or bleeding between groups. CONCLUSIONS: Administration of enteral DHA ameliorates markers of inflammation and improves clinical outcomes in surgical neonates.

Enteral Docosahexaenoic Acid Reduces Analgesic Administration in Neonates Undergoing Cardiovascular Surgery.

BACKGROUND: Neonates undergoing surgery require analgesic medication to ameliorate acute pain. These medications produce negative side effects. Docosahexaenoic acid (DHA) has an antinociceptive effect in animals, but this has not been evaluated in human neonates. We evaluated the DHA effect on cumulative dose and duration of analgesics administered to neonates undergoing cardiovascular surgery. METHODS: A secondary analysis was performed with data from a clinical trial, in which enteral DHA was administered perioperatively compared with sunflower oil (SO). Present study assessed the antinociceptive effect of DHA by measuring the cumulative dose and duration of analgesics administered during postoperative stay in a neonatal intensive care unit. Multivariate linear regression models were performed. RESULTS: Seventeen neonates received DHA and 18 received SO in the control group. Compared with the control group, the DHA group received lower cumulative dose (14.6 ± 2.2 vs. 25.2 ± 4.8 µg/kg, p = 0.029) and shorter duration of buprenorphine (2 days (1-8) vs. 4.5 days (1-12); p = 0.053). After adjusting for confounders, the DHA group received significantly lesser buprenorphine (ß = -27 µg/kg, p = 0.028; R2 model = 0.90) for shorter duration (ß = -9 days, p = 0.003; R2 model = 0.94). No differences in fentanyl or ketorolac were detected. CONCLUSIONS: Buprenorphine administration was reduced in neonates who received DHA, suggesting that DHA likely has analgesic effects.

Differential Expression of O-Glycans in CD4(+) T Lymphocytes from Patients with Systemic Lupus Erythematosus.

T cells from patients with systemic lupus erythematosus (SLE) show a decreased activation threshold and increased apoptosis. These processes seem to be regulated by glycosylated molecules on the T cell surface. Here, we determined through flow cytometry the expression of mucin-type O-glycans on T helper cells in peripheral blood mononuclear cells (PBMC) from 23 SLE patients and its relation with disease activity. We used lectins specific for the disaccharide Gal-GalNAc, such as Amaranthus leucocarpus lectin (ALL), Artocarpus integrifolia lectin (jacalin) and Arachis hypogaea lectin (peanut agglutinin, PNA), as well as lectins for sialic acid such as Sambucus nigra agglutinin (SNA) and Maakia amurensis agglutinin (MAA). The results showed that ALL, but not jacalin or PNA, identified significant differences in O-glycan expression on T helper cells from active SLE patients (n = 10). Moreover, an inverse correlation was found between the frequency of T helper cells recognized by ALL and SLE Disease Activity Index (SLEDAI) score in SLE patients. In contrast, SNA and MAA lectins did not identify any differences between CD4(+) T cells from SLE patients. There was no difference in the recognition by ALL on activated T helper cells and T regulatory (Treg) cells. Our findings point out that activation of SLE disease diminishes the expression of O-glycans in T helper cells; ALL could be considered as a marker to determine activity of the disease.

Pivotal trial with plant cell-expressed recombinant glucocerebrosidase, taliglucerase alfa, a novel enzyme replacement therapy for Gaucher disease.

Taliglucerase alfa (Protalix Biotherapeutics, Carmiel, Israel) is a novel plant cell-derived recombinant human ß-glucocerebrosidase for Gaucher disease. A phase 3, double-blind, randomized, parallel-group, comparison-dose (30 vs 60 U/kg body weight/infusion) multinational clinical trial was undertaken. Institutional review board approvals were received. A 9-month, 20-infusion trial used inclusion/exclusion criteria in treatment-naive adult patients with splenomegaly and thrombocytopenia. Safety end points were drug-related adverse events: Ab formation and hypersensitivity reactions. Primary efficacy end point was reduction in splenic volume measured by magnetic resonance imaging. Secondary end points were: changes in hemoglobin, hepatic volume, and platelet counts. Exploratory parameters included biomarkers and bone imaging. Twenty-nine patients (11 centers) completed the protocol. There were no serious adverse events; drug-related adverse events were mild/moderate and transient. Two patients (6%) developed non-neutralizing IgG Abs; 2 other patients (6%) developed hypersensitivity reactions. Statistically significant spleen reduction was achieved at 9 months: 26.9% (95% confidence interval [CI]: -31.9, -21.8) in the 30-unit dose group and 38.0% (95% CI: -43.4, -32.8) in the 60-unit dose group (both P < .0001); and in all secondary efficacy end point measures, except platelet counts at the lower dose. These results support safety and efficacy of taliglucerase alfa for Gaucher disease.

