Primary and Chronic HIV Infection Differently Modulates Mucosal Vδ1 and Vδ2 T-Cells Differentiation Profile and Effector Functions.

Gut-associated immune system has been identified as a major battlefield during the early phases of HIV infection. γδ T-cells, deeply affected in number and function after HIV infection, are able to act as a first line of defence against invading pathogens by producing antiviral soluble factors and by killing infected cells. Despite the relevant role in mucosal immunity, few data are available on gut-associated γδ T-cells during HIV infection. Aim of this work was to evaluate how primary (P-HIV) and chronic (C-HIV) HIV infection affects differentiation profile and functionality of circulating and gut-associated Vδ1 and Vδ2 T-cells. In particular, circulating and mucosal cells were isolated from respectively whole blood and residual gut samples from HIV-infected subjects with primary and chronic infection and from healthy donors (HD). Differentiation profile and functionality were analyzed by multiparametric flow cytometry. P-HIV and C-HIV were characterized by an increase in the frequency of effector Vδ1-T cells both in circulating and mucosal compartments. Moreover, during P-HIV mucosal Vδ1 T-cells expressed high levels of CD107a, suggesting a good effector cytotoxic capability of these cells in the early phase of infection that was lost in C-HIV. P-HIV induced an increase in circulating effector Vδ2 T-cells in comparison to C-HIV and HD. Notably, P-HIV as well as HD were characterized by the ability of mucosal Vδ2 T-cells to spontaneously produce IFN-γ that was lost in C-HIV. Altogether, our data showed for the first time a functional capability of mucosal Vδ1 and Vδ2 T-cells during P-HIV that was lost in C-HIV, suggesting exhaustion mechanisms induced by persistent stimulation.

Autophagy plays an important role in the containment of HIV-1 in nonprogressor-infected patients.

Recent in vitro studies have suggested that autophagy may play a role in both HIV-1 replication and disease progression. In this study we investigated whether autophagy protects the small proportion of HIV-1 infected individuals who remain clinically stable for years in the absence of antiretroviral therapy, these named long-term nonprogressors (LTNP) and elite controllers (EC). We found that peripheral blood mononuclear cells (PBMC) of the HIV-1 controllers present a significantly higher amount of autophagic vesicles associated with an increased expression of autophagic markers with respect to normal progressors. Of note, ex vivo treatment of PBMC from the HIV-1 controllers with the MTOR inhibitor rapamycin results in a more efficient autophagic response, leading to a reduced viral production. These data lead us to propose that autophagy contributes to limiting viral pathogenesis in HIV-1 controllers by targeting viral components for degradation.

Temporal trend and characteristics of recent HIV-1 infections: application of an algorithm for the identification of recently acquired HIV-1 infections among newly diagnosed individuals over a 10-year period.

Identification of recent infections (RI) may contribute to improve the quality of human immunodeficiency virus (HIV) surveillance, monitoring ongoing transmission and planning and evaluating prevention programs. Our study applied an algorithm combining clinical and serological information to identify RI in individuals newly diagnosed with HIV in Rome, during the years 1999-2008, in order to describe the trend and characteristics of recently infected individuals. RI were documented seroconverters, or people with an HIV avidity index (AI)<0.80. Individuals with advanced infection (CD4 count <200 cells/?L or AIDS-defining illness) or with AI ?0.80 were considered long-standing infections. Overall, we observed 2,563 new HIV diagnoses. The algorithm was applied in 2124/2563 (82.9%). Of these, 355 were RI (16.7%). RI was found independently associated with calendar year (adjusted odds ratio [aOR]= 1.06, 95% confidence intervals [CI]=[CI 1.02-1.11], for every year of increase), HIV-risk category (men having sex with men: aOR=1.44, [CI 1.04-1.98]; injecting drug users: aOR=1.58, [CI 1.03-2.42] vs. heterosexuals), country of origin (foreign-born: vs Italians: aOR=0.46, [CI 0.33-0.62]), and recruitment site (inpatient vs outpatient clinic: aOR=0.49, [CI 0.37-0.66]). By the application of our algorithm we could characterize the pattern of ongoing HIV transmission, identifying groups needing more urgent prevention programs.

