Model for managing scientific research in a public hospital: case study: Chilean National Cancer Institute, from 2015-2022.

Research is an essential element in the practice of healthcare, and hospitals play a fundamental role in its promotion. Research in hospitals can improve the quality of care, knowledge of diseases and the discovery of new therapies. Hospitals can conduct research in various fields, including basic research, clinical research, population-based research and even hospital management research. The findings of hospital research can be directly applied to clinical practice and management, thereby enhancing the quality of patient care, a central paradigm in translational health. This article details the experience of the National Cancer Institute of Chile over the past 8 years in its role as a high-complexity public hospital, specialised institute, healthcare centre, teaching institution, and research facility. It reviews the work of generating and strengthening its institutional research model since its redesign in 2018, the key elements that underpin it, and discusses the challenges the institute faces in its growth amidst the increasing cancer epidemiology in Chile, the recent enactment of a National Cancer Law, the post-pandemic scenario that has left a significant waiting list of oncology patients, and the initiation of the design and construction process for the new institute building.

IL-6, IL-10, sFas, granulysin and indicators of intestinal permeability as early biomarkers for a fatal outcome in COVID-19.

The clinical presentation of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ranges between mild respiratory symptoms and a severe disease that shares many of the features of sepsis. Sepsis is a deregulated response to infection that causes life-threatening organ failure. During sepsis, the intestinal epithelial cells are affected, causing an increase in intestinal permeability and allowing microbial translocation from the intestine to the circulation, which exacerbates the inflammatory response. Here we studied patients with moderate, severe and critical COVID-19 by measuring a panel of molecules representative of the innate and adaptive immune responses to SARS-CoV-2, which also reflect the presence of systemic inflammation and the state of the intestinal barrier. We found that non-surviving COVID-19 patients had higher levels of low-affinity anti-RBD IgA antibodies than surviving patients, which may be a response to increased microbial translocation. We identified sFas and granulysin, in addition to IL-6 and IL-10, as possible early biomarkers with high sensitivity (>73 %) and specificity (>51 %) to discriminate between surviving and non-surviving COVID-19 patients. Finally, we found that the microbial metabolite d-lactate and the tight junction regulator zonulin were increased in the serum of patients with severe COVID-19 and in COVID-19 patients with secondary infections, suggesting that increased intestinal permeability may be a source of secondary infections in these patients. COVID-19 patients with secondary infections had higher disease severity and mortality than patients without these infections, indicating that intestinal permeability markers could provide complementary information to the serum cytokines for the early identification of COVID-19 patients with a high risk of a fatal outcome.

Differential activation of innate and adaptive lymphocytes during latent or active infection with Mycobacterium tuberculosis.

Most individuals infected with Mycobacterium tuberculosis (Mtb) have latent tuberculosis (TB), which can be diagnosed with tests (such as the QuantiFERON-TB Gold test [QFT]) that detect the production of IFN-γ by memory T cells in response to the Mtb-specific antigens 6 kDa early secretory antigenic target EsxA (Rv3875) (ESAT-6), 10 kDa culture filtrate antigen EsxB (Rv3874) (CFP-10), and Mtb antigen of 7.7 kDa (Rv2654c) (TB7.7). However, the immunological mechanisms that determine if an individual will develop latent or active TB remain incompletely understood. Here we compared the response of innate and adaptive peripheral blood lymphocytes from healthy individuals without Mtb infection (QFT negative) and from individuals with latent (QFT positive) or active TB infection, to determine the characteristics of these cells that correlate with each condition. In active TB patients, the levels of IFN-γ that were produced in response to Mtb-specific antigens had high positive correlations with IL-1ß, TNF-α, MCP-1, IL-6, IL-12p70, and IL-23, while the proinflammatory cytokines had high positive correlations between themselves and with IL-12p70 and IL-23. These correlations were not observed in QFT-negative or QFT-positive healthy volunteers. Activation with Mtb-soluble extract (a mixture of Mtb antigens and pathogen-associated molecular patterns [PAMPs]) increased the percentage of IFN-γ-/IL-17-producing NK cells and of IL-17-producing innate lymphoid cell 3 (ILC3) in the peripheral blood of active TB patients, but not of QFT-negative or QFT-positive healthy volunteers. Thus, active TB patients have both adaptive and innate lymphocyte subsets that produce characteristic cytokine profiles in response to Mtb-specific antigens or PAMPs. These profiles are not observed in uninfected individuals or in individuals with latent TB, suggesting that they are a response to active TB infection.