Prolactin levels correlate with abnormal B cell maturation in MRL and MRL/lpr mouse models of systemic lupus erythematosus-like disease.

Prolactin (PRL) plays an important role in modulating the immune response. In B cells, PRL enhances antibody production, including antibodies with self-specificity. In this study, our aims were to determine the level of PRL receptor expression during bone-marrow B-cell development and to assess whether the presence of high PRL serum concentrations influences absolute numbers of developing populations and disease outcome in lupus-prone murine models. We observed that the PRL-receptor is expressed in early bone-marrow B-cell; the expression in lupus-prone mice, which had the highest level of expression in pro-B cells and immature cells, differed from that in wild-type mice. These expression levels did not significantly change in response to hyperprolactinemia; however, populations of pro-B and immature cells from lupus-prone strains showed a decrease in the absolute numbers of cells with high PRL-receptor expression in response to PRL. Because immature self-reactive B cells are constantly being eliminated, we assessed the expression of survival factor BIRC5, which is more highly expressed in both pro-B and immature B-cells in response to PRL and correlates with the onset of disease. These results identify an important role of PRL in the early stages of the B-cell maturation process: PRL may promote the survival of self-reactive clones.

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.

Post-cardioversion time Course of Atrial Remodeling Markers and their Association with Recurrence in Subjects with Long-standing, Persistent Atrial Fibrillation.

BACKGROUND: Activation of the renin-angiotensin-aldosterone axis with elevation of inflammatory markers and the resulting fibrosis play a very important role in atrial remodeling in patients with atrial fibrillation (AF), which is associated with post-cardioversion recurrence. AIM OF THE STUDY: The purpose of the study was to describe the time course of angiotensin II (AngII), aldosterone, and of the amino terminal pro-peptide of type III pro-collagen (PIIINP) following cardioversion, and their association with arrhythmia recurrence. METHODS: Ninety-nine subjects with long-standing, persistent, non-valvular atrial fibrillation who underwent successful electrical cardioversion were included, with a 6 month follow up. Angiotensin II (AngII), aldosterone and PIIINP concentrations were measured at 0, 1, 7, 30, and 180 d. Two groups were formed for the analysis: continuing sinus rhythm and recurrence of AF. RESULTS: 53% of the subjects experienced recurrence of AF. Subjects with recurrence had larger left atrial diameters and lower global peak atrial longitudinal strain (8.7 vs. 19.7%; p <0.001), higher levels of AngII (431.85 vs. 257.97 pg/mL; p = 0.003) at 180 d, higher pre-cardioversion levels of aldosterone, (11.42 vs. 5.46 pg/mL; p = 0.048) at 1 d (12.01 vs. 5.05 pg/mL; p = 0.004) and at 180 d (12.66 vs. 7.51 pg/mL; p = 0.011). There were no differences in PIIINP levels between both groups. CONCLUSIONS: Electrical post-cardioversion recurrence in subjects with long-standing, persistent AF is associated with elevated levels of AngII and aldosterone.

Prolactin promoter polymorphism (-1149 G/T) is associated with anti-DNA antibodies in Mexican patients with systemic lupus erythematosus.

Prolactin (PRL) is a 23-kDa protein hormone that is synthesized mainly by the anterior pituitary gland. However, PRL can also be synthesized and secreted by extrapituitary tissues, particularly immune cells. A biallelic polymorphism (-1149 G/T) in the prolactin promoter has been shown to be functionally important, as modulation of prolactin expression has been associated with SLE in some populations. We have performed an association study using Mexican patients with SLE. We used qPCR to determine the SNP allele and genotype frequencies. We did not find statistically significant differences in allele and genotype frequencies between patients and healthy controls. However, we found a statistically significant association between the G allele and the presence of anti-dsDNA antibodies in serum (Allele frequency (G): P = 0.005; Genotyping frequency (GG): P = 0.001, OR = 7.8, 95% CI 3.59-27.1). Our data demonstrate that the prolactin promoter polymorphism -1149 G/T does not significantly contribute to SLE disease susceptibility but does predispose carriers to other immunological changes.

Increased expression of hypoxia-induced factor 1α mRNA and its related genes in myeloid blood cells from critically ill COVID-19 patients.

