T-Cell Activation Independently Associates With Immune Senescence in HIV-Infected Recipients of Long-term Antiretroviral Treatment.

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.

Human Immunodeficiency Virus-Induced Interferon-Stimulated Gene Expression Is Associated With Monocyte Activation and Predicts Viral Load.

Background: Chronic immune activation is one of the hallmarks of human immunodeficiency virus (HIV) pathogenesis. Persistent upregulation of interferons (IFNs) and interferon-stimulated genes (ISGs) has previously been associated with chronic immune activation and HIV progression. Here a longitudinal analysis of the IFN and ISG response during HIV infection was performed to gain insights into the ongoing immune activation during HIV infection. Methods: IFN and ISG levels were determined using quantitative polymerase chain reaction in peripheral blood mononuclear cells of people with HIV at pre-seroconversion, during acute and chronic HIV infection, and during suppressive antiretroviral therapy (ART). Results: HIV infection induced the expression of a set of 4 ISGs-RSAD2, ISG15, IFI44L, and IFI27-which remained upregulated during chronic infection. This set of ISGs showed no clear correlations with T-cell activation as determined by co-expression of CD38 and HLA-DR. However, a strong correlation with monocyte activation marker soluble CD163 in serum was found. Furthermore, the expression of this ISG cluster was predictive of viral load before ART initiation and, on ART, expression levels normalized to pre-seroconversion levels. Conclusions: The results presented here suggests that ISG expression is linked to monocyte activation, possibly driven by viral replication.

Hepatitis a vaccine immunogenicity and boostability in adults receiving immunosuppressive therapy and adults living with HIV: a prospective single-Centre cohort study.

INTRODUCTION: Hepatitis A (hepA) vaccination is highly immunogenic in healthy individuals, however there is uncertainty about the immunogenicity in immunocompromised populations (ICPs). METHODS: In this prospective cohort study, people living with HIV (PLWH), patients on immunosuppressive mono- and combination therapy, and controls received two hepA vaccine doses at months 0 and 6-12, or three combined hepA/B vaccine doses at months 0, 1 and 6-12. Antibody levels were measured before and at different time-points post-vaccination (T2, 6, 8, 12 months). The primary endpoint was the seroconversion rate (SCR) at T8, defined as hepA antibodies ≥20 mIU/ml. To assess boostability, an additional vaccine dose was administered 1-5 years after T12 in those with antibodies < 50 mIU/ml, with antibody measurements before and seven days after the booster dose. RESULTS: We included 150 participants. At T2 SCRs ranged between 35-58% in ICPs versus 94% in controls. Among PLWH, patients on monotherapy, combination therapy and controls SCRs at T8 were 33/34 (97%), 32/34 (94%), 25/30 (83%) and 28/28 (100%) respectively. The booster dose resulted in 71% additional seroconversion (17/24), with only patients using combination therapy not responding. CONCLUSIONS: HepA vaccination is highly immunogenic in virologically suppressed PLWH and patients on immunosuppressive monotherapy, with SCRs after the complete hepA vaccination schedule similar to controls and adequate booster responses in case of waning immunity. However, patients using immunosuppressive combination therapy as well as all ICPs who did not receive the complete hepA vaccination schedule, are at risk of non-response to vaccination and post-vaccination antibody measurements are recommended.

Energy demanding RNA and protein metabolism drive dysfunctionality of HIV-specific T cell changes during chronic HIV infection.

