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Lymphoblastoid cell lines (LCLs) transformed by Epstein-Barr virus (EBV) serve as an unlimited resource of human genomic DNA. The protocol that is widely used to establish LCLs involves peripheral blood mononuclear cell isolation by density gradient centrifugation, however, that method requires as much as 5 ml of peripheral blood. In this study, in order to provide a more simple and efficient method for the generation of LCLs, we developed a new protocol using hemolytic reaction to enrich white blood cells for EBV transformation and found that the hemolytic protocol successfully generated LCLs from a small volume (i.e., 0.1 ml) of peripheral blood. To assess the quality of genomic DNA extracted from LCLs established by the hemolytic protocol (LCL-hemolytic), we performed single nucleotide polymorphism (SNP) microarray genotyping using the GeneChip ® 100 K Array Set (Affymetrix, Inc.). The concordances of the SNP genotyping resulting from genomic DNA from LCL-hemolytic (99.92%) were found to be as good as the technical replicate (99.90%), and Kappa statistics results confirmed the reliability. The findings of this study reveal that the hemolytic protocol is a simple and reliable method for the generation of LCLs, even from a small volume of peripheral blood.

Antibody-dependent enhancement (ADE) is a mechanism by which the pathogenesis of certain viral infections is enhanced in the presence of sub-neutralizing or cross-reactive non-neutralizing antiviral antibodies. In vitro modelling of ADE has attributed enhanced pathogenesis to Fcγ receptor (FcγR)-mediated viral entry, rather than canonical viral receptor-mediated entry. However, the putative FcγR-dependent mechanisms of ADE overlap with the role of these receptors in mediating antiviral protection in various viral infections, necessitating a detailed understanding of how this diverse family of receptors functions in protection and pathogenesis. Here, we discuss the diversity of immune responses mediated upon FcγR engagement and review the available experimental evidence supporting the role of FcγRs in antiviral protection and pathogenesis through ADE. We explore FcγR engagement in the context of a range of different viral infections, including dengue virus and SARS-CoV, and consider ADE in the context of the ongoing SARS-CoV-2 pandemic.Antibody-dependent enhancement (ADE) has been described as a mechanism that contributes to the pathogenesis of dengue virus infection. Limited evidence also suggests that it can also occur in other viral infections. Here, the authors explore the history of the ADE phenomenon, discuss the diversity of Fc effector functions and consider its potential relevance in the context of SARS-CoV-2 infection.

Despite effective antiretroviral therapy (ART), people with HIV (PWH) experience persistent immune activation and inflammation, increasing the risk of non-AIDS-related comorbidities. The contribution of the HIV reservoir to this chronic inflammatory state remains debated. Understanding the relationship between HIV persistence, immune activation, and inflammation is crucial for optimizing long-term therapeutic strategies. This study assessed HIV persistence, immune activation, and systemic inflammation in 49 PWH treated with the same dolutegravir-based triple ART regimen. HIV reservoir size and activity were evaluated by measuring total HIV DNA in peripheral blood mononuclear cells (PBMCs) and rectal tissue, cell-associated (CA) unspliced (US) HIV RNA, and residual viremia. Over 20 inflammatory biomarkers, including sCD14, IL-6, TNF-α, and CXCL10, were analyzed, along with comprehensive immune profiling using a 26-color spectral flow cytometry panel. Clinical parameters such as age, nadir CD4 count, and co-infections were also considered. Our findings showed a limited association between HIV persistence markers and systemic inflammation or immune activation. Compared to previous studies, participants had lower reservoir sizes and transcriptional activity, likely due to early ART initiation and prolonged suppression. Immune preservation was evident, with high CD4/CD8 ratios and reduced activation markers. These results challenge the idea that the HIV reservoir is the primary driver of chronic inflammation in PWH on a dolutegravir-based long-term ART. Instead, the reservoir may evolve toward a more transcriptionally silent and defective state, reducing its impact on systemic immune activation.

