HIV Persistence in Gut-Associated Lymphoid Tissues: Pharmacological Challenges and Opportunities

Novel Immunological Markers of Intestinal Impairment Indicative of HIV-1 Status and/or Subclinical Atherosclerosis

Antiretroviral therapy (ART) controls HIV-1 replication in people with HIV-1 (PWH), but immunological restauration at mucosal barrier surfaces is not achieved. This fuels microbial translocation, chronic immune activation, and increased comorbidities, including cardiovascular disease (CVD). Here, we sought to identify novel markers of mucosal barrier impairment in the blood to predict the HIV and/or CVD status. Flow cytometry was used to characterize CD326/EpCAM + intestinal epithelial cells (IEC); CD4 + T-cells; CD8 + and CD4 + intraepithelial lymphocytes (IELs); and subsets of CD4 + T-cells expressing Th17 (CCR6) and gut-homing (Itgβ7) markers. To this aim, we collected peripheral blood mononuclear cells (PBMCs) from 42 ART-treated PWH (HIV + ) and 40 uninfected participants (HIV - ) from the Canadian HIV and Aging Cohort Study (CHACS). Both groups were categorized based on the presence of coronary atherosclerotic plaques measured by CT scan angiography as total plaque volume (TPV, mm 3 ). Our findings associate the HIV-1 status with increased frequencies of circulating CD326 + IEC; CD326 + CD4 + T-cells with activated (CD69 + HLA-DR + ) and gut-homing (ItgαE + CCR6 + CCR9 + ) phenotypes, CCR6 + Itgβ7 - CD4 + T-cells; and decreased frequencies of CD8 + IELs. Logistic regression analyses confirmed the predictive capacity of the above cellular markers regarding HIV status. Spearman correlation revealed a positive correlation between TPV and CCR6 + Itgβ7 - and CCR6 + Itgβ7 + CD4 + T-cell frequencies.Together, these results highlighted significant immune dysregulation and persistent mucosal barrier alterations despite effective viral suppression by ART and linked the abundance of CCR6 + Itgβ7 + and CCR6 + Itgβ7 - CD4 + T-cells to increased atherosclerotic plaque burden. Thus, strategies targeting the gut-immune axis restoration may reduce CVD onset and improve long-term health outcomes in PWH.

Plasma, intracellular and lymph node antiretroviral concentrations and HIV DNA change during primary HIV infection: Results from the INACTION P25 study

Despite its effectiveness, combination antiretroviral treatment (cART) has a limited effect on HIV DNA reservoir, which establishes early during primary HIV infection (PHI) and is maintained by latency, homeostatic T-cells proliferation, and residual replication. This limited effect can be associated with low drug exposure in lymphoid tissues and/or suboptimal adherence to antiretroviral drugs (ARVs). The aim of this study was to assess ARV concentrations in plasma, peripheral blood mononuclear cells (PBMCs) and lymph nodes (LNs), and their association to HIV RNA and HIV DNA decay during PHI. Participants were randomised to receive standard doses of darunavir/cobicistat (Arm I), dolutegravir (Arm II) or both (Arm III), with a backbone of tenofovir alafenamide and emtricitabine. Total HIV DNA was measured using digital-droplet PCR in PBMCs at baseline, 12 and 48 weeks. Drug concentrations in plasma and PBMCs were determined at 2, 12 and 48 weeks (LNs at 12 weeks) by UHPLC-MS/MS. Seventy-two participants were enrolled, mostly male (n=68), with a median age of 34 years and variable Fiebig stages (V-VI 57.7%, I-II 23.9%, and III-IV 18.3%). Twenty-six patients were assigned to Arm I, 27 to Arm II and 19 to Arm III. After 48 weeks, most patients had undetectable viremia, with minor differences in HIV RNA decay between arms. Patients with Fiebig I-II showed faster HIV RNA and HIV DNA decay. Intracellular tissue penetration was high for nucleoside analogues and low-moderate for darunavir and dolutegravir. Only tenofovir diphosphate concentrations in PBMCs showed correlation with HIV DNA decay. Overall, these results indicate that the timing of treatment initiation and intracellular tenofovir penetration are primary and secondary factors, respectively, affecting HIV reservoir.

Endogenous retroelement expression in the gut microenvironment of people living with HIV-1

BACKGROUND

Endogenous retroelements (EREs), including human endogenous retroviruses (HERVs) and long interspersed nuclear elements (LINEs), comprise almost half of the human genome. Our previous studies of the interferome in the gut suggest potential mechanisms regarding how IFNb may drive HIV-1 gut pathogenesis. As ERE activity is suggested to partake in type 1 immune responses and is incredibly sensitive to viral infections, we sought to elucidate underlying interactions between ERE expression and gut dynamics in people living with HIV-1 (PLWH).