Antiretroviral treatment of HIV infected individuals cannot eliminate the HIV reservoir and immune control of HIV is rarely seen upon treatment interruption. In long-term non-progressors (LTNP), an effective CD8 T cell response is thought to contribute to be immune control of HIV. Here we studied the transcriptional profile of virus specific CD8 T cells during the asymptomatic phase of disease, to gain molecular insights in CD8 T cell functionality in HIV progressors and different groups of LTNP: HLA-B*57 LTNP, non-HLA-B*57 LTNP and individuals carrying the MAVS minor genotype (rs7262903/rs7269320). Principal component analysis revealed distinct overall transcriptional profiles between the groups. The transcription profile of HIV-specific CD8 T cells of LTNP groups was associated with increased cytokine/IL-12 signaling and protein/RNA metabolism pathways, indicating an increased CD8 T cell functionality. Although the transcription profile of CMV-specific CD8 T cells differed from that of HIV-specific CD8 T cells, with mainly an upregulation of gene expression in progressors, similar affected pathways were identified. Moreover, CMV-specific CD8 T cells from progressors showed increased expression of genes related to effector functions and suggests recent antigen exposure. Our data shows that changes in cytokine signaling and the energy demanding RNA and protein metabolism are related to CD8 T cell dysfunction, which may indicate that mitochondrial dysfunction is an important driver of T cell dysfunctionality during chronic HIV infection. Indeed, improvement of mitochondrial function by IL-12 and mitoTempo treatment, enhanced in vitro IFNγ release by PBMC from PWH upon HIV gag and CMV pp65 peptide stimulation. Our study provides new insights into the molecular pathways associated with CD8 T cell mediated immune control of chronic HIV infection which is important for the design of novel treatment strategies to restore or improve the HIV-specific immune response.

A genetic variation in fucosyltransferase 8 accelerates HIV-1 disease progression indicating a role for N-glycan fucosylation.

OBJECTIVES: Core fucosylation by fucosyltransferase 8 (FUT8) is an important posttranslational modification that impacts components of the immune system. Genetic variations in FUT8 can alter its function and could, therefore, play a role in the antiviral immune response and pathogenesis of HIV-1. This study analysed the effect of a single nucleotide polymorphism (SNP) in FUT8 on the clinical course of HIV-1 infection. DESIGN/METHODS: The effect of SNPs in FUT8 on untreated HIV-1 disease outcome were analysed in a cohort of 304 people with HIV-1 (PWH) using survival analysis. Flow-cytometry was used to determine the effect of SNP on T-cell activation, differentiation and exhaustion/senescence. T-cell function was determined by proliferation assay and by measuring intracellular cytokine production. The effect of the SNP on HIV-1 replication was determined by in-vitro HIV-1 infections. Sensitivity of HIV-1 produced in PBMC with or without the SNP to broadly neutralizing antibodies was determined using a TZM-bl based neutralization assay. RESULTS: Presence of the minor allele of SNP rs4131564 was associated with accelerated disease progression. The SNP had no effect on T-cell activation and T-cell differentiation in PWH. Additionally, no differences in T-cell functionality as determined by proliferation and cytokine production was observed. HIV-1 replication and neutralization sensitivity was also unaffected by the SNP in FUT8. CONCLUSION: SNP rs4131564 in FUT8 showed a major impact on HIV-1 disease course underscoring a role for N-glycan fucosylation even though no clear effect on the immune system or HIV-1 could be determined in vitro .

Comparison of human immunodeficiency virus type 1 tropism profiles in clinical samples by the Trofile and MT-2 assays.

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.

Terminal differentiation of T cells is strongly associated with CMV infection and increased in HIV-positive individuals on ART and lifestyle matched controls.

HIV-1-positive individuals on successful antiretroviral therapy (ART) are reported to have higher rates of age-associated non-communicable comorbidities (AANCCs). HIV-associated immune dysfunction has been suggested to contribute to increased AANCC risk. Here we performed a cross-sectional immune phenotype analysis of T cells in ART-treated HIV-1-positive individuals with undetectable vireamia (HIV-positives) and HIV-1-negative individuals (HIV-negatives) over 45 years of age. In addition, two control groups were studied: HIV negative adults selected based on lifestyle and demographic factors (Co-morBidity in Relation to AIDS, or COBRA) and unselected age-matched donors from a blood bank. Despite long-term ART (median of 12.2 years), HIV-infected adults had lower CD4+ T-cell counts and higher CD8+ T-cell counts compared to well-matched HIV-negative COBRA participants. The proportion of CD38+HLA-DR+ and PD-1+ CD4+ T-cells was higher in HIV-positive cohort compared to the two HIV-negative cohorts. The proportion CD57+ and CD27-CD28- cells of both CD4+ and CD8+ T-cells in HIV-positives was higher compared to unselected adults (blood bank) as reported before but this difference was not apparent in comparison with well-matched HIV-negative COBRA participants. Multiple regression analysis showed that the presence of an increased proportion of terminally differentiated T cells was strongly associated with CMV infection. Compared to appropriately selected HIV-negative controls, HIV-positive individuals on ART with long-term suppressed viraemia exhibited incomplete immune recovery and increased immune activation/exhaustion. CMV infection rather than treated HIV infection appears to have more consistent effects on measures of terminal differentiation of T cells.