In vivo interferon-alpha/ribavirin treatment modulates Vγ9Vδ2 T-cell function during chronic HCV infection.

In chronic hepatitis C virus (HCV) infection, treatment failure and defective host immune response highly demand improved therapy strategies. Vγ9Vδ2 T-cells represent a good target for HCV immunotherapy, since phosphoantigen (PhAg)-activated Vγ9Vδ2 T-lymphocytes are able to inhibit subgenomic HCV replication by interferon (IFN)-γ release. A profound impairment of IFN-γ production by Vγ9Vδ2 T-cells during chronic HCV infection was previously shown. Interestingly, in vitro IFN-α partially restored Vγ9Vδ2 T-cells responsiveness to PhAg, by stabilizing IFN-γ-mRNA. To verify how in vivo IFN-α/ribavirin (RBV) treatment could affect Vγ9Vδ2 T-cells phenotype and responsiveness to PhAg in HCV-infected patients, 10 subjects underwent a longitudinal study before and after treatment. IFN-α/RBV therapy did not significantly modify Vγ9Vδ2 T-cell numbers and differentiation profile. Interestingly, Vγ9Vδ2 T-cell responsiveness remained unmodified until 3 weeks of therapy, but dropped after 1 month, suggesting that repeated in vivo IFN-α administration in the absence of T-cell receptor (TCR)-mediated signals results in Vγ9Vδ2 T-cell anergy. The present work defines the window of possible application of combined strategies targeting Vγ9Vδ2 T-cells during chronic HCV infection; specifically, the first 3 weeks from the beginning of treatment may represent the optimal time to target Vγ9Vδ2 T-cells in vivo, since their function in terms of IFN-γ production is preserved.

Ultra-deep sequencing reveals hidden HIV-1 minority lineages and shifts of viral population between the main cellular reservoirs of the infection after therapy interruption.

Viral quasispecies population dynamics between monocytes and T-lymphocytes were analyzed in patients after highly active antiretroviral therapy (HAART) interruption, during a follow-up of 3-6 months. V3 env region underwent ultra-deep pyrosequencing. Co-receptor usage prediction was performed by Position Specific Score Matrix Analysis. Phylogenetic trees were constructed to evaluate the relationships between the variants. Gene flow was also investigated. Even though at the moment of therapy interruption monocyte-derived HIV-1 genomes presented higher genetic heterogeneity than that of T-lymphocytes, at subsequent times, this difference in genetic heterogeneity disappeared, due to different waves of expansion and reduction of quasispecies variability associated with monocytes and T-lymphocytes. Phylogenetic analysis and gene flow evaluation supported the hypothesis of extensive interchange of variants between cellular compartments of the infection. A spread of proviral X4 lineages hidden in monocytes to T cells was observed, but this was not associated with an overall shift towards CXCR4 using variants during the observation period.

Interferon-α improves phosphoantigen-induced Vγ9Vδ2 T-cells interferon-γ production during chronic HCV infection.

In chronic HCV infection, treatment failure and defective host immune response highly demand improved therapy strategies. Vγ9Vδ2 T-cells may inhibit HCV replication in vitro through IFN-γ release after Phosphoantigen (PhAg) stimulation. The aim of our work was to analyze Vγ9Vδ2 T-cell functionality during chronic HCV infection, studying the role of IFN-α on their function capability. IFN-γ production by Vγ9Vδ2 T-cells was analyzed in vitro in 24 HCV-infected patients and 35 healthy donors (HD) after PhAg stimulation with or without IFN-α. The effect of in vivo PhAg/IFN-α administration on plasma IFN-γ levels was analyzed in M. fascicularis monkeys. A quantitative analysis of IFN-γ mRNA level and stability in Vγ9Vδ2 T-cells was also evaluated. During chronic HCV infection, Vγ9Vδ2 T-cells showed an effector/activated phenotype and were significantly impaired in IFN-γ production. Interestingly, IFN-α was able to improve their IFN-γ response to PhAg both in vitro in HD and HCV-infected patients, and in vivo in Macaca fascicularis primates. Finally, IFN-α increased IFN-γ-mRNA transcription and stability in PhAg-activated Vγ9Vδ2 T-cells. Altogether our results show a functional impairment of Vγ9Vδ2 T-cells during chronic HCV infection that can be partially restored by using IFN-α. A study aimed to evaluate the antiviral impact of PhAg/IFN-α combination may provide new insight in designing possible combined strategies to improve HCV infection treatment outcome.