Increased TNF-α production in response to IL-6 in patients with systemic inflammation without infection.

Acute systemic inflammation can lead to life-threatening organ dysfunction. In patients with sepsis, systemic inflammation is triggered in response to infection, but in other patients, a systemic inflammatory response syndrome (SIRS) is triggered by non-infectious events. IL-6 is a major mediator of inflammation, including systemic inflammatory responses. In homeostatic conditions, when IL-6 engages its membrane-bound receptor on myeloid cells, it promotes pro-inflammatory cytokine production, phagocytosis, and cell migration. However, under non-physiologic conditions, such as SIRS and sepsis, leucocyte dysfunction could modify the response of these cells to IL-6. So, our aim was to evaluate the response to IL-6 of monocytes from patients diagnosed with SIRS or sepsis. We observed that monocytes from patients with SIRS, but not from patients with sepsis, produced significantly more TNF-α than monocytes from healthy volunteers, after stimulation with IL-6. Monocytes from SIRS patients had a significantly increased baseline phosphorylation of the p65 subunit of NF-κB, with no differences in STAT3 phosphorylation or SOCS3 levels, compared with monocytes from septic patients, and this increased phosphorylation was maintained during the IL-6 activation. We found no significant differences in the expression levels of the membrane-bound IL-6 receptor, or the serum levels of IL-6, soluble IL-6 receptor, or soluble gp130, between patients with SIRS and patients with sepsis. Our results suggest that, during systemic inflammation in the absence of infection, IL-6 promotes TNF-α production by activating NF-κB, and not the canonical STAT3 pathway.

The histone deacetylase inhibitor valproic acid attenuates phospholipase Cγ2 and IgE-mediated mast cell activation.

Mast cell activation through the high-affinity IgE receptor (FcεRI) plays a central role in allergic reactions. FcεRI-mediated activation triggers multiple signaling pathways leading to degranulation and synthesis of different inflammatory mediators. IgE-mediated mast cell activation can be modulated by different molecules, including several drugs. Herein, we investigated the immunomodulatory activity of the histone deacetylase inhibitor valproic acid (VPA) on IgE-mediated mast cell activation. To this end, bone marrow-derived mast cells (BMMC) were sensitized with IgE and treated with VPA followed by FcεRI cross-linking. The results indicated that VPA reduced mast cell IgE-dependent degranulation and cytokine release. VPA also induced a significant reduction in the cell surface expression of FcεRI and CD117, but not other mast cell surface molecules. Interestingly, VPA treatment inhibited the phosphorylation of PLCγ2, a key signaling molecule involved in IgE-mediated degranulation and cytokine secretion. However, VPA did not affect the phosphorylation of other key components of the FcεRI signaling pathway, such as Syk, Akt, ERK1/2, or p38. Altogether, our data demonstrate that VPA affects PLCγ2 phosphorylation, which in turn decreases IgE-mediated mast cell activation. These results suggest that VPA might be a key modulator of allergic reactions and might be a promising therapeutic candidate.

Extracellular vesicles released by J774A.1 macrophages reduce the bacterial load in macrophages and in an experimental mouse model of tuberculosis.