METHODS

ERE expression profiles from bulk RNA sequencing of colon biopsies and PBMC were compared between a cohort of PLWH not on antiretroviral therapy (ART) and uninfected controls.

FINDINGS

59 EREs were differentially expressed in the colon of PLWH when compared to uninfected controls (padj <0.05 and FC ≤ -1 or ≥ 1) [Wald's Test]. Of these 59, 12 EREs were downregulated in PLWH and 47 were upregulated. Colon expression of the ERE loci LTR19_12p13.31 and L1FLnI_1q23.1s showed significant correlations with certain gut immune cell subset frequencies in the colon. Furthermore L1FLnI_1q23.1s showed a significant upregulation in peripheral blood mononuclear cells (PBMCs) of PLWH when compared to uninfected controls suggesting a common mechanism of differential ERE expression in the colon and PBMC.

INTERPRETATION

ERE activity has been largely understudied in genomic characterizations of human pathologies. We show that the activity of certain EREs in the colon of PLWH is deregulated, supporting our hypotheses that their underlying activity could function as (bio)markers and potential mediators of pathogenesis in HIV-1 reservoirs.

FUNDING

US NIH grants NCI CA260691 (DFN) and NIAID UM1AI164559 (DFN).

Targeted delivery methods for RNA interference are necessary to obtain a potential functional cure for HIV/AIDS

Ribonucleic acid (RNA) is of great interest in many different therapeutic areas including infectious diseases such as immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Thanks to current, advanced treatments for HIV, the diagnosis is no longer a death sentence. However, even with these treatments, latency is suggested to persist in T-lymphocyte-rich tissues including gut-associated lymphatic tissue (GALT), spleen, and bone marrow making HIV an incurable disease. Therefore, it is important to design systems that can effectively deliver therapeutics to these tissues to fight latent infection and find a functional cure. Numerous therapeutics ranging from small molecules to cell therapies have been explored as a cure for HIV but have failed to maintain therapeutic longevity. RNA interference (RNAi) provides a unique opportunity to achieve a functional cure for those who suffer from chronic HIV/AIDS by suppressing replication of the virus. However, RNA has certain imitations in delivery as it cannot be delivered without a carrier due to its negative charge and degradation from endogenous nucleases. Here, we provide a detailed analysis of explored systems for siRNA delivery for HIV/AIDS in the context of RNA therapeutic design and nanoparticle design. In addition, we suggest strategies that should be used to target specific tissues that are rich in lymphatic tissue.

Evaluation of Archival HIV DNA in Brain and Lymphoid Tissues

HIV reservoirs persist in anatomic compartments despite antiretroviral therapy (ART). Characterizing archival HIV DNA in the central nervous system (CNS) and other tissues is crucial to inform cure strategies. We evaluated paired autopsy brain-frontal cortex (FC), occipital cortex (OCC), and basal ganglia (BG)-and peripheral lymphoid tissues from 63 people with HIV. Participants passed away while virally suppressed on ART at the last visit and without evidence of CNS opportunistic disease. We quantified total HIV DNA in all participants and obtained full-length HIV-envelope (FL HIV-env) sequences from a subset of 14 participants. We detected HIV DNA (gag) in most brain (65.1%) and all lymphoid tissues. Lymphoid tissues had higher HIV DNA levels than the brain (P < 0.01). Levels of HIV gag between BG and FC were similar (P > 0.2), while OCC had the lowest levels (P = 0.01). Females had higher HIV DNA levels in tissues than males (gag, P = 0.03; 2-LTR, P = 0.05), suggesting possible sex-associated mechanisms for HIV reservoir persistence. Most FL HIV-env sequences (n = 143) were intact, while 42 were defective. Clonal sequences were found in 8 out of 14 participants, and 1 participant had clonal defective sequences in the brain and spleen, suggestive of cell migration. From 10 donors with paired brain and lymphoid sequences, we observed evidence of compartmentalized sequences in 2 donors. Our data further the idea that the brain is a site for archival HIV DNA during ART where compartmentalized provirus may occur in a subset of people. Future studies assessing FL HIV-provirus and replication competence are needed to further evaluate the HIV reservoirs in tissues. IMPORTANCE HIV infection of the brain is associated with adverse neuropsychiatric outcomes, despite efficient antiretroviral treatment. HIV may persist in reservoirs in the brain and other tissues, which can seed virus replication if treatment is interrupted, representing a major challenge to cure HIV. We evaluated reservoirs and genetic features in postmortem brain and lymphoid tissues from people with HIV who passed away during suppressed HIV replication. We found a differential distribution of HIV reservoirs across brain regions which was lower than that in lymphoid tissues. We observed that most HIV reservoirs in tissues had intact envelope sequences, suggesting they could potentially generate replicative viruses. We found that women had higher HIV reservoir levels in brain and lymphoid tissues than men, suggesting possible sex-based mechanisms of maintenance of HIV reservoirs in tissues, warranting further investigation. Characterizing the archival HIV DNA in tissues is important to inform future HIV cure strategies.

