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The efficacy of anti-viral T-cell vaccines may greatly depend on their ability to generate high-magnitude responses targeting a broad range of different epitopes. Recently, we created the HIV T-cell immunogen HTI, designed to generate T-cell responses to protein fragments more frequently targeted by HIV controllers. In the present study, we aim to maximize the breadth and magnitude of the T-cell responses generated by HTI by combining different vaccine vectors expressing HTI. We evaluated the ability to induce strong and broad T-cell responses to the HTI immunogen through prime vaccination with DNA plasmid (D) or Chimpanzee Adenovirus Ox1 (ChAdOx1; C) vectors, followed by a Modified Virus Ankara (MVA; M) vaccine boost (DDD, DDDM, C, and CM). HTI-specific T-cell responses after vaccination were measured by IFN-γ-ELISpot assays in two inbred mice strains (C57BL/6 and BALB/c). CM was the schedule triggering the highest magnitude of the response in both mice strains. However, this effect was not reflected in an increase in the breadth of the response but rather in an increase in the magnitude of the response to specific immunodominant epitopes. Immunodominance profiles in the two mouse strains were different, with a clear dominance of T-cell responses to a Pol-derived peptide pool after CM vaccination in C57BL/6. Responses to CM vaccination were also maintained at higher magnitudes over time (13 weeks) compared to other vaccination regimens. Thus, while a ChAdOx1 prime combined with MVA booster vaccination generated stronger and more sustained T-cell responses compared to three DNA vaccinations, the ChAdOx1 primed responses were more narrowly targeted. In conclusion, our findings suggest that the choice of vaccine vectors and prime-boost regimens plays a crucial role in determining the strength, duration, breadth, and focus of T-cell responses, providing further guidance for selecting vaccination strategies. [ABSTRACT FROM AUTHOR]

Despite the important role of gut microbiota in the maturation of the immune system, little is known about its impact on the development of T-cell responses to vaccination. Here, we immunized C57BL/6 mice with a prime-boost regimen using DNA plasmid, the Chimpanzee Adenovirus, and the modified Vaccinia Ankara virus expressing a candidate HIV T-cell immunogen and compared the T-cell responses between individuals with an intact or antibiotic-depleted microbiota. Overall, the depletion of the gut microbiota did not result in significant differences in the magnitude or breadth of the immunogen-specific IFNγ T-cell response after vaccination. However, we observed marked changes in the serum levels of four cytokines after vaccinating microbiota-depleted animals, particularly a significant reduction in IL-22 levels. Interestingly, the level of IL-22 in serum correlated with the abundance of Roseburia in the large intestine of mice in the mock and vaccinated groups with intact microbiota. This short-chain fatty acid (SCFA)-producing bacterium was significantly reduced in the vaccinated, microbiota-depleted group. Therefore, our results indicate that, although microbiota depletion reduces serum levels of IL-22, the powerful vaccine regime used could have overcome the impact of microbiota depletion on IFNγ-producing T-cell responses. [ABSTRACT FROM AUTHOR]

Background: We analyzed humoral and cellular immune responses induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines in people with human immunodeficiency virus (HIV; PWH) who had CD4+ T-cell counts <200/µL (HIV<200 group).Methods: This prospective cohort study included 58 PWH in the HIV<200 group, 36 with CD4+ T-cell counts >500/µL (HIV>500 group), and 33 HIV-1-negative controls (control group). Antibodies against the SARS-CoV-2 spike protein (anti-S immunoglobulin [Ig] G) and the receptor-binding domain (anti-RBD IgG) were quantified before and 4 weeks after the first and the second doses of BNT162b2 or mRNA-1273 (at week 8). Viral neutralization activity and T-cell responses were also determined.Results: At week 8, anti-S/anti-RBD IgG responses increased in all groups (P < .001). Median (interquartile range) anti-S and anti-RBD IgG levels at week 8 were 153.6 (26.4-654.9) and 171.9 (61.8-425.8) binding antibody units (BAU)/mL, respectively, in the HIV<200 group, compared with 245.6 (145-824) and 555.8 (166.4-1751) BAU/mL in the HIV>500 group and 274.7 (193.7-680.4) and 281.6 (181-831.8) BAU/mL in controls (P < .05). Neutralizing capacity and specific T-cell immune responses were absent or reduced in 33% of those in the HIV<200 group, compared with 3.7% in the HIV>500 group (P < .01).Conclusions: One-third of PWH with CD4+ T-cell counts <200/µL show low anti-S/anti-RBD IgG levels, reduced in vitro neutralization activity against SARS-CoV-2, and no vaccine-induced T cells after receiving coronavirus disease 2019 mRNA vaccines. [ABSTRACT FROM AUTHOR]