BACKGROUND: Tuberculosis is the leading cause of death by an infectious microorganism worldwide. Conventional treatment lasts at least six months and has adverse effects; therefore, it is important to find therapeutic alternatives that reduce the bacterial load and may reduce the treatment duration. The immune response against tuberculosis can be modulated by several mechanisms, including extracellular vesicles (EVs), which are nano-sized membrane-bound structures that constitute an efficient communication mechanism among immune cells. METHODS: The EVs released by the J774A.1 mouse macrophage cell line, both spontaneously (S-EV) and after infection with Mycobacterium tuberculosis H37Rv (Mtb-EV), were purified by ultra-centrifugation and size-exclusion chromatography. The size distribution and chemical composition of these EVs were evaluated, and their effect on the bacterial load and the production of cytokines was determined in both in vitro and in vivo models of M. tuberculosis infection. RESULTS: Mtb-EV are larger than S-EV, they contain M. tuberculosis-specific antigens (not detected in EVs released from M. fortuitum-infected J774A.1 cells) and are rich in phosphatidylserine, present in their outer membrane layer. S-EV, but not Mtb-EV, reduced the bacterial load and the production of MCP-1 and TNF-α in M. tuberculosis-infected macrophages, and these effects were reversed when phosphatidylserine was blocked with annexin V. Both S-EV and Mtb-EV significantly reduced the lung bacterial load in mice infected with M. tuberculosis after 60 days of treatment, but they had no effect on survival or on the lung pneumonic area of these mice. CONCLUSION: J774A.1 macrophages infected with M. tuberculosis H37Rv released EVs that differed in size and phosphatidylserine content from spontaneously released EVs, and these EVs also had different biological effects: S-EV reduced the mycobacterial load and the cytokine production in vitro (through a phosphatidylserine-dependent mechanism), while both EVs reduced the lung bacterial load in vivo. These results are the basis for further experiments to evaluate whether EVs improve the efficiency of the conventional treatment for tuberculosis.

Valproic acid promotes a decrease in mycobacterial survival by enhancing nitric oxide production in macrophages stimulated with IFN-γ.

Tuberculosis is one of the leading causes of mortality worldwide, it is caused by Mycobacterium tuberculosis (Mtb), a bacteria that employs several strategies to evade the host immune response. For instance, Mtb interferes with the overexpression of class II transactivator (CIITA) in macrophages exposed to IFN-γ by inhibiting histone acetylation at its promoter, which can be reverted by the histone deacetylase inhibitor (HDACi) sodium butyrate. In this work, we evaluated whether a different HDACi, valproic acid (VPA), could revert the inhibition of gene expression induced by Mtb. J774 macrophages treated with VPA and IFN-γ unexpectedly induced a higher expression of the inducible nitric oxide synthase and a higher production of nitric oxide when exposed to the 19 kDa lipoprotein of Mtb or the whole bacteria. However, VPA was unable to revert the inhibition of CIITA expression induced by the 19 kDa lipoprotein of Mtb. Finally, macrophages infected with Mtb and treated with VPA and IFN-γ showed a significant reduction in intracellular bacteria. Our findings suggest a new therapeutic potential of VPA for the treatment of tuberculosis.

Innate Lymphoid Cells Have Decreased HLA-DR Expression but Retain Their Responsiveness to TLR Ligands during Sepsis.

Sepsis, one of the leading causes of death in intensive care units, is caused by a dysregulated host response to infection that leads to life-threatening organ dysfunction. The proinflammatory and anti-inflammatory responses activated by the infecting microorganism become systemic, and the sustained anti-inflammatory response induces a state of immunosuppression that is characterized by decreased expression of HLA-DR on monocytes, T cell apoptosis, and reduced production of TNF-α by monocytes and macrophages in response to TLR ligands. Innate lymphoid cells (ILCs) are lymphocytes that lack Ag-specific receptors and lineage-specific markers; they express HLA-DR and are activated by cytokines and by direct recognition of microbial molecules. In this study, we evaluated if ILCs are affected by the anti-inflammatory response during sepsis. We found that the number of peripheral blood ILCs was decreased in septic patients compared with healthy volunteers; this decrease was caused by a reduction in ILC1 and ILC3 and is associated with apoptosis, because ILCs from septic patients expressed active caspase 3. ILCs from septic patients had decreased HLA-DR expression but increased expression of the activating receptors NKp46 and NKp44; they also showed a sustained expression of CD127 (IL-7R α-chain) and retained their capacity to produce TNF-α in response to TLR ligands. These results indicate that during sepsis, ILCs have decreased HLA-DR expression and die via apoptosis, similar to monocytes and T cells, respectively. However, other effector functions of ILCs (activation through NKp46 and NKp44, TNF-α production) may remain unaffected by the immunosuppressive environment prevailing in septic patients.