Early combination antiretroviral therapy (cART) initiation at the time of primary HIV-1 infection could restrict the establishment of HIV reservoirs. We aimed to assess the effect of a cART regimen intensified with raltegravir and maraviroc, compared with standard triple-drug cART, on HIV-DNA load. In this randomised, open-label, phase 3 trial, we recruited patients from hospitals across France. Inclusion criteria were primary HIV-1 infection (an incomplete HIV-1 western blot and detectable plasma HIV-RNA), with either symptoms or a CD4+ cell count below 500 cells per μL. Patients were randomly assigned (1:1) to an intensive, five-drug cART regimen (raltegravir 400 mg and maraviroc 150 mg twice daily, and a fixed-dose combination of tenofovir disoproxil fumarate 300 g plus emtricitabine 200 g, darunavir 800 g, and ritonavir 100 g once daily) or a standard triple-drug cART regimen (tenofovir disoproxil fumarate 300 g plus emtricitabine 200 g, darunavir 800 g, and ritonavir 100 g once daily) using a predefined randomised list generated by randomly selected variable block sizes. The primary endpoint was the median number of HIV-DNA copies per 106 peripheral blood mononuclear cells (PBMC) at month 24, analysed in the modified intention-to-treat population, defined as all patients who started their assigned treatment. This study is registered with ClinicalTrials.gov, number NCT01033760. Between April 26, 2010, and July 13, 2011, 110 patients were enrolled, of whom 92 were randomly assigned and 90 started treatment (45 in each treatment group). Six (13%) patients in the intensive cART group and two (4%) in the standard cART group discontinued before month 24. At month 24, HIV-DNA loads were similar between groups (2·35 [IQR 2·05–2·50] log10 per 106 PBMC in the intensive cART group vs 2·25 [1·71–2·55] in the standard cART group; p=0·21). Eight grade 3–4 clinical adverse events were reported in seven patients in the intensive cART group and seven grade 3–4 clinical adverse events were reported in seven patients in the standard cART group. Three serious clinical adverse events occurred: two (pancreatitis and lipodystrophy) in the standard cART group, which were regarded as treatment related, and one event (suicide attempt) in the intensive cART group that was unrelated to treatment. After 24 months, cART intensified with raltegravir and maraviroc did not have a greater effect on HIV blood reservoirs than did standard cART. These results should help to design future trials of treatments aiming to decrease the HIV reservoir in patients with primary HIV-1 infection. Inserm–ANRS, Gilead Sciences, Janssen Pharmaceuticals, Merck, and ViiV Laboratories.

Enterovirus 71 (EV71), a major causative agent of hand-foot-and-mouth disease (HFMD), causes outbreaks among children in the Asia-Pacific region. A vaccine is urgently needed. Based on successful pre-clinical work, phase I and II clinical trials of an inactivated EV71 vaccine, which included the participants of 288 and 660 respectively, have been conducted. In the present study, the immune response and the correlated modulation of gene expression in the peripheral blood mononuclear cells (PBMCs) of 30 infants (6 to 11 months) immunized with this vaccine or placebo and consented to join this study in the phase II clinical trial were analyzed. The results showed significantly greater neutralizing antibody and specific T cell responses in vaccine group after two inoculations on days 0 and 28. Additionally, more than 600 functional genes that were up- or down-regulated in PBMCs were identified by the microarray assay, and these genes included 68 genes associated with the immune response in vaccine group. These results emphasize the gene expression profile of the immune system in response to an inactivated EV71 vaccine in humans and confirmed that such an immune response was generated as the result of the positive mobilization of the immune system. Furthermore, the immune response was not accompanied by the development of a remarkable inflammatory response. NCT01391494 and NCT01512706.

Influenza virus infection is a serious threat to humans and animals, with the potential to cause severe pneumonia and death. Annual vaccination strategies are a mainstay to prevent complications related to influenza. However, protection from the emerging subtypes of influenza A viruses (IAV) even in vaccinated individuals is challenging. Innate immune cells are the first cells to respond to IAV infection in the respiratory tract. Virus replication-induced production of cytokines from airway epithelium recruits innate immune cells to the site of infection. These leukocytes, namely, neutrophils, monocytes, macrophages, dendritic cells, eosinophils, natural killer cells, innate lymphoid cells, and γδ T cells, become activated in response to IAV, to contain the virus and protect the airway epithelium while triggering the adaptive arm of the immune system. This review addresses different anti-influenza virus schemes of innate immune cells and how these cells fine-tune the balance between immunoprotection and immunopathology during IAV infection. Detailed understanding on how these innate responders execute anti-influenza activity will help to identify novel therapeutic targets to halt IAV replication and associated immunopathology.

