The effects of cocaine on HIV transcription

Astrocytic HIV-1 Nef Expression Decreases Glutamate Transporter Expression in the Nucleus Accumbens and Increases Cocaine-Seeking Behavior in Rats

BACKGROUND/OBJECTIVES

Cocaine use disorder is an intersecting issue in populations with HIV-1, further exacerbating the clinical course of the disease and contributing to neurotoxicity and neuroinflammation. Cocaine and HIV neurotoxins play roles in neuronal damage during neuroHIV progression by disrupting glutamate homeostasis in the brain. Even with combined antiretroviral therapy (cART), HIV-1 Nef, an early viral protein expressed in approximately 1% of infected astrocytes, remains a key neurotoxin. This study investigates the relationship among Nef, glutamate homeostasis, and cocaine in the nucleus accumbens (NAc), a critical brain region associated with drug motivation and reward.

METHODS

Male and female Sprague Dawley rats were used to compare the effects of astrocytic Nef and cocaine by molecular analysis of glutamate transporters, GLT-1 and the cysteine glutamate exchanger (xCT), in the NAc. Behavioral assessments for cocaine self-administration were used to evaluate cocaine-seeking behavior.

RESULTS

The findings indicate that both cocaine and Nef independently decrease the expression of the glutamate transporter GLT-1 in the NAc. Additionally, rats with astrocytic Nef expression exhibited increased cocaine-seeking behavior but demonstrated sex-dependent molecular differences after the behavioral paradigm.

CONCLUSIONS

The results suggest that the expression of Nef intensifies cocaine-induced alterations in glutamate homeostasis in the NAc, potentially underlying increased cocaine-seeking behavior. Understanding these interactions better may inform therapeutic strategies for managing cocaine use disorder in HIV-infected individuals.

Cocaine-Induced DNA-Dependent Protein Kinase Relieves RNAP II Pausing by Promoting TRIM28 Phosphorylation and RNAP II Hyperphosphorylation to Enhance HIV Transcription

Drug abuse continues to pose a significant challenge in HIV control efforts. In our investigation, we discovered that cocaine not only upregulates the expression of the DNA-dependent protein kinase (DNA-PK) but also augments DNA-PK activation by enhancing its phosphorylation at S2056. Moreover, DNA-PK phosphorylation triggers the higher localization of the DNA-PK into the nucleus. The finding that cocaine increases the nuclear localization of the DNA-PK provides further support to our observation of enhanced DNA-PK recruitment at the HIV long terminal repeat (LTR) following cocaine exposure. By activating and facilitating the nuclear localization of the DNA-PK, cocaine effectively orchestrates multiple stages of HIV transcription, thereby promoting HIV replication. Additionally, our study demonstrates that the cocaine-induced DNA-PK promotes the hyper-phosphorylation of the RNA polymerase II (RNAP II) carboxyl-terminal domain (CTD) at Ser5 and Ser2 sites, enhancing both the initiation and elongation phases, respectively, of HIV transcription. The cocaine-mediated enhancement of transcriptional initiation is supported by its activation of cyclin-dependent kinase 7 (CDK7). Additionally, the induction of transcriptional elongation is marked by higher LTR recruitment and the increased phosphorylation of CDK9, which indicates the stimulation of positive transcriptional elongation factor b (P-TEFb). We demonstrate for the first time that cocaine, through DNA-PK activation, promotes the specific phosphorylation of TRIM28 at serine 824 (p-TRIM28, S824). This modification converts TRIM28 from a transcriptional inhibitor to a transactivator for HIV transcription. Additionally, we observed that the phosphorylation of TRIM28 (p-TRIM28, S824) promotes the transition from the pausing phase to the elongation phase of HIV transcription, thereby facilitating the production of full-length HIV genomic transcripts. This finding corroborates the previously observed enhanced RNAP II CTD phosphorylation at Ser2, a marker of transcriptional elongation, following cocaine exposure. Accordingly, upon cocaine treatment, we observed the elevated recruitment of p-TRIM28-(S824) at the HIV LTR. Overall, our results unravel the intricate molecular mechanisms underlying cocaine-induced HIV transcription and gene expression. These findings hold promise for the development of highly targeted therapeutics aimed at mitigating the detrimental effects of cocaine in individuals living with HIV.