Extracellular Vesicles Released from Mycobacterium tuberculosis-Infected Neutrophils Promote Macrophage Autophagy and Decrease Intracellular Mycobacterial Survival.

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis (Mtb). In the lungs, macrophages and neutrophils are the first immune cells that have contact with the infecting mycobacteria. Neutrophils are phagocytic cells that kill microorganisms through several mechanisms, which include the lytic enzymes and antimicrobial peptides that are found in their lysosomes, and the production of reactive oxygen species. Neutrophils also release extracellular vesicles (EVs) (100-1,000 nm in diameter) to the extracellular milieu; these EVs consist of a lipid bilayer surrounding a hydrophilic core and participate in intercellular communication. We previously demonstrated that human neutrophils infected in vitro with Mtb H37Rv release EVs (EV-TB), but the effect of these EVs on other cells relevant for the control of Mtb infection, such as macrophages, has not been completely analyzed. In this study, we characterized the EVs produced by non-stimulated human neutrophils (EV-NS), and the EVs produced by neutrophils stimulated with an activator (PMA), a peptide derived from bacterial proteins (fMLF) or Mtb, and observed that the four EVs differed in their size. Ligands for toll-like receptor (TLR) 2/6 were detected in EV-TB, and these EVs favored a modest increase in the expression of the co-stimulatory molecules CD80, a higher expression of CD86, and the production of higher amounts of TNF-α and IL-6, and of lower amounts of TGF-ß, in autologous human macrophages, compared with the other EVs. EV-TB reduced the amount of intracellular Mtb in macrophages, and increased superoxide anion production in these cells. TLR2/6 ligation and superoxide anion production are known inducers of autophagy; accordingly, we found that EV-TB induced higher expression of the autophagy-related marker LC3-II in macrophages, and the co-localization of LC3-II with Mtb inside infected macrophages. The intracellular mycobacterial load increased when autophagy was inhibited with wortmannin in these cells. In conclusion, our results demonstrate that neutrophils produce different EVs in response to diverse activators, and that EV-TB activate macrophages and promote the clearance of intracellular Mtb through early superoxide anion production and autophagy induction, which is a novel role for neutrophil-derived EVs in the immune response to Mtb.

Silver-pig skin nanocomposites and mesenchymal stem cells: suitable antibiofilm cellular dressings for wound healing.

BACKGROUND: Treatment of severe or chronic skin wounds is an important challenge facing medicine and a significant health care burden. Proper wound healing is often affected by bacterial infection; where biofilm formation is one of the main risks and particularly problematic because it confers protection to microorganisms against antibiotics. One avenue to prevent bacterial colonization of wounds is the use of silver nanoparticles (AgNPs); which have proved to be effective against non-multidrug-resistant and multidrug-resistant bacteria. In addition, the use of mesenchymal stem cells (MSC) is an excellent option to improve wound healing due to their capability for differentiation and release of relevant growth factors. Finally, radiosterilized pig skin (RPS) is a biomatrix successfully used as wound dressing to avoid massive water loss, which represents an excellent carrier to deliver MSC into wound beds. Together, AgNPs, RPS and MSC represent a potential dressing to control massive water loss, prevent bacterial infection and enhance skin regeneration; three essential processes for appropriate wound healing with minimum scaring. RESULTS: We synthesized stable 10 nm-diameter spherical AgNPs that showed 21- and 16-fold increase in bacteria growth inhibition (in comparison to antibiotics) against clinical strains Staphylococcus aureus and Stenotrophomonas maltophilia, respectively. RPS samples were impregnated with different AgNPs suspensions to develop RPS-AgNPs nanocomposites with different AgNPs concentrations. Nanocomposites showed inhibition zones, in Kirby-Bauer assay, against both clinical bacteria tested. Nanocomposites also displayed antibiofilm properties against S. aureus and S. maltophilia from RPS samples impregnated with 250 and 1000 ppm AgNPs suspensions, respectively. MSC were isolated from adipose tissue and seeded on nanocomposites; cells survived on nanocomposites impregnated with up to 250 ppm AgNPs suspensions, showing 35% reduction in cell viability, in comparison to cells on RPS. Cells on nanocomposites proliferated with culture days, although the number of MSC on nanocomposites at 24 h of culture was lower than that on RPS. CONCLUSIONS: AgNPs with better bactericide activity than antibiotics were synthesized. RPS-AgNPs nanocomposites impregnated with 125 and 250 ppm AgNPs suspensions decreased bacterial growth, decreased biofilm formation and were permissive for survival and proliferation of MSC; constituting promising multi-functional dressings for successful treatment of skin wounds.

