Immune activation and HIV persistence: considerations for novel therapeutic interventions. Curr Opin HIV AIDS. 2013;8:211-216. [PMID: 23454864 DOI: 10.1097/coh.0b013e32835f9788]

Rethinking HIV treatment: How non-integrase strand regimens may hold the key to better immune health

PURPOSE

HIV outcome changed drastically with antiretroviral (ARV) therapy, especially after the introduction of second-generation integrase strand transfer inhibitors (INSTIs). Despite these advances, however, chronic immune activation and exhaustion, marked by programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) upregulation, persist in patients. This study investigates the impact of various ARV regimens on these immune exhaustion markers in newly diagnosed HIV patients over 12 months, taking into consideration cardiovascular risk.

METHODS

This study included 58 newly diagnosed patients with HIV at Pomeranian Medical University, Szczecin, Poland. Participants received ARV regimens classified as INSTI + tenofovir alafenamide, INSTI + tenofovir disoproxil fumarate, or non-INSTI-based (VARIA). Flow cytometry was used to assess PD-1 and PD-L1 expression on CD3+, CD3+CD4+, CD3+CD8+ and CD19+ lymphocytes. Statistical analyses included Wilcoxon paired tests, Kruskal-Wallis tests and multivariate regression, with validation through residual analysis and linear discriminant analysis (LDA).

RESULTS

INSTI-based regimens were linked to higher PD-1 expression on CD3+ and CD3+CD4+ lymphocytes, indicating increased immune exhaustion. Conversely, non-INSTI regimens were associated with lower PD-1 levels, suggesting better retention of immune function. A positive correlation between cardiovascular risk a prediction model to estimate 10-year fatal and non-fatal cardiovascular disease (SCORE2) and PD-1 expression was observed. However, the modest explanatory power of the models suggests variability in the effects of different ARV regimens.

CONCLUSION

This study challenges the assumption that INSTI-based ARV regimens are universally superior, suggesting that non-INSTI therapies may better preserve immune function by reducing PD-1 expression. These findings highlight the potential benefits of non-INSTI regimens in improving long-term clinical outcomes in HIV treatment, warranting further research.

Remodeling of immune system functions by extracellular vesicles

Introduction

The treatment of chronic viral infections can often bring viral replication under control. However, chronic immune activation persists and can lead to the development of comorbid conditions, such as cardiovascular disease and cancer. This is particularly true for people living with HIV (PLWH), who have significantly more extracellular vesicles from membrane budding, also called plasma microparticles (MPs), than healthy individuals (HDs), and a much more immunomodulatory phenotype. We hypothesized that the number and phenotypic heterogeneity of MPs can trigger a functional remodeling of immune responses in PLWH, preventing full immune restoration.

Methods

We investigated the rapid impact of three types of MPs - derived from membrane budding in platelets (CD41a+ PMPs), monocytes (CD14+ MMPs) and lymphocytes (CD3+ LMPs) in the plasma of PLWH or HDs-on four cell types (CD4+ and CD8+T lymphocytes, monocytes and DCs).

Results

These investigations of the short multiple interactions and functions of MPs with these cells revealed an increase in the secretion of cytokines such as IFNg, IL2, IL6, IL12, IL17 and TNFa by the immune cells studied following interactions with MPs. We show that this functional remodeling of immune cells depends not only on the number, but also on the phenotype of MPs.

Conclusion

These data suggest that the large numbers of MPs and their impact on functional remodeling in PLWH may be incompatible with the effective control of chronic infections, potentially leading to chronic immune activation and the onset of comorbid diseases.

Association between markers of hepatitis B virus infection and risk of virological rebound in people with HIV receiving antiretroviral therapy

OBJECTIVES

The aim of this analysis was to investigate the impact of hepatitis B virus (HBV) coinfection on the risk of HIV viral rebound (VR) after achieving suppression for the first time following initiation of antiretroviral therapy (ART) in the real-world setting.

DESIGN

Patients living with HIV (PLWH) who were enrolled in the ICONA Foundation Study cohort and achieved viral suppression ≤50 copies/mL for the first time after starting ART were prospectively evaluated and divided in three exposure groups according to serology test results: (a) HIV-monoinfected; (b) HIV-positive/HBcAb-positive/HBsAg-negative; (c) HIV-positive/HBsAg-positive. The occurrence of VR, defined as two consecutive HIV-RNA values >50 copies/mL after achieving viral suppression for the first time (baseline), was investigated.

METHODS

Standard survival analysis by means of Kaplan-Meier curves and Cox regression analysis with the serology exposure fitted as a time-fixed covariate measured at baseline was employed after controlling for key confounding factors.

RESULTS

Of a total of 5657 patients included, 4090 (72%) were HIV-monoinfected, 1342 (23.7%)were HBcAb-positive, and 225 (3.9%) were HbsAg-positive coinfected. Overall, 654 (11.5%) PLWH experienced VR > 50 copies/mL during follow-up. After controlling for all sources of measured confounding, coinfected PLWH showed an increased risk of experiencing VR compared with those who were HIV-monoinfected. In particular, the strongest associations were seen for the HIV/HBsAg-positive participants [adjusted hazard ratio (aHR) = 1.56, 95% confidence interval (CI): 1.03-2.38, p = 0.037] but an excess of risk was also seen in those who were HIV-positive/HBcAb-positive/HBsAg-negative (aHR = 1.25, 95% CI: 1.00-1.55, p = 0.047).

CONCLUSIONS

Coinfection with HBV seems to have an impact on the probability of maintaining HIV viral suppression achieved for the first time after ART initiation. Of note, even PLWH positive for HBcAb, a marker of inactive HBV infection, appeared to be at higher risk of VR compared with those who were HIV-monoinfected and their HIV-RNA should be carefully monitored.

Pembrolizumab in an HIV-infected patient with glioblastoma

Persons living with human immunodeficiency virus (PLWH) carry increased risk for developing malignancies, including glioblastoma. Despite extensive investigations, both human immunodeficiency virus (HIV) and glioblastoma are incurable. Treatment for a patient with combined glioblastoma and HIV remains an unexplored need. Preliminary evidence suggests that immunotherapy may be effective for the simultaneous treatment of both HIV and cancer by reversing HIV latency and T cell exhaustion. We present a case of glioblastoma in a PLWH who was treated with pembrolizumab. Treatment was well tolerated and safe with a mixed response. Our patient did not develop any opportunistic infections, immune-related adverse events, or worsening of his immunodeficiency. To our knowledge, this is the first reported case of a PLWH and glioblastoma treated with immunotherapy.

Identification of drug candidates targeting monocyte reprogramming in people living with HIV

Introduction

People living with HIV (PLHIV) are characterized by functional reprogramming of innate immune cells even after long-term antiretroviral therapy (ART). In order to assess technical feasibility of omics technologies for application to larger cohorts, we compared multiple omics data layers.

Methods

Bulk and single-cell transcriptomics, flow cytometry, proteomics, chromatin landscape analysis by ATAC-seq as well as ex vivo drug stimulation were performed in a small number of blood samples derived from PLHIV and healthy controls from the 200-HIV cohort study.

Results

Single-cell RNA-seq analysis revealed that most immune cells in peripheral blood of PLHIV are altered in their transcriptomes and that a specific functional monocyte state previously described in acute HIV infection is still existing in PLHIV while other monocyte cell states are only occurring acute infection. Further, a reverse transcriptome approach on a rather small number of PLHIV was sufficient to identify drug candidates for reversing the transcriptional phenotype of monocytes in PLHIV.

Discussion

These scientific findings and technological advancements for clinical application of single-cell transcriptomics form the basis for the larger 2000-HIV multicenter cohort study on PLHIV, for which a combination of bulk and single-cell transcriptomics will be included as the leading technology to determine disease endotypes in PLHIV and to predict disease trajectories and outcomes.

HIV DNA positively correlates with HLA-DR+CD8+ T lymphocytes over 8-year suppressive antiretroviral therapy

We studied the relationship between HIV DNA and CD8 + T-cell activation in a retrospective cohort. We observed that the expression level of HLA-DR remained high in CD8 + T-cells and was positively correlated with total HIV DNA [odds ratio (OR)  =  1.86, P  = 0.028) during 8 years of suppressive antiretroviral therapy (ART). This study illustrated the long-term interplay between HIV DNA reservoir and host inflammatory state despite viral suppression.