HIV Latency and Nanomedicine Strategies for Anti-HIV Treatment and Eradication

Antiretrovirals (ARVs) reduce Human Immunodeficiency Virus (HIV) loads to undetectable levels in infected patients. However, HIV can persist throughout the body in cellular reservoirs partly due to the inability of some ARVs to cross anatomical barriers and the capacity of HIV-1 to establish latent infection in resting CD4⁺ T cells and monocytes/macrophages. A cure for HIV is not likely unless latency is addressed and delivery of ARVs to cellular reservoir sites is improved. Nanomedicine has been used in ARV formulations to improve delivery and efficacy. More specifically, researchers are exploring the benefit of using nanoparticles to improve ARVs and nanomedicine in HIV eradication strategies such as shock and kill, block and lock, and others. This review will focus on mechanisms of HIV-1 latency and nanomedicine-based approaches to treat HIV.

Detection of human feces pecovirus in newly diagnosed HIV patients in Brazil

Circular single stranded DNA viruses (CRESS DNA) encoding a homologous replication-associated protein (REP) have been identified in most of eukaryotic groups. It is not clear yet the role in human diseases or details of the life cycle of these viruses. Recently, much interest has been raised in the evolutionary history of CRESS DNA owing to the increasing number of new sequences obtained by Next-Generation Sequencing (NGS) in distinct host species. In this study we describe two full-length CRESS DNA genomes obtained of two newly diagnosed HIV patients from São Paulo State, Brazil. The initial BLASTx search indicated that both sequences (named SP-FFB/2020 and SP-MJMS/2020) are highly similar (98%) to a previous CRESS DNA sequence detected in human fecal sample from Peru in 2016 and designated as pecovirus (Peruvian stool-associated circo-like virus). This study reported for the first time the Human feces pecovirus in the feces of two newly diagnosed HIV patients in Brazil. Our comparative analysis showed that although pecoviruses in South America share an identical genome structure they diverge and form distinct clades. Thus, we suggest the circulation of different species of pecoviruses in Latin America. Nevertheless, further studies must be done to examine the pathogenicity of this virus.

HIV Symptom Clusters are Similar Using the Dimensions of Symptom Occurrence and Distress

CONTEXT

People living with HIV infection (PLWH) in the United States continue to experience a high symptom burden despite improvements in antiretroviral therapy.

OBJECTIVES

The purpose of this study was to determine if the number and types of symptom clusters differed based on whether symptom occurrence rates or distress ratings were used to create the clusters.

METHODS

Data from 2,000 patients with complete symptom occurrence rates and distress scores on the 20-item HIV Symptom Index from their first ambulatory clinic visit at one of six national HIV centers of excellence in the Center for AIDS Research Network of Integrated Clinical Systems were used in these analyses. Exploratory factor analysis was used to create the symptom clusters.

RESULTS

The same four symptom clusters (i.e., gastrointestinal, psychological, pain, body image) were identified using occurrence rates and distress ratings. For both dimensions of the symptom experience, the psychological, pain, and body image clusters each had the same symptoms. For the gastrointestinal cluster, four symptoms loaded on the occurrence dimension and six symptoms loaded on the distress dimension.

CONCLUSION

The number and types of symptom clusters were relatively similar across the occurrence and distress dimensions of the symptom experience. Symptom clusters in PLWH may provide insights into the development of targeted interventions for multiple co-occurring symptoms.

Altered Expression of ACE2 and Co-receptors of SARS-CoV-2 in the Gut Mucosa of the SIV Model of HIV/AIDS

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the cause of the COVID-19 pandemic, is initiated by its binding to the ACE2 receptor and other co-receptors on mucosal epithelial cells. Variable outcomes of the infection and disease severity can be influenced by pre-existing risk factors. Human immunodeficiency virus (HIV), the cause of AIDS, targets the gut mucosal immune system and impairs epithelial barriers and mucosal immunity. We sought to determine the impact and mechanisms of pre-existing HIV infection increasing mucosal vulnerability to SARS-CoV-2 infection and disease. We investigated changes in the expression of ACE2 and other SARS-CoV-2 receptors and related pathways in virally inflamed gut by using the SIV infected rhesus macaque model of HIV/AIDS. Immunohistochemical analysis showed sustained/enhanced ACE2 expression in the gut epithelium of SIV infected animals compared to uninfected controls. Gut mucosal transcriptomic analysis demonstrated enhanced expression of host factors that support SARS-CoV-2 entry, replication, and infection. Metabolomic analysis of gut luminal contents revealed the impact of SIV infection as demonstrated by impaired mitochondrial function and decreased immune response, which render the host more vulnerable to other pathogens. In summary, SIV infection resulted in sustained or increased ACE2 expression in an inflamed and immune-impaired gut mucosal microenvironment. Collectively, these mucosal changes increase the susceptibility to SARS-CoV-2 infection and disease severity and result in ineffective viral clearance. Our study highlights the use of the SIV model of AIDS to fill the knowledge gap of the enteric mechanisms of co-infections as risk factors for poor disease outcomes, generation of new viral variants and immune escape in COVID-19.

