Human Immunodeficiency Virus Replication Research Articles

The Impact of CRISPR and Cas9 on AIDS

AIDS is a chronic infectious disease caused by the human immunodeficiency virus (HIV), and the current treatment for the disease is a combination of highly effective antiretroviral therapy, consisting of a combination of at least three of these drugs to combat HIV infection. However, this therapy only inhibits HIV replication, but does not completely eliminate the virus. Once antiretroviral treatment is interrupted, the patient's disease is prone to relapse. Therefore we need gene editing, which is the process of modifying, adding, deleting and replacing information in the body's DNA in order to modify diseases caused by genetic mutations, which can only be controlled by drugs. It is hoped that in the near future, gene editing technology will revolutionise the treatment of cancer and genetic diseases, thanks to the work of scientists.

Circulating Plasma Exosomal Proteins of Either SHIV-Infected Rhesus Macaque or HIV-Infected Patient Indicates a Link to Neuropathogenesis.

Despite the suppression of human immunodeficiency virus (HIV) replication by combined antiretroviral therapy (cART), 50-60% of HIV-infected patients suffer from HIV-associated neurocognitive disorders (HAND). Studies are uncovering the role of extracellular vesicles (EVs), especially exosomes, in the central nervous system (CNS) due to HIV infection. We investigated links among circulating plasma exosomal (crExo) proteins and neuropathogenesis in simian/human immunodeficiency virus (SHIV)-infected rhesus macaques (RM) and HIV-infected and cART treated patients (Patient-Exo). Isolated EVs from SHIV-infected (SHIV-Exo) and uninfected (CTL-Exo) RM were predominantly exosomes (particle size < 150 nm). Proteomic analysis quantified 5654 proteins, of which 236 proteins (~4%) were significantly, differentially expressed (DE) between SHIV-/CTL-Exo. Interestingly, different CNS cell specific markers were abundantly expressed in crExo. Proteins involved in latent viral reactivation, neuroinflammation, neuropathology-associated interactive as well as signaling molecules were expressed at significantly higher levels in SHIV-Exo than CTL-Exo. However, proteins involved in mitochondrial biogenesis, ATP production, autophagy, endocytosis, exocytosis, and cytoskeleton organization were significantly less expressed in SHIV-Exo than CTL-Exo. Interestingly, proteins involved in oxidative stress, mitochondrial biogenesis, ATP production, and autophagy were significantly downregulated in primary human brain microvascular endothelial cells exposed with HIV+/cART+ Patient-Exo. We showed that Patient-Exo significantly increased blood-brain barrier permeability, possibly due to loss of platelet endothelial cell adhesion molecule-1 protein and actin cytoskeleton structure. Our novel findings suggest that circulating exosomal proteins expressed CNS cell markers-possibly associated with viral reactivation and neuropathogenesis-that may elucidate the etiology of HAND.

SERPIN-Derived Small Peptide (SP16) as a Potential Therapeutic Agent against HIV-Induced Inflammatory Molecules and Viral Replication in Cells of the Central Nervous System.

Despite the success of combined antiretroviral therapy (cART) increasing the survival rate in human immunodeficiency virus (HIV) patients, low levels of viremia persist in the brain of patients leading to glia (microglia and astrocytes)-induced neuroinflammation and consequently, the reactivation of HIV and neuronal injury. Here, we tested the therapeutic efficacy of a Low-Density Lipoprotein Receptor-Related Protein 1 (LRP-1) agonistic small peptide drug (SP16) in attenuating HIV replication and the secretion of inflammatory molecules in brain reservoirs. SP16 was developed by Serpin Pharma and is derived from the pentapeptide sequence of the serine protease inhibitor alpha-1-antitrypsin (A1AT). The SP16 peptide sequence was subsequently modified to improve the stability, bioavailability, efficacy, and binding to LRP-1; a scavenger regulatory receptor that internalizes ligands to induce anti-viral, anti-inflammatory, and pro-survival signals. Using glial cells infected with HIV, we showed that: (i) SP16 attenuated viral-induced secretion of pro-inflammatory molecules; and (ii) SP16 attenuated viral replication. Using an artificial 3D blood-brain barrier (BBB) system, we showed that: (i) SP16 was transported across the BBB; and (ii) restored the permeability of the BBB compromised by HIV. Mechanistically, we showed that SP16 interaction with LRP-1 and binding lead to: (i) down-regulation in the expression levels of nuclear factor-kappa beta (NF-κB); and (ii) up-regulation in the expression levels of Akt. Using an in vivo mouse model, we showed that SP16 was transported across the BBB after intranasal delivery, while animals infected with EcoHIV undergo a reduction in (i) viral replication and (ii) viral secreted inflammatory molecules, after exposure to SP16 and antiretrovirals. Overall, these studies confirm a therapeutic response of SP16 against HIV-associated inflammatory effects in the brain.

