Probes for INS

Background: Most new HIV infections result from sexual interactions with infected but untreated individuals. Semen is the main vector for viral transmission globally, however, little is known regarding the anatomic origin and form of virus in semen. Methods: In this study, we were able to combine numerous new technologies to characterize the virus present in the semen during SIV infection. Six rhesus macaques (RM) were challenged intravenously with barcoded virus SIVmac239M. Semen and blood samples were collected longitudinally for 17 days post-infection with all male genital tract (MGT) and multiple lymphoid tissues collected at necropsy and subjected to quantitative PCR, next generation sequencing of the viral barcode, and tissue analysis (RNAscope, DNAscope and immunophenotyping). Semen was also collected from 6 animals chronically infected with SIVmac251 and in five CD4 depleted animals in acute phase and 2 weeks post ART initiation. Results: Extremely high levels of viral RNA (vRNA) were detected in seminal plasma (up to 10^9cp/ml) as well as comparable levels of cell associated vRNA and vDNA in seminal cells with detection starting as early as 4 days post-infection. RNAscope and immunophenotyping of seminal cells and MGT tissues revealed myeloid cells as the main source of virus (Fig. 1), while CD4+T cells were harboring vRNA in lymphoid tissues. Sequences show evidence of an early compartment between seminal and blood plasma and no difference in the env gene of virus present in semen/MGT and in Lymph Nodes. Finally, multinuclear giant cells harboring vRNA were the only source of virus in semen in chronically infected and in CD4 depleted RM. Moreover, vRNA + myeloid cells were highly present in semen after 2 weeks on ART.

HIV-1 infection within the central nervous system (CNS) includes evolution of the virus, damaging inflammatory cascades, and the involvement of multiple cell types; however, our understanding of how Env tropism and inflammation can influence CNS infectivity is incomplete. In this study, we utilize macrophage-tropic and T cell-tropic HIV-1 Env proteins to establish accurate infection profiles for multiple CNS cells under basal and interferon alpha (IFN-α) or lipopolysaccharide (LPS)-induced inflammatory states. We found that macrophage-tropic viruses confer entry advantages in primary myeloid cells, including monocyte-derived macrophage, microglia, and induced pluripotent stem cell (iPSC)-derived microglia. However, neither macrophage-tropic or T cell-tropic HIV-1 Env proteins could mediate infection of astrocytes or neurons, and infection was not potentiated by induction of an inflammatory state in these cells. Additionally, we found that IFN-α and LPS restricted replication in myeloid cells, and IFN-α treatment prior to infection with vesicular stomatitis virus G protein (VSV G) Envs resulted in a conserved antiviral response across all CNS cell types. Further, using RNA sequencing (RNA-seq), we found that only myeloid cells express HIV-1 entry receptor/coreceptor transcripts at a significant level and that these transcripts in select cell types responded only modestly to inflammatory signals. We profiled the transcriptional response of multiple CNS cells to inflammation and found 57 IFN-induced genes that were differentially expressed across all cell types. Taken together, these data focus attention on the cells in the CNS that are truly permissive to HIV-1, further highlight the role of HIV-1 Env evolution in mediating infection in the CNS, and point to limitations in using model cell types versus primary cells to explore features of virus-host interaction. IMPORTANCE The major feature of HIV-1 pathogenesis is the induction of an immunodeficient state in the face of an enhanced state of inflammation. However, for many of those infected, there can be an impact on the central nervous system (CNS) resulting in a wide range of neurocognitive defects. Here, we use a highly sensitive and quantitative assay for viral infectivity to explore primary and model cell types of the brain for their susceptibility to infection using viral entry proteins derived from the CNS. In addition, we examine the ability of an inflammatory state to alter infectivity of these cells. We find that myeloid cells are the only cell types in the CNS that can be infected and that induction of an inflammatory state negatively impacts viral infection across all cell types.

To explore genome organization and function in the HIV-infected brain, we applied single-nuclei transcriptomics, cell-type-specific chromosomal conformation mapping, and viral integration site sequencing (IS-seq) to frontal cortex from individuals with encephalitis (HIVE) and without (HIV+). Derepressive changes in 3D genomic compartment structures in HIVE microglia were linked to the transcriptional activation of interferon (IFN) signaling and cell migratory pathways, while transcriptional downregulation and repressive compartmentalization of neuronal health and signaling genes occurred in both HIVE and HIV+ microglia. IS-seq recovered 1,221 brain integration sites showing distinct genomic patterns compared with peripheral lymphocytes, with enrichment for sequences newly mobilized into a permissive chromatin environment after infection. Viral transcription occurred in a subset of highly activated microglia comprising 0.33% of all nuclei in HIVE brain. Our findings point to disrupted microglia-neuronal interactions in HIV and link retroviral integration to remodeling of the microglial 3D genome during infection.

