Stress response in Escherichia coli following sublethal phenalene-1-one mediated antimicrobial photodynamic therapy: an RNA-Seq study.

Since the molecular mechanisms behind adaptation and the bacterial stress response toward antimicrobial photodynamic therapy (aPDT) are not entirely clear yet, the aim of the present study was to investigate the transcriptomic stress response in Escherichia coli after sublethal treatment with aPDT using RNA sequencing (RNA-Seq). Planktonic cultures of stationary phase E. coli were treated with aPDT using a sublethal dose of the photosensitizer SAPYR. After treatment, RNA was extracted, and RNA-Seq was performed on the Illumina NextSeq 500. Differentially expressed genes were analyzed and validated by qRT-PCR. Furthermore, expression of specific stress response proteins was investigated using Western blot analysis.The analysis of the differential gene expression following pathway enrichment analysis revealed a considerable number of genes and pathways significantly up- or down-regulated in E. coli after sublethal treatment with aPDT. Expression of 1018 genes was up-regulated and of 648 genes was down-regulated after sublethal treatment with aPDT as compared to irradiated controls. Analysis of differentially expressed genes and significantly de-regulated pathways showed regulation of genes involved in oxidative stress response and bacterial membrane damage. In conclusion, the results show a transcriptomic stress response in E. coli upon exposure to aPDT using SAPYR and give an insight into potential molecular mechanisms that may result in development of adaptation.

Screening strategies for the diagnosis of asymptomatic Leishmania infection in dialysis patients as a model for kidney transplant candidates.

Despite being considered a tropical disease, visceral leishmaniasis (VL) caused by L. infantum is also endemic in the Mediterranean Europe and represents an increasing cause of morbidity and mortality in solid organ transplant (SOT) recipients. VL occurring in kidney transplant recipients is a severe event, often worsening the renal damage and leading to poor outcome. It is believed that most of VL cases in transplant recipients are caused by reactivation of a pre-existent, dormant leishmanial infection induced by the immunosuppressive drugs. Nevertheless, the prevalence of asymptomatic Leishmania infection in candidates to kidney transplant residing in or visiting endemic areas is unknown. As L. infantum is highly circulating in northeastern Italy, we aimed to examine the occurrence of this parasitic infection in 119 dialysis patients living in the mentioned area, 71 of whom were potential candidates to kidney transplant. By employing a combination of sensitive serological and molecular methods, we observed a prevalence of 15.9% asymptomatic Leishmania infection in the study cohort. This finding emphasizes the need of further evaluating potential screening strategies for Leishmania infection in solid organ transplant candidates residing in or visiting endemic areas.

Pre-Race Sleep Management Strategy and Chronotype of Offshore Solo Sailors.

PURPOSE: To evaluate chronotype and the sleep management strategy adopted by sailors before the offshore solo sailing race "Mini Transat La Boulangère". As secondary aim, we assessed whether adopting pre-race sleep management strategy influences performance at race. MATERIALS AND METHODS: Forty-two solo sailors completed questionnaires on sleep quality, sleepiness, chronotype and an ad hoc questionnaire on the pre-race sleep management strategy adopted. Arrival times, separately for each race's leg, were provided by the race organization team. RESULTS: Solo sailors present mainly with a morning-type (40%) and intermediate-type (60%) chronotype, while none have an evening-type chronotype. Fifty-five percent of sailors adopted pre-race sleep management strategy. Sailors that adopted strategy have travelled more miles in offshore compared to sailors that did not adopt strategy (p<0.05). Significant differences emerged in rMEQ scores, with sailors that adopted strategy presenting lower score compared to sailors that did not adopt sleep strategy (p<0.05), as well as in chronotype distribution with morning-type sailors that are less likely to adopt pre-race sleep management strategy compared to intermediate type sailors (p<0.05). No differences emerged in final arrival times and in arrival time at leg1 and leg2. The most commonly adopted strategy (52% of sailors) consists of sleep extension, followed by the polyphasic sleep (26%), and sleep deprivation (22%) strategy. Sailors trained in polyphasic sleep have higher ESS than sailors trained in sleep deprivation (p<0.05). CONCLUSION: Morning-type chronotype is overrepresented in this large cohort of solo sailors compared to the general population; moreover, chronotype seems to influence the adoption of sleep management strategy. A little over half of solo sailors participating in the Mini Transat trained in sleep management strategy before the race; however, neither the general adoption of pre-race sleep management strategy nor the adoption of a specific sleep strategy seems to significantly influence final arrival times.

