Determining SARS-CoV-2 viral infectivity is crucial for patient clinical assessment and isolation decisions. We assessed subgenomic RNA (sgRNA) as a surrogate marker of SARS-CoV-2 infectivity in ...SARS-CoV-2-positive reverse transcription PCR (RT-PCR) respiratory samples (
= 105) in comparison with viral culture as the reference standard for virus replication. sgRNA and viral isolation results were concordant in 99/105 cases (94%), indicating highly significant agreement between the two techniques (Cohen's kappa coefficient 0.88, 95% confidence interval CI 0.78 to 0.97,
< 0.001). sgRNA RT-PCR showed a sensitivity of 97% and a positive predictive value of 94% to detect replication-competent virus, further supporting sgRNA as a surrogate marker of SARS-CoV-2 infectivity. sgRNA RT-PCR is an accurate, rapid, and affordable technique that can overcome culture and cycle threshold (
) value limitations and be routinely implemented in hospital laboratories to detect viral infectivity, which is essential for optimizing patient monitoring, the efficacy of treatments/vaccines, and work reincorporation policies, as well as for safely shortening isolation precautions.
The presence of neutralizing antibodies (NAbs) is a major correlate of protection for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. Thus, different in vitro ...pseudoviruses‐based assays have been described to detect NAbs against SARS‐CoV‐2. However, the determination of NAbs against SARS‐CoV‐2 in people living with HIV (PLWH) through HIV‐based pseudoparticles could be influenced by cross‐neutralization activity or treatment, impeding accurate titration of NAbs. Two assays were compared using replication‐defective HIV or VSV‐based particles pseudotyped with SARS‐CoV‐2 spike to measure NAbs in COVID‐19‐recovered and COVID‐19‐naïve PLWH. The assay based on HIV‐pseudoparticles displayed neutralization activity in all COVID‐19‐recovered PLWH with a median neutralizing titer 50 (NT50) of 1417.0 (interquartile range IQR: 450.3−3284.0), but also in 67% of COVID‐19‐naïve PLWH (NT50: 631.5, IQR: 16.0−1535.0). Regarding VSV‐pseudoparticles system, no neutralization was observed in COVID‐19‐naïve PLWH as expected, whereas in comparison with HIV‐pseudoparticles assay lower neutralization titers were measured in 75% COVID‐19‐recovered PLWH (NT50: 100.5; IQR: 20.5−1353.0). Treatment with integrase inhibitors was associated with inaccurate increase in neutralization titers when HIV‐based pseudoparticles were used. IgG purification and consequent elimination of drugs from samples avoided the interference with retroviral cycle and corrected the lack of specificity observed in HIV‐pseudotyped assay. This study shows methodological alternatives based on pseudoviruses systems to determine specific SARS‐CoV‐2 neutralization titers in PLWH.
Abstract
Two transplant recipients (1 kidney and 1 hematopoietic stem cell) received maribavir (MBV) after cytomegalovirus (CMV) infection clinically resistant to standard therapy. Both patients ...achieved CMV DNA clearance within 30 and 18 days; however, the UL97 C480F variant emerged, causing recurrent CMV infection after a cumulative 2 months of MBV and 15 or 4 weeks of ganciclovir treatment, respectively. C480F was not detected under ganciclovir before MBV treatment. Recombinant phenotyping showed that C480F conferred the highest level of MBV resistance and ganciclovir cross-resistance, with impaired viral growth. Clinical follow-up and genotypic and phenotypic studies are essential for the assessment and optimization of patients with suspected MBV resistance.
A cytomegalovirus UL97 C480F mutation emerged after maribavir treatment in 2 transplant recipients (1 kidney, 1 hematopoietic stem cell). Phenotypic assay confirmed that C480F confers a high level of maribavir resistance and ganciclovir cross-resistance, with a decreased replicative capacity.
To characterize mitochondrial/apoptotic parameters in chronically human immunodeficiency virus (HIV‐1)‐infected promonocytic and lymphoid cells which could be further used as therapeutic targets to ...test pro‐mitochondrial or anti‐apoptotic strategies as in vitro cell platforms to deal with HIV‐infection. Mitochondrial/apoptotic parameters of U1 promonocytic and ACH2 lymphoid cell lines were compared to those of their uninfected U937 and CEM counterparts. Mitochondrial DNA (mtDNA) was quantified by rt‐PCR while mitochondrial complex IV (CIV) function was measured by spectrophotometry. Mitochondrial‐nuclear encoded subunits II–IV of cytochrome‐c‐oxidase (COXII‐COXIV), respectively, as well as mitochondrial apoptotic events voltage‐dependent‐anion‐channel‐1(VDAC‐1)‐content and caspase‐9 levels were quantified by western blot, with mitochondrial mass being assessed by spectrophotometry (citrate synthase) and flow cytometry (mitotracker green assay). Mitochondrial membrane potential (JC1‐assay) and advanced apoptotic/necrotic events (AnexinV/propidium iodide) were measured by flow cytometry. Significant mtDNA depletion spanning 57.67% (P < 0.01) was found in the U1 promonocytic cells further reflected by a significant 77.43% decrease of mitochondrial CIV activity (P < 0.01). These changes were not significant for the ACH2 lymphoid cell line. COXII and COXIV subunits as well as VDAC‐1 and caspase‐9 content were sharply decreased in both chronic HIV‐1‐infected promonocytic and lymphoid cell lines (<0.005 in most cases). In addition, U1 and ACH2 cells showed a trend (moderate in case of ACH2), albeit not significant, to lower levels of depolarized mitochondrial membranes. The present in vitro lymphoid and especially promonocytic HIV model show marked mitochondrial lesion but apoptotic resistance phenotype that has been only partially demonstrated in patients. This model may provide a platform for the characterization of HIV‐chronicity, to test novel therapeutic options or to study HIV reservoirs.
