Search

OBJECTIVES: Recently, the activated leukocyte cell adhesion molecule (ALCAM) and tyrosylprotein sulfotransferase 2 (TPST2) have been identified as important host dependency factors (HDFs) for in-vitro HIV-1 replication. To determine whether these genes play a role in HIV-1 pathogenesis, we analysed whether naturally occurring genetic variations were associated with the clinical course of infection. DESIGN/METHODS: Single nucleotide polymorphisms (SNPs) in ALCAM and TPST2 were analysed in a cohort of 304 HIV-1-infected men who have sex with men and survival analysis was used to determine their effect on the outcome of untreated HIV-1 infection. Flowcytometry was used to determine the effect of SNPs on CD4 T-cell activation prior to HIV-1 infection and 1 and 5 years after infection. In-vitro HIV-1 infections were performed to analyse the effect of the SNPs on HIV-1 replication. RESULTS: We observed that the minor allele of rs1344861 in ALCAM was associated with accelerated disease progression, whereas the minor allele of rs9613199 in TPST2 was associated with delayed disease progression. In-vitro infection assays did not demonstrate any differences in HIV-1 replication associated with rs9613199. However, the increase in CD4 T-cell immune activation levels during HIV-1 infection was less pronounced in infected individuals homozygous for rs9613199, which is in agreement with delayed disease progression. CONCLUSION: Our data demonstrate that ALCAM and TPST2 play a role in HIV-1 pathogenesis. SNPs in these genes, without known functional implications, had a major effect on disease progression, and therefore, these HDFs may be attractive and effective targets for new treatment strategies.

The urgent need for, but limited availability of, SARS-CoV-2 vaccines worldwide has led to widespread consideration of dose sparing strategies. Here, we evaluate the SARS-CoV-2 specific antibody responses following BNT162b2 vaccination in 150 previously SARS-CoV-2-infected individuals from a population-based cohort. One week after first vaccine dose, spike protein antibody levels are 27-fold higher and neutralizing antibody titers 12-fold higher, exceeding titers of fully vaccinated SARS-CoV-2-naive controls, with minimal additional boosting after the second dose. Neutralizing antibody titers against four variants of concern increase after vaccination, however overall neutralization breadth does not improve. Pre-vaccination neutralizing antibody titers and time since infection have the largest positive effect on titers following vaccination. COVID-19 severity and the presence of comorbidities have no discernible impact on vaccine response. In conclusion, a single dose of BNT162b2 vaccine up to 15 months after SARS-CoV-2 infection offers higher neutralizing antibody titers than two vaccine doses in SARS-CoV-2-naive individuals., Graphical Abstract, In a prospective cohort study, van Gils et al find that a single dose of BNT162b2 mRNA vaccine up to 15 months after SARS-CoV-2 infection provides neutralizing titers exceeding two vaccine doses in SARS-CoV-2-naive individuals. This supports wide implementation of a single-dose mRNA vaccine strategy after prior SARS-CoV-2 infection.

Background and AimsWith current standard of care a functional cure for Chronic Hepatitis B (CHB) is only achieved in 1-3% of patients and therefore novel therapies are needed. Disease activity during CHB can be determined by a broad range of virological biomarkers, however these biomarkers are also targets for novel treatment strategies. The aim of this study was to identify novel miRNAs that are differentially expressed in plasma and liver in CHB, and determine whether these miRNAs may serve as biomarkers of disease stage or treatment outcome.MethodsmiRNA Next-Generation-Sequencing of plasma and liver samples from CHB patient and controls was performed to identify differentially expressed miRNAs. The identified candidate miRNAs were validated by qPCR in additional plasma and liver samples from two CHB cohorts.ResultsSeveral miRNAs in plasma and liver were found to be differentially expressed between CHB patients and controls. Of the identified miRNAs expression levels of miR-122-5p in plasma were associated with plasma HBsAg, and plasma and liver HBV-DNA levels. Expression levels of miR-223-3p, miR-144-5p and miR-133a-3p in liver were associated with plasma alanine aminotransferase levels. No correlation was observed between miRNA expression levels at baseline and treatment outcome.ConclusionsLimited overlap between plasma and liver miRNAs was found, indicating that plasma miRNAs could be useful as biomarkers for treatment outcome or viral activity during treatment. Whereas liver miRNAs are more likely to be regulated by HBV and could be potential therapeutic targets to control viral activity in liver.

A Ugandan child with an unexplained encephalitis was investigated using viral metagenomics. Several sequences from all segments of a novel orthobunyavirus were found. The S-segment, used for typing, showed 41% amino acid diversity to its closest relative. The virus was named Ntwetwe virus, after the hometown of the patient.