Modeling the effects of drugs of abuse on within-host dynamics of two HIV species

Injection drug use is one of the most significant risk factors associated with contracting human immunodeficiency virus (HIV), and drug users infected with HIV suffer from a higher viral load and rapid disease progression. While replication of HIV may result in many mutant viruses that can escape recognition of the host’s immune response, the presence of morphine (a drug of abuse) can decrease the viral mutation rate and cellular immune responses. This study develops a mathematical model to explore the effects of morphine-altered mutation and cellular immune response on the within-host dynamics of two HIV species, a wild-type and a mutant. Our model predicts that the morphine-altered mutation rate and cellular immune response allow the wild-type virus to outcompete the mutant virus, resulting in a higher set point viral load and lower CD4 count. We also compute the basic reproduction numbers and show that the dominant species is determined by morphine concentration, with the mutant dominating below and the wild-type dominating above a threshold. Furthermore, we identified three biologically relevant equilibria, infection-free, mutant-only, and coexistence, which are completely characterized by the fitness cost of mutation, mutant escape rate, and morphine concentration.

Mathematical Modeling of HIV Replicaton and the Response of the Interferon System

Developing physiologically meaningful mathematical models that describe multilevel regulation in a complex network of immune processes, in particular, of the system of interferon-regulated virus production processes, is a fundamental scientific problem, within the framework of an interdisciplinary systems approach to research in immunology. Here, we have presented a detailed high-dimensional model describing HIV (human immunodeficiency virus) replication, the response of type I interferon (IFN) to the virus infection of the cell, and suppression of the action of IFN-induced proteins by HIV accessory proteins. As a result, this model includes interactions of all three processes for the first time. The mathematical model is a system of 37 nonlinear ordinary differential equations including 78 parameters. Importantly, the model describes not only the processes of the IFN response of the cell to virus infection, but also the mechanisms used by the virus to prevent effects of the IFN system.

Introduction of Mutant APOBEC3G Into CD4+ T-Cells to Resist HIV-1

Introduction: Human immunodeficiency virus 1 (HIV-1) is a potentially lethal retrovirus with high genetic diversity and replication ability. HIV-1 mainly targets human CD4+ T-cells, causing a rapid decline in CD4+ T-cell count after infection. Apolipoprotein B mRNA Editing Enzyme Catalytic Subunit 3G (APOBEC3G or A3G) is a human anti-viral enzyme that blocks early stages of HIV-1 replication by deaminating the cytosine residues to uracil in the viral minus-strand DNA during reverse transcription. Nevertheless, HIV-1 overcomes A3G anti-viral activity by employing Vif accessory protein to degrade A3G. Due to a proline/aspartate point mutation in residue 129 (P129D), an artificial A3G mutant, also known as A3G-P129D, was found to be resistant against diverse Vif variants, including HIV-1 Vif, thereby shedding light on a potential A3G-mediated gene therapy for HIV-1. Methods: We propose that, using CRISPR-Cas9 tools, the P129D mutation will be introduced into A3G expressed by human hematopoietic stem cells. Engineered stem cells will be transplanted into Non-Obese Diabetic Severe Combined Immunodeficient Gamma (NSG) mice, which will later be infected with HIV-1. Following infection, flow cytometry will be used to compare the CD4+ T-cell count in mice that express A3G-P129D versus control mice transplanted with unmodified human CD4+ T-cells. Results: We expect a notably higher CD4+ T-cell count in mice carrying the P129D mutation than in the control group, which would be attributed to the efficient inhibition of HIV-1 replication by the mutant A3G. Discussion: Transforming human A3G to A3G-P129D will prevent Vif-mediated degradation of A3G, allowing A3G to efficiently target HIV-1. Thus, this treatment would ultimately block HIV-1 replication and prevent CD4+ T-cell depletion. Conclusion: Overall, our novel gene therapy approach could open the door to a potential one-time treatment for HIV-1 infected patients.