Astrocytic HIV-1 Nef expression decreases glutamate transporter expression in the nucleus accumbens and increases cocaine-seeking behavior in rats

Cocaine use disorder is an intersecting issue in populations with HIV-1, further exacerbating the clinical course of the disease, contributing to neurotoxicity and neuroinflammation. Cocaine and HIV neurotoxins play roles in neuronal damage during neuroHIV progression by disrupting glutamate homeostasis in the brain. Even with cART, HIV-1 Nef, an early viral protein expressed in approximately 1% of infected astrocytes, remains a key neurotoxin. This study investigates the relationship that exists between Nef, glutamate homeostasis, and cocaine in the NAc, a critical brain region associated with drug motivation and reward. Using a rat model, we compared the effects of astrocytic Nef and cocaine by molecular analysis of glutamate transporters in the NAc. We further conducted behavioral assessments for cocaine self-administration to evaluate cocaine-seeking behavior. Our findings indicate that both cocaine and Nef independently decrease the expression of the glutamate transporter GLT-1 in the NAc. Additionally, rats with astrocytic Nef expression exhibited increased cocaine-seeking behavior but demonstrated sex dependent molecular differences after behavioral paradigm. In conclusion, our results suggest the expression of Nef intensifies cocaine-induced alterations in glutamate homeostasis in the NAc, potentially underlying increased cocaine-seeking. Understanding these interactions better may inform therapeutic strategies for managing cocaine use disorder in HIV-infected individuals.

Cocaine-induced DNA-PK relieves RNAP II pausing by promoting TRIM28 phosphorylation

Drug abuse continues to pose a significant challenge in HIV control efforts. In our investigation, we discovered that cocaine not only upregulates the expression of DNA-dependent protein kinase (DNA-PK) but also augments DNA-PK activation by enhancing its phosphorylation at S2056. Moreover, DNA-PK phosphorylation triggers the translocation of DNA-PK into the nucleus. The finding that cocaine promotes nuclear translocation of DNA-PK further validates our observation of enhanced DNA-PK recruitment at the HIV long terminal repeat (LTR) following cocaine exposure. By activating and facilitating the nuclear translocation of DNA-PK, cocaine effectively orchestrates multiple stages of HIV transcription, thereby promoting HIV replication. Additionally, our study indicates that cocaine-induced DNA-PK promotes hyper-phosphorylation of RNA polymerase II (RNAP II) carboxyl-terminal domain (CTD) at Ser5 and Ser2 sites, enhancing both initiation and elongation phases, respectively, of HIV transcription. Cocaine's enhancement of transcription initiation and elongation is further supported by its activation of cyclin-dependent kinase 7 (CDK7) and subsequent phosphorylation of CDK9, thereby promoting positive transcriptional elongation factor b (P-TEFb) activity. We demonstrate for the first time that cocaine, through DNA-PK activation, promotes the specific phosphorylation of TRIM28 at Serine 824 (p-TRIM28, S824). This modification converts TRIM28 from a transcriptional inhibitor to a transactivator for HIV transcription. Additionally, we observe that phosphorylation of TRIM28 (p-TRIM28, S824) promotes the transition from the pausing phase to the elongation phase of HIV transcription, thereby facilitating the production of full-length HIV genomic transcripts. This finding corroborates the observed enhanced RNAP II CTD phosphorylation at Ser2, a marker of transcriptional elongation, following cocaine exposure. Accordingly, upon cocaine treatment, we observed elevated recruitment of p-TRIM28-(S824) at the HIV LTR. Overall, our results have unraveled the intricate molecular mechanisms underlying cocaine-induced HIV transcription and gene expression. These findings hold promise for the development of highly targeted therapeutics aimed at mitigating the detrimental effects of cocaine in individuals living with HIV.

The Impact of Drugs and Substance Abuse on Viral Pathogenesis-A South African Perspective

Illicit drug and alcohol abuse have significant negative consequences for individuals who inject drugs/use drugs (PWID/UDs), including decreased immune system function and increased viral pathogenesis. PWID/UDs are at high risk of contracting or transmitting viral illnesses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). In South Africa, a dangerous drug-taking method known as "Bluetoothing" has emerged among nyaope users, whereby the users of this drug, after injecting, withdraw blood from their veins and then reinject it into another user. Hence, the transmission of blood-borne viruses (BBVs) is exacerbated by this "Bluetooth" practice among nyaope users. Moreover, several substances of abuse promote HIV, HBV, and HCV replication. With a specific focus on the nyaope drug, viral replication, and transmission, we address the important influence of abused addictive substances and polysubstance use in this review.

