High expression of antiviral proteins in mucosa from individuals exhibiting resistance to human immunodeficiency virus

ABSTARCT: Several soluble factors have been reported to have the capacity of inhibiting HIV replication at different steps of the virus life cycle, without eliminating infected cells and through enhancement of specific cellular mechanisms. Yet, it is unclear if these antiviral factors play a role in the protection from HIV infection or in the control of viral replication. Here we evaluated two cohorts: i) one of 58 HIV-exposed seronegative individuals (HESNs) who were compared with 59 healthy controls (HCs), and ii) another of 13 HIV-controllers who were compared with 20 HIV-progressors. Peripheral blood, oral and genital mucosa and gut-associated lymphoid tissue (GALT) samples were obtained to analyze the mRNA expression of ELAFIN, APOBEC3G, SAMHD1, TRIM5α, RNase 7 and SerpinA1 using real-time PCR. RESULTS: HESNs exhibited higher expression of all antiviral factors in peripheral blood mononuclear cells (PBMCs), oral or genital mucosa when compared with HCs. Furthermore, HIV-controllers exhibited higher levels of SerpinA1 in GALT. CONCLUSIONS: These findings suggest that the activity of these factors is compartmentalized and that these proteins have a predominant role depending on the tissue to avoid the infection, reduce the viral load and modulate the susceptibility to HIV infection

Exacerbation of cigarette smoke-induced pulmonary inflammation by Staphylococcus aureus Enterotoxin B in mice

<p>Abstract</p> <p>Background</p> <p>Cigarette smoke (CS) is a major risk factor for the development of COPD. CS exposure is associated with an increased risk of bacterial colonization and respiratory tract infection, because of suppressed antibacterial activities of the immune system and delayed clearance of microbial agents from the lungs. Colonization with <it>Staphylococcus aureus </it>results in release of virulent enterotoxins, with superantigen activity which causes T cell activation.</p> <p>Objective</p> <p>To study the effect of <it>Staphylococcus aureus </it>enterotoxin B (SEB) on CS-induced inflammation, in a mouse model of COPD.</p> <p>Methods</p> <p>C57/Bl6 mice were exposed to CS or air for 4 weeks (5 cigarettes/exposure, 4x/day, 5 days/week). Endonasal SEB (10 μg/ml) or saline was concomitantly applied starting from week 3, on alternate days. 24 h after the last CS and SEB exposure, mice were sacrificed and bronchoalveolar lavage (BAL) fluid and lung tissue were collected.</p> <p>Results</p> <p>Combined exposure to CS and SEB resulted in a raised number of lymphocytes and neutrophils in BAL, as well as increased numbers of CD8⁺T lymphocytes and granulocytes in lung tissue, compared to sole CS or SEB exposure. Moreover, concomitant CS/SEB exposure induced both IL-13 mRNA expression in lungs and goblet cell hyperplasia in the airway wall. In addition, combined CS/SEB exposure stimulated the formation of dense, organized aggregates of B- and T- lymphocytes in lungs, as well as significant higher CXCL-13 (protein, mRNA) and CCL19 (mRNA) levels in lungs.</p> <p>Conclusions</p> <p>Combined CS and SEB exposure aggravates CS-induced inflammation in mice, suggesting that <it>Staphylococcus aureus </it>could influence the pathogenesis of COPD.</p

Inhibition of IFN-γ-dependent antiviral airway epithelial defense by cigarette smoke