Detection of Specific Antibodies against Toscana Virus among Blood Donors in Northeastern Italy and Correlation with Sand Fly Abundance in 2014.

Toscana virus (TOSV) is a Phlebovirus transmitted by phlebotomine sand flies and is an important etiological agent of summer meningitis in the Mediterranean basin. Since TOSV infection is often asymptomatic, we evaluated the seroprevalence in blood donors (BDs) in the Bologna and Ferrara provinces (Northeastern Italy)-the areas with the highest and lowest numbers of TOSV neuroinvasive cases in the region, respectively. A total of 1208 serum samples from BDs were collected in April-June 2014 and evaluated for the presence of specific TOSV-IgG by ELISA. The IgG-reactive samples were confirmed by indirect immunofluorescence assay (IIF) and by microneutralization test (MN). Serum samples were defined as positive for anti-TOSV IgG when reactive by ELISA and by at least one second-level test; TOSV seroprevalence was 6.8% in the Bologna province, while no circulation of TOSV was detected in the Ferrara province. Sand fly abundance in 2014 was also estimated by a geographic information system using a generalized linear model applied to a series of explanatory variables. TOSV seroprevalence rate was strongly associated with the sand fly abundance index in each municipality, pointing out the strong association between sand fly abundance and human exposure to TOSV.

Effects of Antiretroviral Molecules on Survival and Gene Expression of An Osteoblast-like Cell Line.

BACKGROUND: The advent of combined antiretroviral therapy effectively undermined the evolution of HIV disease. Nevertheless, clinical observations indicated a clear association between therapy and the impairment of bone mineral density. OBJECTIVE: We selected some antiretroviral compounds used in clinical practice, to study their impact on bone health and their possible implication in the onset of bone disease. METHOD: Scalar concentrations of several antiretroviral drugs (used in single and in combination) were tested on an osteoblast-like cell line, HOBIT cells, to analyse cell survival and gene expression of selected bone markers. RESULTS: None of the tested concentrations of Tenofovir, Emtricitabine, Nevirapine, Maraviroc or Raltegravir induced any significant apoptosis activation at our experimental conditions. Only some protease inhibitors and Efavirenz, at high concentration, determined a significant activation of programmed cell death. In parallel experiments, protease inhibitors used in combination with Tenofovir and Emtricitabine, increased apoptosis. Furthermore, we performed a study of mRNA expression of specific genes involved in osteoblast biology and in bone synthesis and observed that some protease inhibitors induced a selective decrease of some osteogenic markers. CONCLUSION: All the protease inhibitors included in this study trigger apoptosis at the highest concentration analysed, suggesting great caution in HIV-patients co-infected with HBV or HCV, where elevated plasma concentrations of drugs could be reached as a consequence of liver failure. Lastly, an increased apoptosis rate and an impairment of osteogenic markers were recorded only in the presence of Nelfinavir, suggesting a role of protease inhibitors in the alteration of osteoblast biology.

HIV-1 gp120 impairs the differentiation and survival of cord blood CD34+ HPCs induced to the erythroid lineage.