Hepatitis C virus production requires apolipoprotein A-I and affects its association with nascent low-density lipoproteins.

BACKGROUND/AIMS: The life cycle of hepatitis C virus (HCV) is intimately linked to the lipid metabolism of the host. In particular, HCV exploits the metabolic machinery of the lipoproteins in several steps of its life cycle such as circulation in the bloodstream, cell attachment and entry, assembly and release of viral particles. However, the details of how HCV interacts with and influences the metabolism of the host lipoproteins are not well understood. A study was undertaken to investigate whether HCV directly affects the protein composition of host circulating lipoproteins. METHODS: A proteomic analysis of circulating very low-, low- and high-density lipoproteins (VLDL, LDL and HDL), isolated from either in-treatment naïve HCV-infected patients or healthy donors (HD), was performed using two-dimensional gel electrophoresis and tandem mass spectrometry (MALDI-TOF/TOF). The results obtained were further investigated using in vitro models of HCV infection and replication. RESULTS: A decreased level of apolipoprotein A-I (apoA-I) was found in the LDL fractions of HCV-infected patients. This result was confirmed by western blot and ELISA analysis. HCV cellular models (JFH1 HCV cell culture system (HCVcc) and HCV subgenomic replicons) showed that the decreased apoA-I/LDL association originates from hepatic biogenesis rather than lipoprotein catabolism occurring in the circulation, and is not due to a downregulation of the apoA-I protein concentration. The sole non-structural viral proteins were sufficient to impair the apoA-I/LDL association. Functional evidence was obtained for involvement of apoA-I in the viral life cycle such as RNA replication and virion production. The specific siRNA-mediated downregulation of apoA-I led to a reduction in both HCV RNA and viral particle levels in culture. CONCLUSIONS: This study shows that HCV induces lipoprotein structural modification and that its replication and production are linked to the host lipoprotein metabolism, suggesting apoA-I as a new possible target for antiviral therapy.

Detection of quasispecies variants predicted to use CXCR4 by ultra-deep pyrosequencing during early HIV infection.

OBJECTIVES: HIV-1 V3 quasispecies was analyzed by ultra-deep pyrosequencing, in early HIV-infected patients, to assess possible correlations between quasispecies diversity, frequency of variants predicted to use CXCR4 and need for early antiretroviral treatment. METHODS: Twenty patients were retrospectively enrolled: 10 patients (group A) required HAART within 6 months from seroconversion and 10 (group B) remained free of therapy during this period. V3 quasispecies was assessed on plasma viral RNA and in peripheral blood mononuclear cell-associated proviral DNA. Prediction of coreceptor usage was performed by position-specific score matrix analysis. RESULTS: Variants predicted to use CXCR4 were detected (frequency ≥0.3%) in the plasma of 50% of early infected patients (60% from group A and 40% from group B). Intrapatient frequency of these variants was highly variable (0.3-56.3%). A positive correlation was observed between the proportion of X4 variants and intrapatient quasispecies diversity. Quasispecies diversity and absolute numbers of X4 variants were significantly higher in patients from group A. The analysis of proviral DNA quasispecies, performed in a subgroup of five patients, showed that X4 variants were not detected in patients with RNA frequency below 0.3%, and detected at 3.6% in the patient with 56.3% of X4 plasma variants. CONCLUSION: Our findings show that X4 variants may be frequently found, at variable intrapatient frequency, in early infected patients, and that quasispecies diversity and absolute numbers of X4 variants are significantly higher in patients undergoing early antiretroviral treatment. Further studies are mandatory to explore the clinical relevance of X4 variants present during early infection with respect to clinical progression and possible therapeutic implications.