Background We recently reported that the levels of activation, exhaustion, and terminal differentiation within the peripheral T-cell compartment were increased in men who have sex with men (MSM) compared with blood bank donors. During activation and differentiation, T cells undergo metabolic changes to maintain their energy demand. Methods The effect of cytomeglovirus (CMV) infection and risk behavior on the immune phenotype of peripheral T cells and the immune bioenergy metabolism profile in human immunodeficiency virus-negative MSM (with high or low sexual risk behavior) and blood bank donors was evaluated. Results Men who have sex with men exhibited increased levels of T-cell activation and terminal differentiation and an impairment of the bioenergy metabolism (mitochondrial respiration and glycolysis) compared with blood bank donors. Cytomeglovirus infection was associated with increased terminal differentiation of CD4+ (B = 3.41; 95% confidence interval [CI], 1.98–4.85; P, MSM exhibited increased levels of T-cell activation and terminal differentiation and an impairment of the bioenergy metabolism. Immunological and bioenergy metabolic changes can most likely be attributed to the overall higher infection pressure in MSM.

SUMMARY The HIV latent reservoir forms the major hurdle to an HIV cure. The discovery of CD32 as marker of this reservoir has aroused much interest, but subsequent reports have challenged this finding. Here, we observe a positive correlation between the percentages of CD32+ cells among CD4+ T cells of aviremic cART-treated, HIV-infected individuals and their HIV DNA loads in peripheral blood. Moreover, optimization of the CD32+CD4+ T cell purification protocol reveals prominent enrichment for HIV DNA (mean, 292-fold) in these cells. However, no enrichment for HIV RNA is observed in CD32+CD4+ cells, yielding significantly reduced HIV RNA/DNA ratios. Furthermore, HIV proviruses in CD32+CD4+ cells can be reactivated ex vivo to produce virus, strongly suggesting that these cells support HIV transcriptional latency. Our results underscore the importance of isolating pure, bona fide CD32+CD4+ T cells for future studies and indicate that CD32 remains a promising candidate marker of the HIV reservoir., Graphical Abstract, In Brief CD32a was recently proposed to mark the HIV reservoir, but this finding was subsequently challenged. By using a sequential cell-sorting protocol to purify bona fide CD32+CD4+ cells, Darcis et al. demonstrate HIV DNA enrichment and ex vivo reactivation-mediated virus production in these cells, reinforcing CD32 as an HIV reservoir marker.

The HIV latent reservoir forms the major hurdle to an HIV cure. The discovery of CD32 as marker of this reservoir has aroused much interest, but subsequent reports have challenged this finding. Here, we observe a positive correlation between the percentages of CD32+ cells among CD4+ T cells of aviremic cART-treated, HIV-infected individuals and their HIV DNA loads in peripheral blood. Moreover, optimization of the CD32+CD4+ T cell purification protocol reveals prominent enrichment for HIV DNA (mean, 292-fold) in these cells. However, no enrichment for HIV RNA is observed in CD32+CD4+ cells, yielding significantly reduced HIV RNA/DNA ratios. Furthermore, HIV proviruses in CD32+CD4+ cells can be reactivated ex vivo to produce virus, strongly suggesting that these cells support HIV transcriptional latency. Our results underscore the importance of isolating pure, bona fide CD32+CD4+ T cells for future studies and indicate that CD32 remains a promising candidate marker of the HIV reservoir., info:eu-repo/semantics/published

Background. Aging-associated noncommunicable comorbidities are more prevalent among human immunodeficiency virus type 1 (HIV)–infected individuals than among HIV-uninfected individuals. Residual HIV-related chronic immune activation and senescence may increase the risk of developing comorbidities. Methods. Immune phenotyping, thymic output, and telomere length were assessed in 94 HIV-infected individuals who were aged >45 years and receiving antiretroviral therapy (ART; cases) and 95 age-matched uninfected controls. Results. Cases had lower CD4+ T-cell counts, higher CD8+ T-cell counts, and increased levels of immune activation (ie, increased soluble CD14 [sCD14] level and increased percentages of CD38+HLA-DR+ cells among both CD4+ and CD8+ T cells), regulatory T cells, and percentage of programmed cell death 1 (PD-1)–expressing cells among CD4+ T cells. Immune senescence levels (ie, percentages of CD27−CD28− cells or CD57+ cells) were comparable between cases and controls. Peripheral blood mononuclear cells from cases had shorter telomeres but increased single-joint T-cell receptor excision circle content and CD31+ naive CD4+ T cells. Although cytomegalovirus (CMV) antibody titers were higher in cases, CMV-specific T-cell responses were comparable between cases and controls. T-cell senescence in cases was independently associated with T-cell activation but not with CMV-specific immune responses. Conclusions. Despite long-term receipt of ART, HIV-infected adults had higher levels of immune activation, regulatory T cells, and PD-1–expressing CD4+ cells and shorter telomeres. The increased soluble CD14 levels and percentage of CD38+HLA-DR+ cells among CD4+ T cells correlated with shorter telomeres and increased regulatory T-cell levels. This suggests that HIV influences immune function irreversibly, with several pathways that are persistently abnormal during effective ART. Therapies aimed at improving immune health during ART are needed.