Anemia is the most common hematological abnormality in human immunodeficiency virus (HIV)-infected patients. Besides chronic disease, opportunistic infections, nutritional deficiencies and antiretroviral drug toxicity, the direct role of HIV in the development of anemia has not yet been fully investigated. To explore the HIV-related mechanisms involved in the genesis of anemia, we used two experimental designs. In the first, HPCs purified from cord blood were challenged with HIV-1IIIb or recombinant gp120 (rgp120) and then committed to erythrocyte differentiation (EPO-post-treated HPCs). In the second, HPCs were first committed to differentiate towards the erythroid lineage and only afterwards challenged with HIV-1IIIb or rgp120 (EPO-pre-treated HPCs). Our results showed that HPCs and EPO-induced HPCs were not susceptible to HIV-1 infection. In addition, the two experimental designs (EPO post or pre-treated HPCs) independently showed that HIV-1IIIb or rgp120 were able to induce the impairment of survival, proliferation, and differentiation albeit differing in kinetics and extent. Interestingly, the gp120 interaction with CD4 and CXCR4 played a pivotal role in the impairment of erythrocyte differentiation by inducing TGF-b1 expression. These observations reveal an important additional mechanism involved in the genesis of anemia suggesting a complex competition between EPO-positive regulation and HIV-negative priming regarding erythrocyte survival, proliferation and maturation.

Meningitis Caused by Toscana Virus Is Associated with Strong Antiviral Response in the CNS and Altered Frequency of Blood Antigen-Presenting Cells.

Toscana virus (TOSV) is a Phlebotomus-transmitted RNA virus and a frequent cause of human meningitis and meningoencephalitis in Southern Europe during the summer season. While evidence for TOSV-related central nervous system (CNS) cases is increasing, little is known about the host defenses against TOSV. We evaluated innate immune response to TOSV by analyzing frequency and activation of blood antigen-presenting cells (APCs) and cytokine levels in plasma and cerebrospinal fluid (CSF) from patients with TOSV neuroinvasive infection and controls. An altered frequency of different blood APC subsets was observed in TOSV-infected patients, with signs of monocytic deactivation. Nevertheless, a proper or even increased responsiveness of toll-like receptor 3 and 7/8 was observed in blood APCs of these patients as compared to healthy controls. Systemic levels of cytokines remained low in TOSV-infected patients, while levels of anti-inflammatory and antiviral mediators were significantly higher in CSF from TOSV-infected patients as compared to patients with other infectious and noninfectious neurological diseases. Thus, the early host response to TOSV appears effective for viral clearance, by proper response to TLR3 and TLR7/8 agonists in peripheral blood and by a strong and selective antiviral and anti-inflammatory response in the CNS.

IFI16 Expression Is Related to Selected Transcription Factors during B-Cell Differentiation.

The interferon-inducible DNA sensor IFI16 is involved in the modulation of cellular survival, proliferation, and differentiation. In the hematopoietic system, IFI16 is consistently expressed in the CD34+ stem cells and in peripheral blood lymphocytes; however, little is known regarding its regulation during maturation of B- and T-cells. We explored the role of IFI16 in normal B-cell subsets by analysing its expression and relationship with the major transcription factors involved in germinal center (GC) development and plasma-cell (PC) maturation. IFI16 mRNA was differentially expressed in B-cell subsets with significant decrease in IFI16 mRNA in GC and PCs with respect to naïve and memory subsets. IFI16 mRNA expression is inversely correlated with a few master regulators of B-cell differentiation such as BCL6, XBP1, POU2AF1, and BLIMP1. In contrast, IFI16 expression positively correlated with STAT3, REL, SPIB, RELA, RELB, IRF4, STAT5B, and STAT5A. ARACNE algorithm indicated a direct regulation of IFI16 by BCL6, STAT5B, and RELB, whereas the relationship between IFI16 and the other factors is modulated by intermediate factors. In addition, analysis of the CD40 signaling pathway showed that IFI16 gene expression directly correlated with NF-κB activation, indicating that IFI16 could be considered an upstream modulator of NF-κB in human B-cells.