To discuss the role of CD4+ T cells with active Human immunodeficiency virus (HIV), meaning infected cells with transcriptional and/or translational viral activity during antiretroviral therapy (ART), focusing on new technologies for its detection, potential cell markers for its characterization, and evidences on the contribution of the active HIV reservoir to long-term viral persistence.HIV-infected cells expressing viral ribonucleic acid are systematically detected in subjects on long-term ART. In recent years, powerful new tools have provided significant insights into the nature, quantification, and identification of cells with active HIV, including the identification of new cell markers, and the presence of viral activity in specific cell populations located in different cellular and anatomical compartments. Moreover, studies on viral sequence integrity have identified cell clones with intact viral genomes and active viral transcription that could potentially persist for years. Together, new investigations support the notion that the active reservoir could represent a relevant fraction of long-term infected cells, and therefore, the study of its cell sources and mechanisms of maintenance could represent a significant advance in our understanding of viral persistence and the development of new curative strategies.The presence of HIV-infected cells with viral expression during ART has been traditionally overlooked for years. Based on recent investigations, this active viral reservoir could play an important role in HIV persistence.

The chronic infection established by the human immunodeficiency virus 1 (HIV-1) produces serious CD4+ T cell immunodeficiency despite the decrease in HIV-1 ribonucleic acid (RNA) levels and the raised life expectancy of people living with HIV-1 (PLWH) through treatment with combined antiretroviral therapies (cART). HIV-1 enters the central nervous system (CNS), where perivascular macrophages and microglia are infected. Serious neurodegenerative symptoms related to HIV-associated neurocognitive disorders (HAND) are produced by infection of the CNS. Despite advances in the treatment of this infection, HAND significantly contribute to morbidity and mortality globally. The pathogenesis and the role of inflammation in HAND are still incompletely understood. Principally, growing evidence shows that the CNS is an anatomical reservoir for viral infection and replication, and that its compartmentalization can trigger the evolution of neurological damage and thus make virus eradication more difficult. In this review, important concepts for understanding HAND and neuropathogenesis as well as the viral proteins involved in the CNS as an anatomical reservoir for HIV infection are discussed. In addition, an overview of the recent advancements towards therapeutic strategies for the treatment of HAND is presented. Further neurological research is needed to address neurodegenerative difficulties in people living with HIV, specifically regarding CNS viral reservoirs and their effects on eradication.

Painful peripheral neuropathy is a common neurological complication associated with human immunodeficiency virus (HIV) infection and anti-retroviral therapy. We characterized the impact of two CB2 cannabinoid agonists (AM1710 and LY2828360 - ligands differing in signaling bias and CNS penetration) on neuropathic nociception induced by the antiretroviral agent Zalcitabine (2',3'-dideoxycytidine; ddC). We also used a conditional knockout approach to identify cell types mediating CB2 agonist-induced antinociceptive efficacy and sparing of morphine tolerance. AM1710 and LY2828360 alleviated ddC-induced neuropathic nociception in mice of both sexes. These benefits were absent in global CB2 knockout mice, which exhibited robust morphine antinociception. Like morphine, AM1710 blunted ddC-induced increases in proinflammatory cytokine (IL-1β, TNF-α) and chemokine (CCL2) mRNA expression levels. We generated advillinCre/+;CB2f/f conditional knockout mice to ascertain the role of CB2 localized to primary sensory neurons in CB2-mediated therapeutic effects. Antinociceptive efficacy of both AM1710 and LY2828360, but not reference analgesics, were absent in advillinCre/+;CB2f/f mice, which exhibited robust ddC-induced neuropathy. In ddC-treated CB2f/f mice, LY2828360 suppressed development of morphine tolerance and reversed established morphine tolerance, albeit with greater efficacy in male compared to female mice. LY2828360 failed to block or reverse morphine tolerance in advillinCre/+;CB2f/f mice. The present studies indicate that CB2 activation may alleviate HIV-associated antiretroviral neuropathy and identify a previously unreported mechanism through which CB2 activation produces antinociceptive efficacy. Our results also provide the first evidence that a CB2 agonist can reverse established morphine tolerance and demonstrate that CB2 localized to peripheral sensory neurons mediates the opioid tolerance sparing efficacy of CB2 agonists.

