Suppressive Combination Antiretroviral Therapy Research Articles

CD4 dim CD8 bright T cells are inversely associated with neuro-inflammatory markers among people with HIV.

HIV-associated neuroinflammation persists in the brain despite suppressive combination antiretroviral therapy (cART). We evaluated associations between a subset of CD8 + T cells, termed CD4 dim CD8 bright T cells, and soluble markers of immune activation and/or neuroinflammation in the cerebrospinal fluid (CSF) and plasma of people with HIV (PWH). Fifteen cART-naive PWH were enrolled and underwent blood draw, lumbar puncture for CSF collection, and neuropsychological tests at week 0 (pre-cART) and 24 weeks after cART initiation. CSF and peripheral blood T cells were evaluated with flow cytometry and soluble markers of immune activation were measured by multiplex and singleplex assays. Spearman bootstrap correlation coefficients with 10 000 resamples were computed and reported with corresponding 95% confidence intervals (CIs) for each marker of interest and T-cell type. The frequency of CSF CD4 dim CD8 bright T cells at week 0 was inversely related with CSF neopterin. In contrast, at week 24, CSF CD4 - CD8 + T cells were positively correlated with CSF s100β, a marker of brain injury. In the blood, at week 0, CD4 dim CD8 bright T cells were inversely correlated with MCP-1, IP-10, IL-8, IL-6, G-CSF, and APRIL and positively correlated with plasma RANTES and MMP1. At week 0, the frequency of blood CD4 - CD8 + were positively correlated with CRP and BAFF. CD4 dim CD8 bright T cells are associated with some anti-inflammatory properties, whereas CD4 - CD8 + T cells may contribute to inflammation and injury. Assessing the contrast between these two cell populations in neuroHIV may inform targeted therapeutic intervention to reduce neuroinflammation and associated neurocognitive impairment.

Impact of the first-line antiretroviral therapy on soluble markers of inflammation in cohort of human immunodeficiency virus type 1 in Moroccan patients: a prospective study.

Chronic inflammation and immune activation are a hallmark of HIV-1 infection. In this study, we assessed inflammation biomarkers in a cohort of people living with HIV-1 (PLWH) before and after long-term suppressive combined antiretroviral therapy (cART). A single-center prospective cohort study was conducted to assess inflammatory biomarkers in 86 cART-naive PLWH and after receiving suppressive cART and 50 uninfected controls. Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and soluble CD14 (sCD14) were measured using enzyme-linked immunosorbent assay (ELISA). No significant difference was found in IL-6 levels between cART-naïve PLWH and controls (p = 0.753). In contrast, TNF-α level showed a significant difference between cART naïve-PLWH and controls (p = 0.019). Interestingly, IL-6 and TNF-α levels were significantly decreased in PLWH after cART (p < 0.0001). The sCD14 showed no significant difference between cART-naïve patients and controls (p = 0.839) and similar levels were observed in pre- and post-treatment (p = 0.719). Our results highlight the critical importance of early treatment to reduce inflammation and its consequences during HIV infection.

Neuroinflammatory Profiling in SIV-Infected Chinese-Origin Rhesus Macaques on Antiretroviral Therapy.

The central nervous system (CNS) HIV reservoir is an obstacle to achieving an HIV cure. The basal ganglia harbor a higher frequency of SIV than other brain regions in the SIV-infected rhesus macaques of Chinese-origin (chRMs) even on suppressive combination antiretroviral therapy (ART). Since residual HIV/SIV reservoir is associated with inflammation, we characterized the neuroinflammation by gene expression and systemic levels of inflammatory molecules in healthy controls and SIV-infected chRMs with or without ART. CCL2, IL-6, and IFN-γ were significantly reduced in the cerebrospinal fluid (CSF) of animals receiving ART. Moreover, there was a correlation between levels of CCL2 in plasma and CSF, suggesting the potential use of plasma CCL2 as a neuroinflammation biomarker. With higher SIV frequency, the basal ganglia of untreated SIV-infected chRMs showed an upregulation of secreted phosphoprotein 1 (SPP1), which could be an indicator of ongoing neuroinflammation. While ART greatly reduced neuroinflammation in general, proinflammatory genes, such as IL-9, were still significantly upregulated. These results expand our understanding of neuroinflammation and signaling in SIV-infected chRMs on ART, an excellent model to study HIV/SIV persistence in the CNS.