Tyrosine kinase inhibitors (TKIs) have been extensively used as a treatment for chronic myeloid leukemia (CML). Dasatinib is a broad-spectrum TKI with off-target effects that give it an ...immunomodulatory capacity resulting in increased innate immune responses against cancerous cells and viral infected cells. Several studies reported that dasatinib expanded memory-like natural killer (NK) cells and γδ T cells that have been related with increased control of CML after treatment withdrawal. In the HIV infection setting, these innate cells are associated with virus control and protection, suggesting that dasatinib could have a potential role in improving both the CML and HIV outcomes. Moreover, dasatinib could also directly induce apoptosis of senescence cells, being a new potential senolytic drug. Here, we review in depth the current knowledge of virological and immunogenetic factors associated with the development of powerful cytotoxic responses associated with this drug. Besides, we will discuss the potential therapeutic role against CML, HIV infection and aging.
The health effects of a supplemented Mediterranean diet (SMD) with extra-virgin olive oil (EVOO) and nuts are well documented in non-HIV-infected individuals. We hypothesised that the benefits of an ...SMD could be mediated by changes in the gut microbiota, even in those with an altered intestinal microbiota such as people living with HIV.
Individuals living with HIV (
= 102) were randomised to receive an SMD with 50 g/day of EVOO and 30 g/day of walnuts (SMD group) or continue with their regular diet (control group) for 12 weeks.
Adherence to the Mediterranean diet was assessed using the validated 14-item MD-Adherence-Screener (MEDAS) from the PREDIMED study. A sub-study classifying the participants according to their MEDAS scores was performed.
The lipid profile was improved in the SMD group vs. that in the control group (delta-total cholesterol and delta-B-lipoprotein). The immune activation (CD4+HLADR+CD38+ and CD8+HLADR+CD38+ cells) and IFN-γ-producing T-cells significantly decreased at week 12 compared to the baseline in the SMD group but not in the control group. The gut microbiota in those from the high-adherence group presented significantly high diversity and richness at the end of the intervention.
and
abundances were influenced by the adherence to the MD and significantly correlated with Treg cells.
The Mediterranean diet improved metabolic parameters, immune activation, Treg function, and the gut microbiota composition in HIV-1-infected individuals. Further, Mediterranean diet increased the
abundances after the intervention, and it was associated to a beneficial profile.
: We assessed if the increase on viral reservoir after long-term antiretroviral therapy (ART) interruption (ATI) is reversible upon ART resumption in chronic HIV-1 infected patients. Total HIV-1 DNA ...increased to pre-ART levels after 48 weeks of ATI to return to pre-ATI levels after 104 weeks of ART resumption. Conversely, integrated HIV-1 DNA remained elevated after ART reinitiation. These data suggest that the increase in reservoir after long-term ART discontinuation might not be reversible at midterm.
Antiretroviral treatment (ART) during acute/recent HIV infection decreases transmission and optimizes immune recovery but the optimal ART-regimen in this setting is unknown. The objectives were to ...analyze the virological efficacy, immunological reconstitution and tolerability of different ART-regimens at 3 years after starting ART during acute/recent HIV infection.
Retrospective cohort study of consecutive acutely/recently infected patients who started ART within 6 months postinfection.
We compared regimens based on protease-inhibitors (N = 28), integrase-strand-transfer-inhibitors (InSTI, N = 87) and nonnucleoside-reverse-transcriptase-inhibitors (N = 22). Virological suppression (viral load <50 copies/ml), immune reconstitution (CD4 T-cell count >900 cells/μl and CD4/CD8 ratio >1) and adverse events leading to ART discontinuation at 1 and 3 years were compared.
Baseline characteristics were comparable among groups. Overall viral suppression at 1 (96%) and 3 years (99%) was comparable in all ART regimens and, InSTI group, comparable for dolutegravir and elvitegravir within InSTIs. CD4 T-cell counts at 1 year were comparable in all ART regimens. Overall proportion of patients reaching CD4 cell count more than 900 cells/μl and CD4/CD8 ratio more than 1 was 36% and 40% and 46% and 63% at 1 and 3 years, respectively with no differences among ART regimens. Starting ART during the earliest Fiebig stages (I-V vs. VI) was associated with higher rates of CD4 cell count more than 900 cells/μl at 3 years (P = 0.027). Discontinuation due to adverse events was more frequent with nonnucleoside-reverse-transcriptase-inhibitors compared with other ART classes.
Viral suppression and immunological recovery were excellent, with no differences between ART regimens. Earlier ART initiation was associated with a higher proportion of long-term immunological recovery.
HIV‐1 infection triggers lateral membrane diffusion following interaction of the viral envelope with cell surface receptors. We show that these membrane changes are necessary for infection, as ...initial gp120–CD4 engagement leads to redistribution and clustering of membrane microdomains, enabling subsequent interaction of this complex with HIV‐1 co‐receptors. Disruption of cell membrane rafts by cholesterol depletion before viral exposure inhibits entry by both X4 and R5 strains of HIV‐1, although viral replication in infected cells is unaffected by this treatment. This inhibitory effect is fully reversed by cholesterol replenishment of the cell membrane. These results indicate a general mechanism for HIV‐1 envelope glycoprotein‐mediated fusion by reorganization of membrane microdomains in the target cell, and offer new strategies for preventing HIV‐1 infection.
PDF