The basal activation state of DC subsets correlates with anti-HCV treatment outcome in HCV/HIV co-infected patients.

In this work we evaluated plasmacytoid (pDC) and myeloid dendritic (mDC) cells activation before and during anti-HCV treatment in HCV+/HIV+ individuals. HCV+/HIV+ patients received Peg-IFN-α2b subcutaneously for 28 days, followed by oral weight-based ribavirin. DCs activation was evaluated by flow cytometry. Baseline pDC CD80 and CD86 expression was correlated with HIV, but not with HCV viral load. A transient decrease of HIV RNA was found not associated with DC activation. When patients were grouped according to early/sustained virological response (EVR/SVR) to anti-HCV treatment, baseline pDC CD80 and CD86 expression was higher in non-EVR and non-SVR compared to EVR and SVR. Moreover, in responder patients CD80 and CD86 were upregulated by IFN-α. Our data suggest a correlation between DCs activation and response to therapy. These findings could be helpful to better understand the mediators of IFN-α action in HCV+/HIV+ patients and to explore possible exploitation of this knowledge to improve therapeutic response.

Changes in cognition during antiretroviral therapy: comparison of 2 different ranking systems to measure antiretroviral drug efficacy on HIV-associated neurocognitive disorders.

OBJECTIVE: Although HIV-associated neurocognitive disorders should be treated with highly active antiretroviral treatment (HAART) regimens with good central nervous system (CNS) penetration, the definition of neuroactive HAART remains controversial. We compared 2 ranking systems to measure HAART neuroeffectiveness. METHODS: Patients with (n = 93) or at risk for (n = 92) HIV-associated neurocognitive disorders underwent neuropsychological (NP) test batteries before HAART initiation and at follow-up. Changes in normatively adjusted summary NP test z scores were calculated for each subject. Two neuropenetration scores were calculated: the central nervous system penetration reference score (number of drugs in the combination among zidovudine, abacavir, stavudine, lamivudine, efavirenz, nevirapine, indinavir, and lopinavir-ritonavir) and the CNS penetration-effectiveness (CPE) score: a summary score of 1 (high: penetration: [corrected] zidovudine, abacavir, delavirdine, [corrected] nevirapine, amprenavir-ritonavir, fosamprenavir-ritonavir, [corrected] indinavir-ritonavir, and lopinavir-ritonavir), 0.5 (intermediate penetration: [corrected] stavudine, lamivudine, emtricitabine, efavirenz, amprenavir, fosamprenavir, [corrected] atazanavir-ritonavir, atazanavir, [corrected] and indinavir), and 0 (low penetration: remaining ARVs) [corrected] for each drug in the combination. Main outcome measures were changes in global NPZ scores and in summary z scores on 5 domains. RESULTS: At regression analyses, higher CPE scores correlated with greater improvements in NPZ-4 (P = 0.0283), NPZ-8 (P = 0.0071), concentration and speed of mental processing (P = 0.0046), and mental flexibility (P = 0.0262) summary z scores. The correlation was stronger among NP-impaired patients. By contrast, higher estimates of neuroeffectiveness with the alternative system showed no correlation. No association was seen between CD4 and plasma viral load changes with both scores. CONCLUSIONS: The CPE score represents a step forward toward the identification of a clinically useful approach to estimating HAART ability to improve cognition.

Zoledronic acid and interleukin-2 treatment improves immunocompetence in HIV-infected persons by activating Vgamma9Vdelta2 T cells.