High Serum Levels of High-Mobility Group Box 1 (HMGB1) and Low Levels of Heat Shock Protein 70 (Hsp70) are Associated with Poor Prognosis in Patients with Acute Pancreatitis.

INTRODUCTION: Cell damage in Acute Pancreatitis (AP) lead to release of cytokines and HMGB1 and Hsp70. While Hsp70 plays a role in cytoprotection, when released to extracellular milieu constitutes, as HMGB1, a danger signal and trigger pro-inflammatory responses. These molecules seem to be related to the clinical progression; but because no evidence exists about them as molecular network in AP development, we quantify HSP70, HMGB1, and cytokines in patients with AP and search for correlations with severity and prognosis. METHODS: Fifteen patients with AP were included. The average age was 52 years. Six patients had mild pancreatitis, 4 were moderately severe and 5 with a severe form. Blood samples were taken within the first 24 h, at 3d and 7d from the start. Serum HMGB1 and Hsp70 were determined using ELISA; TNF-α, IL-1ß, IL-6, IL-8, IL-10 and IL-12p70 were determined by bead based immuassay. RESULTS: Of all 15 patients recruited, 4 were women. Eight patients had APACHEII score higher than 8. Two patients died from AP related complications. Increase in serum HMGB1 and decrease of Hsp70 were associated with the severity and mortality. TNF-α, IL-6 and IL-8 were higher in patients that did not survive, in those with an APACHE II >8, and in those with severe AP. CONCLUSIONS: High HMGB1 and low Hsp70 were associated with poor prognosis. Hsp70 might play a protective role in AP. TNF-α, IL-6, IL-8, HMGB1 and Hsp70 during hospital admissions might serve to evaluate risk of death due to AP.

[Innate lymphoid cells and their role in immune response regulation]. / Las células linfoides innatas y su papel en la regulación de la respuesta inmune.

Innate lymphoid cells (ILCs) are lymphocytes lacking antigen recognition receptors and become activated in response to cytokines and through microbe-associated molecular pattern (MAMP) receptors. ILCs are found mainly in mucosal tissues and participate in the immune response against infections and in chronic inflammatory conditions. ILCs are divided in ILC-1, ILC-2 and ILC-3, and these cells have analogue functions to those of immune adaptive response lymphocytes Th1, Th2 and Th17. ILC-1 express T-bet, produce IFNγ, protect against infections with intracellular microorganisms and are related to inflammatory bowel disease immunopathology. ILC-2 express GATA3, produce IL-4, IL-5, IL-13 and amphiregulin, protect against parasitic infections and are related to allergy and obesity immunopathology. ILC-3 express ROR(γt), produce IL-17 and IL-22, protect against fungal infections and contribute to tolerance to intestinal microbiota and intestinal repair. They are related to inflammatory bowel disease and psoriasis immunopathology. In general terms, ILCs maintain homeostasis and coadjuvate in the protection against infections.

Las células linfoides innatas (ILC) son linfocitos que carecen de receptores de reconocimiento de antígenos y se activan en respuesta a citocinas y a través de receptores de patrones moleculares asociados a microorganismos (MAMP). Las ILC se localizan preferentemente en las mucosas, y participan en la respuesta inmune contra infecciones y en enfermedades inflamatorias crónicas. Las ILC se dividen en ILC-1, ILC-2 e ILC-3, y estas células tienen funciones análogas a las de los linfocitos Th1, Th2 y Th17 de la respuesta inmune adaptativa. Las ILC-1 expresan T-bet, producen IFNγ, protegen contra infecciones con microorganismos intracelulares y están relacionados con la inmunopatología de la enfermedad inflamatoria intestinal. Las ILC-2 expresan GATA3, producen IL-4, IL-5, IL-13 y anfirregulina, protegen contra infecciones parasitarias y se relacionan con la inmunopatología de la alergia y la obesidad. Las ILC-3 expresan RORγt, producen IL-17 e IL-22, protegen contra infecciones con hongos y participan en la tolerancia a la microbiota intestinal y en la reparación intestinal. Se relacionan con la inmunopatología de la enfermedad inflamatoria intestinal y la psoriasis. En términos generales, las ILC mantienen la homeostasis y coadyuvan en la protección contra las infecciones.