Calcaneal quantitative ultrasound (QUS) and dual X-ray absorptiometry (DXA) bone analysis in adult HIV-positive patients.

Human immunodeficiency virus (HIV)-infected patients have an increased risk of developing osteopenia or osteoporosis compared with healthy individuals. Our aim was to compare dual X-ray absorptiometry (DXA), the gold standard for measuring bone mineral density (BMD), with bone quantitative ultrasound (QUS), an alternative technique for predicting fractures and screening low BMD, at least in postmenopausal populations. We analyzed DXA and QUS parameters to investigate their accuracy in the diagnosis and prediction of bone alterations in a cohort of 224 HIV-1-positive patients. The speed of sound (SOS), broadband ultrasound attenuation (BUA) and stiffness index (SI) parameters showed a moderate correlation with DXA, especially with total-body BMD (r coefficient of 0.38, 0.4 and 0.42 respectively), particularly in the female subgroup. In addition, multivariate analysis of HIV-positive patients assessed for vertebral fractures indicated that QUS was more effective than DXA at predicting the risk of fracture. QUS can be used as an additional tool for analyzing bone density in HIV-positive patients and its case of use and low cost make it especially suitable for resource-limited settings where DXA is not employed.

Durable viral suppression in an HIV-infected patient in the absence of antiretroviral therapy.

We describe the case of a young woman with an acute HIV infection characterized at onset by neurological features. The patient spontaneously controlled her HIV infection and recovered in a short period of time. The patient's clinical and virological history showed a peculiar evolution of HIV infection, with an MDR HIV-1 in CSF and a wild HIV strain in PBMCs. The patient's PBMC showed a rapid shift from a wild type to an MDR strain in few days.

Effects of human immunodeficiency virus on the erythrocyte and megakaryocyte lineages.

Anaemia and thrombocytopenia are haematological disorders that can be detected in many human immunodeficiency virus (HIV)-positive patients during the development of HIV infection. The progressive decline of erythrocytes and platelets plays an important role both in HIV disease progression and in the clinical and therapeutic management of HIV-positive patients. HIV-dependent impairment of the megakaryocyte and erythrocyte lineages is multifactorial and particularly affects survival, proliferation and differentiation of bone marrow (BM) CD34+ haematopoietic progenitor cells, the activity of BM stromal cells and the regulation of cytokine networks. In this review, we analyse the major HIV-related mechanisms that are involved in the genesis and development of the anaemia and thrombocytopenia observed in HIV positive patients.

Peptide-derivatized SB105-A10 dendrimer inhibits the infectivity of R5 and X4 HIV-1 strains in primary PBMCs and cervicovaginal histocultures.

Peptide dendrimers are a class of molecules that exhibit a large array of biological effects including antiviral activity. In this report, we analyzed the antiviral activity of the peptide-derivatized SB105-A10 dendrimer, which is a tetra-branched dendrimer synthetized on a lysine core, in activated peripheral blood mononuclear cells (PBMCs) that were challenged with reference and wild-type human immunodeficiency virus type 1 (HIV-1) strains. SB105-A10 inhibited infections by HIV-1 X4 and R5 strains, interfering with the early phases of the viral replication cycle. SB105-A10 targets heparan sulfate proteoglycans (HSPGs) and, importantly, the surface plasmon resonance (SPR) assay revealed that SB105-A10 strongly binds gp41 and gp120, most likely preventing HIV-1 attachment/entry through multiple mechanisms. Interestingly, the antiviral activity of SB105-A10 was also detectable in an organ-like structure of human cervicovaginal tissue, in which SB105-A10 inhibited the HIV-1ada R5 strain infection without altering the tissue viability. These results demonstrated the strong antiviral activity of SB105-A10 and suggest a potential microbicide use of this dendrimer to prevent the heterosexual transmission of HIV-1.

HIV-related mechanisms in atherosclerosis and cardiovascular diseases.