OBJECTIVE: gammadelta T cells bearing the Vgamma9Vdelta2 T-cell receptor exert many antiviral effector functions in humans, including release of anti-HIV factors and direct cytotoxicity against virus-infected cells. Moreover, they are known to activate dendritic cells, improving antigen presentation function. After HIV infection, Vgamma9Vdelta2 T-cell number and reactivity are rapidly affected and they decrease upon disease progression. Bisphosphonate drugs such as zoledronic acid (Zol), used to treat bone diseases, have been shown to induce in vivo, in combination with interleukin-2, Vgamma9Vdelta2 T-cells' activation. The aim of this work was to verify whether the administration of Zol in combination with interleukin-2 in HIV-infected patients might improve Vgamma9Vdelta2 T-cell function, including immune adjuvancy mediated by gammadelta-dendritic cell cross-talk. DESIGN AND METHODS: In HIV patients naive to antiretroviral therapy, we analyzed the effect of combined Zol and interleukin-2 treatment, in comparison to Zol alone, on Vgamma9Vdelta2 T-cell number, maturation and function, on dendritic cell activation and on HIV-specific CD8 T-cell response. RESULTS: Zol and interleukin-2-combined treatment induced in-vivo Vgamma9Vdelta2 T-cell expansion and maturation. Paralleling Vgamma9Vdelta2 T-cell activation, increased dendritic cell maturation and HIV-specific CD8 T-cell responses were found. CONCLUSION: The specific modulation of Vgamma9Vdelta2 T-cell number and responsiveness after HIV infection may be at least transiently restored in vivo by Zol and interleukin-2 treatment. In this way, the immune effector mechanisms, secondary to Vgamma9Vdelta2 T-cell activation, were improved, suggesting a possible adjuvancy role of Zol and interleukin-2 treatment in restoring innate and specific competence in HIV-infected persons.

Interferon may prevent HIV viral rebound after HAART interruption in HIV patients.

In the pre-highly active antiretroviral therapy (HAART) era, clinical trials showed that interferon (IFN) treatment was able to delay AIDS progression and prolong survival. Along with HAART, ancillary use of IFN during primary infection and before HAART therapy initiation has been effective. Also endogenous IFN may positively affect the progression of HIV infection, as suggested in GB virus type C (GBV-C) coinfected patients. In this pilot study, we tried to prevent rebound of HIV replication in patients who interrupted HAART by covering the drug-free time with administration of pegylated IFN (PEGIFN). Twenty-four HIV-hepatitis C virus (HCV) patients who started IFN treatment for liver disease, after variable time from having interrupted HAART, were enrolled. HIV RNA was determined during a 2-month period. In patients who interrupted HAART at variable times before initiating IFN and, therefore, had experienced a complete viral rebound, IFN caused a significant reduction of viral load lasting at least 4 weeks. Moreover, 3 of the 4 patients who started IFN concomitantly with the HAART discontinuation showed complete control of viral rebound, delaying the resumption of viral replication for more than 2 weeks. These preliminary findings suggest that a structured therapy interruptions (STI) strategy may be feasible provided that IFN is administered during the drug-free times, possibly delaying drug resistance, lessening toxicity, reducing costs, and prolonging survival.

Persistence of neuropsychologic deficits despite long-term highly active antiretroviral therapy in patients with HIV-related neurocognitive impairment: prevalence and risk factors.

OBJECTIVE: Although highly active antiretroviral therapy (HAART) can reverse HIV-related neurocognitive impairment (NCI), neuropsychologic (NP) deficits may persist in a substantial proportion of patients despite antiretroviral treatment. We assessed the prevalence and predictors of persistent NP deficits despite long-term HAART in patients with HIV-related NCI. METHODS: A group of 94 patients with HIV-related NCI underwent 2 to 7 serial NP batteries, neurologic examination, and brain imaging studies. Patients received HAART for a mean of 63 (range: 6-127) months. According to NP assessment results, patients were considered to have reversible or persistent NP deficits. Kaplan-Meier analyses and Cox proportional hazards models were used to analyze time to first evidence of NP deficit reversion. RESULTS: Persistent NP deficits were observed in 59 (62.8%) patients. Age, gender, Centers for Disease Control and Prevention stage, risk category, CD4 cell count, plasma viral load, and use of central nervous system-penetrating drugs were not associated with persistent NP deficits. By contrast, patients with persistent NP deficits were less educated and showed poorer baseline performances in NP measures exploring concentration and speed of mental processing, memory, and mental flexibility. In multivariable analyses, only the baseline severity of NCI, as measured by the composite NPZ8 global score (odds ratio = 3.07, 95% confidence interval: 1.54 to 6.08; P = 0.001) remained significantly associated with persistent NP deficits. CONCLUSIONS: The severity of NCI at HAART initiation seems to be the strongest predictor of persistent NP deficits despite long-term HAART. Our data indicate that HAART should be initiated as soon as NCI is diagnosed to avoid potentially irreversible neurologic damage.