EcoHIV Infection Modulates the Effects of Cocaine Exposure Pattern and Abstinence on Cocaine Seeking and Neuroimmune Protein Expression in Male Mice

Cocaine use disorders (CUDs) and human immunodeficiency virus (HIV) remain persistent public health dilemmas throughout the world. One major hurdle for treating CUD is the increase in cocaine craving and seeking behavior that occurs over a protracted period of abstinence, an effect known as the incubation of craving. Little is known about how HIV may modulate this process. Thus, we sought to examine the impact of chronic HIV infection on the incubation of cocaine craving and associated changes in the central and peripheral immune systems. Here, mice were inoculated with EcoHIV, which is a chimeric HIV-1 construct that produces chronic HIV infection in mice. EcoHIV- and sham-infected mice were conditioned with cocaine daily or intermittently in a conditioned place preference (CPP) paradigm, followed by 1 or 21 days of forced abstinence prior to assessing preference for the cocaine-paired chamber. Under both conditioning regimens, sham mice exhibited incubation of cocaine CPP after 21 days of abstinence. EcoHIV-infected mice conditioned daily with cocaine showed enhanced cocaine seeking at both abstinence timepoints, whereas infected mice conditioned intermittently showed a reversal of the incubation effect, with higher cocaine seeking after 1 day of abstinence compared to 21 days. Analysis of corticolimbic CX3CL1-CX3CR1 and glutamate receptor expression revealed alterations in medial prefrontal cortex (mPFC) CX3CL1 and nucleus accumbens (NAc) GluN2A receptors that correlated with cocaine seeking following daily cocaine exposure. Moreover, examination of peripheral immune markers showed that the effect of abstinence and EcoHIV infection on these measures depended on the cocaine exposure regimen. Altogether, these results highlight the importance of cocaine abstinence and exposure pattern as critical variables that modulate HIV-associated neuroimmune outcomes and relapse vulnerability.

The Synthetic Opioid Fentanyl Increases HIV Replication and Chemokine Co-Receptor Expression in Lymphocyte Cell Lines

BACKGROUND

In the United States, the illicit use of synthetic opioids such as fentanyl has led to a serious public health crisis. Synthetic opioids are known to enhance viral replication and to suppress immunologic responses, but their effects on HIV pathogenesis remain unclear. Thus, we examined the impact of fentanyl on HIV-susceptible and HIV-infected cell types.

METHODS

TZM-bl and HIV-infected lymphocyte cells were incubated with fentanyl at varying concentrations. Expression levels of the CXCR4 and CCR5 chemokine receptors and HIV p24 antigen were quantified with ELISA. HIV proviral DNA was quantified using SYBR RT-PCR. Cell viability was detected with the MTT assay. RNAseq was performed to characterize cellular gene regulation in the presence of fentanyl.

RESULTS

Fentanyl enhanced expression of both chemokine receptor levels in a dose-dependent manner in HIV-susceptible and infected cell lines. Similarly, fentanyl induced viral expression in HIV-exposed TZM-bl cells and in HIV-infected lymphocyte cell lines. Multiple genes associated with apoptosis, antiviral/interferon response, chemokine signaling, and NFκB signaling were differentially regulated.

CONCLUSIONS

Synthetic opioid fentanyl impacts HIV replication and chemokine co-receptor expression. Increased virus levels suggest that opioid use may increase the likelihood of transmission and accelerate disease progression.

Cocaine sensitizes the CD4+ T cells for HIV infection by co-stimulating NFAT and AP-1

The productive infection of HIV, which generates new viral progeny, depends on the activation status of the cell. In this study, we found cocaine exposure sensitizes partially active CD4+ T cells and makes them poised for productive HIV infection. We discovered that cocaine treatment enhances the metabolic state of the cells by co-stimulating several transcription factors, mainly NFAT and AP-1, the two transcription factors, which specifically play a crucial role in enhancing both HIV and the overall cellular gene expression in T cells. We found that cocaine-induced AP-1 works in tandem with NFAT to boost HIV transcription. The enhanced HIV transcription upon cocaine exposure was further confirmed through higher phosphorylation of the crucial serine residues at the carboxyl-terminal domain (CTD) of RNA polymerase II. The insights gained from this study could aid in developing highly specialized therapeutics combating the deleterious effects of cocaine on the cocaine-using HIV population.