Alterations in Abundance and Compartmentalization of miRNAs in Blood Plasma Extracellular Vesicles and Extracellular Condensates during HIV/SIV Infection and Its Modulation by Antiretroviral Therapy (ART) and Delta-9-Tetrahydrocannabinol (Δ9-THC)

In this follow-up study, we investigated the abundance and compartmentalization of blood plasma extracellular miRNA (exmiRNA) into lipid-based carriers-blood plasma extracellular vesicles (EVs) and non-lipid-based carriers-extracellular condensates (ECs) during SIV infection. We also assessed how combination antiretroviral therapy (cART), administered in conjunction with phytocannabinoid delta-9-tetrahydrocannabinol (THC), altered the abundance and compartmentalization of exmiRNAs in the EVs and ECs of SIV-infected rhesus macaques (RMs). Unlike cellular miRNAs, exmiRNAs in blood plasma may serve as minimally invasive disease indicators because they are readily detected in stable forms. The stability of exmiRNAs in cell culture fluids and body fluids (urine, saliva, tears, cerebrospinal fluid (CSF), semen, blood) is based on their association with different carriers (lipoproteins, EVs, and ECs) that protect them from the activities of endogenous RNases. Here, we showed that in the blood plasma of uninfected control RMs, significantly less exmiRNAs were associated with EVs compared to the level (30% higher) associated with ECs, and that SIV infection altered the profile of EVs and ECs miRNAome (Manuscript 1). In people living with HIV (PLWH), host-encoded miRNAs regulate both host and viral gene expression, which may serve as indicators of disease or treatment biomarkers. The profile of miRNAs in blood plasma of PLWH (elite controllers versus viremic patients) are different, indicating that HIV may alter host miRNAome. However, there are no studies assessing the effect of cART or other substances used by PLWH, such as THC, on the abundance of exmiRNA and their association with EVs and ECs. Moreover, longitudinal exmiRNA profiles following SIV infection, treatment with THC, cART, or THC+cART remains unclear. Here, we serially analyzed miRNAs associated with blood plasma derived EVs and ECs. Methods: Paired EVs and ECs were separated from EDTA blood plasma of male Indian rhesus macaques (RMs) in five treatment groups, including VEH/SIV, VEH/SIV/cART, THC/SIV, THC/SIV/cART, or THC alone. Separation of EVs and ECs was achieved with the unparalleled nano-particle purification tool ─PPLC, a state-of-the-art, innovative technology equipped with gradient agarose bead sizes and a fast fraction collector that allows high resolution separation and retrieval of preparative quantities of sub-populations of extracellular structures. Global miRNA profiles of the paired EVs and ECs were determined with RealSeq Biosciences (Santa Cruz, CA) custom sequencing platform by conducting small RNA (sRNA)-seq. The sRNA-seq data were analyzed using various bioinformatic tools. Validation of key exmiRNA was performed using specific TaqMan microRNA stem-loop RT-qPCR assays. Results: We investigated the effect of cART, THC, or both cART and THC together on the abundance and compartmentalization of blood plasma exmiRNA in EVs and ECs in SIV-infected RMs. As shown in Manuscript 1 of this series, were in uninfected RMs, ~30% of exmiRNAs were associated with ECs, we confirmed in this follow up manuscript that exmiRNAs were present in both lipid-based carriers-EVs and non-lipid-based carriers-ECs, with 29.5 to 35.6% and 64.2 to 70.5 % being associated with EVs and ECs, respectively. Remarkably, the different treatments (cART, THC) have distinct effects on the enrichment and compartmentalization pattern of exmiRNAs. In the VEH/SIV/cART group, 12 EV-associated and 15 EC-associated miRNAs were significantly downregulated. EV-associated miR-206, a muscle-specific miRNA that is present in blood, was higher in the VEH/SIV/ART compared to the VEH/SIV group. ExmiR-139-5p that was implicated in endocrine resistance, focal adhesion, lipid and atherosclerosis, apoptosis, and breast cancer by miRNA-target enrichment analysis was significantly lower in VEH/SIV/cART compared to VEH/SIV, irrespective of the compartment. With respect to THC treatment, 5 EV-associated and 21 EC-associated miRNAs were significantly lower in the VEH/THC/SIV. EV-associated miR-99a-5p was higher in VEH/THC/SIV compared to VEH/SIV, while miR-335-5p counts were significantly lower in both EVs and ECs of THC/SIV compared to VEH/SIV. EVs from SIV/cART/THC combined treatment group have significant increases in the count of eight (miR-186-5p, miR-382-5p, miR-139-5p and miR-652, miR-10a-5p, miR-657, miR-140-5p, miR-29c-3p) miRNAs, all of which were lower in VEH/SIV/cART group. Analysis of miRNA-target enrichment showed that this set of eight miRNAs were implicated in endocrine resistance, focal adhesions, lipid and atherosclerosis, apoptosis, and breast cancer as well as cocaine and amphetamine addiction. In ECs and EVs, combined THC and cART treatment significantly increased miR-139-5p counts compared to VEH/SIV group. Significant alterations in these host miRNAs in both EVs and ECs in the untreated and treated (cART, THC, or both) RMs indicate the persistence of host responses to infection or treatments, and this is despite cART suppression of viral load and THC suppression of inflammation. To gain further insight into the pattern of miRNA alterations in EVs and ECs and to assess potential cause-and-effect relationships, we performed longitudinal miRNA profile analysis, measured in terms of months (1 and 5) post-infection (MPI). We uncovered miRNA signatures associated with THC or cART treatment of SIV-infected macaques in both EVs and ECs. While the number of miRNAs was significantly higher in ECs relative to EVs for all groups (VEH/SIV, SIV/cART, THC/SIV, THC/SIV/cART, and THC) longitudinally from 1 MPI to 5 MPI, treatment with cART and THC have longitudinal effects on the abundance and compartmentalization pattern of exmiRNAs in the two carriers. As shown in Manuscript 1 where SIV infection led to longitudinal suppression of EV-associated miRNA-128-3p, administration of cART to SIV-infected RMs did not increase miR-128-3p but resulted in longitudinal increases in six EV-associated miRNAs (miR-484, miR-107, miR-206, miR-184, miR-1260b, miR-6132). Furthermore, administration of cART to THC treated SIV-infected RMs resulted in a longitudinal decrease in three EV-associated miRNAs (miR-342-3p, miR-100-5p, miR181b-5p) and a longitudinal increase in three EC-associated miRNAs (miR-676-3p, miR-574-3p, miR-505-5p). The longitudinally altered miRNAs in SIV-infected RMs may indicate disease progression, while in the cART Group and the THC Group, the longitudinally altered miRNAs may serve as biomarkers of response to treatment. Conclusions: This paired EVs and ECs miRNAome analyses provided a comprehensive cross-sectional and longitudinal summary of the host exmiRNA responses to SIV infection and the impact of THC, cART, or THC and cART together on the miRNAome during SIV infection. Overall, our data point to previously unrecognized alterations in the exmiRNA profile in blood plasma following SIV infection. Our data also indicate that cART and THC treatment independently and in combination may alter both the abundance and the compartmentalization of several exmiRNA related to various disease and biological processes.

Thymic Exhaustion and Increased Immune Activation Are the Main Mechanisms Involved in Impaired Immunological Recovery of HIV-Positive Patients under ART

Decades of studies in antiretroviral therapy (ART) have passed, and the mechanisms that determine impaired immunological recovery in HIV-positive patients receiving ART have not been completely elucidated yet. Thus, T-lymphocytes immunophenotyping and cytokines levels were analyzed in 44 ART-treated HIV-positive patients who had a prolonged undetectable plasma viral load. The patients were classified as immunological non-responders (INR = 13) and immunological responders (IR = 31), according to their CD4+ T cell levels. Evaluating pre-CD4+ levels, we observed a statistically significant trend between lower CD4+ T cell levels and INR status (Z = 3.486, p < 0.001), and during 18 months of ART, the CD4+ T cell levels maintained statistical differences between the INR and IR groups (WTS = 37.252, p < 0.001). Furthermore, the INRs were associated with an elevated age at ART start; a lower pre-treatment CD4+ T cell count and a percentage that remained low even after 18 months of ART; lower levels of recent thymic emigrant (RTE) CD4+ T cell (CD45RA + CD31+) and a naïve CD4+ T cell (CD45RA + CD62L+); higher levels of central memory CD4+ T cells (CD45RA-CD62L+); and higher immune activation by CD4+ expressing HLA-DR+ or both (HLA-DR+ and CD38+) when compared with IRs. Our study demonstrates that thymic exhaustion and increased immune activation are two mechanisms substantially implicated in the impaired immune recovery of ART-treated HIV patients.

The Many Faces of Immune Activation in HIV-1 Infection: A Multifactorial Interconnection

Chronic immune activation has a significant role in HIV-1 disease pathogenesis and CD4+ T-cell depletion. The causes of chronic inflammation and immune activation are incompletely understood, but they are likely multifactorial in nature, involving both direct and indirect stimuli. Possible explanations include microbial translocation, coinfection, and continued presence of competent replicating virus. In fact, long-term viral suppression treatments are unable to normalize elevated markers of systemic immune activation. Furthermore, high levels of pro-inflammatory cytokines increase susceptibility to premature aging of the immune system. The phenomenon of "inflammaging" has begun to be evident in the last decades, as a consequence of increased life expectancy due to the introduction of cART. Quality of life and survival have improved substantially; however, PLWH are predisposed to chronic inflammatory conditions leading to age-associated diseases, such as inflammatory bowel disease, neurocognitive disorders, cardiovascular diseases, metabolic syndrome, bone abnormalities, and non-HIV-associated cancers. Several approaches have been studied in numerous uncontrolled and/or randomized clinical trials with the aim of reducing immune activation/inflammatory status in PLWH, none of which have achieved consistent results.

T-Cell Immune Dysregulation and Mortality in Women With Human Immunodeficiency Virus

SUMMARY

In women with HIV, higher activation and exhaustion of CD4+ T cells were associated with risk of non-HIV-related mortality during a median of 13.3 years of follow-up, independent of baseline demographic, behavioral, HIV-related, and cardiometabolic factors and longitudinal HIV disease progression.

BACKGROUND

Dysregulation of adaptive immunity is a hallmark of human immunodeficiency virus (HIV) infection that persists on antiretroviral therapy (ART). Few long-term prospective studies have related adaptive immunity impairments to mortality in HIV, particularly in women.

METHODS

Among 606 women with HIV in the Women's Interagency HIV Study, peripheral blood mononuclear cells collected from 2002 to 2005 underwent multiparameter flow cytometry. Underlying cause of death was ascertained from the National Death Index up to 2018. We examined associations of CD4+ and CD8+ T-cell activation (%CD38+HLA-DR+), senescence (%CD57+CD28-), exhaustion (%PD-1+), and nonactivation/normal function (%CD57-CD28+) with natural-cause, HIV-related, and non-HIV-related mortality.