Eradication of human immunodeficiency virus-1 reservoir in the brain microglia.

Eradication of human immunodeficiency virus-1 reservoir in the brain microglia.

New Potential MicroRNA Biomarkers in Human Immunodeficiency Virus Elite Controllers, Human Immunodeficiency Virus Infections, and Coinfections with Hepatitis B Virus or Hepatitis C Virus

Introduction: This research aimed to evaluate the specific microRNA (miRNA) including miR-17-5p, miRN-140-3p miR-191-5p, miR-200c-3p, and miR-N367 and cellular factors (p21, SDF-1, XCL1, CCL-2, and IL-2) in controlling replication of human immunodeficiency virus (HIV) in ECs. Methods: The expression of miRNAs was assessed between healthy control groups and patient groups including ART-naïve HIV, HIV ART, ECs, and coinfection (HIV-HBV and HIV-HCV) via real-time PCR technique. Besides, the expression level of the nef gene and cellular factors were assessed by the ELISA method. The differences in the level of cellular factors and selected miRNAs between study groups were analyzed using the Kruskal-Wallis H or one-way ANOVA test. In addition, the potential of selected miRNAs as biomarkers for discriminating study groups was assessed by the receiver-operator characteristic (ROC) curve analysis. Results: Some miRNAs in ECs, HIV ART, and healthy controls have similar expression patterns, whereas a miRNA expression profile of patient groups significantly differed compared to EC and control groups. According to ROC curve analyses, the miR-17-5p, miR-140-3p miR-191-5p, miR-200c-3p, and miR-N367 can be served as biomarkers for discriminating ECs from ART-naïve HIV-infected groups. There was a significant correlation between some miRNAs and cellular factors/the viral load as well. Conclusion: This report demonstrated a differentiation in the expression of selected immunological factors and cellular/viral miRNAs in ECs compared to other patient groups. Some miRNAs and cellular factors are involved in the viral replication control, immune response/modulation and can be used as biomarkers for diagnosis of ECs and differentiation with other groups. Differential expression of these miRNAs and cellular factors in different stages of HIV infection can help in finding novel ways for infection control.

Deubiquitinase ubiquitin-specific protease 3 (USP3) inhibits HIV-1 replication via promoting APOBEC3G (A3G) expression in both enzyme activity-dependent and -independent manners.

Ubiquitination plays an essential role in many biological processes, including viral infection, and can be reversed by deubiquitinating enzymes (DUBs). Although some studies discovered that DUBs inhibit or enhance viral infection by various mechanisms, there is lack of information on the role of DUBs in virus regulation, which needs to be further investigated. Immunoblotting, real-time polymerase chain reaction, in vivo / in vitro deubiquitination, protein immunoprecipitation, immunofluorescence, and co-localization biological techniques were employed to examine the effect of ubiquitin-specific protease 3 (USP3) on APOBEC3G (A3G) stability and human immunodeficiency virus (HIV) replication. To analyse the relationship between USP3 and HIV disease progression, we recruited 20 HIV-infected patients to detect the levels of USP3 and A3G in peripheral blood and analysed their correlation with CD4 + T-cell counts. Correlation was estimated by Pearson correlation coefficients (for parametric data). The results demonstrated that USP3 specifically inhibits HIV-1 replication in an A3G-dependent manner. Further investigation found that USP3 stabilized 90% to 95% of A3G expression by deubiquitinating Vif-mediated polyubiquitination and blocking its degradation in an enzyme-dependent manner. It also enhances the A3G messenger RNA (mRNA) level by binding to A3G mRNA and stabilizing it in an enzyme-independent manner. Moreover, USP3 expression was positively correlated with A3G expression ( r = 0.5110) and CD4 + T-cell counts ( r = 0.5083) in HIV-1-infected patients. USP3 restricts HIV-1 viral infections by increasing the expression of the antiviral factor A3G. Therefore, USP3 may be an important target for drug development and serve as a novel therapeutic strategy against viral infections.