Citrate shuttling in astrocytes is required for processing cocaine-induced neuron-derived excess peroxidated fatty acids

Disturbances in lipid metabolism in the CNS contribute to neurodegeneration and cognitive impairments. Through tight metabolic coupling, astrocytes provide energy to neurons by delivering lactate and cholesterol and by taking up and processing neuron-derived peroxidated fatty acids (pFA). Disruption of CNS lipid homeostasis is observed in people who use cocaine and in several neurodegenerative disorders, including HIV. The brain's main source of energy is aerobic glycolysis, but numerous studies report a switch to β-oxidation of FAs in response to cocaine. Unlike astrocytes, in response to cocaine, neurons cannot efficiently consume excess pFAs for energy. Accumulation of pFA in neurons induces autophagy and release of pFA. Astrocytes endocytose the pFA for oxidation as an energy source. Our data show that blocking mitochondrial/cytosolic citrate transport reduces the neurotrophic capacity of astrocytes, leading to decreased neuronal fitness.

Role of macrophages in HIV pathogenesis and cure: NIH perspectives

Macrophages play a significant role in HIV infection and contribute to pathogenesis of comorbidities as well as establishment of the viral reservoir in people living with HIV. While CD4+ T cells are considered the main targets of HIV infection, infected macrophages resist the cytopathic effects of infection, contributing to the persistent HIV reservoir. Furthermore, activated macrophages drive inflammation and contribute to the development of comorbidities, including HIV-associated CNS dysfunction. Better understanding the role of macrophages in HIV infection, persistence, and comorbidities can lead to development of innovative therapeutic strategies to address HIV-related outcomes in people living with HIV. In October 2021, the National Institute of Mental Health and the Ragon Institute of MGH, MIT, and Harvard conducted a virtual meeting on role of macrophages in HIV infection, pathogenesis, and cure. This review article captures the key highlights from this meeting and provides an overview of interests and activities of various NIH institutes involved in supporting research on macrophages and HIV.

Crack cocaine use frequency is associated with HIV disease severity independent of antiretroviral therapy exposure: a prospective cohort study

We sought to evaluate the effect of crack cocaine use frequency on HIV disease severity among HIV-positive people who use unregulated drugs (PWUD). We analyzed data from the ACCESS study, an open prospective cohort of HIV-positive PWUD including comprehensive HIV clinical monitoring in a setting with no-cost healthcare. Multivariable generalized linear mixed-effects models were used to estimate the independent effect of time-updated crack cocaine use frequency on HIV disease severity, adjusting for ART exposure and relevant confounders. In multivariable adjusted models, daily or greater frequency of crack cocaine use was significantly associated with higher VACS Index scores (β = 0.8, 95% confidence interval: 0.1, 1.5) as compared to none. Our finding suggests that daily or greater frequency of crack cocaine use exacerbates HIV disease severity independent of ART exposure. The observed effect may reflect an underlying biological mechanism or other factors linked with crack cocaine use; further investigation is warranted.

Crossroads of Drug Abuse and HIV Infection: Neurotoxicity and CNS Reservoir

Drug abuse is a common comorbidity in people infected with HIV. HIV-infected individuals who abuse drugs are a key population who frequently experience suboptimal outcomes along the HIV continuum of care. A modest proportion of HIV-infected individuals develop HIV-associated neurocognitive issues, the severity of which further increases with drug abuse. Moreover, the tendency of the virus to go into latency in certain cellular reservoirs again complicates the elimination of HIV and HIV-associated illnesses. Antiretroviral therapy (ART) successfully decreased the overall viral load in infected people, yet it does not effectively eliminate the virus from all latent reservoirs. Although ART increased the life expectancy of infected individuals, it showed inconsistent improvement in CNS functioning, thus decreasing the quality of life. Research efforts have been dedicated to identifying common mechanisms through which HIV and drug abuse lead to neurotoxicity and CNS dysfunction. Therefore, in order to develop an effective treatment regimen to treat neurocognitive and related symptoms in HIV-infected patients, it is crucial to understand the involved mechanisms of neurotoxicity. Eventually, those mechanisms could lead the way to design and develop novel therapeutic strategies addressing both CNS HIV reservoir and illicit drug use by HIV patients.