Background: HIV-specific chimeric antigen receptor T (CAR T) cells are being developed as a potential approach towards curing HIV infection. During infection, HIV replication is concentrated in B cell follicles, and viral reservoirs such as B cell follicles are a significant barrier to an HIV cure. We developed HIV-specific CAR T cells expressing the follicular homing receptor CXCR5 (CAR/CXCR5 T cells) to target follicular HIV reservoirs. We hypothesized after infusion of CAR/CXCR5 T cells in humanized HIV-infected DRAGA mice, CAR/CXCR5 T cells would accumulate in lymphoid follicles, make direct contact with HIV+ cells, lead to reductions in HIV viral loads, and preserve human CD4 T cells. Methods: Fourteen female humanized DRAGA mice were included in this study. Twelve mice were infected with 10 000 TCID50 of HIV-1 BaL. Levels of HIV-1 plasma viral loads and CD4 T cells were monitored using qRT-PCR and flow cytometry. Two spleens from uninfected mice were used to produce transduced CAR/CXCR5 T cells and transduced cell products (2×105 cells/gram) were infused in six HIV-infected mice. RNAscope combined with immunohistochemistry was used to visualize locations and quantities of CAR/CXCR5 T cells and HIV vRNA+ cells in lymphoid tissues. Results: All mice were HIV-1 detectable nbefore infusion of CAR/CXCR5 T cells. High levels of CAR/CXCR5 T cells and HIV vRNA+ cells were detected at 6 days post-infusion in lymphoid tissues. Many CAR/CXCR5 T cells were found in direct contact with HIV vRNA+ cells. However, many CAR/CXCR5 T cells, presumably CD4+ cells, were HIV vRNA+ and likely spreading infection. No differences in HIV plasma viral loads or CD4 T cell counts were observed between control and treated animals. Conclusions: These studies support the use of the HIV-infected DRAGA mouse model for HIV cure research studies. Using this model, we showed CAR/CXCR5 T cells accumulate in follicle-like structures with HIV vRNA+ cells and come in contact with vRNA+ cells. The simultaneous detection of CAR T cells with high levels of HIV vRNA+ cells indicates the need for HIV-resistant CAR T cells. These preliminary findings demonstrate the HIV-infected DRAGA mouse model is extremely valuable for evaluating HIV cure approaches.

Although current antiretroviral therapy (ART) has increased life expectancy, a cure for human immunodeficiency virus (HIV) remains elusive due to the persistence of the virus in tissue reservoirs. In the present study, we sought to elucidate the relationship between antiretrovirals (ARVs) and viral expression in the spleen. We performed mass spectrometry imaging (MSI) of 6 different ARVs, RNAscope in situ hybridization of viral RNA, and immunohistochemistry of three different fibrosis markers in the spleens of 8 uninfected and 10 reverse transcriptase simian-human immunodeficiency virus (RT-SHIV)-infected rhesus macaques (infected for 6 weeks) that had been dosed for 10 days with combination ART. Using MATLAB, computational quantitative imaging analysis was performed to evaluate the spatial and pharmacological relationships between the 6 ARVs, viral RNA, and fibrotic deposition. In these spleens, >50% of the spleen tissue area was not covered by any detectable ARV response (any concentration above the limits of detection for individual ARVs). The median spatial ARV coverage across all tissues was driven by maraviroc followed by efavirenz. Yet >50% of RNA-positive cells were not exposed to any detectable ARV. Quantifiable maraviroc and efavirenz colocalization with RNA-positive cells was usually greater than the in vitro concentration inhibiting 50% replication (IC50). Fibrosis markers covered more than 50% of the spleen tissue area and had negative relationships with cumulative ARV coverages. Our findings suggest that a heterogeneous ARV spatial distribution must be considered when evaluating viral persistence in lymphoid tissue reservoirs.

Emerging literature suggests that experiences of discrimination negatively influence health and well-being. It is unfortunately common for people living with HIV (PLWH) to be stigmatized and discriminated against because of their HIV status and other marginalized identities (e.g., ethnicity/race, sexual identity and orientation). To date, little research has specifically examined discrimination in PWLH and its associations with pain and other pain-relevant factors such as mood and sleep. The purpose of this ongoing study was to preliminarily analyze associations among daily experiences of discrimination, pain severity and interference, depressive symptoms, and sleep in PLWH. Participants included 24 PLWH recruited from a local HIV treatment center. Participants completed The Everyday Discrimination Scale (TEDS) followed by the Brief Pain Inventory - Short Form (BPI-SF), the Insomnia Severity Index (ISI), and the Center for Epidemiologic Studies - Depression Scale (CES-D). Initial findings tentatively suggest that more frequent daily experiences of discrimination may be significantly associated with greater pain interference on the BPI-SF (p = .030) and greater severity of insomnia symptoms on the ISI (p = .059). However, it appears that daily experiences of discrimination may not be meaningfully associated with pain severity on the BPI-SF (p = .401) or depressive symptoms on the CES-D (p = .235). Our findings highlight the potentially deleterious effects of daily discrimination experiences on pain and sleep in in PLWH. As this ongoing study recruits a larger sample of PLWH, data will need to be reanalyzed to better determine the durability of these preliminary findings. However, there is potential that findings from this study may assist in elucidating causal pathways linking discrimination to pain and pain relevant health behaviors like sleep in PLWH. Grant support from The Impact of Insomnia on Pain, Physical Function, and Inflammation in HIV (3R01HL147603-03S1).

