13 research outputs found

    Cell Death Induced by the Herpes Simplex Virus-1 Thymidine Kinase Delivered by Human Immunodeficiency Virus-1-Based Virus-like Particles

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    HIV-1 Nef incorporates into virions at low levels, likely about 10 molecules per viral particle. Here, we describe a Nef mutant (Nef7) apparently showing more than 100-fold higher efficiency of virion incorporation. Interestingly, Nef7 can act as a cargo molecule for protein delivery into the cells, as its virion incorporation appeared conserved even upon C-terminal fusion with proteins of up to 30 kDa. This was demonstrated first by assessing the intracellular fluorescence of cells challenged with lentivirus-based virus-like particles (VLPs) pseudotyped with the vesicular stomatitis virus envelope glycoprotein (VSV-G) and incorporating Nef7 fused with the green fluorescent protein. Furthermore, the biologic activity of products delivered by Nef7-based VLPs was demonstrated by tagging Nef7 with the herpes simplex virus-1 thymidine kinase (HSV-1 TK). In fact, we observed that both cell lines and primary human macrophages challenged with (VSV-G) Nef7/TK VLPs died after 5 to 7 days of treatment with ganciclovir (GCV). In sum, our findings support the notion that Nef7-based VLPs can be considered platforms for original systems of protein delivery. In particular, the here- described Nef7/TK VLPs represent a first applicative example opening the way toward new HSV-1 TK/GCV-based cell suicide therapies circumventing cell gene engineering procedures

    HIV-1 Nef enhances both membrane expression and virion incorporation of Env products. A model for the Nef-dependent increase of HIV-1 infectivity.

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    The expression of human immunodeficiency virus Nef increases the viral infectivity through mechanisms still not fully elucidated. Here we report that wild-type (wt) human immunodeficiency virus, type 1 (HIV-1), particles were neutralized by higher concentrations of either anti-Env glycoprotein (gp) 41 antibodies or recombinant soluble human CD4 compared with Δnef HIV-1. This appeared to be the result of a Nef-induced increase of virion incorporation of both gp41 (transmembrane (TM)) and surface gp120 Env products likely originating from enhanced steady-state levels of cell membrane-associated Env products. This, in turn, seemed to be the consequence of a reduced retention of the Env precursor. Most interesting, we found that both the Nef-directed increase of Env membrane expression and the Nef-induced enhancement of HIV-1 infectivity relied on the presence of the intracytoplasmic domain of TM, supporting the hypothesis of a functional correlation between these effects. Mutagenesis studies allowed us to establish that the two leucine residues at the TM C terminus, which are part of a sorting motif involved in the control of Env membrane expression, and the 181–210-residue Nef C-terminal region were critically involved in the Nef/Env functional interaction. In conclusion, we propose that Nef increases the infectivity of HIV-1 at least in part by enhancing the amounts of Env products incorporated into virus particles

    PROGETTO E-PROs: COSTRUZIONE DI UNA PIATTAFORMA DIGITALE PER LA GESTIONE DI STRUMENTI CENTRATI SUL PAZIENTE NELLA PRATICA CLINICA (The E-PROs Project: creation of a digital platform to manage patient-oriented tools in clinical practice).

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    The need to use PROs in both research and clinical practice is now widely shared. The PROs (Patient-Reported Outcomes) allow a complete and more reliable assessment of the health status of a patient through information provided by the patient himself and not detectable through clinical examinations. In clinical practice, PROs can play a central role in improving the management of chronic or disabling conditions. The application of PROs in clinical practice, however, seems to be complex, given the need to guarantee the patient adequate levels of comfort to correctly use the PROs tools (questionnaires). The E-PROs Project is a pilot study aiming to fill these gaps through the digital technology. A web platform was therefore created. By using common devices (smartphones, tablets, PC) in total privacy, patients were able to complete the "ISS-HIV-Symptoms-Scale", a PROs tool selected to test the website platform

    SARS-CoV-2-Specific CD8<sup>+</sup> T-Cells in Blood but Not in the Lungs of Vaccinated K18-hACE2 Mice after Infection

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    Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 enters the host by infecting nasal ciliated cells. Then, the virus can spread towards the oropharyngeal cavity and the pulmonary tissues. The antiviral adaptive immunity is promptly induced in response to the virus’s detection, with virus-specific T-lymphocytes appearing before antiviral antibodies. Both the breadth and potency of antiviral CD8+ T-cell immunity have a key role in containing viral spread and disease severity. Current anti-SARS-CoV-2 vaccines do not impede the virus’s replication in the upper respiratory tract, and there is consensus on the fact that the best potency of the antiviral immune response in both blood and the upper respiratory tract can be reached upon infection in vaccinees (i.e., breakthrough infection). However, whether the antiviral CD8+ T-cells developing in response to the breakthrough infection in the upper respiratory tract diffuse to the lungs is also still largely unknown. To fill the gap, we checked the CD8+ T-cell immunity elicited after infection of K18-hACE2 transgenic mice both at 3 weeks and 3 months after anti-spike vaccination. Virus-specific CD8+ T-cell immunity was monitored in both blood and the lungs before and after infection. By investigating the de novo generation of the CD8+ T-cells specific for SARS-CoV-2 viral proteins, we found that both membrane (M) and/or nucleocapsid (N)-specific CD8+ T-cells were induced at comparable levels in the blood of both unvaccinated and vaccinated mice. Conversely, N-specific CD8+ T-cells were readily found in the lungs of the control mice but were either rare or absent in those of vaccinated mice. These results support the idea that the hybrid cell immunity developing after asymptomatic/mild breakthrough infection strengthens the antiviral cell immunity in the lungs only marginally, implying that the direct exposition of viral antigens is required for the induction of an efficient antiviral cell immunity in the lungs