Two-drug HIV regimens: more data still needed.

The advent of suppressive combination antiretroviral therapy (ART) has transformed HIV from a death sentence into a controllable, chronic disease. Effective ART extends life expectancy of people living with HIV nearly to that of the general population; thus, improving life-long ART therapy options remains a research priority. There is growing evidence that two-drug ART regimens could reduce adverse effects and potentially reduce therapy costs without compromising efficacy or future treatment options.

Near normalization of peripheral blood markers in HIV-infected patients on long-term suppressive antiretroviral therapy: a case-control study.

To explore the differences in peripheral blood markers between HIV well controlled patients on long-term suppressive antiretroviral therapy (HIV-group) and age-matched healthy controls, to evaluate the benefits of virological suppression in those patients. We performed a case-control study in 22 individuals in the HIV-group and 14 in the healthy control-group. RNA-seq analysis was performed from peripheral blood mononuclear cells. Peripheral blood T-cell subsets were evaluated by flow cytometry and plasma biomarkers by immunoassays. All P values were corrected by the false discovery rate (q values). Only the serine/arginine repetitive matrix 4 gene, which is involved in alternative RNA splicing events, was differentially expressed between HIV and healthy control groups (q value ≤0.05 and fold-change ≥2). However, 147 differentially expressed genes were found with a more relaxed threshold (P value ≤0.05 and fold-change ≥1.5), of which 67 genes with values of variable importance in projection at least one were selected for pathway analysis. We found that six ribosomal genes represented significant ribosome-related pathways, all of them downregulated in the HIV-group, which may be a strategy to facilitate viral production. T cells subset and plasma biomarkers did not show significant differences after false discovery rate correction (q value >0.05), but a noncorrected analysis showed higher values of regulatory CD4 T cells (CD4CD25CD127), MCP-1, and sVEGF-R1 in the HIV-group (P value ≤0.05). T-cell subsets, plasma biomarkers, and gene expression were close to normalization in HIV-infected patients on long-term suppressive combination antiretroviral therapy compared with healthy controls. However, residual alterations remain, mainly at the gene expression, which still reveals the impact of HIV infection in these patients.

Polyfunctional HIV-1 specific response by CD8+ T lymphocytes expressing high levels of CD300a

CD300a receptor is found on different CD8+ T cell subsets and its expression has been associated to a more cytotoxic molecular signature. CD300a has an important role in some viral infections and its expression levels are known to be modulated by human immunodeficiency virus (HIV)−1 infection on several cell types. The main objective of this work was to investigate CD300a expression and its regulation during HIV-1 specific CD8+ T cell responses. CD300a receptor expression was analysed by multiparametric flow cytometry on CD8+ T lymphocytes from HIV negative donors, naive HIV-1+ individuals and HIV-1+ subjects under suppressive combined antiretroviral therapy (cART). HIV-1 specific CD8+ T cell response was studied by stimulating cells with HIV-1 derived peptides or with a Gag HIV-1 peptide. Our results showed that HIV-1 specific CD8+ T cells expressing higher levels of CD300a were more polyfunctional showing an increased degranulation and cytokine production. Moreover, we observed an up-regulation of CD300a expression after Gag HIV-1 peptide stimulation. Finally, our results demonstrated an inverse correlation between CD300a expression on CD8+ T lymphocytes and HIV disease progression markers. In conclusion, CD300a expression is associated to a better and more polyfunctional HIV-1 specific CD8+ T cell response.

Genetic Diversity, Compartmentalization, and Age of HIV Proviruses Persisting in CD4+ T Cell Subsets during Long-Term Combination Antiretroviral Therapy.