RESULTS

At baseline, median participant age was 41, and 67% were on ART. Among 100 deaths during a median of 13.3 years follow-up, 90 were natural-cause (53 non-HIV-related, 37 HIV-related). Higher activation and exhaustion of CD4+ T cells were associated with risk of natural-cause and non-HIV-related mortality, adjusting for age, demographic, behavioral, HIV-related, and cardiometabolic factors at baseline. Additional adjustment for time-varying viral load and CD4+ T-cell count did not attenuate these associations. CD8+ T-cell markers were not associated with any outcomes adjusting for baseline factors.

CONCLUSIONS

Persistent CD4+ T-cell activation and exhaustion may contribute to excess long-term mortality risk in women with HIV, independent of HIV disease progression.

Menopause Is Associated With Immune Activation in Women With HIV

BACKGROUND

Persistent immune activation due to gut barrier dysfunction is a suspected cause of morbidity in HIV, but the impact of menopause on this pathway is unknown.

METHODS

In 350 women with HIV from the Women's Interagency HIV Study, plasma biomarkers of gut barrier dysfunction (intestinal fatty acid binding protein; IFAB), innate immune activation (soluble CD14 and CD163; sCD14, sCD163), and systemic inflammation (interleukin-6 and tumor necrosis factor receptor 1; IL-6, TNFR1) were measured at 674 person-visits spanning ≤2 years.

RESULTS

Menopause (post- vs premenopausal status) was associated with higher plasma sCD14 and sCD163 in linear mixed-effects regression adjusting for age and other covariates (β = 161.89 ng/mL; 95% confidence interval [CI], 18.37-305.41 and 65.48 ng/mL, 95% CI, 6.64-124.33, respectively); but not with plasma IFAB, IL-6, or TNFR1. In piece-wise linear mixed-effects regression of biomarkers on years before/after the final menstrual period, sCD14 increased during the menopausal transition by 250.71 ng/mL per year (95% CI, 16.63-484.79; P = .04), but not in premenopausal or postmenopausal periods.

CONCLUSIONS

In women with HIV, menopause may increase innate immune activation, but data did not support an influence on the gut barrier or inflammation. Clinical implications of immune activation during menopausal transition warrant further investigation.

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.

Pulmonary Immune Dysregulation and Viral Persistence During HIV Infection

Despite the success of antiretroviral therapy (ART), people living with HIV continue to suffer from high burdens of respiratory infections, lung cancers and chronic lung disease at a higher rate than the general population. The lung mucosa, a previously neglected HIV reservoir site, is of particular importance in this phenomenon. Because ART does not eliminate the virus, residual levels of HIV that remain in deep tissues lead to chronic immune activation and pulmonary inflammatory pathologies. In turn, continuous pulmonary and systemic inflammation cause immune cell exhaustion and pulmonary immune dysregulation, creating a pro-inflammatory environment ideal for HIV reservoir persistence. Moreover, smoking, gut and lung dysbiosis and co-infections further fuel the vicious cycle of residual viral replication which, in turn, contributes to inflammation and immune cell proliferation, further maintaining the HIV reservoir. Herein, we discuss the recent evidence supporting the notion that the lungs serve as an HIV viral reservoir. We will explore how smoking, changes in the microbiome, and common co-infections seen in PLWH contribute to HIV persistence, pulmonary immune dysregulation, and high rates of infectious and non-infectious lung disease among these individuals.

Prevalence and risk of residual viremia after ART in low- and middle-income countries: A cross-sectional study

ABSTRACT

In order to design effective strategies to eradicate the HIV, an understanding of persistent viral reservoirs is needed. Many studies have demonstrated HIV residual viremia prevalence in high income countries, data from low- and middle-income countries (LMIC) are limited. We assessed the prevalence, and factors associated with residual viremia in people with HIV (PWH), who were virally-suppressed on antiretroviral therapy (ART) in LMIC. We also compared residual viremia prevalence between the LMIC and US.This is a cross-sectional, retrospective study that utilized stored specimen samples from the AIDS clinical trials group (ACTG) studies A5175 and A5208. The last available sample among participants with plasma HIV RNA < 400 copies/mL for ≥3 years were tested by the HIV molecular and monitoring core gag (HMMCgag) single copy assay (SCA). Residual viremia was defined as detectable if ≥1 copy/mL. Spearman's correlation and multivariable stepwise logistic regression were used to assess associations of various factors with SCA.A total of 320 participants, 246 (77%) from LMIC and 74 (23%) from US, were analyzed. Median (IQR) age was 33 (2840) years; baseline CD4 166 (88,230) cells/mm3; HIV RNA 5.0 (4.5, 5.3) log10 copies/mL; duration of viral suppression 3.4 (3.1, 4.0) years and 48% were male. In 85 participants with information available, 53% were subtype C, 42% subtype B and 5% other subtypes. Overall prevalence of residual viremia was 57% [95% CI, 52-63] with 51% [40-63] in US and 59% [53-65] in LMIC. Among participants with detectable SCA, the median (IQR) HIV RNA was 3.8 (2.2, 8.1) copies/mL. The multivariable model conducted in LMIC participants showed that higher baseline HIV RNA was associated with detectable residual RNA (OR 2.9, 95% CI 1.8, 4.6 for every log10 increase, P < .001). After including both US and LMIC in the final model, baseline HIV RNA remained significant. No difference in SCA detestability was found between US and LMIC sites (OR 1.1 [0.6, 2.0], P = .72) after adjusting for baseline RNA and parent study.The prevalence of residual viremia between both groups were not different and more than half of the participants had detectable viremia. Higher baseline HIV RNA was independently associated with residual viremia.

Clinical consequences of asymptomatic cytomegalovirus in treated human immunodeficency virus infection

PURPOSE OF REVIEW

Despite antiretroviral therapy (ART)-mediated viral suppression, people with human immunodeficiency virus (HIV) (PWH) have increased morbidity and mortality. Immune activation and inflammation persist on ART and predict these complications. Over 90% of PWH have cytomegalovirus (CMV) co-infection, and CMV is considered a plausible contributor to this persistent immune activation.

RECENT FINDINGS

A detailed understanding of the link between CMV and multimorbidity is needed, particularly as research moves toward identifying potential targeted therapeutics to attenuate inflammation-mediated morbidity and mortality in treated HIV. We review the literature on the association between CMV and immune activation as well as multiple end-organ complications including cardiovascular disease, venous thromboembolic disease, metabolic complications, gastrointestinal dysfunction, central nervous system involvement, birth sex-related differences, and the relation to the HIV reservoir. We conclude with a discussion of ongoing therapeutic efforts to target CMV.

SUMMARY

As CMV is a plausible driver of multiple comorbidities through persistent immune activation in treated HIV, future research is needed and planned to address its causal role as well as to test novel therapeutics in this setting.

Chronic HIV infection induces transcriptional and functional reprogramming of innate immune cells

Chronic inflammation and immune dysfunction play a key role in the development of non-AIDS–related comorbidities. The aim of our study was to characterize the functional phenotype of immune cells in people living with HIV (PLHIV). We enrolled a cross-sectional cohort study of PLHIV on stable antiretroviral therapy and healthy controls. We assessed ex vivo cytokine production capacity and transcriptomics of monocytes and T cells upon bacterial, fungal, and viral stimulation. PLHIV exhibited an exacerbated proinflammatory profile in monocyte-derived cytokines, but not in lymphocyte-derived cytokines. Particularly, the production of the IL-1β to imiquimod, E. coli LPS, and Mycobacterium tuberculosis was increased, and this production correlated with plasma concentrations of high-sensitivity C-reactive protein and soluble CD14. This increase in monocyte responsiveness remained stable over time in subsequent blood sampling after more than 1 year. Transcriptome analyses confirmed priming of the monocyte IL-1β pathway, consistent with a monocyte-trained immunity phenotype. Increased plasma concentrations of β-glucan, a well-known inducer of trained immunity, were associated with increased innate cytokine responses. Monocytes of PLHIV exhibited a sustained proinflammatory immune phenotype with priming of the IL-1β pathway. Training of the innate immune system in PLHIV likely plays a role in long-term HIV complications and provides a promising therapeutic target for inflammation-related comorbidities.

Adherence to a Supplemented Mediterranean Diet Drives Changes in the Gut Microbiota of HIV-1-Infected Individuals

OBJECTIVE

The health effects of a supplemented Mediterranean diet (SMD) with extra-virgin olive oil (EVOO) and nuts are well documented in non-HIV-infected individuals. We hypothesised that the benefits of an SMD could be mediated by changes in the gut microbiota, even in those with an altered intestinal microbiota such as people living with HIV.

DESIGN

Individuals living with HIV (n = 102) were randomised to receive an SMD with 50 g/day of EVOO and 30 g/day of walnuts (SMD group) or continue with their regular diet (control group) for 12 weeks.

METHODS

Adherence to the Mediterranean diet was assessed using the validated 14-item MD-Adherence-Screener (MEDAS) from the PREDIMED study. A sub-study classifying the participants according to their MEDAS scores was performed.

RESULTS

The lipid profile was improved in the SMD group vs. that in the control group (delta-total cholesterol and delta-B-lipoprotein). The immune activation (CD4+HLADR+CD38+ and CD8+HLADR+CD38+ cells) and IFN-γ-producing T-cells significantly decreased at week 12 compared to the baseline in the SMD group but not in the control group. The gut microbiota in those from the high-adherence group presented significantly high diversity and richness at the end of the intervention. Succinivibrio and Bifidobacterium abundances were influenced by the adherence to the MD and significantly correlated with Treg cells.

CONCLUSION

The Mediterranean diet improved metabolic parameters, immune activation, Treg function, and the gut microbiota composition in HIV-1-infected individuals. Further, Mediterranean diet increased the Bifidobacterium abundances after the intervention, and it was associated to a beneficial profile.