Associations amongst form of cocaine used (powder vs crack vs both) and HIV-related outcomes

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Among PWH, cocaine use vs no-use was associated with worse HIV treatment outcomes.

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Powder cocaine only users were more likely to be younger, Hispanic, and employed.

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Users of powder + crack cocaine had lower viral suppression than users of either alone.

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Harm reduction efforts addressing substance use should be a key component of HIV care.

Introduction

Cocaine (including powder and crack) use is common among people with HIV (PWH). We identified socio-demographic and behavioral factors associated with cocaine use (overall and various forms) among PWH; we also examined differences in HIV treatment outcomes across cocaine exposure groups.

Methods

The study sample (N = 1166) was derived from two cohorts of PWH in Florida between 2014 and 2020. Baseline data were linked to the Enhanced HIV/AIDS Reporting System (eHARS) which tracks HIV viral load. Socio-demographics and polysubstance use were compared by cocaine use and the three cocaine use groups (powder only n = 101, crack only n = 91, or both n = 65). The association between the three cocaine use groups, ART adherence, and HIV viral suppression (<200 copies/mL) in the following year was assessed by multivariate logistic regression.

Results

People who used cocaine had lower HIV treatment adherence and viral suppression than those who did not use. People who used powder cocaine only were more likely to be younger, Hispanic/Latinx, and employed than those who used crack only or both. Compared to people who used both powder and crack cocaine, those who used one form of cocaine had 3 + odds of having durable viral suppression in the following year.

Conclusion

The dual use of both powder and crack cocaine was associated with significantly worse HIV outcomes compared to use of only one form of cocaine. Screening for powder and crack cocaine use and timely intervention are needed to improve HIV treatment outcomes among this high-risk population.

Drugs of Abuse and Their Impact on Viral Pathogenesis

Commonly misused substances such as alcohol, cocaine, heroin, methamphetamine, and opioids suppress immune responses and may impact viral pathogenesis. In recent years, illicit use of opioids has fueled outbreaks of several viral pathogens, including the human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). This review focuses on the myriad of mechanisms by which drugs of abuse impact viral replication and disease progression. Virus–drug interactions can accelerate viral disease progression and lead to increased risk of virus transmission.

Human Immunodeficiency Virus Type-1 (HIV-1) Transcriptional Regulation, Latency and Therapy in the Central Nervous System

The central nervous system (CNS) is highly compartmentalized and serves as a specific site of human immunodeficiency virus (HIV) infection. Therefore, an understanding of the cellular populations that are infected by HIV or that harbor latent HIV proviruses is imperative in the attempts to address cure strategies, taking into account that HIV infection and latency in the CNS may differ considerably from those in the periphery. HIV replication in the CNS is reported to persist despite prolonged combination antiretroviral therapy due to the inability of the current antiretroviral drugs to penetrate and cross the blood–brain barrier. Consequently, as a result of sustained HIV replication in the CNS even in the face of combination antiretroviral therapy, there is a high incidence of HIV-associated neurocognitive disorders (HAND). This article, therefore, provides a comprehensive review of HIV transcriptional regulation, latency, and therapy in the CNS.

Using mobile health technologies to test the association of cocaine use with sexual desire and risky sexual behaviors among people with and without HIV who use illicit stimulants

BACKGROUND

Cocaine use is broadly associated with risky sexual behavior potentially through elevated sexual desire. Understanding the within-person effects of cocaine on sexual desire and risky sexual behavior and the modification of HIV infection may inform primary and secondary HIV interventions.

METHODS

We conducted a mobile health (mHealth) study in a community sample of males and females with (n = 28) and without (n = 32) HIV who use illicit stimulant drugs. Participants completed ecological momentary assessments (EMAs) and daily diaries over 28 days. Mixed effects models were employed to examine the within-person association of cocaine use with sexual desire and risky sexual behavior.