High Cellular Monocyte Activation in People Living With Human Immunodeficiency Virus on Combination Antiretroviral Therapy and Lifestyle-Matched Controls Is Associated With Greater Inflammation in Cerebrospinal Fluid.

BACKGROUND: Increased monocyte activation and intestinal damage have been shown to be predictive for the increased morbidity and mortality observed in treated people living with human immunodeficiency virus (PLHIV). METHODS: A cross-sectional analysis of cellular and soluble markers of monocyte activation, coagulation, intestinal damage, and inflammation in plasma and cerebrospinal fluid (CSF) of PLHIV with suppressed plasma viremia on combination antiretroviral therapy and age and demographically comparable HIV-negative individuals participating in the Comorbidity in Relation to AIDS (COBRA) cohort and, where appropriate, age-matched blood bank donors (BBD). RESULTS: People living with HIV, HIV-negative individuals, and BBD had comparable percentages of classical, intermediate, and nonclassical monocytes. Expression of CD163, CD32, CD64, HLA-DR, CD38, CD40, CD86, CD91, CD11c, and CX3CR1 on monocytes did not differ between PLHIV and HIV-negative individuals, but it differed significantly from BBD. Principal component analysis revealed that 57.5% of PLHIV and 62.5% of HIV-negative individuals had a high monocyte activation profile compared with 2.9% of BBD. Cellular monocyte activation in the COBRA cohort was strongly associated with soluble markers of monocyte activation and inflammation in the CSF. CONCLUSIONS: People living with HIV and HIV-negative COBRA participants had high levels of cellular monocyte activation compared with age-matched BBD. High monocyte activation was predictive for inflammation in the CSF.

The presence of CXCR4-using HIV-1 prior to start of antiretroviral therapy is an independent predictor of delayed viral suppression.

The emergence of CXCR4-using HIV variants (X4-HIV) is associated with accelerated disease progression in the absence of antiretroviral therapy. However, the effect of X4-HIV variants on the treatment response remains unclear. Here we determined whether the presence of X4-HIV variants influenced the time to undetectable viral load and CD4+ T cell reconstitution after initiation of cART in 732 patients. The presence of X4-HIV variants was determined by MT-2 assay prior to cART initiation and viral load and CD4+ T cell counts were analyzed every 3 to 6 months during a three year follow-up period. Kaplan-Meier and Cox proportional hazard analyses were performed to compare time to viral suppression and the absolute CD4+ T cell counts and increases in CD4+ T cell counts during follow-up were compared for patients with and without X4-HIV at start of cART. Patients harboring X4-HIV variants at baseline showed a delay in time to achieve viral suppression below the viral load detection limit. This delay in viral suppression was independently associated with high viral load and the presence of X4-HIV variants. Furthermore, the absolute CD4+ T cell counts were significantly lower in patients harboring X4-HIV variants at all time points during follow-up. However, no differences were observed in the increase in absolute CD4+ T cell numbers after treatment initiation, indicating that the reconstitution of CD4+ T cells is independent of the presence of X4-HIV variants. The emergence of X4-HIV has been associated with an accelerated CD4+ T cell decline during the natural course of infection and therefore, patients who develop X4-HIV variants may benefit from earlier treatment initiation in order to obtain faster reconstitution of the CD4+ T cell population to normal levels.

Rising HIV-1 viral load set point at a population level coincides with a fading impact of host genetic factors on HIV-1 control.

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.