Effect of Oral ω3-Polyunsaturated Fatty Acids as a Complement Management to Control Fistula Output and Inflammation in Patients With Digestive Fistula.

BACKGROUND: The presence of digestive fistula involves chronic inflammation and fibrosis. It has been reported that ω3-polyunsaturated fatty acids stimulate the resolution of inflammation. AIM: Determine if the administration of oral ω3 reduces fistula output and the time required for fistula closure. METHODS: Forty-nine patients with postoperative fistula were randomly divided in two groups: 26 received conventional treatment and 23 received the conventional treatment supplemented with ω3 (540 mg eicosapentaenoic acid and 360 mg docosahexaenoic acid) for 35 days. Patients were monitored daily for fistula output and spontaneous closure. Additionally, serum pro-inflammatory cytokines and C-reactive protein were quantified in four patients with conventional and in seven patients with ω3 treatment. RESULTS: Patients with ω3 had significantly decreased fistula output from days 2 to 27, compared to control (p < 0.05). Spontaneous fistula closure was achieved in 15 patients (65%) in the ω3 group and in 14 (54%) in the control group. ω3-polyunsaturated fatty intake also decreased the serum concentrations of interleukin-6 and C-reactive protein (p < 0.05). CONCLUSIONS: Our results suggest that ω3 supplementation to conventional medical treatment decreases fistula output and reduces inflammation (interleukin-6 and C-reactive protein), and these effects may increase the efficiency of conventional medical treatment.

Activation-Induced Killer Cell Immunoglobulin-like Receptor 3DL2 Binding to HLA-B27 Licenses Pathogenic T Cell Differentiation in Spondyloarthritis.

OBJECTIVE: In the spondyloarthritides (SpA), increased numbers of CD4+ T cells express killer cell immunoglobulin-like receptor 3DL2 (KIR-3DL2). The aim of this study was to determine the factors that induce KIR-3DL2 expression, and to characterize the relationship between HLA-B27 and the phenotype and function of KIR-3DL2-expressing CD4+ T cells in SpA. METHODS: In total, 34 B27+ patients with SpA, 28 age- and sex-matched healthy controls (20 B27- and 8 B27+), and 9 patients with rheumatoid arthritis were studied. KIR-3DL2 expression and other phenotypic characteristics of peripheral blood and synovial fluid CD4+ T cells were studied by flow cytometry, quantitative polymerase chain reaction, and Western blotting. T cell receptor clonality was determined by template-switch anchored reverse transcription-polymerase chain reaction and sequencing analysis. Cytokines were measured by enzyme-linked immunosorbent assay. RESULTS: Cellular activation induced KIR-3DL2 expression on both naive and effector CD4+ T cells. KIR-3DL2 binding to B27+ cells promoted expression of KIR-3DL2, the Th17-specific transcription factor retinoic acid receptor-related orphan nuclear receptor γt, and the antiapoptotic factor B cell lymphoma 2. KIR-3DL2+CD4+ T cells in patients with ankylosing spondylitis were oligoclonal and enriched for markers of T cell activation and for the gut homing receptor CCR9. In the presence of B27+ antigen-presenting cells, KIR-3DL2+CD4+ T cells produced less interleukin-2 (IL-2) but more IL-17. This effect was blocked by HC10, an antibody that inhibits the binding of KIR-3DL2 to B27 heavy chains. CONCLUSION: KIR-3DL2 binding to HLA-B27 licenses Th17 cell differentiation in SpA. These findings raise the therapeutic potential of targeting HLA-B27-KIR-3DL2 interactions for the treatment of B27+ patients with SpA.