In simian-human immunodeficiency virus (SHIV)-infected non-human primates, broadly neutralizing antibodies (bNAbs) against the virus appear to stimulate T cell immunity. To determine whether this phenomenon also occurs in humans we measured HIV-1-specific cellular immunity longitudinally in individuals with HIV-1 starting antiviral therapy (ART) with or without adjunctive bNAb 3BNC117 treatment. Using the activation-induced marker (AIM) assay and interferon-γ release, we observe that frequencies of Pol- and Gag-specific CD8+ T cells, as well as Gag-induced interferon-γ responses, are significantly higher among individuals that received adjunctive 3BNC117 compared to ART-alone at 3 and 12 months after starting ART. The observed changes in cellular immunity were directly correlated to pre-treatment 3BNC117-sensitivity. Notably, increased HIV-1-specific immunity is associated with partial or complete ART-free virologic control during treatment interruption for up to 4 years. Our findings suggest that bNAb treatment at the time of ART initiation maintains HIV-1-specific CD8+ T cell responses that are associated with ART-free virologic control. Broadly neutralising anti-HIV-1 antibody (bNAb) administration in nonhuman primates has been shown to stimulate adaptive T cell-specific immunity, with infection prevention observed. In this work, the authors longitudinally analyse HIV-1 specific cellular immunity in HIV-1- infected individuals starting ART with or without adjunctive bNAb treatment. [ABSTRACT FROM AUTHOR]

Background: The relationship between host microRNAs (miRNA), viral control and immune response has not yet been elucidated in the field of HIV. The aim of this study was to assess the differential miRNA profile in CD8+ T-cells between HIV-infected individuals who differ in terms of viral replication control and immune response. Methods: miRNA profile from resting and CD3/CD28-stimulated CD8+ T-cells from uninfected individuals (HIV-, n = 11), Elite Controllers (EC, n = 15), Viremic Controllers (VC, n = 15), Viremic Progressors (VP, n = 13) and HIV-infected patients on therapy (ART, n = 14) was assessed using Affymetrix miRNA 3.1 arrays. After background correction, quantile normalization and median polish summarization, normalized data were fit to a linear model. The analysis comprised: resting samples between groups; stimulated samples between groups; and stimulated versus resting samples within each group. Enrichment analyses of the putative target genes were perfomed using bioinformatic algorithms. Results: A downregulated miRNA pattern was observed when resting samples from all infected groups were compared to HIV-. A miRNA downregulation was also observed when stimulated samples from EC, ART and HIV- groups were compared to VP, being hsa-miR-4492 the most downregulated. Although a preferential miRNA downregulation was observed when stimulated samples were compared to the respective resting samples, VP presented a differential miRNA expression pattern. In fact, hsa-miR-155 and hsa-miR-181a were downregulated in VP whereas in the other groups, either an upregulation or no differences were observed after stimulation, respectively. Overall, functional enrichment analysis revealed that the predicted target genes were involved in signal transduction pathways, metabolic regulation, apoptosis, and immune response. Conclusions: Resting CD8+ T-cells do not exhibit a differential miRNA expression between HIV-infected individuals but they do differ from non-infected individuals. Moreover, a specific miRNA pattern is present in stimulated CD8+ T-cells from VP which could reflect a detrimental pattern in terms of CD8+ T-cell immune response. [ABSTRACT FROM AUTHOR]