HIV-infected patients have a significantly higher risk of developing cardiovascular events during the progression of HIV disease. Atherosclerosis, myocardial infarction, cerebrovascular injury, pulmonary hypertension and thrombosis are consistently described in both combined antiretroviral therapy (cART)-treated and naive HIV-positive patients as major clinical complications. Recent studies indicate that the pathogenesis of cardiovascular lesions in HIV-positive patients is related to direct and indirect effects of HIV infection on vessel structures, independently of traditional risk factors. HIV infection strongly interferes with the biology of several cellular targets such as macrophage and endothelial cells. Moreover, HIV induces a profound derangement of lipid metabolism and inflammatory cytokine networks that are directly involved in atherogenesis and progressive impairment of the cardiovascular system.In this review, we discuss these major HIV-related mechanisms able to promote atherosclerosis and cardiovascular diseases in HIV-positive patients.

Prevalence of R5 strains in multi-treated HIV subjects and impact of new regimens including maraviroc in a selected group of patients with CCR5-tropic HIV-1 infection.

OBJECTIVES: Maraviroc currently represents an important antiretroviral drug for multi-experienced and viremic HIV patients. This study focused on two main points: (1) determining the prevalence of R5 and X4 HIV strains in antiretroviral-experienced patients using two main tests currently in use to determine viral tropism, and (2) the follow-up to 3 years of a limited number of patients who started a new antiretroviral protocol including maraviroc. METHODS: A group of 56 HIV patients, previously multi-treated, were first analyzed by genotyping assay and Trofile™ to establish their eligibility for maraviroc treatment. In addition, 25 subjects selected to follow a new therapeutic protocol including a CCR5 antagonist were monitored by HIV RNA viral load and CD4+ cell count. RESULTS: The determination of viral tropism showed a large percentage of patients with an R5 profile (72% by genotyping assay and 74% by Trofile). The follow-up of most (21 out 25) patients who started the new antiretroviral protocol showed an undetectable viral load throughout the observation period, accompanied by a major improvement in CD4 cell count (cells/mm(3)) (baseline: median CD4 cell count 365, interquartile range (IQR) 204-511; 12 months: median value 501, IQR 349-677, p=0.042; 24 months: median value 503, IQR 386-678, p=0.026; 36 months: median value 601, IQR 517-717, p=0.001). Among the four non-responder subjects, two showed a lack of drug compliance and two switched from R5 to X4. CONCLUSION: Although our patient cohort was small, the results showed a high prevalence of R5 viral strains in multi-experienced patients. As well as showing the advantages of genotyping, which can be performed in plasma samples with low viral load replication, the follow-up of HIV patients selected for an alternative drug protocol, including a CCR5 antagonist, showed a persistent undetectable viral replication and a good recovery of CD4 cell count in most treated HIV patients.

Antiretroviral molecules and cardiovascular diseases.

Antiretroviral therapy has effectively tackled HIV replication and prevented the development of AIDS-related complications in the majority of HIV-positive patients. This pharmacological approach has dramatically increased the life expectancy of HIV-positive subjects transforming HIV infection into a chronic disease. Notwithstanding this major improvement in HIV disease management, several HIV-positive patients show an earlier and significant onset of aging related chronic conditions such as cardiovascular disease, osteoporosis, diabetes and neoplasias with respect to uninfected individuals. In particular, cardiovascular diseases are associated with both HIV infection and antiretroviral treatment, and represent major clinical complications in HIV-positive patients. Here, we discuss the interaction between antiretroviral therapy and cardiovascular system in HIV-positive patients focusing on the antiretroviral-related mechanisms involved in cardiovascular alterations.

Recent and long-lasting infections: the need for avidity testing in HIV-1 infected subjects.