Inversed Ratio of CD39/CD73 Expression on γδ T Cells in HIV Versus Healthy Controls Correlates With Immune Activation and Disease Progression

Background

γδ T cells are unconventional T cells that have been demonstrated to be crucial for the pathogenesis and potentially for the cure of HIV-1 infection. The ectonucleotidase CD39 is part of the purinergic pathway that regulates immune responses by degradation of pro-inflammatory ATP in concert with CD73. Few studies on the expression of the ectoenzymes CD73 and CD39 on human γδ T cells in HIV have been performed to date.

Methods

PBMC of n=86 HIV-1-infected patients were compared to PBMC of n=26 healthy individuals using 16-color flow cytometry determining the surface expression of CD39 and CD73 on Vδ1 and Vδ2 T cells in association with differentiation (CD45RA, CD28, CD27), activation and exhaustion (TIGIT, PD-1, CD38, and HLA-DR), and assessing the intracellular production of pro- and anti-inflammatory cytokines (IL-2, TGF-ß, TNF-α, Granzyme B, IL-10, IFN-γ) after in vitro stimulation with PMA/ionomycin.

Results

CD39 and CD73 expression on γδ T cells were inversed in HIV infection which correlated with HIV disease progression and immune activation. CD39, but not CD73 expression on γδ T cells of ART-treated patients returned to levels comparable with those of healthy individuals. Only a small subset (<1%) of γδ T cells co-expressed CD39 and CD73 in healthy or HIV-infected individuals. There were significantly more exhausted and terminally differentiated CD39+ Vδ1 T cells regardless of the disease status. Functionally, IL-10 was only detectable in CD39+ γδ T cells after in vitro stimulation in all groups studied. Viremic HIV-infected patients showed the highest levels of IL-10 production. The highest percentage of IL-10+ cells was found in the small CD39/CD73 co-expressing γδ T-cell population, both in healthy and HIV-infected individuals. Also, CD39+ Vδ2 T cells produced IL-10 more frequently than their CD39+ Vδ1 counterparts in all individuals regardless of the HIV status.

Conclusions

Our results point towards a potential immunomodulatory role of CD39+ and CD73+ γδ T cells in the pathogenesis of chronic HIV infection that needs further investigation.

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.

The Importance of Tissue Sanctuaries and Cellular Reservoirs of HIV-1

Purpose of Review - There have been significant developments in the treatment of people living with HIV-1/AIDS with current antiretroviral therapies; however, these developments have not been able to achieve a functional or sterilizing cure for HIV-1. While there are multiple barriers, one such barrier is the existence of pharmacological sanctuaries and viral reservoirs where the concentration of antiretrovirals is suboptimal, which includes the gut-associated lymphoid tissue, central nervous system, lymph nodes, and myeloid cells. This review will focus on illustrating the significance of these sanctuaries, specific barriers to optimal antiretroviral concentrations in each of these sites, and potential strategies to overcome these barriers. Recent Findings - Research and studies have shown that a uniform antiretroviral distribution is not achieved with current therapies. This may allow for low-level replication associated with low antiretroviral concentrations in these sanctuaries/reservoirs. Many methods are being investigated to increase antiretroviral concentrations in these sites, such as blocking transporting enzymes functions, modulating transporter expression and nanoformulations of current antiretrovirals. While these methods have been shown to increase antiretroviral concentrations in the sanctuaries/reservoirs, no functional or sterilizing cure has been achieved due to these approaches. Summary - New methods of increasing antiretroviral concentrations at the specific sites of HIV-1 replication has the potential to target cellular reservoirs. In order to optimize antiretroviral distribution into viral sanctuaries/reservoirs, additional research is needed.