    Antiviral effect of SARS-CoV-2 N-specific CD8+ T cells induced in lungs by engineered extracellular vesicles

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    Abstract Induction of effective immunity in the lungs should be a requisite for any vaccine designed to control the severe pathogenic effects generated by respiratory infectious agents. We recently provided evidence that the generation of endogenous extracellular vesicles (EVs) engineered for the incorporation of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 Nucleocapsid (N) protein induced immunity in the lungs of K18-hACE2 transgenic mice, which then can survive the lethal virus infection. However, nothing is known about the ability of the N-specific CD8+ T cell immunity in controlling viral replication in the lungs, a major pathogenic signature of severe disease in humans. To fill the gap, we investigated the immunity generated in the lungs by N-engineered EVs in terms of induction of N-specific effectors and resident memory CD8+ T lymphocytes before and after virus challenge carried out three weeks and three months after boosting. At the same time points, viral replication extents in the lungs were evaluated. Three weeks after the second immunization, virus replication was reduced in mice best responding to vaccination by more than 3-logs compared to the control group. The impaired viral replication matched with a reduced induction of Spike-specific CD8+ T lymphocytes. The antiviral effect appeared similarly strong when the viral challenge was carried out 3 months after boosting, and associated with the persistence of N-specific CD8+ T-resident memory lymphocytes. In view of the quite low mutation rate of the N protein, the present vaccine strategy has the potential to control the replication of all emerging variants

    Validation of a self-reported HIV symptoms list: the ISS-HIV symptoms scale.

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    Background: To describe the development and the psychometric properties of the Istituto Superiore di Sanità-HIV symptoms scale (lSS-HIV symptoms scale). Methods: The ISS-HIV symptom scale was developed by an Italian working team including researchers, physicians and people living with HIV. The development process went through the following steps: (1) review of HIV/AIDS literature; (2) focus group; (3) pre-test analysis; (4) scale validation. Results: The 22 symptoms of HIV-ISS symptoms scale were clustered in five factors: pain/general discomfort (7 items); depression/anxiety (4 items); emotional reaction/psychological distress (5 items); gastrointestinal discomfort (4 items); sexual discomfort (2 items). The internal consistence reliability was for all factors within the minimum accepted standard of 0.70. Conclusions: The results of this study provide a preliminary evidence of the reliability and validity of the ISS-HIV symptoms scale. In the new era where HIV infection has been transformed into a chronic diseases and patients are experiencing a complex range of symptoms, the ISS-HIV symptoms scale may represent an useful tool for a comprehensive symptom assessment with the advantage of being easy to fill out by patients and potentially attractive to physicians mainly because it is easy to understand and requires short time to interpret the results

    Retention in Care of Adult HIV Patients Initiating Antiretroviral Therapy in Tigray, Ethiopia: A Prospective Observational Cohort Study

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    <div><p>Introduction</p><p>Although Ethiopia has been scaling up the antiretroviral therapy (ART) services, low retention in care of patients remains one of the main obstacles to treatment success. We report data on retention in care and its associated determinants in Tigray, Ethiopia.</p><p>Methods</p><p>We used data from the CASA project, a prospective observational and multi-site study of a cohort of HIV-infected patients who initiated ART for the first time in Tigray. Four participating health facilities (HFs) located in the South of Tigray were considered for this study. Patients were followed for one year after ART initiation. The main outcome measure was represented by the current retention in care, defined as the proportion of patients who were alive and receiving ART at the same HF one year after ART initiation. Patients who started ART between January 1, 2013 and December 31, 2013 were included in this analysis. Patients were followed for one year after ART initiation. The determinants of retention were analysed using univariate and multivariate Cox Proportional Hazards model with robust sandwich estimates to account for within HF correlation.</p><p>Results</p><p>The four participating HFs in Tigray were able to retain overall 85.1% of their patients after one year from starting ART. Loss to follow-up (5.5%) and transfers to other HF (6.6) were the main determinant of attrition. A multivariate analysis shows that the factors significantly associated with retention were the type of HF, gender and active TB. Alamata health center was the HF with the highest attrition rate (HR 2.99, 95% CI: 2.77–3.23). Active TB (HR 1.72, 95% CI: 1.23–2.41) and gender (HR 1.64, 95% CI: 1.10–2.56) were also significantly associated with attrition.</p><p>Conclusions</p><p>Although Ethiopia has significantly improved access to the ART program, achieving and maintaining a satisfactory long-term retention rate is a future goal. This is difficult because of different retention rates among HFs. Moreover specific interventions should be directed to people of different sex to improve retention in care in male population.</p></div
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