Cell-Associated HIV-1 Unspliced-to-Multiply-Spliced RNA Ratio at 12 Weeks of ART Predicts Immune Reconstitution on Therapy

Human immunodeficiency virus (HIV) infection is currently managed by antiretroviral drugs, which block virus replication and promote immune restoration. However, the latter effect is not universal, with a proportion of infected individuals failing to sufficiently reconstitute their immune function despite a successful virological response to antiretroviral therapy (ART).

Incomplete restoration of CD4⁺ T-cell counts on antiretroviral therapy (ART) is a major predictor of HIV-related morbidity and mortality. To understand the possible mechanisms behind this poor immunological response despite viral suppression, we longitudinally measured more than 50 virological and immunological biomarkers in a cohort of HIV-infected individuals at several time points during the first 96 weeks of virologically suppressive ART. No baseline virological or immunological marker was predictive of the degree of immune reconstitution. However, the cell-associated HIV-1 unspliced-to-multiply-spliced (US/MS) RNA ratio at 12 weeks of ART positively correlated with markers of CD4⁺ T-cell activation and apoptosis and negatively predicted both the absolute and relative CD4⁺ T-cell counts at 48 and 96 weeks. A higher US/MS RNA ratio may reflect the higher frequency of productively infected cells that could exert pressure on the immune system, contributing to persistent immune activation and apoptosis and subsequently to a poor immunological response to ART.

Food Insecurity and T-cell Dysregulation in Women Living With Human Immunodeficiency Virus on Antiretroviral Therapy

BACKGROUND

Food insecurity is associated with increased morbidity and mortality in people with human immunodeficiency virus (HIV) on antiretroviral therapy, but its relationship with immune dysregulation, a hallmark of HIV infection and comorbidity, is unknown.

METHODS

In 241 women participating in the Women's Interagency HIV Study, peripheral blood mononuclear cells were characterized by flow cytometry to identify cell subsets, comprising surface markers of activation (%CD38+HLADR+), senescence (%CD57+CD28-), exhaustion (%PD-1+), and co-stimulation (%CD57- CD28+) on CD4+ and CD8+ T cells. Mixed-effects linear regression models were used to assess the relationships of food insecurity with immune outcomes, accounting for repeated measures at ≤3 study visits and adjusting for sociodemographic and clinical factors.

RESULTS

At the baseline study visit, 71% of participants identified as non-Hispanic Black, 75% were virally suppressed, and 43% experienced food insecurity. Food insecurity was associated with increased activation of CD4+ and CD8+ T cells, increased senescence of CD8+ T cells, and decreased co-stimulation of CD4+ and CD8+ T cells (all P < .05), adjusting for age, race/ethnicity, income, education, substance use, smoking, HIV viral load, and CD4 count. In stratified analyses, the association of food insecurity with CD4+ T-cell activation was more pronounced in women with uncontrolled HIV (viral load >40 copies/mL and CD4 <500 cells/mm3) but remained statistically significant in those with controlled HIV.

CONCLUSIONS

Food insecurity may contribute to the persistent immune activation and senescence in women with HIV on antiretroviral therapy, independently of HIV control. Reducing food insecurity may be important for decreasing non-AIDS-related disease risk in this population.

HIV Infection and Persistence in Pulmonary Mucosal Double Negative T Cells In Vivo

The lungs are relatively unexplored anatomical human immunodeficiency virus (HIV) reservoirs in the antiretroviral therapy (ART) era. Double negative (DN) T cells are a subset of T cells that lack expression of CD4 and CD8 (CD4^- CD8^-) and may have both regulatory and effector functions during HIV infection. Notably, circulating DN T cells were previously described as cellular HIV reservoirs. Here, we undertook a thorough analysis of pulmonary versus blood DN T cells of people living with HIV (PLWH) under ART. Bronchoalveolar lavage (BAL) fluid and matched peripheral blood were collected from 35 PLWH on ART and 16 uninfected volunteers without respiratory symptoms. Both PLWH and HIV-negative (HIV^-) adults displayed higher frequencies of DN T cells in BAL versus blood, and these cells mostly exhibited an effector memory phenotype. In PLWH, pulmonary mucosal DN T cells expressed higher levels of HLA-DR and several cellular markers associated with HIV persistence (CCR6, CXCR3, and PD-1) than blood. We also observed that DN T cells were less senescent (CD28^- CD57⁺) and expressed less immunosuppressive ectonucleotidase (CD73/CD39), granzyme B, and perforin in the BAL fluid than in the blood of PLWH. Importantly, fluorescence-activated cell sorter (FACS)-sorted DN T cells from the BAL fluid of PLWH under suppressive ART harbored HIV DNA. Using the humanized bone marrow-liver-thymus (hu-BLT) mouse model of HIV infection, we observed higher infection frequencies of lung DN T cells than those of the blood and spleen in both early and late HIV infection. Overall, our findings show that HIV is seeded in pulmonary mucosal DN T cells early following infection and persists in these potential cellular HIV reservoirs even during long-term ART.IMPORTANCE Reservoirs of HIV during ART are the primary reasons why HIV/AIDS remains an incurable disease. Indeed, HIV remains latent and unreachable by antiretrovirals in cellular and anatomical sanctuaries, preventing its eradication. The lungs have received very little attention compared to other anatomical reservoirs despite being immunological effector sites exhibiting characteristics ideal for HIV persistence. Furthermore, PLWH suffer from a high burden of pulmonary non-opportunistic infections, suggesting impaired pulmonary immunity despite ART. Meanwhile, various immune cell populations have been proposed to be cellular reservoirs in blood, including CD4^- CD8^- DN T cells, a subset that may originate from CD4 downregulation by HIV proteins. The present study aims to describe DN T cells in human and humanized mice lungs in relation to intrapulmonary HIV burden. The characterization of DN T cells as cellular HIV reservoirs and the lungs as an anatomical HIV reservoir will contribute to the development of targeted HIV eradication strategies.

Elevated Plasma Levels of sCD14 and MCP-1 Are Associated With HIV Associated Neurocognitive Disorders Among Antiretroviral-Naive Individuals in Nigeria

BACKGROUND

Mononuclear cells play key roles in the pathogenesis of HIV-associated neurocognitive disorders (HAND). Limited studies have looked at the association of markers of monocyte activation with HAND in Africa. We examined this association among HIV-1-infected patients in Nigeria.

METHOD

A total of 190 HIV-infected treatment-naive participants with immune marker data were included in this cross-sectional study. Plasma levels of soluble CD14 (sCD14), soluble CD163, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), and neopterin were measured. Demographically adjusted T scores obtained from a 7-domain neuropsychological test battery were generated, and functional status was assessed using activities of daily living questionnaire. Participants were classified as unimpaired, having asymptomatic neurocognitive impairment (ANI), mild neurocognitive disorder (MND), or HIV-associated dementia (HAD) in line with the "Frascati" criteria.

RESULTS

Thirty-two participants (16.8%) had ANI, 14 (7.4%) had MND, whereas none had HAD. In multivariable linear regression analyses, after adjusting for age, gender, education, CD4 count, and viral load, mean levels of sCD14 were higher among those with ANI and MND as compared with the unimpaired (P = 0.033 and 0.023, respectively). Similarly, the mean level of MCP-1 was greater among those with HAND as compared with the unimpaired (P = 0.047). There were also trends for higher levels of sCD163 and TNF-α among females with MND in univariable analyses.

CONCLUSIONS

Levels of monocyte activation markers correlate with the severity of impairment among individuals with HAND. The mechanisms that underlie these effects and the potential role of gender require further study.

Glycoprotein Profile Assessed by 1H-NMR as a Global Inflammation Marker in Patients with HIV Infection. A Prospective Study

Plasma glycoproteins are a composite biomarker of inflammation and can be detected by ¹H-NMR. The aim of this study was to prospectively appraise the clinical value of plasma glycoproteins assessed by ¹H-NMR in people living with HIV (PLWH). A total of 221 patients with HIV infection were recruited and studied at baseline and at 48 and 144 weeks. Patients were distributed into two groups according to baseline CD4⁺ T-cell number below or above 200 cells/µL. Patients with fewer than 200 cells/µL were distributed into the responders and nonresponders according to antiretroviral therapy (ART) response at 144 weeks. Glycoprotein concentrations were determined by ¹H-NMR arising from the protein bond N-acetylglucosamine and N-acetylgalactosamine signals (GlycA); and N-acetylneuraminic acid signal (GlycB) associated with the sugar–protein bond concentration and aggregation state (shapes (height/width)). Basal glycoprotein concentrations were higher in patients with < 200 CD4⁺ T-cell/μL (Glyc A: 1040(917.9–1199.1) vs. 950.4(845.5–1050.9), p < 0.001, and Glyc B: 521(440.3–610.3) vs. 468.6(417.9–507.0) μ mol/L, p < 0.001) being reduced by ART. The height/width (H/W) ratio was the parameter showing a better association with this clinical status. Baseline glycoproteins predict the condition of responder/nonresponder. In this study, ¹H-NMR glycoproteins provide novel insights to assess inflammation status and have prognostic value in PLWH.