A pigtailed macaque model of Kyasanur Forest disease virus and Alkhurma hemorrhagic disease virus pathogenesis

Kyasanur Forest disease virus (KFDV) and the closely related Alkhurma hemorrhagic disease virus (AHFV) are emerging flaviviruses that cause severe viral hemorrhagic fevers in humans. Increasing geographical expansion and case numbers, particularly of KFDV in southwest India, class these viruses as a public health threat. Viral pathogenesis is not well understood and additional vaccines and antivirals are needed to effectively counter the impact of these viruses. However, current animal models of KFDV pathogenesis do not accurately reproduce viral tissue tropism or clinical outcomes observed in humans. Here, we show that pigtailed macaques (Macaca nemestrina) infected with KFDV or AHFV develop viremia that peaks 2 to 4 days following inoculation. Over the course of infection, animals developed lymphocytopenia, thrombocytopenia, and elevated liver enzymes. Infected animals exhibited hallmark signs of human disease characterized by a flushed appearance, piloerection, dehydration, loss of appetite, weakness, and hemorrhagic signs including epistaxis. Virus was commonly present in the gastrointestinal tract, consistent with human disease caused by KFDV and AHFV where gastrointestinal symptoms (hemorrhage, vomiting, diarrhea) are common. Importantly, RNAseq of whole blood revealed that KFDV downregulated gene expression of key clotting factors that was not observed during AHFV infection, consistent with increased severity of KFDV disease observed in this model. This work characterizes a nonhuman primate model for KFDV and AHFV that closely resembles human disease for further utilization in understanding host immunity and development of antiviral countermeasures.

Human Immunodeficiency Virus Persistence in the Spleen: Opportunities for Pharmacologic Intervention

The persistence of HIV in the spleen, despite combination antiretroviral therapy, is not well understood. Sustained immune dysregulation and delayed immune recovery, in addition to immune cell exhaustion, may contribute to persistence of infection in the spleen. Eliminating HIV from this secondary lymphoid organ will require a thorough understanding of antiretroviral (ARV) pharmacology in the spleen, which has been minimally investigated. Low ARV exposure within the spleen may hinder the achievement of a functional or sterilizing cure if cells are not protected from HIV infection. In this study, we provide an overview of the anatomy and physiology of the spleen, review the evidence of the spleen as a site for persistence of HIV, discuss the consequences of persistence of HIV in the spleen, address challenges to eradicating HIV in the spleen, and examine opportunities for future curative efforts.

Markers of Gut Barrier Function and Microbial Translocation Associate with Lower Gut Microbial Diversity in People with HIV

People with human immunodeficiency virus (HIV) (PWH) have reduced gut barrier integrity ("leaky gut") that permits diffusion of microbial antigens (microbial translocation) such as lipopolysaccharide (LPS) into the circulation, stimulating inflammation. A potential source of this disturbance, in addition to gut lymphoid tissue CD4+ T-cell depletion, is the interaction between the gut barrier and gut microbes themselves. We evaluated the relationship of gut barrier integrity, as indexed by plasma occludin levels (higher levels corresponding to greater loss of occludin from the gut barrier), to gut microbial diversity. PWH and people without HIV (PWoH) participants were recruited from community sources and provided stool, and 16S rRNA amplicon sequencing was used to characterize the gut microbiome. Microbial diversity was indexed by Faith's phylogenetic diversity (PD). Participants were 50 PWH and 52 PWoH individuals, mean ± SD age 45.6 ± 14.5 years, 28 (27.5%) women, 50 (49.0%) non-white race/ethnicity. PWH had higher gut microbial diversity (Faith's PD 14.2 ± 4.06 versus 11.7 ± 3.27; p = 0.0007), but occludin levels were not different (1.84 ± 0.311 versus 1.85 ± 0.274; p = 0.843). Lower gut microbial diversity was associated with higher plasma occludin levels in PWH (r = -0.251; p = 0.0111), but not in PWoH. A multivariable model demonstrated an interaction (p = 0.0459) such that the correlation between Faith's PD and plasma occludin held only for PWH (r = -0.434; p = 0.0017), but not for PWoH individuals (r = -0.0227; p = 0.873). The pattern was similar for Shannon alpha diversity. Antiretroviral treatment and viral suppression status were not associated with gut microbial diversity (ps > 0.10). Plasma occludin levels were not significantly related to age, sex or ethnicity, nor to current or nadir CD4 or plasma viral load. Higher occludin levels were associated with higher plasma sCD14 and LPS, both markers of microbial translocation. Together, the findings suggest that damage to the gut epithelial barrier is an important mediator of microbial translocation and inflammation in PWH, and that reduced gut microbiome diversity may have an important role.

Gastrointestinal symptoms in HIV-positive kidney transplant candidates and recipients from an HIV-positive donor

Gastrointestinal symptoms (GIS) are common in kidney transplant candidates and recipients and may be worsened by HIV. Objective: To determine the frequency and severity of GIS in HIV-positive kidney transplant recipients from HIV-positive donors, and those waiting to receive one. A GIS rating scale (GSRS) was completed by 76 participants at baseline and at 6 months. GIS frequency was defined as having at least one symptom (GSRS > 1). Severity was indicated by the GSRS score. Transplant candidates: GIS frequency was 88.9% and 86.3% at baseline and 6 months respectively. Indigestion was the most frequent (79.6% and 66.7% at baseline and 6 months), and severe GIS (GSRS 2.3). Women reported global mean (p = 0.030) severity significantly more than men. Transplant recipients: GIS frequency was 95.2% and 76.2% at baseline and 6 months respectively. At both assessment points, indigestion occurred most frequently (85.7% and 61.9% respectively). Highest GSRS was reported for indigestion at baseline (2.33) and at 6 months (1.33). Waist circumference (WC) was positively associated with the severity of constipation GSRS. GIS are common in both groups, especially indigestions. WC in transplant recipients should be monitored.