BACKGROUND: COVID-19 counts 46 million people infected and killed more than 1.2 million. Hypoxaemia is one of the main clinical manifestations, especially in severe cases. HIF1α is a master transcription factor involved in the cellular response to oxygen levels. The immunopathogenesis of this severe form of COVID-19 is poorly understood. METHODS: We performed scRNAseq from leukocytes from five critically ill COVID-19 patients and characterized the expression of hypoxia-inducible factor1α and its transcriptionally regulated genes. Also performed metanalysis from the publicly available RNAseq data from COVID-19 bronchoalveolar cells. RESULTS: Critically-ill COVID-19 patients show a shift towards an immature myeloid profile in peripheral blood cells, including band neutrophils, immature monocytes, metamyelocytes, monocyte-macrophages, monocytoid precursors, and promyelocytes-myelocytes, together with mature monocytes and segmented neutrophils. May be the result of a physiological response known as emergency myelopoiesis. These cellular subsets and bronchoalveolar cells express HIF1α and their transcriptional targets related to inflammation (CXCL8, CXCR1, CXCR2, and CXCR4); virus sensing, (TLR2 and TLR4); and metabolism (SLC2A3, PFKFB3, PGK1, GAPDH and SOD2). CONCLUSIONS: The up-regulation and participation of HIF1α in events such as inflammation, immunometabolism, and TLR make it a potential molecular marker for COVID-19 severity and, interestingly, could represent a potential target for molecular therapy. Key messages Critically ill COVID-19 patients show emergency myelopoiesis. HIF1α and its transcriptionally regulated genes are expressed in immature myeloid cells which could serve as molecular targets. HIF1α and its transcriptionally regulated genes is also expressed in lung cells from critically ill COVID-19 patients which may partially explain the hypoxia related events.

A Shift Towards an Immature Myeloid Profile in Peripheral Blood of Critically Ill COVID-19 Patients.

BACKGROUND: SARS-CoV-2, the etiological agent causing COVID-19, has infected more than 27 million people with over 894000 deaths worldwide since its emergence in December 2019. Factors for severe diseases, such as diabetes, hypertension, and obesity have been identified however, the precise pathogenesis is poorly understood. To understand its pathophysiology and to develop effective therapeutic strategies, it is essential to define the prevailing immune cellular subsets. METHODS: We performed whole circulating immune cells scRNAseq from five critically ill COVID-19 patients, trajectory and gene ontology analysis. RESULTS: Immature myeloid populations, such as promyelocytes-myelocytes, metamyelocytes, band neutrophils, monocytoid precursors, and activated monocytes predominated. The trajectory with pseudotime analysis supported the finding of immature cell states. While the gene ontology showed myeloid cell activation in immune response, DNA and RNA processing, defense response to the virus, and response to type 1 interferon. Lymphoid lineage was scarce. Expression of genes such as C/EBPß, IRF1and FOSL2 potentially suggests the induction of trained immunity. CONCLUSIONS: Our results uncover transcriptomic profiles related to immature myeloid lineages and suggest the potential induction of trained 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 Amaranthus leucocarpus lectin enhances the anti-CD3 antibody-mediated activation of human peripheral blood CD4+ T cells.

Activation of CD4(+) T cells plays a main role in adaptive immune response by regulating cellular and humoral immunity via processes associated with changes in cell surface oligosaccharide receptors. Lectins are glycoproteins that specifically recognize oligosaccharides and have been used to characterize changes in oligosaccharides present on T cell surface and their effects on activation. A lectin from Amaranthus leucocarpus seeds (ALL) is specific for glycoprotein structures containing galactose-N-acetylgalactosamine and is able to bind to human and murine CD4(+) T cells, however, its effect on activation remains unclear. We examined the effect of ALL on the activation of peripheral blood human CD4(+) T cells and analyzed cell proliferation, expression of the activation-associated molecule CD25, secretion of the activation-dependent cytokine interleukin (IL)-2 and intracellular calcium influx changes using flow cytometry. CD4(+) T cells were stimulated with anti-CD3 antibodies that provided the first activation signal in the presence or absence of ALL. ALL alone did not induce CD4(+) T cell activation but when also stimulated with anti-CD3 antibodies, ALL up-regulated CD25 expression, cell proliferation, IL-2 secretion and an intracellular calcium influx in a dose-dependent manner. In addition, ALL recognized CD4(+) T cells expressing the CD69 and Ki67 molecules expressed only by activated T cells and induced production of the TH1-type cytokine interferon-gamma. Our findings indicate that ALL binds to human activated CD4(+) T cells and enhances the degree of activation of CD4(+) T cells that are stimulated with anti-CD3 antibodies. ALL provides a new tool for analyzing T cell activation mechanisms.