Activation of NRF2 blocks HIV replication and apoptosis in macrophages

Abnormal oxidative stress caused by human immunodeficiency virus (HIV) infection affects viral replication and causes non-acquired immune deficiency syndrome-related complications in infected individuals. The transcription factor NFE2-related factor 2 (NRF2), a key regulator of oxidative stress, responds to abnormal oxidative stress by regulating the expression of NRF2-dependent cytoprotective genes. The present study aimed to determine whether inhibition of oxidative stress could control HIV replication and improve cell survival. In this study, the NRF2 activator, methyl bardoxolone, was used to treat cells for HIV infection. The effects on HIV replication and apoptosis pathways were confirmed by NRF2 activation or knockdown. The results showed that NRF2 activation could block HIV replication in macrophages before the integration phase and inhibited the expression of apoptotic pathways in virus-exposed macrophages. The study presents an unconventional anti-viral strategy of activation antioxidant response for HIV infection blocking.

HIV-1 Transcription Inhibitor 1E7-03 Decreases Nucleophosmin Phosphorylation

Transcription activation of latent human immunodeficiency virus-1 (HIV-1) occurs due to HIV-1 rebound, the interruption of combination antiretroviral therapy, or development of drug resistance. Thus, novel HIV-1 inhibitors, targeting HIV-1 transcription are needed. We previously developed an HIV-1 transcription inhibitor, 1E7-03, that binds to the noncatalytic RVxF-accommodating site of protein phosphatase 1 and inhibits HIV-1 replication in cultured cells and HIV-1–infected humanized mice by impeding protein phosphatase 1 interaction with HIV-1 Tat protein. However, host proteins and regulatory pathways targeted by 1E7-03 that contribute to its overall HIV-1 inhibitory activity remain to be identified. To address this issue, we performed label-free quantitative proteome and phosphoproteome analyses of noninfected and HIV-1–infected CEM T cells that were untreated or treated with 1E7-03. 1E7-03 significantly reprogramed the phosphorylation profile of proteins including PPARα/RXRα, TGF-β, and PKR pathways. Phosphorylation of nucleophosmin (NPM1) at Ser-125 residue in PPARα/RXRα pathway was significantly reduced (>20-fold, p = 1.37 × 10−9), followed by the reduced phosphorylation of transforming growth factor-beta 2 at Ser-46 (TGF-β2, >12-fold, p = 1.37 × 10−3). Downregulation of NPM1’s Ser-125 phosphorylation was further confirmed using Western blot. Phosphorylation mimicking NPM1 S125D mutant activated Tat-induced HIV-1 transcription and exhibited enhanced NPM1–Tat interaction compared to NPM1 S125A mutant. Inhibition of Aurora A or Aurora B kinases that phosphorylate NPM1 on Ser-125 residue inhibited HIV-1, further supporting the role of NPM1 in HIV-1 infection. Taken together, 1E7-03 reprogrammed PPARα/RXRα and TGF-β pathways that contribute to the inhibition of HIV-1 transcription. Our findings suggest that NPM1 phosphorylation is a plausible target for HIV-1 transcription inhibition.