HIV-infected cells in semen facilitate viral transmission. We studied the establishment of HIV reservoirs in semen and blood during PHI, along with systemic immune activation and the impact of early cART. Patients in the ANRS-147-OPTIPRIM trial received two years of early cART. Nineteen patients of the trial were analyzed, out of which 8 had acute PHI (WB ≤1 Ab). We quantified total cell-associated (ca) HIV-DNA in blood and semen and HIV-RNA in blood and semen plasma samples, collected during PHI and at 24 months of treatment. At enrollment, HIV-RNA load was higher in blood than in semen (median 5.66 vs 4.22 log10 cp/mL, p<0.0001). Semen HIV-RNA load correlated strongly with blood HIV-RNA load (r = 0.81, p = 0.02, the CD4 cell count (r = -0.98, p<0.0001), and the CD4/CD8 ratio (r = -0.85, p<0.01) in acute infection but not in later stages of PHI. Median blood and seminal cellular HIV-DNA levels were 3.59 and 0.31 log10cp/106 cells, respectively. HIV-DNA load peaked in semen later than in blood and then correlated with blood IP10 level (r = 0.62, p = 0.04). HIV-RNA was undetectable in blood and semen after two years of effective cART. Semen HIV-DNA load declined similarly, except in one patient who had persistently high IP-10 and IL-6 levels and used recreational drugs. HIV reservoir cells are found in semen during PHI, with gradual compartmentalization. Its size was linked to the plasma IP-10 level. Early treatment purges both the virus and infected cells, reducing the high risk of transmission during PHI. NCT01033760.

Novel coronavirus disease 2019 (COVID-19) is associated with a hypercoagulable state, characterized by abnormal coagulation parameters and by increased incidence of cardiovascular complications. With this study, we aimed to investigate the activation state and the expression of transmembrane proteins in platelets of hospitalized COVID-19 patients. We investigated transmembrane proteins expression with a customized mass cytometry panel of 21 antibodies. Platelets of 8 hospitalized COVID-19 patients not requiring intensive care support and without pre-existing conditions were compared to platelets of healthy controls (11 donors) with and without in vitro stimulation with thrombin receptor-activating peptide (TRAP). Mass cytometry of non-stimulated platelets detected an increased surface expression of activation markers P-Selectin (0.67 vs. 1.87 median signal intensity for controls vs. patients, p  = 0.0015) and LAMP-3 (CD63, 0.37 vs. 0.81, p  = 0.0004), the GPIIb/IIIa complex (4.58 vs. 5.03, p  < 0.0001) and other adhesion molecules involved in platelet activation and platelet–leukocyte interactions. Upon TRAP stimulation, mass cytometry detected a higher expression of P-selectin in COVID-19 samples compared to controls ( p  < 0.0001). However, we observed a significantly reduced capacity of COVID-19 platelets to increase the expression of activation markers LAMP-3 and P-Selectin upon stimulation with TRAP. We detected a hyperactivated phenotype in platelets during SARS-CoV-2 infection, consisting of highly expressed platelet activation markers, which might contribute to the hypercoagulopathy observed in COVID-19. In addition, several transmembrane proteins were more highly expressed compared to healthy controls. These findings support research projects investigating antithrombotic and antiplatelet treatment regimes in COVID-19 patients, and provide new insights on the phenotypical platelet expression during SARS-CoV-2 infection.

A novel phlebovirus has been identified as a cause of a febrile thrombocytopenic syndrome in two patients in Missouri. The closest relative of this virus is the recently described phlebovirus associated with a hemorrhagic fever in China. The phlebovirus genus contains more than 70 antigenically distinct viruses, which are divided into virus complexes according to whether they are borne by sand flies, mosquitoes, or ticks. 1 Sand-fly–borne viruses are found in the Americas, Asia, Africa, and the Mediterranean region, and infection with these viruses commonly results in a self-limiting 3-day fever, with the exception of Toscana virus, which can cause aseptic meningitis. 2 The prototype mosquito-borne phlebovirus is Rift Valley fever virus, which causes large-scale epizootics; human infection is often a self-limiting febrile illness that can progress to hepatitis, encephalitis, or hemorrhagic fever. 3 The only tickborne phlebovirus known to . . .

The emergence of mutations conferring ganciclovir resistance was evaluated in an open-label randomized clinical trial that compared oral valganciclovir with intravenous ganciclovir as induction therapy, followed by maintenance with valganciclovir, for newly diagnosed cytomegalovirus (CMV) retinitis in 148 patients with acquired immunodeficiency syndrome. The presence of CMV mutations was directly assessed in patient leukocytes by polymerase chain reaction, followed by restriction fragment–length polymorphism (RFLP) for detection of the most common UL97 mutations associated with ganciclovir resistance and by sequencing of the viral UL97 gene. The cumulative percentages of patients with UL97-mutant viruses at 3, 6, 12, and 18 months (based on the number of patients on treatment at each time point) was 2.2%, 6.5%, 12.8%, and 15.3%, respectively. Of the 20 relevant UL97 mutations found by sequencing in 14 patients, 14 (70%) were detected by RFLP analysis. The rate of emergence of ganciclovir-resistant viruses with use of oral valganciclovir is no greater than that reported with use of intravenous ganciclovir