RESULTS

Participants completed 3505 EMA responses, with 36 % involving recent cocaine use, including powder and/or crack cocaine. They completed 1427 daily diary responses, with cocaine use reported on 49 % of these days and sexual behavior on 21 % of these days. Sexual desire was highest in the first hour since cocaine use and gradually decreased with time. Sexual desire was lowest when participants had not used any cocaine in the past 6 h, and it correlated positively with the amount of use. Participants were more likely to have risky sexual behavior on days they used cocaine. These associations were similar for participants with and without HIV.

CONCLUSION

This study demonstrates the dynamic and proximal effects of cocaine use on sexual desire and risky sexual behavior. Our findings support the development of HIV prevention interventions that utilize mHealth technology to reduce sexual risk behavior among persons who use stimulant drugs.

Neuroimmune Mechanisms as Novel Treatment Targets for Substance Use Disorders and Associated Comorbidities

Recent studies examining the neurobiology of substance abuse have revealed a significant role of neuroimmune signaling as a mechanism through which drugs of abuse induce aberrant changes in synaptic plasticity and contribute to substance abuse-related behaviors. Immune signaling within the brain and the periphery critically regulates homeostasis of the nervous system. Perturbations in immune signaling can induce neuroinflammation or immunosuppression, which dysregulate nervous system function including neural processes associated with substance use disorders (SUDs). In this review, we discuss the literature that demonstrates a role of neuroimmune signaling in regulating learning, memory, and synaptic plasticity, emphasizing specific cytokine signaling within the central nervous system. We then highlight recent preclinical studies, within the last 5 years when possible, that have identified immune mechanisms within the brain and the periphery associated with addiction-related behaviors. Findings thus far underscore the need for future investigations into the clinical potential of immunopharmacology as a novel approach toward treating SUDs. Considering the high prevalence rate of comorbidities among those with SUDs, we also discuss neuroimmune mechanisms of common comorbidities associated with SUDs and highlight potentially novel treatment targets for these comorbid conditions. We argue that immunopharmacology represents a novel frontier in the development of new pharmacotherapies that promote long-term abstinence from drug use and minimize the detrimental impact of SUD comorbidities on patient health and treatment outcomes.

The role of gut-immune-brain signaling in substance use disorders

Substance use disorders (SUDs) are debilitating neuropsychiatric conditions that exact enormous costs in terms of loss of life and individual suffering. While much progress has been made defining the neurocircuitry and intracellular signaling cascades that contribute to SUDs, these studies have yielded limited effective treatment options. This has prompted greater exploration of non-traditional targets in addiction. Emerging data suggest inputs from peripheral systems, such as the immune system and the gut microbiome, impact multiple neuropsychiatric diseases, including SUDs. Until recently the gut microbiome, peripheral immune system, and the CNS have been studied independently; however, current work shows the gut microbiome and immune system critically interact to modulate brain function. Additionally, the gut microbiome and immune system intimately regulate one another via extensive bidirectional communication. Accumulating evidence suggests an important role for gut-immune-brain communication in the pathogenesis of substance use disorders. Thus, a better understanding of gut-immune-brain signaling could yield important insight to addiction pathology and potential treatment options.

Presence of Tat and transactivation response element in spinal fluid despite antiretroviral therapy

OBJECTIVE

The aim of this study was to measure the protein concentration and biological activity of HIV-1 Tat in cerebrospinal fluid (CSF) of individuals on suppressive antiretroviral therapy (ART).

DESIGN

CSF was collected from 68 HIV-positive individuals on ART with plasma viral load less than 40 copies/ml, and from 25 HIV-negative healthy controls. Duration of HIV infection ranged from 4 to more than 30 years.

METHODS

Tat levels in CSF were evaluated by an ELISA. Tat protein and viral RNA were quantified from exosomes isolated from CSF, followed by western blot or quantitative reverse transcription PCR, respectively. Functional activity of Tat was assessed using an LTR transactivation assay.

RESULTS

Tat protein was detected in 36.8% of CSF samples from HIV-positive patients. CSF Tat concentration increased in four out of five individuals after initiation of therapy, indicating that Tat was not inhibited by ART. Similarly, exosomes from 34.4% of CSF samples were strongly positive for Tat protein and/or TAR RNA. Exosomal Tat retained transactivation activity in a CEM-LTR reporter assay in 66.7% of samples assayed, which indicates that over half of the Tat present in CSF is functional. Presence of Tat in CSF was highly associated with previous abuse of psychostimulants (cocaine or amphetamines; P = 0.01) and worse performance in the psychomotor speed (P = 0.04) and information processing (P = 0.02) cognitive domains.