Neurocognitive impairment and survival in a cohort of HIV-infected patients treated with HAART.

Before the introduction of HAART, HIV-associated neurocognitive impairment (NCI) was recognized as an independent risk factor for death. Since 1996, we conducted a prospective study to assess whether NCI still represents a negative prognostic factor for mortality. Patients were administered measures of neurocognitive function (a battery of 17 neuropsychological tests), clinical and neurological evaluation, laboratory testing, and brain imaging studies. Among the 412 enrolled patients, 224 (54.4%) were neurocognitively impaired and 188 (45.6%) were neurocognitively unimpaired. A durable virological suppression under highly active antiretroviral therapy (HAART) was achieved by 63.3% of unimpaired patients and by 49.6% of impaired patients (p = 0.007). Overall, 47 deaths were recorded, 38 among impaired and 9 among unimpaired patients. At 84 months, the estimated survival proportions in impaired and unimpaired patients were 68.5% and 84.9%, respectively (p < 0.001). At univariate analysis the virological response to HAART was the variable most strongly associated with survival, since patients with virological failure had a nearly 10-fold increased risk of death than those with durable virological suppression (HR = 9.9, 95% CI: 3.9-25.0). After stratification for virological response to HAART, an increased risk of death for neurocognitively impaired patients was seen only among the 182 patients with virological failure (HR: 2.9, 95% CI: 1.2-7.1), while the survival probability of the 230 patients with durable virological suppression was not affected by neurocognitive impairment (p = 0.89). Our results highlight the clinical relevance of HIV-related central nervous system (CNS) involvement in the HAART era, and raise concerns regarding the clinical relevance of CNS involvement as potent antiretroviral therapies become less effective.

Prevalence and risk factors for human immunodeficiency virus-associated neurocognitive impairment, 1996 to 2002: results from an urban observational cohort.

To assess prevalence and risk factors for human immunodeficiency virus (HIV)-related neurocognitive impairment (NCI), the authors performed a 7-year survey in the period 1996 to 2002. A total of 432 patients were examined. HIV-related NCI was diagnosed in 238 patients (55.1%), meeting the HIV dementia (HIV-D) criteria in 45 (10.4%). The prevalence of both NCI and HIV-D did not change significantly during the study period. Compared with patients without NCI, patients with NCI were older (40.4 versus 38.2 years; P = .003), had a higher prevalence of positive HCV serology (61.1% versus 38.9%; P = .003), and a lower nadir CD4 cell count (156 versus 222 cells/microl; P < .001). Compared with patients seen during 1996 to 1999, patients with NCI seen during 2000 to 2002 were older (40.7 versus 38.8 years; P = .004), had a less advanced disease stage (previous acquired immunodeficiency syndrome [AIDS] 28.8% versus 65.7%; P < .001) and a higher nadir CD4 count (174 versus 132 cells/microl; P = .026). This study showed an unchanged prevalence of both HIV-related NCI and HIV-D in the period 1996 to 2002. The authors found evidences for new additional potential risk factors for HIV-related NCI (older age, lower nadir CD4 count, positive hepatitis C virus [HCV] serology), and for a change of risk factors for NCI in the late highly active antiretroviral therapy (HAART) era (older age, less advanced disease, higher nadir CD4 count).