The HIV reservoir, which comprises diverse proviruses integrated into the genomes of infected, primarily CD4+ T cells, is the main barrier to developing an effective HIV cure. Our understanding of the genetics and dynamics of proviruses persisting within distinct CD4+ T cell subsets, however, remains incomplete. Using single-genome amplification, we characterized subgenomic proviral sequences (nef region) from naive, central memory, transitional memory, and effector memory CD4+ T cells from five HIV-infected individuals on long-term combination antiretroviral therapy (cART) and compared these to HIV RNA sequences isolated longitudinally from archived plasma collected prior to cART initiation, yielding HIV data sets spanning a median of 19.5 years (range, 10 to 20 years) per participant. We inferred a distribution of within-host phylogenies for each participant, from which we characterized proviral ages, phylogenetic diversity, and genetic compartmentalization between CD4+ T cell subsets. While three of five participants exhibited some degree of proviral compartmentalization between CD4+ T cell subsets, combined analyses revealed no evidence that any particular CD4+ T cell subset harbored the longest persisting, most genetically diverse, and/or most genetically distinctive HIV reservoir. In one participant, diverse proviruses archived within naive T cells were significantly younger than those in memory subsets, while for three other participants we observed no significant differences in proviral ages between subsets. In one participant, "old" proviruses were recovered from all subsets, and included one sequence, estimated to be 21.5 years old, that dominated (>93%) their effector memory subset. HIV eradication strategies will need to overcome within- and between-host genetic complexity of proviral landscapes, possibly via personalized approaches.IMPORTANCE The main barrier to HIV cure is the ability of a genetically diverse pool of proviruses, integrated into the genomes of infected CD4+ T cells, to persist despite long-term suppressive combination antiretroviral therapy (cART). CD4+ T cells, however, constitute a heterogeneous population due to their maturation across a developmental continuum, and the genetic "landscapes" of latent proviruses archived within them remains incompletely understood. We applied phylogenetic techniques, largely novel to HIV persistence research, to reconstruct within-host HIV evolutionary history and characterize proviral diversity in CD4+ T cell subsets in five individuals on long-term cART. Participants varied widely in terms of proviral burden, genetic diversity, and age distribution between CD4+ T cell subsets, revealing that proviral landscapes can differ between individuals and between infected cell types within an individual. Our findings expose each within-host latent reservoir as unique in its genetic complexity and support personalized strategies for HIV eradication.

Imaging correlates of the blood-brain barrier disruption in HIV-associated neurocognitive disorder and therapeutic implications.

HIV-associated neurocognitive disorders (HANDs) in the context of suppressive combination antiretroviral therapy (cART) still occur. We explored the role of blood-brain barrier (BBB) disruption in the pathogenesis of HAND in the context of fully suppressive cART using dynamic contrast enhanced perfusion (DCE-P) MRI. DCE-P is a new MRI technique that measures capillary permeability as an indicator for BBB integrity. We hypothesized that virally suppressed incident HAND would be associated with an impaired BBB as determined by DCE-P. A cross sectional study. K-trans, a metric derivative of DCE-P, was obtained from different regions of the brain in a cohort of 20 patients with HAND who were virally suppressed in both cerebrospinal fluid (CSF) and blood compared with CSF and blood markers of neuroinflammation as well as with neurometabolites derived from magnetic resonance (MR) spectroscopy. The K-trans data showed significantly impaired BBB in HAND patients when compared with the controls in the regions of the basal ganglia and anterior frontal white matter (both P < 0.0001). CSF neopterin and CSF/serum albumin ratio correlated positively with K-trans but not with blood levels. This study indicates that HAND in the context of viral suppression is associated with BBB disruption and the DCE MR derived K-trans metric is a very sensitive parameter to identify the BBB disruption. The finding of region-specific BBB disruption rather than globally and the lack of correlation with blood markers of neuroinflammation suggest that HIV and not systemic inflammation is driving the BBB disturbance and that the BBB disruption is a consequence of HIV already in the brain as opposed to HIV first causing BBB disruption then brain disease.

X4-Tropic Latent HIV-1 Preferentially Accumulates in Peripheral Follicular Helper T Cells and Serves as a Biomarker for Disease Progression