Multivariate Computational Analysis of Gamma Delta T Cell Inhibitory Receptor Signatures Reveals the Divergence of Healthy and ART-Suppressed HIV+ Aging

Even with effective viral control, HIV-infected individuals are at a higher risk for morbidities associated with older age than the general population, and these serious non-AIDS events (SNAEs) track with plasma inflammatory and coagulation markers. The cell subsets driving inflammation in aviremic HIV infection are not yet elucidated. Also, whether ART-suppressed HIV infection causes premature induction of the inflammatory events found in uninfected elderly or if a novel inflammatory network ensues when HIV and older age co-exist is unclear. In this study we measured combinational expression of five inhibitory receptors (IRs) on seven immune cell subsets and 16 plasma markers from peripheral blood mononuclear cells (PBMC) and plasma samples, respectively, from a HIV and Aging cohort comprised of ART-suppressed HIV-infected and uninfected controls stratified by age (≤35 or ≥50 years old). For data analysis, multiple multivariate computational algorithms [cluster identification, characterization, and regression (CITRUS), partial least squares regression (PLSR), and partial least squares-discriminant analysis (PLS-DA)] were used to determine if immune parameter disparities can distinguish the subject groups and to investigate if there is a cross-impact of aviremic HIV and age on immune signatures. IR expression on gamma delta (γδ) T cells exclusively separated HIV+ subjects from controls in CITRUS analyses and secretion of inflammatory cytokines and cytotoxic mediators from γδ T cells tracked with TIGIT expression among HIV+ subjects. Also, plasma markers predicted the percentages of TIGIT+ γδ T cells in subjects with and without HIV in PSLR models, and a PLS-DA model of γδ T cell IR signatures and plasma markers significantly stratified all four of the subject groups (uninfected younger, uninfected older, HIV+ younger, and HIV+ older). These data implicate γδ T cells as an inflammatory driver in ART-suppressed HIV infection and provide evidence of distinct “inflamm-aging” processes with and without ART-suppressed HIV infection.

B-cell and T-cell activation in South African HIV-1-positive non-Hodgkin's lymphoma patients

Background

Altered immune mechanisms play a critical role in the pathogenesis of non-Hodgkin’s lymphoma (NHL). HIV-1 (HIV) infection is associated with a state of excessive T-cell activation, which can lead to increased T-cell turnover and lymph node fibrosis.

Objectives

This study aimed to determine the serum levels of circulating B-cell activation markers, and the expression of T-cell activation and regulatory markers in HIV-positive NHL patients.

Method

The serum levels of circulating soluble(s) sCD20, sCD23, sCD27, sCD30 and sCD44 molecules, all of which are biomarkers of B-cell activation, were determined by enzyme-linked immunosorbent assays (ELISA), while biomarkers of T-cell activation (CD8+CD38+) and regulation (FoxP3) were determined by flow cytometry in 141 subjects who were divided into five groups: Combination antiretroviral therapy (ART)-naïve HIV-positive patients; ART-treated HIV-positive patients; HIV-negative NHL patients; HIV-positive NHL patients on ART; and healthy controls.

Results

HIV-positive NHL patients had significantly higher serum levels of sCD20, sCD23, sCD30 and sCD44 than HIV-negative NHL patients, while all five biomarkers were significantly elevated in HIV-positive NHL patients when compared with ART-treated HIV-positive patients. HIV-positive NHL patients had higher CD8+CD38+ and lower FoxP3 expression than HIV-negative NHL and ART-treated HIV-positive patients.

Conclusion

B-cell activation is increased in HIV-positive NHL patients and is associated with reduced regulatory T-cell populations and increased CD8+ T-cell activation.

HIV persistence in mucosal CD4+ T cells within the lungs of adults receiving long-term suppressive antiretroviral therapy

Background:

The lungs were historically identified as one of the major anatomic sites for HIV replication in the pre-antiretroviral therapy (ART) era. However, their contribution to HIV persistence in individuals under suppressive ART remains understudied.

Design:

We assessed HIV persistence and comprehensively characterized pulmonary mucosal CD4⁺ T cells in HIV-infected (HIV⁺) individuals receiving long-term suppressive ART versus uninfected participants.

Methods:

Bronchoalveolar lavage (BAL), bronchial biopsies, and matched peripheral blood were obtained from n = 24 HIV-infected adults receiving long-term suppressive ART (median: 9 years) and n = 8 healthy volunteers without respiratory symptoms. HIV-DNA and cell-associated HIV-RNA were quantified by ultra-sensitive PCR, and lung mucosal CD4⁺ T-cell subsets were characterized by multiparameter flow cytometry.

Results:

The levels of HIV-DNA were 13-fold higher in total BAL cells compared to blood. Importantly, FACS-sorted CD4⁺ T cells from BAL contained greater levels of HIV-DNA compared to peripheral CD4⁺ T cells. BAL CD4⁺ T cells in HIV⁺ individuals were characterized mostly by an effector memory phenotype, whereas naive and terminally differentiated cells were underrepresented compared to blood. Furthermore, BAL CD4⁺ T cells expressed higher levels of immune activation (HLA-DR/CD38) and senescence (CD57) markers. Importantly, BAL was enriched in T-cell subsets proposed to be preferential cellular HIV reservoirs, including memory CD4⁺CCR6⁺, Th1Th17 (CD4⁺CCR6⁺CCR4⁻CXCR3⁺), CD4⁺CCR6⁺CXCR3⁻CCR4⁻, and CD4⁺CD32a⁺ T cells.

Conclusion:

The pulmonary mucosa represents an important immunological effector site highly enriched in activated and preferential CD4⁺ T-cell subsets for HIV persistence during long-term ART in individuals without respiratory symptoms. Our findings raise new challenges for the design of novel HIV eradication strategies in mucosal tissues.

Immune response to a Tdap booster in vertically HIV-infected adolescents

BACKGROUND

Pertussis cases have increased worldwide and knowledge on immune response and cytokine profile after Tdap vaccine in immunodeficient adolescents is scarce.

OBJECTIVE

To evaluate the immune response after Tdap in HIV-infected (HIV) and in healthy adolescents (CONTROL).

METHODOLOGY

Thirty HIV adolescents with CD4 cell counts >200 and 30 CONTROLs were immunized with Tdap, after a prior whole-cell DTP vaccine primary scheme. Blood samples were collected immediately before and after vaccine. Lymphocyte immunophenotyping was performed by flow cytometry; tetanus, diphtheria and pertussis toxin antibodies were assessed by ELISA; whole blood was stimulated with tetanus toxoid and Bordetella pertussis and supernatants were assessed for cytokines by xMAP.

RESULTS

Mean age of HIV and CONTROL groups were 17.9 e 17.1 years, respectively. Pain at injection site was more intense in CONTROL group. HIV group had similar increase in tetanus antibodies at 28 days (geometric mean concentration, GMC, 15.6; 95% CI, 7.52-32.4) than CONTROL group (GMC, 23.1; 95% CI, 15.0-35.5), but lower diphtheria antibodies at 28 days (GMC, 2.3; 95% CI, 0.88-6.19) than CONTROL group (GMC, 16.4; 95% CI, 10.3-26.2); for pertussis, the percentage of individuals who seroconverted was lower in HIV than CONTROL group (HIV, 62.1% versus CONTROL, 100%; p = .002). Both groups built a cellular immune response to tetanus, with a Th2 (IL-4, IL-5 and IL-13) and Th1 (IFN-γ) response, with lower cytokine levels in HIV than in CONTROL group. Especially for pertussis, cellular and humoral responses were less intense in HIV adolescents, with a lower Th1 and Th17 profile and higher IL-10 levels. HIV-infected adolescents on viral suppression showed an enhanced immune response to all the three vaccine antigens, although still at lower levels if compared to CONTROL group.

CONCLUSIONS

Both groups tolerated well and built an immune response after Tdap. However, HIV-infected adolescents would probably benefit from more frequent booster doses.

Factors Associated With Persistence of Plasma HIV-1 RNA During Long-term Continuously Suppressive Firstline Antiretroviral Therapy

Background

Persistence of plasma HIV-1 RNA during seemingly effective antiretroviral thereapy (ART) is incompletely understood. Using an ultrasensitive assay, this cross-sectional study investigated residual plasma HIV-1 RNA in subjects maintained on firstline ART with continuous viral load suppression <50 copies/mL for ≤15 years without recognized viral load blips or treatment interruptions and explored its relationship with the duration of suppressive ART, efavirenz concentrations in plasma, 2-LTR circular HIV-1 DNA (2-LTRc DNA) in peripheral blood mononuclear cells, and cellular (CD4 plus CD26/CD38/CD69; CD8 plus CD38/HLA-DR/DP/DQ) and soluble (sCD14, sCD27, sCD30, IL-6) markers of immune activation in peripheral blood.

Methods

Residual plasma HIV-1 RNA, total HIV-1 DNA and 2-LTRc DNA were quantified by real-time and digital droplet PCR. Cellular (CD4 plus CD26/CD38/CD69; CD8 plus CD38/HLA-DR/DP/DQ) and soluble (sCD14, sCD27, sCD30, IL-6) markers of immune activation were measured by flow cytometry and ELISA.

Results

Residual plasma HIV-1 RNA and 2-LTRc DNA were detected in 52/104 (50%) and 24/104 (23%) subjects, respectively. Among subjects with detectable HIV-1 RNA, 50/52 showed levels ≤11 copies/mL. In adjusted analyses, HIV-1 RNA levels were 0.37 log₁₀ copies/mL higher with each log₁₀ U/mL increase in sCD27 (95% confidence interval, 0.01-0.73; P = .02). No significant association was found between residual plasma HIV-1 RNA and other explored parameters.

Conclusions

These findings point to an ongoing relationship between plasma HIV-1 RNA and selected markers of immune activation during continuously suppressive ART. The novel direct association with levels of sCD27 warrants further investigation.