Effect of Interleukin-17 in the Activation of Monocyte Subsets in Patients with ST-Segment Elevation Myocardial Infarction.

Interleukin- (IL-) 17 is increased in acute myocardial infarction (AMI) and plays a key role in inflammatory diseases through its involvement in the activation of leukocytes. Here, we describe for the first time the effect of IL-17 in the migration and activation of monocyte subsets in patients during ST-segment elevation myocardial infarction (STEMI) and post-STEMI. We analyzed the circulating levels of IL-17 in patient plasma. A gradual increase in IL-17 was found in STEMI and post-STEMI patients. Additionally, IL-17 had a powerful effect on the recruitment of CD14++CD16+/CD14+CD16++ monocytes derived from patients post-STEMI compared with the monocytes from patients with STEMI, suggesting that IL-17 recruits monocytes with inflammatory activity post-STEMI. Furthermore, IL-17 increased the expression of TLR4 on CD14 + CD16 - and CD14++CD16+/CD14+CD16++ monocytes post-STEMI and might enhance the response to danger-associated molecular patterns post-STEMI. Moreover, IL-17 induced secretion of IL-6 from CD14++CD16- and CD14++CD16+/CD14+CD16++ monocytes both in STEMI and in post-STEMI, which indicates that IL-17 has an effect on the secretion of proinflammatory cytokines from monocytes during STEMI and post-STEMI. Overall, we demonstrate that in STEMI and post-STEMI, IL-17 is increased and induces the migration and activation of monocyte subsets, possibly contributing to the inflammatory response through TLR4 and IL-6 secretion.

Effect of the monocyte locomotion inhibitory factor (MLIF) produced by E. histolityca on cytokines and chemokine receptors in T CD4+ lymphocytes.

Entamoeba histolytica produces Monocyte Locomotion Inhibitory Factor (MLIF), which may contribute to the delayed inflammation observed in amoebic hepatic abscesses. Leukocytes are affected through the modulation of cytokine expression and/or production. We evaluated the effects of MLIF on the activation and production of intracellular cytokines in human CD4+ T lymphocytes by flow cytometry. Cells were stimulated for 24 h with PMA, MLIF, or PMA+MLIF. Cellular activation was measured using anti-CD69. Th1/Th2 production was studied by the expression of intracellular cytokines and cytokine/chemokine receptors. MLIF increased CD69 and induced the over-expression of the IL-lss, IFN-gamma, IL-2, IL-4, and IL-10 intracellular cytokines; PMA+MLIF inhibited Th1 cytokine (IFN-gamma) and increased Th2 cytokines (IL-4 and IL-10). The co-expression of the cytokine and chemokine receptors IFN-gamma/CCR5 and IL-1ss/CCR5 was inhibited by PMA+MLIF and Th2 co-expression was increased. MLIF effects varied depending on the conditions. MLIF alone activated the Th1 and Th2 cytokines and cytokine/receptor expression; however, PMA+MLIF increased the expression of Th2 but inhibited it in Th1.

[Human trichinosis. A case simulating polymyositis]. / Triquinosis humana. Un caso que simula polimiositis.

The human trichinosis is a cosmopolitan rare zoonosis in Mexico. It presents clinically, with an infectious toxic pattern. Typical symptomatology includes: fever, diarrhea, facial edema and myalgias, which can resemble other illnesses like typhoid fever, angioneurotic edema, septicemia, rheumatic disease-like vasculitis and dermato-polymyositis. The treatment is based on the use of antiparasites. In this paper a trichinosis case is described in a woman, 29 years old who lives in the metropolitan area, with a clinical pattern that suggest polymyositis. The diagnosis was confirmed through a muscle biopsy. The treatment was albendazole and prednisone with successful results.

Role of interleukin-17 in acute myocardial infarction.

Acute myocardial infarction (AMI) is a leading cause of death worldwide. Myocardial necrosis generates damage signals and triggers an intense inflammatory response. Many cytokines that contribute to repair tissue can also cause adverse left ventricular remodeling and heart failure. Several studies have revealed that interleukin-17 (IL-17) is a cytokine with a potential role in AMI. IL-17 plays an important role in the immune response and affects the production of different inflammatory mediators in several types of cells, involved in the damage or scar process in myocardial tissue. In this review, we will discuss the current knowledge of the role of IL-17 in AMI and the effect of IL-17 in different cells, such as cardiomyocytes, smooth muscle cells and immune system cells, in AMI pathogenesis.