Background: Follicular helper T (TFH) cells are quantitatively and functionally altered in chronic human immunodeficiency virus type 1 (HIV-1) infection and harbor a significant amount of replication-competent latent viruses. However, the viral characteristics of this latent reservoir and its clinical relevance remain unclear. Methods: The viral tropism of proviral DNA in and replication-competent virus from peripheral TFH, non-TFH memory CD4+ T and non-TFH naive CD4+ T cells from 47 HIV-1 infected individuals on suppressive combined antiretroviral therapy (cART) were assessed by deep-sequencing. The relationship between the ratio of X4-tropic latent HIV-1 and blood CD4+ T cell counts at least 6 months before and 12 months after the reference point was analyzed. Findings: X4-tropic latent HIV-1 were preferentially enriched in pTFH cells compared to other blood CD4+ T cell subsets (19.68% ± 4.54%, 13.06% ± 3.17% and in pTFH and mCD4, respectively; mean and SEM; P < 0.05). Interestingly, the ratio of X4-tropic latent HIV-1 in pTFH cells was not only robustly and inversely correlated with blood CD4+ T cell count across patients (R = -0.80; P < 0.0001) but prognostic of the T cell recovery in individuals on long-term cART. Moreover, patients with higher X4-tropic latent HIV-1 ratios in pTFH cells showed greater risks of opportunistic co-infections. Interpretation: These findings reveal the characteristics of latent HIV-1 in TFH cells and suggest that the ratio of X4-tropic latent HIV-1 in pTFH cells can serve as a valuable biomarker for disease progression and efficacy of cART. Funding Statement: This work was supported by the National Special Research Program of China for Important Infectious Diseases (2018ZX10302103 and 2017ZX10202102), the Important Key Program of Natural Science Foundation of China (81730060), the Joint-innovation Program in Healthcare for Special Scientific Research Projects of Guangzhou (201803040002) to H.Z; supported by National Natural Science Foundation of China (81672024), Natural Science Foundation of Guangdong Province of China (2017A030306005, 2016A030313325), Pearl River Scholar Program of Guangdong, Guangdong Innovative and Entrepreneurial Research Team Program (2016ZT06S638) to K.D; supported by the Natural Science Foundation of Guangdong (2016A030313826) to HH.L. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: The Guangzhou Eighth People's Hospital Review Board approved all protocols for human study. All subjects gave informed consent.

Glutaminolysis and lipoproteins are key factors in late immune recovery in successfully treated HIV-infected patients.

The immunological, biochemical and molecular mechanisms associated with poor immune recovery are far from known, and metabolomic profiling offers additional value to traditional soluble markers. Here, we present novel and relevant data that could contribute to better understanding of the molecular mechanisms preceding a discordant response and HIV progression under suppressive combined antiretroviral therapy (cART). Integrated data from nuclear magnetic resonance (NMR)-based lipoprotein profiles, mass spectrometry (MS)-based metabolomics and soluble plasma biomarkers help to build prognostic and immunological progression tools that enable the differentiation of HIV-infected subjects based on their immune recovery status after 96 weeks of suppressive cART. The metabolomic signature of ART-naïve HIV subjects with a subsequent late immune recovery is the expression of pro-inflammatory molecules and glutaminolysis, which is likely related to elevate T-cell turnover in these patients. The knowledge about how these metabolic pathways are interconnected and regulated provides new targets for future therapeutic interventions not only in HIV infection but also in other metabolic disorders such as human cancers where glutaminolysis is the alternative pathway for energy production in tumor cells to meet their requirement of rapid proliferation.

H-102 The potential role of “defective” proviruses in the pathogenesis of HIV-1 infection

A pool of CD4+T cells harboring HIV-1 proviruses is established early during HIV-1 infection and persists despite years of suppressive combination antiretroviral therapy (cART). Greater than 95% of the proviruses in these pools are “defective” due to large internal deletions and lethal genetic mutations. Although unable to encode intact viruses, these “defective” proviruses are biologically active, transcribe HIV-RNA and produce HIV-1 proteins in vivo. We hypothesize that ongoing production of foreign proteins from these translationally-competent yet defective HIV-1 proviruses contribute to the persistent immune activation and systemic inflammation during suppressive ART.

HIV-1 reservoirs in urethral macrophages of patients under suppressive antiretroviral therapy.

Human immunodeficiency virus type 1 (HIV-1) eradication is prevented by the establishment on infection of cellular HIV-1 reservoirs that are not fully characterized, especially in genital mucosal tissues (the main HIV-1 entry portal on sexual transmission). Here, we show, using penile tissues from HIV-1-infected individuals under suppressive combination antiretroviral therapy, that urethral macrophages contain integrated HIV-1 DNA, RNA, proteins and intact virions in virus-containing compartment-like structures, whereas viral components remain undetectable in urethral T cells. Moreover, urethral cells specifically release replication-competent infectious HIV-1 following reactivation with the macrophage activator lipopolysaccharide, while the T-cell activator phytohaemagglutinin is ineffective. HIV-1 urethral reservoirs localize preferentially in a subset of polarized macrophages that highly expresses the interleukin-1 receptor, CD206 and interleukin-4 receptor, but not CD163. To our knowledge, these results are the first evidence that human urethral tissue macrophages constitute a principal HIV-1 reservoir. Such findings are determinant for therapeutic strategies aimed at HIV-1 eradication.