Background: The emerging relationship between microRNAs (miRNA) and viral-control is a topic of interest in the field of HIV. Host-genome might play an important role in the control of viremia. The aim of this study was to assess the specific miRNA profile that could contribute to the control of HIV replication in Elite Controllers Results: After adequate normalization, expression profile of 286 human miRNAs (hsa-miR) was evaluated in phytohaemagglutinin-stimulated PBMCs from 29 individuals classified in 4 groups: 8 elite controllers (EC; viral load <50 cp/ml without treatment), 8 viremic progressors (VP; VL>5000 cp/ml without treatment), 8 patients under antiretroviral treatment (ART; VL<200 cp/ml) and 5 uninfected individuals (HIV-) through TaqMan Array Human microRNA Cards v3.0. A differential expression pattern consisting of 23 miRNAs became significantly different when comparing EC and VP. Profiling analysis segregated the population in two different blocks: while EC and HIV- clustered together in the same block (EC/HIV-_block 1), VP and ART individuals clustered together in a second block (VP/ART_block 2). Two inversely expressed miRNA patterns were determined within those two blocks: a set of 4 miRNAs (hsa-miR-221, -27a, -27b and -29b) was up-expressed in EC/HIV-_block and down-expressed in VP/ART_block while 19 miRNAs were down-expressed in block 1 and up-expressed in block 2. Differential miRNAs were successfully validated through individual RT-qPCR assays. Conclusions: Profile in EC resembled HIV- and differentially clusters with VP and ART. Therefore, differential clustering does not rely on undetectable viremia. [ABSTRACT FROM AUTHOR]

Objectives: General population studies have shown associations between copy number variation (CNV) of the LPA gene Kringle-IV type-2 (KIV-2) coding region, single-nucleotide polymorphism (SNP) rs6415084 in LPA and coronary heart disease (CHD). Because risk factors for HIV-infected patients may differ from the general population, we aimed to assess whether these potential associations also occur in HIV-infected patients. Methods: A unicenter, retrospective, case-control (1:3) study. Eighteen HIV-patients with confirmed diagnosis of acute myocardial infarction (AMI) were adjusted for age, gender, and time since HIV diagnosis to 54 HIV-patients without CHD. After gDNA extraction from frozen blood, both CNV and SNP genotyping were performed using real-time quantitative PCR. All genetic and non-genetic variables for AMI were assessed in a logistic regression analysis. Results: Our results did not confirm any association in terms of lipoprotein(a) LPA structural genetic variants when comparing KIV-2 CNV (p = 0.67) and SNP genotypes (p = 0.44) between AMI cases and controls. However, traditional risk factors such as diabetes mellitus, hypertension, and CD4+ T cell count showed association (p < 0.05) with CHD. Conclusion: Although significant associations of AMI with diabetes, hypertension and CD4+ T cell count in HIV-patients were found, this study could not confirm the feasibility neither of KIV-2 CNV nor rs6415084 in LPA as genetic markers of CHD in HIV-infected patients. [ABSTRACT FROM AUTHOR]

Introduction Peripheral blood mononuclear cells (PBMCs) are frequently used for genomic analyses, but several factors can affect the yield and integrity of nucleic acids, including the methods of cell collection and isolation. The goal of this work was to analyze the utility of systematic isolation of different immune cell subsets by immunomagnetic separation and the RNA integrity after isolated cells from samples of HIV-infected patients. Methods PBMC from Healthy Controls (HC, n = 15), Elite Controllers (EC, n = 15), Viremic Controllers (VC, n = 15), Viremic Progressors (VP, n = 15) and HIV-infected patients on therapy (ART, n = 15) were isolated by Ficoll-Paque density gradient centrifugation. Subsets were separated with monoclonal antibodies (CD56, CD14, CD4, and CD8) conjugated to microbeads. We evaluated the yield and purity of each subset isolated from PBMCs under resting and activated conditions; LPS, anti-CD3/CD28 and anti-CD16 were used to activate monocytes, PBMC, T cells and NK cells, respectively. The quality of extracted RNA was tested by 2100 Bioanalyzer. Results In resting conditions, the average yield of CD14 + (monocytes) was decreased (p = 0.021) in HIV + patients compared with healthy controls. CD56 + (Natural Killer-NKs; p = 0.03) and CD8 + (Cytotoxic T lymphocytes-CTL p = 0.001) cells were increased in HIV + patients after 72 h of activation. The purity assay detected significant differences in CD14 + (p ≤ 0.001) and CD8 + (p = 0.034) subpopulations when comparing PBMC isolated either from healthy controls or HIV + patients. The number of activated cells in HIV + presented differences in CD8 subset (p = 0.003). Finally, similar quantities of high quality RNA were extracted from immune cells subsets obtained by our method. Specifically, we show that Bioanalyzer electrophenograms reveal optimal RIN values in HIV positive and negative patients in resting condition (EC:8;HC:6.5;VC:8.80;VP:8;HAART:7.5) and activated condition (EC:9;HC:6.7;VC:8.2;VP:7.2;HAART:8.6). Conclusion This method allowed us to obtain a sufficient quantity of different isolated immune cell subsets from HIV–infected individuals at different disease stages. Moreover, the assessed qualities of nucleic acids allow us to perform subsequent molecular studies, such as microRNA profiling. [ABSTRACT FROM AUTHOR]