BLOOD AND CEREBROSPINAL FLUID HIV LOAD INPATIENTS WITH HIV-ASSOCIATED NEUROLOGICAL DISORDERS

Relevance. The issues of replication and concentration of the human immunodeficiency virus (HIV) in various tissues and body fluids remain insufficiently studied. Solving this problem is hindered by the lack of simple, cheap and accessible methods for quantitative determination of HIV in various tissue samples.&#x0D; Objective is to establish a relationship between the presence of HIV-associated damage of the central nervous system (CNS), the number of CD4+ lymphocytes in the blood, and the level of HIV load in blood plasma and cerebrospinal fluid. The difference between the level of HIV viral load in different tissues and biological fluids may reflect the formation of several independent reservoirs of HIV replication in the human body.&#x0D; Materials and methods. 87 patients with HIV infection with clinical signs of central nervous system damage who had no experience of taking antiretroviral drugs (ARVP) were examined. Paired samples of blood and cerebrospinal fluid were analyzed to determine the level of viral load in both biological fluids, as well as the number of CD4+ lymphocytes in the blood.&#x0D; Results. It was established that the patient's presence of clinical signs of CNS damage was reliably correlated with the level of HIV load in the cerebrospinal fluid (logistic regression, P&lt;0.001) and was not associated with the content of CD4+ lymphocytes or the level of HIV load in the blood (logistic regression, P &gt;0.05).&#x0D; The level of HIV load in the cerebrospinal fluid (CSF) was on average 1.5 lg RNA copies/ml higher (P&lt;0.001) in patients with neurological disorders despite the fact that the mean CD4+-lymphocyte count and HIV load in blood in both groups of patients did not differ. The difference between the HIV load in blood and cerebrospinal fluid of patients with neurological disorders was only 0.8 lg RNA copies/ml.&#x0D; Despite the similar indicators of the content of CD4+ lymphocytes and the amount of HIV in the blood, in HIV-infected patients with clinical signs of CNS damage, the level of HIV load in CSF is 1.5 lg RNA copies/ml higher, compared with patients without symptoms of CNS dysfunction (P &lt;0.001). The difference between HIV load in blood and cerebrospinal fluid in the presence of neurocognitive disorders was reduced to 0.7 lg RNA copies/ml compared to 1.8 lg RNA copies/ml in the group of individuals without signs of CNS damage. The presence of HIV-associated damage to the central nervous system is not statistically related to the content of CD4+ lymphocytes or the level of HIV load in the blood.&#x0D; Statistical analysis showed that a CSF HIV load equal to or greater than 4.00 lg RNA copies/mL (10,000 RNA copies/mL) indicated a significant likelihood of HIV-associated CNS involvement in patients (P&lt;0.001) .&#x0D; Conclusion. The method of determining the level of HIV load in cerebrospinal fluid samples can be used to optimize the diagnostic algorithm of HIV-associated lesions of the central nervous system, differential diagnosis with neurocognitive disorders of non-infectious etiology. The threshold for making a clinical decision is the level of HIV load in the CSF sample, which is equal to or exceeds 4.00 lg RNA copies/ml, which indicates a significant probability of the presence of an HIV-associated lesion of the CNS in the patient.

A Literature Review on Recent Advancements in the Treatment of Human Immunodeficiency Virus

Abstract: The aim of this study is to conduct an extensive literature review on recent advancements in the treatment of human immunodeficiency virus (HIV). This is because in extant studies, the care of the HIV infected patient has changed dramatically in the last few years. Potent new antiretroviral drugs combined with updated treatment strategies have now achieved efficient inhibition of HIV replication in most patients. Classes of drugs include both nucleoside and non-nucleoside inhibitors of the viral enzyme reverse transcriptase (RT) and inhibitors of the viral protease and integrase enzymes. The methodology used in this study was reviewed from secondary sources of information including journals, articles, newspaper, and textbooks. In this study, authors found that a major drawback of the highly active antiretroviral therapy (HAART) is the selection of resistant mutants under suboptimal dosage, in advanced stages of disease or after pre-treatment with mono- or double-combination regimens. In addition, monitoring of antiretroviral therapy is achieved by measurement of viral load using nucleic acid amplification techniques. Strict adherence to HIV drug regimens was reported to be essential for reaching and maintaining therapeutic levels of anti-retro-virals and avoiding development of drug-resistant HIV strains. This strict dosage-taking adherence makes HIV therapies among the most challenging treatments with which to adhere. Future researchers are encouraged to adopt a scientific approach in investigating the various constructs that have emerged in this study in other to provide more generalized findings for the research community and public policy makers. Keywords: Antiretroviral Drugs: Combination Therapy: Medication: Transmission: Inhibitors: Immune System.

Triphosphate Prodrugs of the Anti-HIV-Active Compound 3'-Deoxy-3'-fluorothymidine (FLT).

3'-Fluoro-3'-deoxythymidine (FLT) was identified as one of the most potent inhibitors of human immunodeficiency virus (HIV) replication. However, FLT also showed severe toxicity so that it was abundant as a potential chemotherapeutic agent. Here, we describe various triphosphate prodrugs of FLT aiming for (a) a bypass of all phosphorylation steps needed to convert the nucleoside analogue into its triphosphate (TP) form, (b) an intracellular delivery of hydrolytically and enzymatically stable triphosphate derivatives, and (c) increasing the selectivity for HIV-RT vs three cellular DNA polymerases including the mitochondrial DNA polymerase γ. γ-Alkylated FLTTP compounds fulfill all of these requirements because these compounds proved highly resistant to dephosphorylation and showed strong selectivity for HIV-RT. Moreover, a prodrug form of these compounds proved to be nontoxic in CEM cells.