HIV as a Cause of Immune Activation and Immunosenescence

Systemic immune activation has emerged as an essential component of the immunopathogenesis of HIV. It not only leads to faster disease progression, but also to accelerated decline of overall immune competence. HIV-associated immune activation is characterized by an increase in proinflammatory mediators, dysfunctional T regulatory cells, and a pattern of T-cell-senescent phenotypes similar to those seen in the elderly. These changes predispose HIV-infected persons to comorbid conditions that have been linked to immunosenescence and inflamm-ageing, such as atherosclerosis and cardiovascular disease, neurodegeneration, and cancer. In the antiretroviral treatment era, development of such non-AIDS-defining, age-related comorbidities is a major cause of morbidity and mortality. Treatment strategies aimed at curtailing persistent immune activation and inflammation may help prevent the development of these conditions. At present, the most effective strategy appears to be early antiretroviral treatment initiation. No other treatment interventions have been found effective in large-scale clinical trials, and no adjunctive treatment is currently recommended in international HIV treatment guidelines. This article reviews the role of systemic immune activation in the immunopathogenesis of HIV infection, its causes and the clinical implications linked to immunosenescence in adults, and the therapeutic interventions that have been investigated.

Differential effects of antiretrovirals on microbial translocation and gut microbiota composition of HIV-infected patients

INTRODUCTION

Increased bacterial translocation and alterations to gut microbiota composition have been described in HIV infection and contribute to immune activation and inflammation. These effects persist despite combined antiretroviral therapy (cART). However, the contribution of different cART combinations has not yet been investigated. The aim of this study was to analyse the long-term effects of different combinations of cART on bacterial translocation and gut microbiota composition in HIV-infected patients.

METHODS

We carried out a cross-sectional study of 45 HIV-infected patients on cART, classified as nucleoside reverse transcriptase inhibitors (NRTIs)+ protease inhibitors (PIs) (n = 15), NRTIs+ non-nucleoside reverse transcriptase inhibitors (NNRTIs) (n = 22), and NRTIs+ integrase strand transfer inhibitors (INSTIs) (n = 8). Untreated HIV-infected patients (n = 5) and non-infected volunteers (n = 21) were also included. Soluble markers of bacterial translocation and inflammation were measured and gut microbiota composition was analysed using 16S rDNA pyrosequencing (Illumina MiSeq).

RESULTS

The NRTIs+INSTIs regimen was associated with levels of systemic inflammation that were similar to uninfected controls. The reduction in faecal bacterial diversity induced by HIV infection was also restored by this regimen. HIV infection was more closely related to changes in lower taxonomic units and diversity rather than at the phylum level. The NRTIs+PIs regimen showed the highest reduction in bacterial species, whereas NRTIs+INSTIs induced a minor loss of bacterial species and a significant increase in others.

CONCLUSION

Our study demonstrated that INSTI-based ART was associated with levels of systemic inflammation and microbial diversity similar to that of uninfected controls. The role of INSTIs other than raltegravir needs to be further investigated. Patients on the NRTIs+PIs regimen presented the highest reduction in bacterial species compared with other antiretrovirals and naive patients. Thus, different cART regimens are associated with diverse profiles in gut microbiota composition. Longitudinal and functional studies are needed to better understand these findings.

Mortal allies: human immunodeficiency virus and noncommunicable diseases

PURPOSE OF REVIEW

HIV-infected individuals have improved access to antiretroviral therapy. This has resulted in a shift in causes of mortality from infectious diseases to noncommunicable diseases including cardiovascular disease, chronic kidney disease (CKD) and malignancies. This review will look at the epidemiological shift, risk factors for the development of these diseases and examine some of the supporting laboratory diagnostic testing, which may be required.

RECENT FINDINGS

Risk factors for the development of these diseases in HIV-infected patients include underlying genetic predisposition, lifestyle risk factors, chronic inflammation as a consequence of HIV infection, the presence and persistence of opportunistic infections and in some cases, highly active antiretroviral therapy, itself. Morbidity and mortality from HIV-associated conditions are increasing in low-income and middle-income countries (LMICs) with increased prevalence of HIV-associated cancers, cardiovascular disease and CKD.

SUMMARY

Management of these conditions in LMICs requires an integrated pathology solution that will enable early screening, diagnosis and monitoring.

Predict disease progression from T-cell phenotypes in northern pig-tailed macaques (Macaca leonina) during SIVmac239 infection

Macaca leonina (northern pig-tailed macaques, NPMs) have variable disease progression during SIVmac239 infection. In the present study, we analysed, for the first time, the correlations between T-cell phenotypes and disease progression in NPMs during SIVmac239 infection. In comparison to normal progressors (NPs), slow progressors (SPs) had lower chronic T-cell activation and exhaustion levels. In addition, SPs showed higher peripheral CD4⁺ T-cell count and CD4 : CD8 ratio, and lower plasma viral load than NPs. CD4⁺ T-cell count and CD4 : CD8 ratio decreased more sharply in NPs than in SPs. Furthermore, T cells in NPs were more highly differentiated, at least in acute infection, than in SPs. These results indicated that T-cell phenotypes were correlated with disease progression in SIVmac239-infected NPMs and these correlations may provide valuable guidance for the improvement of therapeutic strategies tested in NPMs.

Longitudinal sequencing of HIV-1 infected patients with low-level viremia for years while on ART shows no indications for genetic evolution of the virus

HIV-infected patients on antiretroviral therapy (ART) may present low-level viremia (LLV) above the detection level of current viral load assays. In many cases LLV is persistent but does not result in overt treatment failure or selection of drug resistant viral variants. To elucidate whether LLV reflects active virus replication, we extensively sequenced pol and env genes of the viral populations present before and during LLV in 18 patients and searched for indications of genetic evolution. Maximum likelihood phylogenetic trees were inspected for temporal structure both visually and by linear regression analysis of root-to-tip and pairwise distances. Viral coreceptor tropism was assessed at different time points before and during LLV. In none of the patients consistent indications for genetic evolution were found over a median period of 4.8 years of LLV. As such these findings could not provide evidence that active virus replication is the main driver of LLV.

Cytomegalovirus and HIV: A Dangerous Pas de Deux

Human immunodeficiency virus (HIV)-infected adults who take stable antiretroviral therapy (ART) are at risk for early onset of age-related diseases. This is likely due to a complex interaction between traditional risk factors, HIV infection itself, and other factors, such as underlying immune dysfunction and persistent inflammation. HIV disrupts the balance between the host and coinfecting microbes, worsening control of these potential pathogens. For example, HIV-infected adults are more likely than the general population to have subclinical bursts of cytomegalovirus (CMV) replication at mucosal sites. Production of antigens can activate the immune system and stimulate HIV replication, and it could contribute to the pathogenesis of adverse outcomes of aging, like cardiovascular disease and neurocognitive impairment. Further investigation of the relationships between CMV, immune dysfunction, and unsuccessful aging during chronic HIV infection is warranted.

Immunologic Biomarkers, Morbidity, and Mortality in Treated HIV Infection

Despite marked improvements in the modern treatment era, human immunodeficiency virus (HIV)-infected individuals, particularly those who initiated antiretroviral therapy (ART) at advanced disease stages, continue to have increased age-related morbidity and mortality, compared with the general population. Immune activation and inflammation persist despite suppressive ART and predict many of these morbidities. The goal of this review is to examine the evidence suggesting a link between the persistent inflammatory state and morbidity and mortality in this setting, to describe the impact of early ART initiation on these factors, and to highlight important unanswered questions for the field. We also advance a hypothesis to explain why some morbidities-and their root inflammatory drivers-may be prevented more than others by early ART initiation.

Plasma IP-10 Concentrations Correlate Positively with Viraemia and Inversely with CD4 Counts in Untreated HIV Infection

Background:

Chronic immune activation is a feature of HIV infection associated with accelerated HIV disease progression. There is conflicting data on the association of biomarkers of immune activation with traditional markers of HIV disease progression; CD4 counts and viral load (VL).

Objective:

The study aimed to determine the association of biomarkers of immune activation; interferon (IFN)-γ-induced protein 10 (IP-10) and soluble cluster of differentiation 14 (sCD14) in chronic HIV infection with traditional markers of HIV disease progression.

Methods:

We collected demographic data, enumerated CD4 counts and quantified VL in 183 antiretroviral therapy (ART)-naive adults with chronic HIV infection. Plasma concentrations of IP-10 and sCD14 were quantified in the ART-naive adults with chronic HIV infection and 75 HIV-uninfected controls.

Results:

IP-10 concentrations were significantly higher in the HIV-infected group (median; 257.40pg/ml, IQR; 174.08-376.32) than in the HIV-uninfected (median; 86.19pg/ml, IQR; 67.70-116.39) (P<0.001). Similarly, sCD14 concentrations were significantly higher in the HIV-infected (median; 1.45µg/ml, IQR; 1.02-2.16) group than in the controls (median; 0.89µ/ml, IQR; 0.74-1.18) (P<0.001). High log₁₀ IP-10 concentrations were positively correlated with high log₁₀ viral loads (Spearman’s correlation coefficient [R]=0.21, P=0.003) and inversely correlated with low CD4 counts (R= -0.19, P=0.011). In contrast, log₁₀ sCD14 was not significantly associated with either log₁₀ viral loads (R=0.03, P=0.707) nor CD4 count (R=-0.04, P=0.568).

Conclusion:

We conclude that plasma sCD14 and IP-10 were elevated in the HIV-infected patients compared to HIV-uninfected individuals possibly due to on-going immune activation. In addition, plasma high concentrations of IP-10 but not sCD14 concentrations are associated with high VL and low CD4 count.