Objective: Heterozygosity for a 32 base pair deletion in the CCR5 gene (CCR5wt/Δ32) and the minor alleles of a single-nucleotide polymorphism in the HCP5 gene (rs2395029) and in the HLA-C gene region (−35HLA-C; rs9264942) has been associated with a lower viral load set point. Recent studies have shown that over calendar time, viral load set point has significantly increased at a population level. Here we studied whether this increase coincides with a fading impact of above-mentioned host genetic markers on HIV-1 control. Methods: We compared the association between viral load set point and HCP5 rs2395029, −35HLA-C rs9264942, and the CCR5wt/Δ32 genotype in HIV-1-infected individuals in the Netherlands who had seroconverted between 1982 and 2002 (pre-2003 seroconverters, n = 459) or between 2003 and 2009 (post-2003 seroconverters, n = 231). Results: Viral load set point in post-2003 seroconverters was significantly higher than in pre-2003 seroconverters (P = 4.5 × 10−5). The minor alleles for HCP5 rs2395029, −35HLA-C rs9264942 and CCR5wt/Δ32 had a similar prevalence in both groups and were all individually associated with a significantly lower viral load set point in pre-2003 seroconverters. In post-2003 seroconverters, this association was no longer observed for HCP5 rs2395029 and CCR5wt/Δ32. The association between viral load set point and HCP5 rs2395029 had significantly changed over time, whereas the change in impact of the CCR5wt/Δ32 genotype over calendar time was not independent from the other markers under study. Conclusion: The increased viral load set point at a population level coincides with a lost impact of certain host genetic factors on HIV-1 control.

The Wnt signaling cascade is a central regulator of cell fate determination during embryonic development, whose deregulation contributes to oncogenesis. Naked cuticle is the first Wnt-induced antagonist found in this pathway, establishing a negative-feedback loop that limits the Wnt signal required for early segmentation. In addition, Naked cuticle is proposed to function as a switch, acting to restrict classical Wnt signaling and to activate a second Wnt signaling pathway that controls planar cell polarity during gastrulation movements in vertebrates. Little is known about the biochemical function of Naked cuticle or its regulation. Here we report that PR72, a Protein Phosphatase type 2A regulatory subunit of unknown function, interacts both physically and functionally with Naked cuticle. We show that PR72, like Naked cuticle, acts as a negative regulator of the classical Wnt signaling cascade, establishing PR72 as a novel regulator of the Wnt signaling pathway. Our data provide evidence that the inhibitory effect of Naked cuticle on Wnt signaling depends on the presence of PR72, both in mammalian cell culture and in Xenopus embryos. Moreover, PR72 is required during early embryonic development to regulate cell morphogenetic movements during body axis formation.

The recent availability of CCR5 antagonists as anti-human immunodeficiency virus (anti-HIV) therapeutics has highlighted the need to accurately identify CXCR4-using variants in patient samples when use of this new drug class is considered. The Trofile assay (Monogram Biosciences) has become the method that is the most widely used to define tropism in the clinic prior to the use of a CCR5 antagonist. By comparison, the MT-2 assay has been used since early in the HIV epidemic to define tropism in clinical specimens. Given that there are few data from direct comparisons of these two assays, we evaluated the performance of the plasma-based Trofile assay and the peripheral blood mononuclear cell (PBMC)-based MT-2 assay for the detection of CXCR4 use in defining the tropism of HIV isolates derived from clinical samples. The various samples used for this comparison were derived from participants of the Amsterdam Cohort Studies on HIV infection and AIDS who underwent consecutive MT-2 assay testing of their PBMCs at approximately 3-month intervals. This unique sample set was specifically selected because consecutive MT-2 assays had demonstrated a shift from negative to positive in PBMCs, reflecting the first emergence of CXCR4-using virus in PBMCs above the level of detection of the assay in these individuals. Trofile testing was performed with clonal HIV type 1 (HIV-1) variants (n= 21), MT-2 cell culture-derived cells (n= 20) and supernatants (n= 42), and plasma samples (n= 76). Among the clonal HIV-1 variants and MT-2 cell culture-derived samples, the results of the Trofile and MT-2 assays demonstrated a high degree of concordance (95% to 98%). Among consecutive plasma samples, detection of CXCR4-using virus was at or before the time of first detection by the MT-2 assay in 5/10 patients by the original Trofile assay and in 9/10 patients by the enhanced-sensitivity Trofile assay. Differences in the time to the first detection of CXCR4 use between the MT-2 assay (PBMCs) and the original Trofile assay (plasma) were greatly reduced by the enhanced-sensitivity Trofile assay, suggesting that sensitivity for the detection of minor CXCR4-using variants may be a more important determinant of discordant findings than compartmentalization. The similarities in performance of the enhanced-sensitivity Trofile and MT-2 assays suggest that either may be an appropriate methodology to define tropism in patient specimens.