Synthetic gRNA/Cas9 Ribonucleoprotein Inhibits HIV Reactivation and Replication.

The current antiretroviral therapy (ART) for human immunodeficiency virus (HIV) can halt viral replication but cannot eradicate HIV infection because proviral DNA integrated into the host genome remains genetically silent in reservoir cells and is replication-competent upon interruption or cessation of ART. CRISPR/Cas9-based technology is widely used to edit target genes via mutagenesis (i.e., nucleotide insertion/deletion and/or substitution) and thus can inactivate integrated proviral DNA. However, CRISPR/Cas9 delivery systems often require viral vectors, which pose safety concerns for therapeutic applications in humans. In this study, we used synthetic guide RNA (gRNA)/Cas9-ribonucleoprotein (RNP) as a non-viral formulation to develop a novel HIV gene therapy. We designed a series of gRNAs targeting different HIV genes crucial for HIV replication and tested their antiviral efficacy and cellular cytotoxicity in lymphoid and monocytic latent HIV cell lines. Compared with the scramble gRNA control, HIV-gRNA/Cas9 RNP-treated cells exhibited efficient viral suppression with no apparent cytotoxicity, as evidenced by the significant inhibition of latent HIV DNA reactivation and RNA replication. Moreover, HIV-gRNA/Cas9 RNP inhibited p24 antigen expression, suppressed infectious viral particle production, and generated specific DNA cleavages in the targeted HIV genes that are confirmed by DNA sequencing. Because of its rapid DNA cleavage, low off-target effects, low risk of insertional mutagenesis, easy production, and readiness for use in clinical application, this study provides a proof-of-concept that synthetic gRNA/Cas9 RNP drugs can be utilized as a novel therapeutic approach for HIV eradication.

Zipper interacting protein kinase (ZIPK) is a negative regulator of HIV-1 replication that is restricted by viral Nef protein through proteasomal degradation

Human immunodeficiency virus-1 (HIV-1) infection leads to the development of acquired immunodeficiency syndrome (AIDS). To establish a productive infection, HIV-1 hijacks the cellular machinery and modulates various physiological processes to propagate itself. The pathways altered by HIV-1 include cell cycle, autophagy, apoptosis, cell stress pathways, immune response, antiviral response, etc. Zipper interacting protein kinase (ZIPK) is a member of the death-associated protein kinase (DAPK) family of proteins, known to be one of the key regulators of cell death and cell survival pathways. ZIPK is also involved in regulating many cellular processes that are altered during HIV-1 infection; thus, we have explored the functional role of ZIPK in HIV-1 infection. Our results show that ZIPK protein expression is downregulated during HIV-1 infection in Nef dependent manner. Overexpression of ZIPK leads to downregulation in LTR-driven gene expression and virus production, whereas ZIPK knockdown induces viral gene expression and replication. HIV-1 promoter activity is reportedly enhanced by Nef-mediated activation of some transcription factors like NFκB and STAT3. ZIPK is reported to inhibit the STAT3 activity by phosphorylating it at ser-727. Our results show that STAT3 (ser-727) phosphorylation is decreased upon overexpression of Nef with simultaneous downregulation of ZIPK expression. We finally show that HIV-1 Nef interacts with ZIPK and induces its proteasomal degradation. Overall, our data suggests that Nef is involved in downregulation of ZIPK thereby increasing the virus production through rescue of STAT3 activity.

Targeted Immuno-Antiretroviral to Promote Dual Protection against HIV: A Proof-of-Concept Study.

The C–C motif chemokine receptor-5 (CCR5) expression on the T-cell surface is the prime barrier to HIV/AIDS eradication, as it promotes both active human immunodeficiency virus (HIV)-infection and latency; however, antiretrovirals (ARVs) suppress plasma viral loads to non-detectable levels. Keeping this in mind, we strategically designed a targeted ARVs-loaded nanoformulation that targets CCR5 expressing T-cells (e.g., CD4+ cells). Conceptually, CCR5-blocking and targeted ARV delivery would be a dual protection strategy to prevent HIV infection. For targeting CCR5+ T-cells, the nanoformulation was surface conjugated with anti-CCR5 monoclonal antibodies (CCR5 mAb) and loaded with dolutegravir+tenofovir alafenamide (D+T) ARVs to block HIV replication. The result demonstrated that the targeted-ARV nanoparticle’s multimeric CCR5 binding property improved its antigen-binding affinity, prolonged receptor binding, and ARV intracellular retention. Further, nanoformulation demonstrated high binding affinity to CCR5 expressing CD4+ cells, monocytes, and other CCR5+ T-cells. Finally, the short-term pre-exposure prophylaxis study demonstrated that prolonged CCR5 blockage and ARV presence further induced a “protective immune phenotype” with a boosted T-helper (Th), temporary memory (TM), and effector (E) sub-population. The proof-of-concept study that the targeted-ARV nanoformulation dual-action mechanism could provide a multifactorial solution toward achieving HIV “functional cure.”