Latent X4-Tropic HIV-1 Preferentially Accumulates in Peripheral Follicular Helper T Cells and Serve as a Biomarker for Disease Progression

Background: Follicular helper T (TFH) cells play a prominent role in immune responses to human immunodeficiency virus type 1 (HIV-1), but these cells are quantitatively and functionally altered in chronic HIV-1 infection and harbor a significant amount of replication-competent latent viruses. We aimed to identify the viral characteristics of this latent reservoir and its clinical relevance. Methods: We enrolled 41 HIV-1 infected individuals (including 25 AE strain, 12 C strain and 4 B strain infected subjects) on suppressive combined antiretroviral therapy (ranging from 1.7 to 10 years). The viral tropism of proviral DNA in and replication-competent virus from peripheral follicular helper T cells (TFH), non-TFH memory CD4+ T (mCD4) and non-TFH naive CD4+ T cells were assessed by deep-sequencing. Furthermore, the relationship between the ratio of X4-tropic latent HIV-1 and blood CD4+ T cell counts at least 6 months before and 12 months after the reference point was analyzed. Findings: We found that X4-tropic latent HIV-1 preferentially enriched in pTFH cells, comparing to other blood CD4+ T cell subsets (19.68% ± 4.54%, 13.06% ± 3.17% and in pTFH and mCD4, respectively; mean and SEM; P < 0.05). In addition, pTFH harbored a two-fold larger replication-competent of X4-tropic HIV-1 compared to mCD4 (0.50 ± 0.18 and 0.24 ± 0.08 IUPM in pTFH and mCD4, respectively; mean and SEM; P < 0.05). In cART-suppressed individuals, the ratio of X4-tropic latent HIV-1 in pTFH cells was precisely and inversely correlated with CD4+ T cell count in the peripheral blood (R = -0.80; P < 0.0001) and predicted its recovery after long-term cART treatment. The individuals with higher ratios of X4-tropic latent HIV-1 in pTFH cells were more likely to develop opportunistic co-infections. Interpretation: Given that few methods are currently available to quantify HIV-1 latent infection and it is difficult to analyze the virion-associated RNA in the presence of suppressive cART, we propose that the ratio of X4-tropic latent HIV-1 in pTFH cells could be an easily-measured indicator for the character of viral reservoir and disease progression. Funding Statement: National Special Research Program of China. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: All human samples were anonymously coded in accordance with the local ethical guidelines (as stipulated by the Declaration of Helsinki). Written informed consents were provided by all study participants, and the protocol was approved by the IRB of Guangzhou Eighth People's Hospital (Guangzhou, China).

Biomarkers of aging in HIV: inflammation and the microbiome.

HIV-infected subjects present increased levels of inflammatory cytokines and T cell activation in the peripheral blood despite suppressive combination antiretroviral therapy which renders them susceptible to premature aging. The purpose of the present work was to review existing evidence on the ways in which the anatomical and microbiological abnormalities of the gastrointestinal tract can represent a major cause of organ disease in HIV infection. We conducted a systematic review of the Pubmed database for articles published from 2014 to 2018. We included studies on inflammatory/activation biomarkers associated with cardiovascular and bone disease, neurocognitive impairment and serious non-AIDS events in HIV-infected subjects. We also included researches which linked peripheral inflammation/activation to the anatomical, immune and microbiological alterations of the gastrointestinal tract. Recent literature data confirm the association between non-infectious comorbidities and inflammation in HIV infection which may be driven by gastrointestinal tract abnormalities, specifically microbial translocation and dysbiosis. Furthermore, there is mounting evidence on the possible role of metabolic functions of the microbiota in the pathogenesis of premature aging in the HIV-infected population. Biomarkers need to be validated for their use in the management of HIV infection. Compounds which counteract microbial translocation, inflammation and dysbiosis have been investigated as alternative therapeutic strategies in viro-suppressed HIV-infected individuals, but appear to have limited efficacy, probably due to the multifactorial pathogenesis of non-infectious comorbidities in this setting.