Recognition of Candida albicans by Dectin-1 induces mast cell activation.

Mast cells are crucial elements of the innate immune response. They reside in tissues that are commonly exposed to the external environment, such as the skin and mucosae, where they can rapidly detect the presence of pathogens and mount a potent inflammatory response that recruits other cellular effectors of the immune response. The contribution of mast cells to the immune response to viruses, bacteria, protozoa and multicellular parasites is well established, but there is scarce information about the role of these cells in fungal infections. In this study, we analyzed if mast cells are activated by Candida albicans and if the C-type lectin receptor Dectin-1 is involved in its recognition. We found that both yeasts and hyphae of C. albicans-induced mast cell degranulation and production of TNF-α, IL-6, IL-10, CCL3 and CCL4, while only yeasts were able to induce IL-1ß. Mast cells also produced ROS after stimulation with both dimorphic phases of C. albicans. When mast cells were activated with yeasts and hyphae, they showed decreased expression of IκBα and increased presence of phosphorylated Syk. Blockade of the receptor Dectin-1, but not Toll-like receptor 2, decreased TNF-α production by mast cell in response to C. albicans. These results indicate that mast cells are capable of sensing the two phases of C. albicans, and suggest that mast cells participate as an early inductor of inflammation during the early innate immune response to this fungus.

Mast Cells in Lung Homeostasis: Beyond Type I Hypersensitivity.

Lungs are indispensable organs for the respiratory process, and maintaining their homeostasis is essential for human health and survival. However, during the lifetime of an individual, the lungs suffer countless insults that put at risk their delicate organization and function. Many cells of the immune system participate to maintain this equilibrium and to keep functional lungs. Among these cells, mast cells have recently attracted attention because of their ability to rapidly secrete many chemical and biological mediators that modulate different processes like inflammation, angiogenesis, cell proliferation, etc. In this review, we focus on recent advances in the understanding of the role that mast cells play in lung protection during infections, and of the relation of mast cell responses to type I hypersensitivity-associated pathologies. Furthermore, we discuss the potential role of mast cells during wound healing in the lung and its association with lung cancer, and how mast cells could be exploited as therapeutic targets in some diseases.

Salmonella Typhi OmpS1 and OmpS2 porins are potent protective immunogens with adjuvant properties.

Salmonella enterica serovar Typhi (S. Typhi) is the causal agent of typhoid fever, a disease that primarily affects developing countries. Various antigens from this bacterium have been reported to be targets of the immune response. Recently, the S. Typhi genome has been shown to encode two porins--OmpS1 and OmpS2--which are expressed at low levels under in vitro culture conditions. In this study, we demonstrate that immunizing mice with either OmpS1 or OmpS2 induced production of specific, long-term antibody titres and conferred protection against S. Typhi challenge; in particular, OmpS1 was more immunogenic and conferred greater protective effects than OmpS2. We also found that OmpS1 is a Toll-like receptor 4 (TLR4) agonist, whereas OmpS2 is a TLR2 and TLR4 agonist. Both porins induced the production of tumour necrosis factor and interleukin-6, and OmpS2 was also able to induce interleukin-10 production. Furthermore, OmpS1 induced the over-expression of MHC II molecules in dendritic cells and OmpS2 induced the over-expression of CD40 molecules in macrophages and dendritic cells. Co-immunization of OmpS1 or OmpS2 with ovalbumin (OVA) increased anti-OVA antibody titres, the duration and isotype diversity of the OVA-specific antibody response, and the proliferation of T lymphocytes. These porins also had adjuvant effects on the antibody response when co-immunized with either the Vi capsular antigen from S. Typhi or inactivated 2009 pandemic influenza A(H1N1) virus [A(H1N1)pdm09]. Taken together, the data indicate that OmpS1 and OmpS2, despite being expressed at low levels under in vitro culture conditions, are potent protective immunogens with intrinsic adjuvant properties.

Premature impairment of methylation pathway and cardiac metabolic dysfunction in fa/fa obese Zucker rats.