CONCLUSION

Tat and TAR are produced in the central nervous system despite adequate ART and are packaged into CSF exosomes. Tat remains biologically active within this compartment. These studies suggest that Tat may be a quantifiable marker of the viral reservoir and highlight a need for new therapies that directly inhibit Tat.

Neuroimmune mechanisms of psychostimulant and opioid use disorders

Substance use disorders are global health problems with few effective treatment options. Unfortunately, most potential pharmacological treatments are hindered by abuse potential of their own, limited efficacy, or adverse side effects. As a consequence, there is a pressing need for the development of addiction treatments with limited abuse potential and fewer off target effects. Given the difficulties in developing new pharmacotherapies for substance use disorders, there has been growing interest in medications that act on non-traditional targets. Recent evidence suggests a role for dysregulated immune signaling in the pathophysiology of multiple psychiatric diseases. While there is evidence that immune responses in the periphery and the central nervous system are altered by exposure to drugs of abuse, the contributions of neuroimmune interactions to addictive behaviors are just beginning to be appreciated. In this review, we discuss the data on immunological changes seen in clinical populations with substance use disorders, as well as in translational animal models of addiction. Importantly, we highlight those mechanistic findings showing causal roles for central or peripheral immune mediators in substance use disorder and appropriate animal models. Based on the literature reviewed here, it is clear that brain-immune system interactions in substance use disorders are much more complex and important than previously understood. While much work remains to be done, there are tremendous potential therapeutic implications for immunomodulatory treatments in substance use disorders.

Prevalence and Associations of Illicit Drug and Polydrug Use in People Living with HIV in Vienna

We aimed to determine the prevalence of drug and polydrug use in people living with HIV in Austria for the first time for which a two center cross-sectional study was performed. Participants were recruited from consecutive patients during their regularly scheduled visits. In total 438 participants were included in the analysis. For this study we used paper-pencil and online-based questionnaires. The prevalence of illicit drug use was 60.5%; with cannabis use at 31.5%, nitrates at 31.5%, sildenafil/tadalafil at 24% and cocaine at 14%, being the most used substances. Use of more than one substance (polydrug) in drug users was 69.4% or 42.0% in the total study population. Younger age, male gender, and living in an urban area were associated with drug use. Moreover, drug use during clubbing and sex, HIV therapy non-adherence and younger age were associated with polydrug use. Drug users reported condomless sex in 42.4% and performing sexual acts they would not do sober in 44.1%. Results indicate a high prevalence of illicit drug use in PLWHIV in Austria. New research focusing on illicit drug use in PLWHIV should focus on the use of substances during sex and surrounding practices.

Cocaine evokes a profile of oxidative stress and impacts innate antiviral response pathways in astrocytes

HIV-1 and Zika virus (ZIKV) represent RNA viruses with neurotropic characteristics. Infected individuals suffer neurocognitive disorders aggravated by environmental toxins, including drugs of abuse such as cocaine, exacerbating HIV-associated neurocognitive disorders through a combination of astrogliosis, oxidative stress and innate immune signaling; however, little is known about how cocaine impacts the progression of ZIKV neural perturbations. Impaired innate immune signaling is characterized by weakened antiviral activation of interferon signaling and alterations in inflammatory signaling, factors contributing to cognitive sequela associated with cocaine in HIV-1/ZIKV infection. We employed cellular/molecular biology techniques to test if cocaine suppresses the efficacy of astrocytes to initiate a Type 1 interferon response to HIV-1/ZIKV, in vitro. We found cocaine activated antiviral signaling pathways and type I interferon in the absence of inflammation. Cocaine pre-exposure suppressed antiviral responses to HIV-1/ZIKV, triggering antiviral signaling and phosphorylation of interferon regulatory transcription factor 3 to stimulate type I interferon gene transcription. Our data indicate that oxidative stress is a major driver of cocaine-mediated astrocyte antiviral immune responses. Although astrocyte antiviral signaling is activated following detection of foreign pathogenic material, oxidative stress and increased cytosolic double-stranded DNA (dsDNA) can drive antiviral signaling via stimulation of pattern recognition receptors. Pretreatment with the glial modulators propentofylline (PPF) or pioglitazone (PIO) reversed cocaine-mediated attenuation of astrocyte responses to HIV-1/ZIKV. Both PPF/PIO protected against cocaine-mediated generation of reactive oxygen species (ROS), increased dsDNA, antiviral signaling pathways and increased type I interferon, indicating that cocaine induces astrocyte type I interferon signaling in the absence of virus and oxidative stress is a major driver of cocaine-mediated astrocyte antiviral immunity. Lastly, PPF and PIO have therapeutic potential to ameliorate cocaine-mediated dysregulation of astrocyte antiviral immunity possibly via a myriad of protective actions including decreases in reactive phenotype and damaging immune factors.