The Cys-Asn-Ser carboxyl-terminal end group is the pharmacophore of the amebic anti-inflammatory monocyte locomotion inhibitory factor (MLIF).

The monocyte locomotion inhibitory factor (MLIF) is an anti-inflammatory oligopeptide produced by Entamoeba histolytica. Among its different effects, it inhibits locomotion of human monocytes, hence its original name. Previous experimental studies have shown that the anti-inflammatory properties of MLIF (Met-Gln-Cys-Asn-Ser) remained when aminoacid glutamine was substituted by a proline in the second position (pMLIF: Met-Pro-Cys-Asn-Ser). By changing the order of MLIF amino acids, the resulting scrambled oligopeptide (sMLIF: Gln-Cys-Met-Ser-Asn) has failed activity. By means of ab initio study at the Hartree-Fock and Density Functional Theory levels, it was found that MLIF and pMLIF peptides maintain a great structural similarity among the last three amino acids (...Cys-Asn-Ser) predicting a pharmacophore. The objective of this work was to experimentally verify in vivo and in vitro the existence of the pharmacophore group in MLIF. We assayed three tripeptides by respiratory burst and delayed hypersensitivity skin reactions. The tripeptide Cys-Asn-Ser carboxyl-terminal end group maintained 100% of its biological properties, as well as the anti-inflammatory activity of MLIF, while the other tripeptides tested did not do that.

Effect of prolactin on lymphocyte activation from systemic lupus erythematosus patients.

The aim was to explore the role of prolactin (PRL) in the lymphocyte activation process in systemic lupus erythematosus (SLE) patients in an in vitro model. Peripheral blood mononuclear cells (PBMCs) were isolated from SLE patients and healthy individuals. The mRNA for PRL and its receptor obtained by standard techniques, with an appropriate primer, were subjected to polymerase chain reaction (PCR) and visualized. The PBMCs were cultured with (a) medium alone as a negative control, (b) unspecific mitogen as a positive control, (c) PRL alone, (d) mitogen plus PRL, (e) mitogen plus antibody anti-PRL, and (f) mitogen plus a nonrelated antibody. Then CD69 and CD154 were determined by flow cytometry analysis. Twelve inactive and 15 active SLE patients were studied. Twenty-five percent of the active patients displayed hyperprolactinemia. Under basal conditions CD69 expression was associated with disease activity. The PBMCs activated in vitro were capable of producing and secreting PRL, measured by mRNA and Nb2 assay. In a similar way, the mRNA for the PRL receptor was visualized. Cells from SLE patients cultivated with PRL alone did not display increased CD69 and CD154 expression. The addition of PRL to the unspecific stimulated culture does not have an additive effect. In contrast, the addition of antibodies against PRL in order to block the autocrine PRL resulted in a striking reduction of CD69 and CD154 expression.

Effect of Native and Minimally Modified Low-density Lipoprotein on the Activation of Monocyte Subsets.

BACKGROUND: In atherosclerosis, monocytes are essential and secrete pro-inflammatory cytokines in response to modified low-density lipoprotein (LDL). Human CD14++CD16-, CD14++CD16+ and CD14+CD16++ monocytes produce different cytokines. The objective of this research was to determine the number of monocyte subsets positives to cytokines in response to native (nLDL) and minimally modified LDL (mmLDL). METHODS: Human monocytes from healthy individuals were purified by negative selection and were stimulated with nLDL, mmLDL or LPS. Subsequently, human total monocytes were incubated with monoclonal antibodies specific for CD14 or both CD14 and CD16 to characterize total monocytes and monocyte subsets and with antibodies specific to anti-tumor necrosis factor (TNF)-α, anti-interleukin (IL)-6 and anti-IL-10. The number of cells positive for cytokines was determined and cells cultured with nLDL, mmLDL and LPS were compared with cells cultured only with culture medium. RESULTS: We found that nLDL does not induce in the total monocyte population or in the three monocyte subsets positives to cytokines. MmLDL induced in total monocytes positives to TNF-α and IL-6 as well as in both CD14++CD16+ and CD14+CD16++ and in CD14++CD16+ monocytes, respectively. Moreover, total monocytes and the three monocyte subsets expressed few amounts of cells positives to IL-10 in response to mmLDL. CONCLUSION: Our study demonstrated that nLDL did not induce cells positives to cytokines and that the CD14++CD16+ and CD14+CD16++ monocyte subsets could be the main sources of TNF-α and IL-6, respectively, in response to mmLDL, which promotes the development and progression of atherosclerotic plaque.