Imaging Correlates of the Blood Brain Barrier Disruption in HIV Associated Neurocognitive Disorder and Therapeutic Implications

Background and Purpose: Neurocognitive impairment in HIV infection, known as HIV associated neurocognitive disorder (HAND), in the context of suppressive combination antiretroviral therapy still occurs. We hypothesized that ongoing chronic systemic inflammation, a feature of HIV disease despite viral suppression, causes blood brain barrier (BBB) disruption thereby allowing entry of neurotoxic cytokines/chemokines or HIV itself. To test this hypothesis, we have used dynamic contrast enhancement derived metrics (K-trans) to measure the capillary permeability as a direct indicator for BBB disruption and correlated it with neuro inflammatory markers in the cerebrospinal fluid as well as with MR spectroscopy derived metabolites and clinical indices of neurocognition (neuropsychological scores). Materials and Methods: We used the Dynamic contrast enhanced perfusion MR metric, K-trans to measure the BBB disruption in a cohort of 20 patients with HAND who were virally suppressed in both CSF and blood compared with 16 healthy age and sex matched volunteers. Measurement of K-trans, a marker for capillary permeability and hence BBB integrity, was obtained from different regions of the brain and was compared to the age and sex matched controls. Results: The K-trans data showed significantly impaired BBB when compared to the normal controls in the region of basal ganglia and anterior frontal white matter above the ventricular level (both p<0.0001). The CSF -Blood albumin ratios as well as neopterin have correlated positively with K-trans. Conclusion: This study indicates that HAND in the context of viral suppression is associated with BBB disruption and the DCE MR derived K-trans metric is a very sensitive parameter to identify the BBB disruption. The finding of region specific (areas known to be vulnerable to HIV) BBB disruption rather than globally and the lack of correlation with blood markers of neuroinflammation suggest that 1. HIV and not systemic inflammation is driving the BBB disturbance and 2. That the BBB disruption is a consequence of HIV already in the brain as opposed to HIV first causing BBB disruption then brain disease. These findings generate novel testable hypotheses for HAND pathogenesis with potentially significant therapeutic implications.

Altered Expression of CD300a Inhibitory Receptor on CD4+ T Cells From Human Immunodeficiency Virus-1-Infected Patients: Association With Disease Progression Markers.

The ability of the CD300a inhibitory receptor to modulate immune cell functions and its involvement in the pathogenesis of many diseases has aroused a great interest in this molecule. Within human CD4+ T lymphocytes from healthy donors, the inhibitory receptor CD300a is differentially expressed among different T helper subsets. However, there are no data about the expression and regulation of CD300a receptor on CD4+ T cells from human immunodeficiency virus (HIV)-1-infected patients. The objective of this study was to investigate the expression of CD300a on CD4+ T cells from HIV-infected patients on suppressive combined antiretroviral therapy (cART) and cART naïve patients. Our results have demonstrated that the expression levels of this inhibitory receptor were higher on CD4+ T cells from HIV-1 infected subjects compared with healthy donors, and that cART did not reverse the altered expression of CD300a receptor in these patients. We have observed an increase of CD300a expression on both PD1+CD4+ and CD38+CD4+ T cells from HIV-1 infected people. Interestingly, a triple positive (CD300a+PD1+CD38+) subset was expanded in naïve HIV-1 infected patients, while it was very rare in healthy donors and patients on cART. Finally, we found a negative correlation of CD300a expression on CD4+ T lymphocytes and some markers associated with HIV-1 disease progression. Thus, our results show that HIV-1 infection has an impact in the regulation of CD300a inhibitory receptor expression levels, and further studies will shed light into the role of this cell surface receptor in the pathogenesis of HIV infection.

Peripheral and cerebrospinal fluid immune activation and inflammation in chronically HIV-infected patients before and after virally suppressive combination antiretroviral therapy (cART).