<p>Abstract</p> <p>Background</p> <p>Although individuals exposed to cigarette smoke are more susceptible to respiratory infection, the effects of cigarette smoke on lung defense are incompletely understood. Because airway epithelial cell responses to type II interferon (IFN) are critical in regulation of defense against many respiratory viral infections, we hypothesized that cigarette smoke has inhibitory effects on IFN-γ-dependent antiviral mechanisms in epithelial cells in the airway.</p> <p>Methods</p> <p>Primary human tracheobronchial epithelial cells were first treated with cigarette smoke extract (CSE) followed by exposure to both CSE and IFN-γ. Epithelial cell cytotoxicity and IFN-γ-induced signaling, gene expression, and antiviral effects against respiratory syncytial virus (RSV) were tested without and with CSE exposure.</p> <p>Results</p> <p>CSE inhibited IFN-γ-dependent gene expression in airway epithelial cells, and these effects were not due to cell loss or cytotoxicity. CSE markedly inhibited IFN-γ-induced Stat1 phosphorylation, indicating that CSE altered type II interferon signal transduction and providing a mechanism for CSE effects. A period of CSE exposure combined with an interval of epithelial cell exposure to both CSE and IFN-γ was required to inhibit IFN-γ-induced cell signaling. CSE also decreased the inhibitory effect of IFN-γ on RSV mRNA and protein expression, confirming effects on viral infection. CSE effects on IFN-γ-induced Stat1 activation, antiviral protein expression, and inhibition of RSV infection were decreased by glutathione augmentation of epithelial cells using N-acetylcysteine or glutathione monoethyl ester, providing one strategy to alter cigarette smoke effects.</p> <p>Conclusions</p> <p>The results indicate that CSE inhibits the antiviral effects of IFN-γ, thereby presenting one explanation for increased susceptibility to respiratory viral infection in individuals exposed to cigarette smoke.</p

Alveolar Epithelial Type II Cells Activate Alveolar Macrophages and Mitigate P. Aeruginosa Infection

Although alveolar epithelial type II cells (AECII) perform substantial roles in the maintenance of alveolar integrity, the extent of their contributions to immune defense is poorly understood. Here, we demonstrate that AECII activates alveolar macrophages (AM) functions, such as phagocytosis using a conditioned medium from AECII infected by P. aeruginosa. AECII-derived chemokine MCP-1, a monocyte chemoattractant protein, was identified as a main factor in enhancing AM function. We proposed that the enhanced immune potency of AECII may play a critical role in alleviation of bacterial propagation and pneumonia. The ability of phagocytosis and superoxide release by AM was reduced by MCP-1 neutralizing antibodies. Furthermore, MCP-1−/− mice showed an increased bacterial burden under PAO1 and PAK infection vs. wt littermates. AM from MCP-1−/− mice also demonstrated less superoxide and impaired phagocytosis over the controls. In addition, AECII conditioned medium increased the host defense of airway in MCP-1−/− mice through the activation of AM function. Mechanistically, we found that Lyn mediated NFκB activation led to increased gene expression and secretion of MCP-1. Consequently Lyn−/− mice had reduced MCP-1 secretion and resulted in a decrease in superoxide and phagocytosis by AM. Collectively, our data indicate that AECII may serve as an immune booster for fighting bacterial infections, particularly in severe immunocompromised conditions

Trappin-2/Elafin Modulate Innate Immune Responses of Human Endometrial Epithelial Cells to PolyI∶C

BACKGROUND: Upon viral recognition, innate and adaptive antiviral immune responses are initiated by genital epithelial cells (ECs) to eradicate or contain viral infection. Such responses, however, are often accompanied by inflammation that contributes to acquisition and progression of sexually transmitted infections (STIs). Hence, interventions/factors enhancing antiviral protection while reducing inflammation may prove beneficial in controlling the spread of STIs. Serine antiprotease trappin-2 (Tr) and its cleaved form, elafin (E), are alarm antimicrobials secreted by multiple cells, including genital epithelia. METHODOLOGY AND PRINCIPAL FINDINGS: We investigated whether and how each Tr and E (Tr/E) contribute to antiviral defenses against a synthetic mimic of viral dsRNA, polyinosine-polycytidylic acid (polyI:C) and vesicular stomatitis virus. We show that delivery of a replication-deficient adenovector expressing Tr gene (Ad/Tr) to human endometrial epithelial cells, HEC-1A, resulted in secretion of functional Tr, whereas both Tr/E were detected in response to polyI:C. Moreover, Tr/E were found to significantly reduce viral replication by either acting directly on virus or through enhancing polyI:C-driven antiviral protection. The latter was associated with reduced levels of pro-inflammatory factors IL-8, IL-6, TNFα, lowered expression of RIG-I, MDA5 and attenuated NF-κB activation. Interestingly, enhanced polyI:C-driven antiviral protection of HEC-Ad/Tr cells was partially mediated through IRF3 activation, but not associated with higher induction of IFNβ, suggesting multiple antiviral mechanisms of Tr/E and the involvement of alternative factors or pathways. CONCLUSIONS AND SIGNIFICANCE: This is the first evidence of both Tr/E altering viral binding/entry, innate recognition and mounting of antiviral and inflammatory responses in genital ECs that could have significant implications for homeostasis of the female genital tract