Bacteroides are associated with GALT iNKT cell function and reduction of microbial translocation in HIV-1 infection

Invariant natural killer T (iNKT) cells are innate-like T cells that respond to lipid antigens presented by CD1d. These immunoregulatory cells have the capacity for rapid cytokine release after antigen recognition and are essential for the activation of multiple arms of the immune response. HIV-1 infection is associated with iNKT cell depletion in the peripheral blood; however, their role in the gastrointestinal-associated lymphoid tissue (GALT) is less well studied. Our results show that iNKT cells are found at a higher frequency in GALT compared with blood, particularly in HIV-1 elite controllers. The capacity of iNKT cells to produce interleukin-4 (IL-4) and IL-10 in the GALT was associated with less immune activation and lower markers of microbial translocation, whereas regulatory T cell frequency showed positive associations with immune activation. We hypothesized that the composition of the microbiota would influence iNKT cell frequency and function. We found positive associations between the abundance of several Bacteroides species and iNKT cell frequency and their capacity to produce IL-4 in the GALT but not in the blood. Overall, our results are consistent with the hypothesis that GALT iNKT cells, influenced by certain bacterial species, may have a key role in regulating immune activation in HIV-1 infection.

Immune tolerance properties of the testicular tissue as a viral sanctuary site in ART-treated HIV-infected adults

OBJECTIVE

HIV persistence in long-lived infected cells and in anatomical sanctuary sites are major hurdles to HIV eradication. Testicular tissue may represent a significant viral sanctuary site as it constitutes an immunologically privileged compartment. We assessed immunotolerance properties of the testicular tissue in individuals receiving suppressive antiretroviral therapy (ART).

DESIGN AND METHODS

Testicular tissue and matched blood samples were collected from six virally suppressed adults and 10 HIV-uninfected controls prior to sex reassignment surgery. T cells were purified from freshly isolated testicular interstitial cell suspensions. T-cell subsets, expression of immune activation markers and HIV DNA were assessed in matched testicular cells and peripheral blood mononuclear cells (PBMCs).

RESULTS

When compared with PBMCs, testes were characterized by a lower CD4 T-cell proportion among total T cells, a decrease in the frequency of naive cells, an increase in the frequency of effector-memory T cells and an increase in CCR5 expression in both the HIV+ and HIV- groups. In HIV-infected individuals on ART, testes displayed higher T-cell immune activation (Coexpression of CD38 and Human Leukocyte Antigen - antigen D Related) than PBMCs. In both groups, testes were characterized by higher frequencies of immunosuppressive CD39 regulatory T cells and a massive increase in CD73 expression on CD8 T cells. In addition, a remarkable increase in indoleamine-pyrrole 2,3-dioxygenase immunosuppressive enzyme involved in tryptophan/kynurenine catabolism was observed in testes versus blood. Rare cells harboring HIV DNA were detected in testes from five out six participants.

CONCLUSION

These findings suggest that the adenosine and tryptophan/kynurenine immune-metabolic pathways contribute to immune tolerance in testicular tissue. Our results suggest that testes may represent a distinctive HIV sanctuary site during ART.

Rosuvastatin Is Effective to Decrease CD8 T-Cell Activation Only in HIV-Infected Patients With High Residual T-Cell Activation Under Antiretroviral Therapy

OBJECTIVE

The aim of the trial was to evaluate in patients under antiretroviral therapy (ART) the effect of rosuvastatin on cellular and soluble markers of immune activation/inflammation, as well as to identify patients who better benefit from statin administration.

METHODS

IMEA-043-CESAR was a phase II open-label pilot trial that enrolled patients under suppressive ART and CD4 <500/mm. Patients received rosuvastatin (20 mg/d) for 12 weeks. The primary outcome was the variation at week 12 (W12) in the proportion of CD38HLA-DRCD8 T lymphocytes. Secondary outcomes included evolution of other markers of T-cell activation and of inflammatory biomarkers between baseline, W12, and W24.

RESULTS

Fifty patients were enrolled; end points were available for 43 patients. When considering all patients, the proportion of CD38HLA-DRCD8 T cells did not significantly decline throughout the follow-up. However, the proportion of CD38CD8T cells significantly decreased at W12 [median percentage change of -22.2% (-32.3; +1.4)]. Principal component analysis allowed identification of 3 groups of patients based on their baseline activation/inflammation profiles, 1 group with elevated levels of CD8 T-cell activation, and a small group with high levels of systemic inflammation and low levels of T-cell activation. Half of the patients exhibited relatively low levels of inflammation and activation. The proportion of activated CD8 T cells significantly decreased only in the particular group of patients with high baseline CD8 T-cell activation.

CONCLUSIONS

This study shows that combining rosuvastatin with effective ART can result in a sustained decrease in CD8 T-cell activation and highlights the importance of identifying patients who can benefit from specific immunotherapeutic strategies.

Replication of Human Herpesviruses Is Associated with Higher HIV DNA Levels during Antiretroviral Therapy Started at Early Phases of HIV Infection

Asymptomatic replication of human herpesviruses (HHV) is frequent in HIV-infected men and is associated with increased T-cell activation and HIV disease progression. We hypothesized that the presence of replication of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) (the most frequently detected HHV) might influence HIV DNA decay during antiretroviral therapy (ART). We investigated 607 peripheral blood mononuclear cell (PBMC) samples from 107 CMV-seropositive, HIV-infected men who have sex with men, who started ART within a median of 3 months from their estimated date of infection (EDI) and were monitored for a median of 19 months thereafter. Levels of HIV, CMV, and EBV DNA and cellular HIV RNA were measured by droplet digital PCR (ddPCR) for each time point. Using a general linear mixed-effect regression model, we evaluated associations between the presence of detectable CMV DNA and EBV DNA levels and HIV DNA decay and cellular HIV RNA levels, while adjusting for peak HIV RNA, nadir CD4(+)count, CD4/CD8 ratio, CMV IgG levels, time from EDI to ART initiation, time from ART initiation to virologic suppression, detectable CMV DNA pre-ART, and age. The presence of intermittent CMV DNA in PBMC during ART was significantly associated with slower decay of HIV DNA (P= 0.011) but not with increased cellular HIV RNA transcription or more detectable 2-long terminal repeat circles. Higher levels of EBV DNA were also associated with higher levels of HIV DNA (P< 0.001) and increased unspliced cellular HIV RNA transcription (P= 0.010). These observations suggest that replication of HHV may help maintain a larger HIV DNA reservoir, but the underlying mechanisms remain unclear.

IMPORTANCE

Over three-fourths of HIV-infected men have at least one actively replicating human herpesvirus (HHV) in their mucosal secretions at any one time. Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are the most common, and although it is often asymptomatic, such CMV and EBV replication is associated with higher levels of immune activation and HIV disease progression. We hypothesized that HHV-associated activation of HIV-infected CD4(+)T cells might lead to increased HIV DNA. This study found that detectable CMV in blood cells of HIV-infected men was associated with slower decay of HIV DNA even during antiretroviral therapy (ART) that was started during early HIV infection. Similarly, levels of EBV DNA were associated with higher levels of HIV DNA during ART. If this observation points to a causal pathway, interventions that control CMV and EBV replication may be able to reduce the HIV reservoir, which might be relevant to current HIV cure efforts.

Barriers to a cure for HIV in women

Introduction

Distinct biological factors exist that affect the natural history of HIV and the host immune response between women and men. These differences must be addressed to permit the optimal design of effective HIV eradication strategies for much of the HIV-positive population.

Methods and results

Here, we review the literature on sex-based differences in HIV pathogenesis and natural history in tissues and anatomic compartments, HIV latency and transcriptional activity, and host immunity including the role of sex hormones. We then outline the potential effects of these differences on HIV persistence, and on the safety and efficacy of HIV eradication and curative interventions. Finally, we discuss the next steps necessary to elucidate these factors to achieve a cure for HIV, taking in account the complex ethical issues and the regulatory landscape in the hopes of stimulating further research and awareness in these areas.

Conclusions

Targeted enrolment of women in clinical trials and careful sex-based analysis will be crucial to gain further insights into sex-based differences in HIV persistence and to design sex-specific approaches to HIV eradication, if required.

Gut epithelial barrier dysfunction in human immunodeficiency virus-hepatitis C virus coinfected patients: Influence on innate and acquired immunity

Even in cases where viral replication has been controlled by antiretroviral therapy for long periods of time, human immunodeficiency virus (HIV)-infected patients have several non-acquired immunodeficiency syndrome (AIDS) related co-morbidities, including liver disease, cardiovascular disease and neurocognitive decline, which have a clear impact on survival. It has been considered that persistent innate and acquired immune activation contributes to the pathogenesis of these non-AIDS related diseases. Immune activation has been related with several conditions, remarkably with the bacterial translocation related with the intestinal barrier damage by the HIV or by hepatitis C virus (HCV)-related liver cirrhosis. Consequently, increased morbidity and mortality must be expected in HIV-HCV coinfected patients. Disrupted gut barrier lead to an increased passage of microbial products and to an activation of the mucosal immune system and secretion of inflammatory mediators, which in turn might increase barrier dysfunction. In the present review, the intestinal barrier structure, measures of intestinal barrier dysfunction and the modifications of them in HIV monoinfection and in HIV-HCV coinfection will be considered. Both pathogenesis and the consequences for the progression of liver disease secondary to gut microbial fragment leakage and immune activation will be assessed.

Naturally Occurring Subclinical Endotoxemia in Humans Alters Adaptive and Innate Immune Functions through Reduced MAPK and Increased STAT1 Phosphorylation

Multiple studies have shown correlates of immune activation with microbial translocation and plasma LPS during HIV infection. It is unclear whether this activation is due to LPS, residual viral replication, or both. Few studies have addressed the effects of persistent in vivo levels of LPS on specific immune functions in humans in the absence of chronic viral infection or pathological settings such as sepsis. We previously reported on a cohort of HIV-negative men with subclinical endotoxemia linked to alterations in CD4/CD8 T cell ratio and plasma cytokine levels. This HIV-negative cohort allowed us to assess cellular immune functions in the context of different subclinical plasma LPS levels ex vivo without confounding viral effects. By comparing two samples of differing plasma LPS levels from each individual, we now show that subclinical levels of plasma LPS in vivo significantly alter T cell proliferative capacity, monocyte cytokine release, and HLA-DR expression, and induce TLR cross-tolerance by decreased phosphorylation of MAPK pathway components. Using this human in vivo model of subclinical endotoxemia, we furthermore show that plasma LPS leads to constitutive activation of STAT1 through autocrine cytokine signaling, suggesting that subclinical endotoxemia in healthy individuals might lead to significant changes in immune function that have thus far not been appreciated.