Increasing evidence suggests that obesity is a chronic inflammatory disease, in which adipose tissue is involved in a network of endocrine signals to modulate energy homeostasis. These oxidative-inflammatory pathways, which are associated with cardiovascular complications, are also observed during the aging process. In this study, we investigated the interaction between aging and the development of obesity in a hyperphagic rat model. Metabolic profiles of the liver, white adipose tissue (WAT) and heart from young and adult Zucker lean (fa/+) and obese (fa/fa) rats were characterized using a (1)H NMR-based metabonomics approach. We observed premature metabolic modifications in all studied organs in obese animals, some of which were comparable to those observed in adult lean animals. In the cardiac tissue, young obese rats displayed lower lactate and scyllo-inositol levels associated with higher creatine, choline and phosphocholine levels, indicating an early modulation of energy and membrane metabolism. An early alteration of the hepatic methylation and transsulfuration pathways in both groups of obese rats indicated that these pathways were affected before diabetic onset. These findings therefore support the hypothesis that obesity parallels some metabolic perturbations observed in the aging process and provides new insights into the metabolic modifications occurring in prediabetic state.

Lepromatous leprosy patients produce antibodies that recognise non-bilayer lipid arrangements containing mycolic acids

Non-bilayer phospholipid arrangements are three-dimensional structures that form when anionic phospholipids with an intermediate structure of the tubular hexagonal phase II are present in a bilayer of lipids. Antibodies that recognise these arrangements have been described in patients with antiphospholipid syndrome and/or systemic lupus erythematosus and in those with preeclampsia; these antibodies have also been documented in an experimental murine model of lupus, in which they are associated with immunopathology. Here, we demonstrate the presence of antibodies against non-bilayer phospholipid arrangements containing mycolic acids in the sera of lepromatous leprosy (LL) patients, but not those of healthy volunteers. The presence of antibodies that recognise these non-bilayer lipid arrangements may contribute to the hypergammaglobulinaemia observed in LL patients. We also found IgM and IgG anti-cardiolipin antibodies in 77% of the patients. This positive correlation between the anti-mycolic-non-bilayer arrangements and anti-cardiolipin antibodies suggests that both types of antibodies are produced by a common mechanism, as was demonstrated in the experimental murine model of lupus, in which there was a correlation between the anti-non-bilayer phospholipid arrangements and anti-cardiolipin antibodies. Antibodies to non-bilayer lipid arrangements may represent a previously unrecognised pathogenic mechanism in LL and the detection of these antibodies may be a tool for the early diagnosis of LL patients.

The T1048I mutation in ATP7A gene causes an unusual Menkes disease presentation.

BACKGROUND: The ATP7A gene encodes the ATP7A protein, which is a trans-Golgi network copper transporter expressed in the brain and other organs. Mutations in this gene cause disorders of copper metabolism, such as Menkes disease. Here we describe the novel and unusual mutation (p.T1048I) in the ATP7A gene of a child with Menkes disease. The mutation affects a conserved DKTGT1048 phosphorylation motif that is involved in the catalytic activity of ATP7A. We also describe the clinical course and the response to copper treatment in this patient. CASE PRESENTATION: An 11-month-old male Caucasian infant was studied because of hypotonia, ataxia and global developmental delay. The patient presented low levels of serum copper and ceruloplasmin, and was shown to be hemizygous for the p.T1048I mutation in ATP7A. The diagnosis was confirmed when the patient was 18 months old, and treatment with copper-histidinate (Cu-His) was started immediately. The patient showed some neurological improvement and he is currently 8 years old. Because the p.T1048I mutation affects its catalytic site, we expected a complete loss of functional ATP7A and a classical Menkes disease presentation. However, the clinical course of the patient was mild, and he responded to Cu-His treatment, which suggests that this mutation leads to partial conservation of the activity of ATP7A. CONCLUSION: This case emphasizes the important correlation between genotype and phenotype in patients with Menkes disease. The prognosis in Menkes disease is associated with early detection, early initiation of treatment and with the preservation of some ATP7A activity, which is necessary for Cu-His treatment response. The description of this new mutation and the response of the patient to Cu-His treatment will contribute to the growing body of knowledge about treatment response in Menkes disease.