Advances in HIV Eradication Strategies

Abstract Although the advent of combination antiretroviral therapy can efficiently suppress human immunodeficiency virus (HIV) replication, a complete cure for HIV infection cannot be achieved due to the existence of latent viral reservoirs. In recent years, investigation of HIV cure strategies has become a hot topic in the field. In this article, we review the major barriers to HIV cure, compare the progress and challenges of non-specific and specific latent reversal agents in curing HIV, and discuss possible solutions to the current problems.

The BLT Humanized Mouse Model as a Tool for Studying Human Gamma Delta T Cell-HIV Interactions In Vivo.

Gamma-delta (γδ) T cells recognize antigens in a major histocompatibility complex (MHC) independent and have cytotoxic capability. Human immunodeficiency virus (HIV) infection reduces the proportion of the Vδ2 cell subset compared to the Vδ1 cell subset of γδ T cells in the blood in most infected individuals, except for elite controllers. The capacity of Vδ2 T cells to kill HIV-infected targets has been demonstrated in vitro, albeit in vivo confirmatory studies are lacking. Here, we provide the first characterization of γδ T cell-HIV interactions in bone marrow-liver-thymus (BLT) humanized mice and examined the immunotherapeutic potential of Vδ2 T cells in controlling HIV replication in vivo. We demonstrate a reduced proportion of Vδ2 T cells and an increased proportion of Vδ1 T cells in HIV-infected BLT humanized mice, like in HIV-positive individuals. HIV infection in BLT humanized mice also impaired the ex vivo expansion of Vδ2 T cells, like in HIV-positive individuals. Adoptive transfer of activated Vδ2 T cells did not control HIV replication during cell-associated HIV transmission in BLT humanized mice but instead exacerbated viremia, suggesting that Vδ2 T cells may serve as early targets for HIV replication. Our findings demonstrate that BLT humanized mice can model γδ T cell-HIV interactions in vivo.

Learning to Be Elite: Lessons From HIV-1 Controllers and Animal Models on Trained Innate Immunity and Virus Suppression.

Although antiretroviral therapy (ART) has drastically changed the lives of people living with human immunodeficiency virus-1 (HIV-1), long-term treatment has been associated with a vast array of comorbidities. Therefore, a cure for HIV-1 remains the best option to globally eradicate HIV-1/acquired immunodeficiency syndrome (AIDS). However, development of strategies to achieve complete eradication of HIV-1 has been extremely challenging. Thus, the control of HIV-1 replication by the host immune system, namely functional cure, has long been studied as an alternative approach for HIV-1 cure. HIV-1 elite controllers (ECs) are rare individuals who naturally maintain undetectable HIV-1 replication levels in the absence of ART and whose immune repertoire might be a desirable blueprint for a functional cure. While the role(s) played by distinct human leukocyte antigen (HLA) expression and CD8+ T cell responses expressing cognate ligands in controlling HIV-1 has been widely characterized in ECs, the innate immune phenotype has been decidedly understudied. Comparably, in animal models such as HIV-1-infected humanized mice and simian Immunodeficiency Virus (SIV)-infected non-human primates (NHP), viremic control is known to be associated with specific major histocompatibility complex (MHC) alleles and CD8+ T cell activity, but the innate immune response remains incompletely characterized. Notably, recent work demonstrating the existence of trained innate immunity may provide new complementary approaches to achieve an HIV-1 cure. Herein, we review the known characteristics of innate immune responses in ECs and available animal models, identify gaps of knowledge regarding responses by adaptive or trained innate immune cells, and speculate on potential strategies to induce EC-like responses in HIV-1 non-controllers.