Understanding HIV latency: the road to an HIV cure

Treatment with antiretroviral therapy dramatically increases the survival of HIV-infected individuals. However, treatment has to be continued for life because it does not lead to the full eradication of infection. HIV persists in resting CD4(+) T cells, and possibly other cell types, and can reemerge from these cells when therapy is interrupted. Here, we review molecular mechanisms that have been proposed to contribute to HIV latency, as well as the relative roles of cis- and trans-acting mechanisms. We also discuss existing and future therapeutic opportunities regarding HIV latency that might lead to a future cure for HIV infection.

Chloroquine and beyond: exploring anti-rheumatic drugs to reduce immune hyperactivation in HIV/AIDS

The restoration of the immune system prompted by antiretroviral therapy (ART) has allowed drastically reducing the mortality and morbidity of HIV infection. However, one main source of clinical concern is the persistence of immune hyperactivation in individuals under ART. Chronically enhanced levels of T-cell activation are associated with several deleterious effects which lead to faster disease progression and slower CD4⁺ T-cell recovery during ART. In this article, we discuss the rationale, and review the results, of the use of antimalarial quinolines, such as chloroquine and its derivative hydroxychloroquine, to counteract immune activation in HIV infection. Despite the promising results of several pilot trials, the most recent clinical data indicate that antimalarial quinolines are unlikely to exert a marked beneficial effect on immune activation. Alternative approaches will likely be required to reproducibly decrease immune activation in the setting of HIV infection. If the quinoline-based strategies should nevertheless be pursued in future studies, particular care must be devoted to the dosage selection, in order to maximize the chances to obtain effective in vivo drug concentrations.

Two-Year Follow-Up of Macaques Developing Intermittent Control of the Human Immunodeficiency Virus Homolog Simian Immunodeficiency Virus SIVmac251 in the Chronic Phase of Infection

Off-therapy control of viremia by HIV-infected individuals has been associated with two likely players: a restricted viral reservoir and an efficient cell-mediated immune response. We previously showed that a combination of highly suppressive antiretroviral therapy and two experimental drugs, i.e., auranofin and buthionine sulfoximine, was able to reduce the viral reservoir, elicit efficient cell-mediated antiviral responses, and induce intermittent posttherapy viral load control in chronically SIVmac251-infected macaques. We here show that the macaques that had received this drug combination and then stopped antiretroviral therapy were also able to maintain low numbers of activated CD4+ T cells at viral rebound. Moreover, these macaques consistently displayed low-level simian immunodeficiency virus (SIV) diversity, which was in line with the strong and broadly reactive cell-mediated immune responses against conserved Gag antigens. Extended follow-up showed that the two macaques that had received the complete drug combination remained healthy and did not develop AIDS in 2 years of follow-up after therapy suspension. This disease-free survival is longer than twice the average time of progression to AIDS in SIVmac251-infected rhesus macaques. These results suggest that limited numbers of activated T cells at viral rebound and subsequent development of broadly reactive cell-mediated responses may be interrelated in reducing the viral reservoir.

IMPORTANCE

The HIV reservoir in CD4+ T cells represents one main obstacle to HIV eradication. Recent studies, however, show that a drastic reduction of this reservoir is insufficient for inducing a functional cure of AIDS. In the present work, we thoroughly studied and subjected to long-term follow-up two macaques showing intermittent control of the virus following suspension of antiretroviral therapy plus an experimental antireservoir treatment, i.e., the gold salt auranofin and the investigational chemotherapeutic agent buthionione sulfoximine (BSO). We found that these drugs were able to decrease the number of activated CD4+ T cells, which are preferential targets for HIV infection. Then, efficient immune responses against the virus were developed in the macaques, which remained healthy during 2 years of follow-up. This result may furnish another building block for future attempts to cure HIV/AIDS.

Novel CD4-Based Bispecific Chimeric Antigen Receptor Designed for Enhanced Anti-HIV Potency and Absence of HIV Entry Receptor Activity

Adoptive transfer of CD8 T cells genetically engineered to express "chimeric antigen receptors" (CARs) represents a potential approach toward an HIV infection "functional cure" whereby durable virologic suppression is sustained after discontinuation of antiretroviral therapy. We describe a novel bispecific CAR in which a CD4 segment is linked to a single-chain variable fragment of the 17b human monoclonal antibody recognizing a highly conserved CD4-induced epitope on gp120 involved in coreceptor binding. We compared a standard CD4 CAR with CD4-17b CARs where the polypeptide linker between the CD4 and 17b moieties is sufficiently long (CD4-35-17b CAR) versus too short (CD4-10-17b) to permit simultaneous binding of the two moieties to a single gp120 subunit. When transduced into a peripheral blood mononuclear cell (PBMC) or T cells thereof, all three CD4-based CARs displayed specific functional activities against HIV-1 Env-expressing target cells, including stimulation of gamma interferon (IFN-γ) release, specific target cell killing, and suppression of HIV-1 pseudovirus production. In assays of spreading infection of PBMCs with genetically diverse HIV-1 primary isolates, the CD4-10-17b CAR displayed enhanced potency compared to the CD4 CAR whereas the CD4-35-17b CAR displayed diminished potency. Importantly, both CD4-17b CARs were devoid of a major undesired activity observed with the CD4 CAR, namely, rendering the transduced CD8(+) T cells susceptible to HIV-1 infection. Likely mechanisms for the superior potency of the CD4-10-17b CAR over the CD4-35-17b CAR include the greater potential of the former to engage in the serial antigen binding required for efficient T cell activation and the ability of two CD4-10-17b molecules to simultaneously bind a single gp120 subunit.

IMPORTANCE

HIV research has been energized by prospects for a cure for HIV infection or, at least, for a "functional cure" whereby antiretroviral therapy can be discontinued without virus rebound. This report describes a novel CD4-based "chimeric antigen receptor" (CAR) which, when genetically engineered into T cells, gives them the capability to selectively respond to and kill HIV-infected cells. This CAR displays enhanced features compared to previously described CD4-based CARs, namely, increased potency and avoidance of the undesired rendering of the genetically modified CD8 T cells susceptible to HIV infection. When adoptively transferred back to the individual, the genetically modified T cells will hopefully provide durable killing of infected cells and sustained virus suppression without continued antiretroviral therapy, i.e., a functional cure.

The Interplay Between Host Genetic Variation, Viral Replication, and Microbial Translocation in Untreated HIV-Infected Individuals

Systemic immune activation, a major determinant of human immunodeficiency virus (HIV) disease progression, is the result of a complex interplay between viral replication, dysregulation of the immune system, and microbial translocation due to gut mucosal damage. Although human genetic variants influencing HIV load have been identified, it is unknown how much the host genetic background contributes to interindividual differences in other determinants of HIV pathogenesis such as gut damage and microbial translocation. Using samples and data from 717 untreated participants in the Swiss HIV Cohort Study and a genome-wide association study design, we searched for human genetic determinants of plasma levels of intestinal fatty acid-binding protein (I-FABP/FABP2), a marker of gut damage, and of soluble CD14 (sCD14), a marker of lipopolysaccharide bioactivity and microbial translocation. We also assessed the correlations between HIV load, sCD14, and I-FABP. Although we found no genome-wide significant determinant of the tested plasma markers, we observed strong associations between sCD14 and both HIV load and I-FABP, shedding new light on the relationships between processes that drive progression of untreated HIV infection.

The effect of HAART-induced HIV suppression on circulating markers of inflammation and immune activation

OBJECTIVES

To investigate the impact of HAART-induced HIV suppression on levels of 24 serological biomarkers of inflammation and immune activation.

DESIGN

A prospective cohort study.

METHODS

Biomarkers were measured with multiplex assays in centralized laboratories using stored serum samples contributed by 1697 men during 8903 person-visits in the Multicenter AIDS Cohort Study (MACS) from 1984 to 2009. Using generalized gamma models, we compared biomarker values across three groups, adjusting for possible confounders: HIV-uninfected (NEG); HIV-positive, HAART-naive (NAI); and HAART-exposed with HIV RNA suppressed to less than 50 copies/ml plasma (SUP). We also estimated changes in biomarker levels associated with duration of HIV suppression, using splined generalized gamma regression with a knot at 1 year.

RESULTS

Most biomarkers were relatively normalized in the SUP group relative to the NAI group; however, 12 biomarkers in the SUP group were distinct (P < 0.002) from NEG values: CXCL10, C-reactive protein (CRP), sCD14, sTNFR2, tumour necrosis factor-alpha (TNF-α), sCD27, sGP130, interleukin (IL)-8, CCL13, BAFF, GM-CSF and IL-12p70. Thirteen biomarkers exhibited significant changes in the first year after viral suppression, but none changed significantly after that time.

CONCLUSION

Biomarkers of inflammation and immune activation moved towards HIV-negative levels within the first year after HAART-induced HIV suppression. Although several markers of T-cell activation returned to levels present in HIV-negative men, residual immune activation, particularly monocyte/macrophage activation, was present. This residual immune activation may represent a therapeutic target to improve the prognosis of HIV-infected individuals receiving HAART.