Standard serological tests have reached high levels of sensitivity and reproducibility but do not indicate whether infection is recent or long-standing. Among the 59960 sera analyzed for HIV positivity at the Retrovirus Laboratory, Operative Unit of Microbiology, Bologna, Italy, from January 2010 to July 2011, 134 samples showed an initial positive result. Application of the avidity test, able to distinguish between recent or long-standing HIV infection, classified 59 subjects as recently infected and 75 as chronically infected. Besides all the public health implications, the distinction between acute and chronic infection might serve to establish the time of infection and therefore reach any potential partners who might have been infected in a specific period of time. Although our results are limited to subjects referred to our laboratory and hence represent only a limited part of the problem, the routine application of methods able to distinguish recent from long-lasting infection could help monitor disease incidence, identify high-risk groups, and enhance epidemiological conclusions.

Analysis of the effects of HIV-1 Tat on the survival and differentiation of vessel wall-derived mesenchymal stem cells.

HIV infection is an independent risk factor for atherosclerosis development and cardiovascular damage. As vessel wall mesenchymal stem cells (MSCs) are involved in the regulation of vessel structure homeostasis, we investigated the role of Tat, a key factor in HIV replication and pathogenesis, in MSC survival and differentiation. The survival of subconfluent MSCs was impaired when Tat was added at high concentrations (200-1,000 ng/ml), whereas lower Tat concentrations (1-100 ng/ml) did not promote apoptosis. Tat enhanced the differentiation of MSC toward adipogenesis by the transcription and activity upregulation of PPARγ. This Tat-related modulation of adipogenesis was tackled by treatment with antagonists of Tat-specific receptors such as SU5416 and RGD Fc. In contrast, Tat inhibited the differentiation of MSCs to endothelial cells by downregulating the expression of VEGF-induced endothelial markers such as Flt-1, KDR, and vWF. The treatment of MSCs with Tat-derived peptides corresponding to the cysteine-rich, basic, and RGD domains indicated that these Tat regions are involved in the inhibition of endothelial marker expression. The Tat-related impairment of MSC survival and differentiation might play an important role in vessel damage and formation of the atherosclerotic lesions observed in HIV-infected patients.

HIV-1 and recombinant gp120 affect the survival and differentiation of human vessel wall-derived mesenchymal stem cells.

BACKGROUND: HIV infection elicits the onset of a progressive immunodeficiency and also damages several other organs and tissues such as the CNS, kidney, heart, blood vessels, adipose tissue and bone. In particular, HIV infection has been related to an increased incidence of cardiovascular diseases and derangement in the structure of blood vessels in the absence of classical risk factors. The recent characterization of multipotent mesenchymal cells in the vascular wall, involved in regulating cellular homeostasis, suggests that these cells may be considered a target of HIV pathogenesis. This paper investigated the interaction between HIV-1 and vascular wall resident human mesenchymal stem cells (MSCs). RESULTS: MSCs were challenged with classical R5 and X4 HIV-1 laboratory strains demonstrating that these strains are able to enter and integrate their retro-transcribed proviral DNA in the host cell genome. Subsequent experiments indicated that HIV-1 strains and recombinant gp120 elicited a reliable increase in apoptosis in sub-confluent MSCs. Since vascular wall MSCs are multipotent cells that may be differentiated towards several cell lineages, we challenged HIV-1 strains and gp120 on MSCs differentiated to adipogenesis and endotheliogenesis. Our experiments showed that the adipogenesis is increased especially by upregulated PPARγ activity whereas the endothelial differentiation induced by VEGF treatment was impaired with a downregulation of endothelial markers such as vWF, Flt-1 and KDR expression. These viral effects in MSC survival and adipogenic or endothelial differentiation were tackled by CD4 blockade suggesting an important role of CD4/gp120 interaction in this context. CONCLUSIONS: The HIV-related derangement of MSC survival and differentiation may suggest a direct role of HIV infection and gp120 in impaired vessel homeostasis and in genesis of vessel damage observed in HIV-infected patients.