The Influence of Radiographic Phenotype and Smoking Status on Peripheral Blood Biomarker Patterns in Chronic Obstructive Pulmonary Disease

Background: Chronic obstructive pulmonary disease (COPD) is characterized by both airway remodeling and parenchymal destruction. The identification of unique biomarker patterns associated with airway dominant versus parenchymal dominant patterns would support the existence of unique phenotypes representing independent biologic processes. A cross-sectional study was performed to examine the association of serum biomarkers with radiographic airway and parenchymal phenotypes of COPD. Methodology/Principal Findings: Serum from 234 subjects enrolled in a CT screening cohort was analyzed for 33 cytokines and growth factors using a multiplex protein array. The association of serum markers with forced expiratory volume in one second percent predicted (FEV1%) and quantitative CT measurements of airway thickening and emphysema was assessed with and without stratification for current smoking status. Significant associations were found with several serum inflammatory proteins and measurements of FEV1%, airway thickening, and parenchymal emphysema independent of smoking status. The association of select analytes with airway thickening and emphysema was independent of FEV1%. Furthermore, the relationship between other inflammatory markers and measurements of physiologic obstruction or airway thickening was dependent on current smoking status. Conclusions/Significance: Airway and parenchymal phenotypes of COPD are associated with unique systemic serum biomarker profiles. Serum biomarker patterns may provide a more precise classification of the COPD syndrome, provide insights into disease pathogenesis and identify targets for novel patient-specific biological therapies. © 2009 Bon et al

Tobacco Upregulates P. gingivalis Fimbrial Proteins Which Induce TLR2 Hyposensitivity

Tobacco smokers are more susceptible to periodontitis than non-smokers but exhibit reduced signs of clinical inflammation. The underlying mechanisms are unknown. We have previously shown that cigarette smoke extract (CSE) represents an environmental stress to which P. gingivalis adapts by altering the expression of several virulence factors - including major and minor fimbrial antigens (FimA and Mfa1, respectively) and capsule - concomitant with a reduced pro-inflammatory potential of intact P. gingivalis.We hypothesized that CSE-regulation of capsule and fimbrial genes is reflected at the ultrastructural and functional levels, alters the nature of host-pathogen interactions, and contributes to the reduced pro- inflammatory potential of smoke exposed P. gingivalis. CSE induced ultrastructural alterations were determined by electron microscopy, confirmed by Western blot and physiological consequences studied in open-flow biofilms. Inflammatory profiling of specific CSE-dysregulated proteins, rFimA and rMfa1, was determined by quantifying cytokine induction in primary human innate and OBA-9 cells. CSE up-regulates P. gingivalis FimA at the protein level, suppresses the production of capsular polysaccharides at the ultrastructural level, and creates conditions that promote biofilm formation. We further show that while FimA is recognized by TLR2/6, it has only minimal inflammatory activity in several cell types. Furthermore, FimA stimulation chronically abrogates the pro-inflammatory response to subsequent TLR2 stimulation by other TLR-2-specific agonists (Pam3CSK4, FSL, Mfa1) in an IkappaBalpha- and IRAK-1-dependent manner.These studies provide some of the first information to explain, mechanistically, how tobacco smoke changes the P. gingivalis phenotype in a manner likely to promote P. gingivalis colonization and infection while simultaneously reducing the host response to this major mucosal pathogen