Oral administration of tipranavir with long-chain triglyceride results in moderate intestinal lymph targeting but no efficient delivery to HIV-1 reservoir in mesenteric lymph nodes

The introduction of combination antiretroviral therapy (cART) led to substantial improvement in mortality and morbidity of HIV-1 infection. However, the poor penetration of antiretroviral agents to HIV-1 reservoirs limit the ability of the antiretroviral agents to eliminate the virus. Mesenteric lymph nodes (MLNs) are one of the main HIV-1 reservoirs in patients under suppressive cART. Intestinal lymphatic absorption pathway substantially increases the concentration of lipophilic drugs in mesenteric lymph and MLNs when they are co-administered with long-chain triglyceride (LCT). Chylomicrons (CM) play a crucial role in the intestinal lymphatic absorption as they transport drugs to the lymph lacteals rather than blood capillary by forming CM-drug complexes in the enterocytes. Thus, lipophilic antiretroviral drugs could potentially be delivered to HIV-1 reservoirs in MLNs by LCT-based formulation approach. In this study, protease inhibitors (PIs) were initially screened for their potential for intestinal lymphatic targeting using a computational model. The candidates were further assessed for their experimental affinity to CM. Tipranavir (TPV) was the only-candidate with substantial affinity to both artificial and natural CM in vitro and ex vivo. Pharmacokinetics and biodistribution studies were then performed to evaluate the oral bioavailability and intestinal lymphatic targeting of TPV in rats. The results showed similar oral bioavailability of TPV with and without co-administration of LCT vehicle. Although LCT-based formulation led to 3-fold higher concentrations of TPV in mesenteric lymph compared to plasma, the levels of the drug in MLNs were similar to plasma in both LCT-based and lipid-free formulation groups. Thus, LCT-based formulation approach alone was not sufficient for effective delivery of TPV to MLNs. Future efforts should be directed to a combined highly lipophilic prodrugs/lipid-based formulation approach to target TPV, other PIs and potentially other classes of antiretroviral agents to viral reservoirs within the mesenteric lymphatic system.

Autoantibodies Among HIV-1 Infected Individuals and the Effect of Anti-Retroviral Therapy (ART) on It

BACKGROUND

Antiretroviral therapy (ART) has led to a decline in autoimmune diseases but lacks studies on its effect on autoantibodies.

METHODS

It is a cross-sectional study with archived samples from 100 paired HIV-1 infected ART naïve and experienced individuals and 100 prospectively collected matched blood-donor controls. Antinuclear antibody, IgG anticardiolipin antibody, IgM and IgG β2 glycoprotein-1 antibodies, and total IgG levels were detected. Results are expressed as mean with standard deviation (SD), median, percentage positivity, and a p<0.05 is considered significant. The study was approved by the Institutional Review Board.

RESULTS

The median viral load of the treatment naïve samples was 4.34 Log copies/mL, while all were virally suppressed post ART with a median duration of treatment for 12 months (range: 3-36 months). The percentage of antinuclear antibody positivity was 5% among ART naïve and controls, with a decrease of 2% post ART (p= 0.441). The positivity for anti-cardiolipin antibody was 15% among ART naïve while none of the ART experienced or controls were positive (p<0.05). IgM β2 glycoprotein-1 were 4%, 1% and 3% among ART naïve, treated and controls, respectively (p<0.05). IgG β2 glycoprotein-1 was 2% among ART naïve while none of the treated and controls were positive (p<0.05). The mean total IgG level among ART naïve, experienced, and controls were 21.82 (SD 6.67), 16.91 (SD 3.38), 13.70 (SD 2.24) grams/Litre, respectively (p<0.05).

CONCLUSION

ART has a significant effect on IgG anti-cardiolipin antibody and total IgG but only a marginal effect on ANA, IgM, and IgG β2 glycoprotein-1 antibodies.