Drug Use is Associated with Anti-CD4 IgG-mediated CD4+ T Cell Death and Poor CD4+ T Cell Recovery in Viral-suppressive HIV-infected Individuals Under Antiretroviral Therapy

BACKGROUND

The role and mechanism of drug use or abuse in Antiretroviral Therapy (ART)-treated HIV disease are not completely known.

METHODS

To investigate the impact of drug use on HIV pathogenesis without confounding by HIV replication and ART adherence, we first analyzed the data from our clinical database in 103 HIV+ subjects with viral-suppressed ART treatment by a multiple regression test.

RESULTS

We found that HIV+ drug users had lower CD4+ T cell counts but higher CD8+ T cell counts compared to HIV+ non-drug users, and both drug use and nadir CD4+ T cell counts was independently associated with CD4+ T cell recovery after controlling for sex and age. Next, we enrolled individuals from four study groups, HIV-negative and HIV+ subjects without any substance use, HIV-negative and HIV+ subjects with current illicit drug use (either non-injection cocaine or cannabis). All HIV+ subjects were viral-suppressed with ART treatment (≥ 2 years). Notably, HIV+ drug users had increased plasma anti-CD4 IgG levels compared to the other three study groups which were inversely correlated with decreased CD4+ T cell counts only in HIV+ drug users. There was a significant increase in CD4+ T cell recovery following ART in HIV+ non-drug users but not in HIV+ drug users. Anti-CD4 IgGs purified from plasma of HIV+ drug users induced CD4+ T cell death in vitro through Antibody-Dependent Cytotoxicity (ADCC).

CONCLUSION

These results suggest that drug use prevents immune reconstitution in HIV-infected individuals despite long-term ART treatment and viral suppression.

Community-acquired lower respiratory tract infections in HIV-infected patients on antiretroviral therapy: predictors in a contemporary cohort study

Community-acquired pneumonia represents the most frequent bacterial infection in patients with HIV/AIDS.

PURPOSE

We aimed to assess variables associated with lower respiratory tract infection (LRTI) among HIV-infected adults using ART.

METHODS

A cohort study of HIV-infected patients aged ≥18 years, enrolled from 2000 to 2015, on ART for at least 60 days, with primary outcome as the 1st episode of LRTI during follow-up. The independent variables included were sex at birth, age, race/skin color, educational level, tobacco smoking, alcohol use, cocaine use, diabetes mellitus, CD4 count, HIV viral load, influenza and pneumococcal vaccination. Extended Cox proportional hazards models accounting for time-updated variables were fitted to assess LRTI predictors.

RESULTS

2669 patients were included; median follow-up was 3.9 years per patient. LRTI was diagnosed in 384 patients; incidence rate was 30.7/1000 PY. In the unadjusted Cox extended models, non-white race [crude hazard ratio (cHR) 1.28, p = 0.020], cocaine use (cHR 2.01, p < 0.001), tobacco smoking (cHR 1.34, p value 0.007), and HIV viral load ≥400 copies/mL (cHR 3.40, p < 0.001) increased the risk of LRTI. Lower risk of LRTI was seen with higher educational level (cHR 0.61, p < 0.001), rise in CD4 counts (cHR 0.81, p < 0.001, per 100 cells/mm3 increase), influenza (cHR 0.60, p = 0.002) and pneumococcal vaccination (cHR 0.57, p < 0.001). In the adjusted model, aHR for CD4 count was 0.86, for cocaine use 1.47 and for viral load ≥400 copies 2.20.

CONCLUSIONS

LRTI has a high incidence in HIV-infected adults using ART. Higher CD4 counts and undetectable viral loads were protective, as were pneumococcal and influenza vaccines.