Cerebrospinal fluid (CSF)/plasma HIV-RNA ratio has been associated with residual neurocognitive impairment on cART, leading us to hypothesize a specific peripheral and/or CSF immune feature in patients with high CSF/plasma ratio (≥ 1). In patients with diverse pre-cART CSF/plasma ratio (61/70 with CSF/plasma ratio < 1, L-CSF, 9/70 with CSF/plasma ratio ≥ 1, H-CSF), we investigated the effects of 12months of effective cART on peripheral and CSF inflammatory markers, on T cell activation/maturation and HIV/CMV-specific intracellular cytokine pattern. We also studied the possible clinical association between peripheral/CSF pro-inflammatory milieu and neurocognitive screening tests (MMSE, FAB, IHDS). Prior to cART, the two groups were comparable for peripheral and CSF inflammation, T cell activation/proliferation and maturation, and HIV/CMV-specific response. Upon cART initiation, both H-CSF and L-CSF featured a significant reduction in plasma TNF-α and circulating CD8 activation, with a redistribution of memory/naïve T cell subsets in L-CSF alone. In the CSF compartment, cART seemed able to reduce pro-inflammatory cytokine/chemokine levels in both H-CSF and L-CSF patients. Interestingly, despite a reduction in the pro-inflammatory milieu, no changes were shown in neurocognitive screening tests in both patients' groups. We hereby show that 12-month cART is able to reduce intratechal and peripheral pro-inflammatory burden; a longer cART exposure and a more comprehensive neuropsychological evaluation might be necessary to gain a broader insight into the possible effects on neurocognitive performance.

Clonal CD4+ T cells in the HIV-1 latent reservoir display a distinct gene profile upon reactivation.

Despite suppressive combination antiretroviral therapy (ART), latent HIV-1 proviruses persist in patients. This latent reservoir is established within 48-72 h after infection, has a long half-life1,2, enables viral rebound when ART is interrupted, and is the major barrier to a cure for HIV-1 3 . Latent cells are exceedingly rare in blood (∼1 per 1 × 106 CD4+ T cells) and are typically enumerated by indirect means, such as viral outgrowth assays4,5. We report a new strategy to purify and characterize single reactivated latent cells from HIV-1-infected individuals on suppressive ART. Surface expression of viral envelope protein was used to enrich reactivated latent T cells producing HIV RNA, and single-cell analysis was performed to identify intact virus. Reactivated latent cells produce full-length viruses that are identical to those found in viral outgrowth cultures and represent clones of in vivo expanded T cells, as determined by their T cell receptor sequence. Gene-expression analysis revealed that these cells share a transcriptional profile that includes expression of genes implicated in silencing the virus. We conclude that reactivated latent T cells isolated from blood can share a gene-expression program that allows for cell division without activation of the cell death pathways that are normally triggered by HIV-1 replication.

Is weak CD4+ gain in the course of suppressive combination antiretroviral therapy for HIV infection a current clinical challenge? A case report and brief review of the literature

BackgroundIndividuals lacking immune recovery during suppressive cART will still represent a clinical issue in the years to come, given the high proportion of HIV-infected subjects introducing therapy late in the course of disease. Understanding the mechanisms underlying poor CD4+ T-cell gain is crucial for the correct clinical management of individuals in this context.Case presentationAn HIV-infected subject with poor CD4+ T-cell gain in the course of suppressive antiretroviral therapy was extensively investigated to identify the mechanisms behind inadequate CD4+ reconstitution. In particular, we studied the phenotype of circulating T-cells, interleukin-7 signaling in peripheral blood and bone marrow, gut function and microbial translocation markers as well as the composition of the faecal microbiota. Numerous therapeutic interventions ranging from antiretroviral therapy intensification to immunotherapy and anti-hepatitis C virus treatment were also employed in order to target the possible causes of poor immune-recovery.ConclusionsPoor CD4+ T-cell gain on suppressive antiretroviral therapy is multifactorial and thus represents a clinical challenge. Clinicians should investigate subjects’ immune profile as well as possible causes of chronic antigenic stimulation for the administration of the most appropriate therapeutic strategies in this setting.

Neurological Complications of HIV Infection.

HIV-associated neurocognitive disorders (HAND) are common in patients with HIV disease, even during suppressive combination antiretroviral therapy (cART). This review article addresses the pathogenesis of HAND, focusing on important findings from the last 5years. While HIV-associated dementia is now rare in settings with cART availability, mild forms of HAND are increasing in prevalence. Biomarkers of cellular injury, such as neurofilament light chain and neopterin, can detect early stages of neuroinflammation associated with HIV infection and are increased even in asymptomatic individuals with chronic HIV infection. Several recent studies form a growing body of evidence that HIV can infect and replicate in monocytes and that blocking monocyte activity can potentially improve neurological outcomes in HIV. Early cART may also prevent HAND. Understanding the multifactorial causes of CNS infection and inflammation is critical to devising treatment and preventive strategies for HAND.