Background: Early after primary infection, HIV reservoirs are established within multiple tissues, including the brain. As these viral reservoirs are not targeted by antiretroviral therapy (cART), we require robust methods of detection, quantification, and characterization of these viral reservoirs in human tissues. Our recent work developed a multi-component imaging methodology that characterizes and quantifies viral reservoirs within the brain. Methods: The imaging methodology demonstrated utilizes the simultaneous staining of brain tissue from HIV-infected donors using DNAscope, RNAscope, and antibodies for HIV-DNA, HIV-mRNA, and either viral or host proteins, respectively. The panel of patients included in these analyses varied in cART regimen, viral load, years living with HIV, and neurocognitive status, all contrasted to age-matched tissues from uninfected patients. Results: Our group demonstrated that cART is sufficient to reduce the size of the viral reservoirs within the brains of HIV patients. We also found that about half of the cells positive for HIV-DNA expressed HIV-mRNA, and only about one-third expressed viral proteins. HIV proteins varied in expression and bystander uptake by uninfected cells but could provide insight into bystander toxicity. Conclusions: The results found were present irrespective of cART regimen and systemic viral replication but suggested that these viral reservoirs are a major barrier to curing HIV and treating associated neurocognitive disorders.

Since the first HIV-cured person was reported in 2009, a strong interest in developing highly sensitive HIV and SIV reservoir assays has emerged. In particular, the question arose about the comparative value of state-of-the-art assays to measure and characterize the HIV reservoir, and how these assays can be applied to accurately detect changes in the reservoir during efforts to develop a cure for HIV infection. Secondly, it is important to consider the impact on the outcome of clinical trials if these relatively new HIV reservoir assays are incorporated into clinical trial endpoints and/or used for clinical decision-making. To understand the advantages and limitations and the regulatory implications of HIV reservoir assays, the National Institute of Allergy and Infectious Diseases (NIAID) sponsored and convened a meeting on September 16, 2022, to discuss the state of knowledge concerning these questions and best practices for selecting HIV reservoir assays for a particular research question or clinical trial protocol.

Background: HIV infection persists predominantly within follicular helper CD4+ T cell-rich B cell follicles of lymphoid tissues. Cytotoxic CD8+ T cells, which are associated with natural control of HIV infection in peripheral blood, are relatively excluded from this niche, representing a potential barrier to cellular immunity and HIV cure. To better understand the mechanisms of HIV control within lymph nodes (LN), we investigated functionality, clonotypic compartmentalization, spatial localization, phenotypic characteristics and transcriptional profiles of LN-resident virus-specific and CXCR5-expressing follicular CD8+ T cells (fCD8) in persons who control HIV without medications. Methods: We obtained paired excisional inguinal LN biopsies and peripheral blood (PB) from 19 spontaneous HIV controllers and 17 HIV+ individuals on long-term ART. HIV-specific CD8+ T cell responses were identified by IFN-γ ELISpot and functional response to antigenic stimulation was measured by flow cytometry and CFSE-based proliferation assay. Clonotypic compartmentalization and transcriptional signatures associated with localization of HIV-specific CD8+ T cells were assessed via TCR and RNA-sequencing. Spatial relationships between ongoing viral replication and fCD8 cytotoxic effector potential in GCs were measured by HIV gagpol RNAscope and immunofluorescence on fixed LN sections. Results: Antigen-induced HIV-specific CD8+ T cell proliferation and cytolytic effector upregulation consistently distinguished spontaneous controllers from noncontrollers in PB (p=0.03) and LN (p=0.04). HIV-specific CD8+ T cells from both compartments shared TCR clonotypic composition (Morisita-Horn Similarity Index 0.8-1.0), consistent with ongoing infiltration from circulation. Migration into LNs was associated with gene signatures of inflammatory chemotaxis and antigen-induced effector function. The cytolytic effectors perforin and granzyme B were elevated among virus-specific CXCR5 + fCD8 s (p