Cannabis and the Gut-Brain Axis Communication in HIV Infection

People living with HIV infection (PWH) disclose that cannabis is an effective strategy for alleviating symptoms associated with HIV disease. However, some medical providers feel ill-informed to engage in evidence-based conversations. HIV leads to alterations in the gut microbiome, gut-brain axis signaling, and chronic inflammation. The endocannabinoid system regulates homeostasis of multiple organ systems. When deficient, dysregulation of the gut-brain axis can result in chronic inflammation and neuroinflammation. Cannabis along with the naturally occurring endocannabinoids has antioxidant and anti-inflammatory properties that can support healing and restoration as an adjunctive therapy. The purpose of this literature review is to report the physiologic mechanisms that occur in the pathology of HIV and discuss potential benefits of cannabinoids in supporting health and reducing the negative effects of comorbidities in PWH.

Phylogenetic analysis of HIV-1 archived DNA in blood and gut-associated lymphoid tissue in two patients under antiretroviral therapy

One of the approaches to cure human immunodeficiency virus (HIV) is the use of therapeutic vaccination. We have launched the Provir/Latitude 45 study to identify conserved CTL epitopes in archived HIV-1 DNA according to the HLA class I alleles in aviremic patients under antiretroviral therapy (ART). A HIV-1 polypeptidic therapeutic vaccine based on viral sequence data obtained from circulating blood was proposed; here, our aim was to compare the proviral DNA in blood and gut-associated lymphoid tissue (GALT). Peripheral blood mononuclear cells and gut biopsies were obtained from two HIV-1 infected patients under successful antiretroviral therapy. Total DNA was extracted including the proviral DNA. The HIV-1 reverse transcriptase was sequenced in both compartments using next generation sequencing followed by single genome sequencing; phylogenetic trees were established and compared. The proviral sequences of both compartments intra-patient exhibited a very low genetic divergence while it was possible to differentiate the sequences inter-patients; single genome sequencing analysis of two couples of samples confirmed that there was no compartmentalization of the sequences intra-patient. We conclude that, considering these two cases, the proviral DNA sequences in blood and GALT are similar and that the epitope analysis of HIV-1 provirus in blood should be considered as relevant to that observed in the GALT, a hard-to-reach major compartment, and can therefore be used for therapeutic vaccine approaches.

Genital Shedding of Human Immunodeficiency Virus Type-1 (HIV) When Antiretroviral Therapy Suppresses HIV Replication in the Plasma

BACKGROUND

During antiretroviral treatment (ART) with plasma HIV RNA below the limit of quantification, HIV RNA can be detected in genital or rectal secretions, termed discordant shedding (DS). We hypothesized that proliferating cells produce virions without HIV replication.

METHODS

ART-naive Peruvians initiating ART were observed for DS over 2 years. HIV env and pol genomes were amplified from DS. Antiretrovirals and cytokines/chemokines concentrations were compared at DS and control time points.

RESULTS

Eighty-two participants had ART suppression. DS was detected in 24/82 (29%) participants: 13/253 (5%) cervicovaginal lavages, 20/322 (6%) seminal plasmas, and 6/85 (7%) rectal secretions. HIV RNA in DS specimens was near the limit of quantification and not reproducible. HIV DNA was detected in 6/13 (46%) DS cervicovaginal lavages at low levels. Following DNase treatment, 5/39 DS specimens yielded HIV sequences, all without increased genetic distances. Women with and without DS had similar plasma antiretroviral levels and DS in 1 woman was associated with inflammation.

CONCLUSIONS

HIV RNA and DNA sequences and therapeutic antiretroviral plasma levels did not support HIV replication as the cause of DS from the genital tract. Rather, our findings infer that HIV RNA is shed due to proliferation of infected cells with virion production.

Heterogeneous antiretroviral drug distribution and HIV/SHIV detection in the gut of three species

HIV replication within tissues may increase in response to a reduced exposure to antiretroviral drugs. Traditional approaches to measuring drug concentrations in tissues are unable to characterize a heterogeneous drug distribution. Here, we used mass spectrometry imaging (MSI) to visualize the distribution of six HIV antiretroviral drugs in gut tissue sections from three species (two strains of humanized mice, macaques, and humans). We measured drug concentrations in proximity to CD3+ T cells that are targeted by HIV, as well as expression of HIV or SHIV RNA and expression of the MDR1 drug efflux transporter in gut tissue from HIV-infected humanized mice, SHIV-infected macaques, and HIV-infected humans treated with combination antiretroviral drug therapy. Serial 10-μm sections of snap-frozen ileal and rectal tissue were analyzed by MSI for CD3+ T cells and MDR1 efflux transporter expression by immunofluorescence and immunohistochemistry, respectively. The tissue slices were analyzed for HIV/SHIV RNA expression by in situ hybridization and for antiretroviral drug concentrations by liquid chromatography-mass spectrometry. The gastrointestinal tissue distribution of the six drugs was heterogeneous. Fifty percent to 60% of CD3+ T cells did not colocalize with detectable drug concentrations in the gut tissue. In all three species, up to 90% of HIV/SHIV RNA was found to be expressed in gut tissue with no exposure to drug. These data suggest that there may be gut regions with little to no exposure to antiretroviral drugs, which may result in low-level HIV replication contributing to HIV persistence.