A growing number of studies indicate that mRNAs and long ncRNAs can affect protein populations by assembling dynamic ribonucleoprotein (RNP) granules. These phase-separated molecular 'sponges', stabilized by quinary (transient and weak) interactions, control proteins involved in numerous biological functions. Retroviruses such as HIV-1 form by self-assembly when their genomic RNA (gRNA) traps Gag and GagPol polyprotein precursors. Infectivity requires extracellular budding of the particle followed by maturation, an ordered processing of ∼2400 Gag and ∼120 GagPol by the viral protease (PR). This leads to a condensed gRNA-NCp7 nucleocapsid and a CAp24-self-assembled capsid surrounding the RNP. The choreography by which all of these components dynamically interact during virus maturation is one of the missing milestones to fully depict the HIV life cycle. Here, we describe how HIV-1 has evolved a dynamic RNP granule with successive weak-strong-moderate quinary NC-gRNA networks during the sequential processing of the GagNC domain. We also reveal two palindromic RNA-binding triads on NC, KxxFxxQ and QxxFxxK, that provide quinary NC-gRNA interactions. Consequently, the nucleocapsid complex appears properly aggregated for capsid reassembly and reverse transcription, mandatory processes for viral infectivity. We show that PR is sequestered within this RNP and drives its maturation/condensation within minutes, this process being most effective at the end of budding. We anticipate such findings will stimulate further investigations of quinary interactions and emergent mechanisms in crowded environments throughout the wide and growing array of RNP granules.

A novel chemical approach integrating the benefits of nanoparticles with versatility of coordination chemistry is reported herein to increase the effectiveness of well-known HIV antiretroviral drugs. The novelty of our approach is illustrated using a catechol ligand tethered to the known antiretroviral azidothymidine (AZT) as a constitutive building block of the nanoparticles. The resulting nanoscale coordination polymers (NCPs) ensure good encapsulation yields and equivalent antiretroviral activity while significantly diminishing its cytotoxicity. Moreover, this novel family of nanoparticles also offers (i) long-lasting drug release that is dissimilar inside and outside the cells depending on pH, (ii) triggered release in the presence of esterases, activating the antiviral activity in an on-off manner due to a proper chemical design of the ligand and (iii) improved colloidal stabilities and cellular uptakes (up to 50-fold increase). The presence of iron nodes also adds multifunctionality as possible contrast agents. The present study demonstrates the suitability of NCPs bearing pharmacologically active ligands as an alternative to conventional antiretroviral treatments.

Cholesterol efflux (CE) capacity has been inversely associated with atherosclerosis and may provide an insight on inflammation occurring in human immunodeficiency virus (HIV) individuals. We address this by studying CE in HIV patients at different stages of HIV disease progression. In this cross-sectional study, CE from ApoB-depleted plasma, lipids levels, viral load (VL), CD4+/CD8+ T-cells, high-sensitive C-reactive protein (hsCRP), and lipoprotein (a) were evaluated in untreated HIV-infected patients (UHIVs; n = 43), elite controllers (ECs; n = 8), HIV-exposed seronegative individuals (HESNs; n = 32), and healthy controls (HCs; n = 14). Among UHIVs, those with CD4+ <500 cells/mm 3 presented the lowest significant CE, HDL cholesterol (HDL-C), and ApoAI levels. ECs showed similar HDL-C, ApoAI, and CE compared with HCs. Among UHIVs, CE positively correlated with CD4+ T-cell counts (Beta: 1.05; 95% CI: 1.02; 1.07), and for VL higher than 3.8 log, CE was inversely associated with VL (Beta: 0.70; 95% CI: 0.51; 0.95). Remarkably, HESNs presented higher CE (0.78 ± 0.14) than UHIVs (0.65 ± 0.17; P = 0.0005), but lower than HCs (0.90 ± 0.13; P = 0.009). hsCRP levels were highest in the UHIV group (0.45 ± 0.49). CE was sensitive to HIV disease progression. Low CE in HIV patients was associated with lower CD4+ T-cells and higher VL and hsCRP. CE was also lower in HESNs compared with HCs. Our results suggest that immune status secondary to HIV progression and exposure influence plasma HDL-CE capacity., (Copyright © 2018 Tort et al. Published by The American Society for Biochemistry and Molecular Biology, Inc.)