Innovative Study Designs Optimizing Clinical Pharmacology Research in Infants and Children

Almost half of recent pediatric trials failed to achieve labeling indications, in large part because of inadequate study design. Therefore, innovative study methods are crucial to optimizing trial design while also reducing the potential harms inherent with drug investigation. Several methods exist to optimize the amount of pharmacokinetic data collected from the smallest possible volume and with the fewest number of procedures, including the use of opportunistic and sparse sampling, alternative and noninvasive matrices, and microvolume assays. In addition, large research networks using master protocols promote collaboration, reduce regulatory burden, and increase trial efficiency for both early- and late-phase trials. Large pragmatic trials that leverage electronic health records can capitalize on central management strategies to reduce costs, enroll patients with rare diseases on a large scale, and augment study generalizability. Further, trial efficiency and safety can be optimized through Bayesian adaptive techniques that permit planned protocol changes based on analyses of prior and accumulated data. In addition to these trial design features, advances in modeling and simulation have paved the way for systems-based and physiologically based models that individualize pediatric dosing recommendations and support drug approval. Last, given the low prevalence of many pediatric diseases, collecting deidentified genetic and clinical data on a large scale is a potentially transformative way to augment clinical pharmacology research in children.

Highlights from the 8th International Workshop on HIV Persistence during Therapy, 12-15 December 2017, Miami, FL, USA

Over 4 days, more than 500 scientists involved in HIV persistence research shared their new unpublished data and designed future perspectives towards ART-free HIV remission. This 8th International Workshop on HIV Persistence followed the format of past conferences but further focused on encouraging participation of young investigators, especially through submission of oral and poster presentations. The topic of the workshop was HIV persistence. Consequently, issues of HIV reservoirs and HIV cure were also addressed. In this article, we report the discussions as closely as possible; however, all the workshop abstracts can be found online at www.viruseradication.com.

Increased T cell trafficking as adjunct therapy for HIV-1

Although antiretroviral drug therapy suppresses human immunodeficiency virus-type 1 (HIV-1) to undetectable levels in the blood of treated individuals, reservoirs of replication competent HIV-1 endure. Upon cessation of antiretroviral therapy, the reservoir usually allows outgrowth of virus and approaches to targeting the reservoir have had limited success. Ongoing cycles of viral replication in regions with low drug penetration contribute to this persistence. Here, we use a mathematical model to illustrate a new approach to eliminating the part of the reservoir attributable to persistent replication in drug sanctuaries. Reducing the residency time of CD4 T cells in drug sanctuaries renders ongoing replication unsustainable in those sanctuaries. We hypothesize that, in combination with antiretroviral drugs, a strategy to orchestrate CD4 T cell trafficking could contribute to a functional cure for HIV-1 infection.

Virological and immunological responses to raltegravir and dolutegravir in the gut-associated lymphoid tissue of HIV-infected men and women

BACKGROUND

Raltegravir (RTG) and dolutegravir (DTG) have different pharmacokinetic patterns in the gastrointestinal tract. To determine if this results in pharmacodynamic differences, we compared HIV RNA, HIV DNA and immunological markers in gut-associated lymphoid tissue (GALT) of HIV-infected participants receiving RTG or DTG with tenofovir+emtricitabine (TDF/FTC).

METHODS

GALT specimens from the terminal ileum, splenic flexure and rectum were obtained by colonoscopy at a single time point in 20 adults treated with RTG (n=10) or DTG (n=10) with HIV RNA <50 copies/ml. Flow cytometry, drug concentrations, and HIV RNA and DNA were analysed in tissue. CD4/8+ T-cells were tested for γδ TCR, and markers of T-cell activation and exhaustion. Data are reported as median (Q1-Q3).

RESULTS

A total of 15 men and 5 women were enrolled. There was no difference in time since HIV diagnosis for those on RTG (9.5 [4-22] years) and DTG (17 [1-24] years; P=0.6), although time on RTG (5.4 [2.3-6.7] years) was greater than DTG (1.0 [0.1-1.5] years; P<0.001). Concentrations of RTG and DTG in rectal tissue were similar to previous reports: median tissue:plasma ratio was 11.25 for RTG and 0.44 for DTG. RNA:DNA ratios were 1.14 (0.18-5.10) for the RTG group and 0.90 (0.30-18.87) for the DTG group (P=0.95). No differences (P≥0.1) between CD4+ and CD8+ T-cell markers were found.

CONCLUSIONS

RTG produced higher tissue exposures than DTG, but no significant differences in GALT HIV RNA, DNA or most immunological markers were observed. ClinicalTrials.gov NCT02218320.