RESUMO
PURPOSE OF REVIEW: HIV reservoirs are the main barrier to cure. CD4+ T cells have been extensively studied as the primary HIV-1 reservoir. However, there is substantial evidence that HIV-1-infected myeloid cells (monocytes/macrophages) also contribute to viral persistence and pathogenesis. RECENT FINDINGS: Recent studies in animal models and people with HIV-1 demonstrate that myeloid cells are cellular reservoirs of HIV-1. HIV-1 genomes and viral RNA have been reported in circulating monocytes and tissue-resident macrophages from the brain, urethra, gut, liver, and spleen. Importantly, viral outgrowth assays have quantified persistent infectious virus from monocyte-derived macrophages and tissue-resident macrophages. The myeloid cell compartment represents an important target of HIV-1 infection. While myeloid reservoirs may be more difficult to measure than CD4+ T cell reservoirs, they are long-lived, contribute to viral persistence, and, unless specifically targeted, will prevent an HIV-1 cure.
Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Humanos , Infecções por HIV/patologia , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Macrófagos , Linfócitos T CD4-Positivos , Latência Viral , Carga ViralRESUMO
The development of persistent cellular reservoirs of latent human immunodeficiency virus (HIV) is a critical obstacle to viral eradication since viral rebound takes place once anti-retroviral therapy (ART) is interrupted. Previous studies show that HIV persists in myeloid cells (monocytes and macrophages) in blood and tissues in virologically suppressed people with HIV (vsPWH). However, how myeloid cells contribute to the size of the HIV reservoir and what impact they have on rebound after treatment interruption remain unclear. Here we report the development of a human monocyte-derived macrophage quantitative viral outgrowth assay (MDM-QVOA) and highly sensitive T cell detection assays to confirm purity. We assess the frequency of latent HIV in monocytes using this assay in a longitudinal cohort of vsPWH (n = 10, 100% male, ART duration 5-14 yr) and find half of the participants showed latent HIV in monocytes. In some participants, these reservoirs could be detected over several years. Additionally, we assessed HIV genomes in monocytes from 30 vsPWH (27% male, ART duration 5-22 yr) utilizing a myeloid-adapted intact proviral DNA assay (IPDA) and demonstrate that intact genomes were present in 40% of the participants and higher total HIV DNA correlated with reactivatable latent reservoirs. The virus produced in the MDM-QVOA was capable of infecting bystander cells resulting in viral spread. These findings provide further evidence that myeloid cells meet the definition of a clinically relevant HIV reservoir and emphasize that myeloid reservoirs should be included in efforts towards an HIV cure.
Assuntos
Infecções por HIV , HIV-1 , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Masculino , Humanos , Feminino , Infecções por HIV/tratamento farmacológico , Vírus da Imunodeficiência Símia/genética , Antirretrovirais/uso terapêutico , HIV-1/genética , Latência Viral , MacrófagosRESUMO
OBJECTIVE: Simian immunodeficiency virus (SIV) infection of macaques recapitulates many aspects of HIV pathogenesis and is similarly affected by both genetic and environmental factors. Psychosocial stress is associated with immune system dysregulation and worse clinical outcomes in people with HIV. This study assessed the impact of single housing, as a model of psychosocial stress, on innate immune responses of pigtailed macaques ( Macaca nemestrina ) during acute SIV infection. METHODS: A retrospective analysis of acute SIV infection of 2- to si6-year-old male pigtailed macaques was performed to compare the innate immune responses of socially ( n = 41) and singly ( n = 35) housed animals. Measures included absolute monocyte count and subsets, and in a subset ( n ≤ 18) platelet counts and activation data. RESULTS: SIV infection resulted in the expected innate immune parameter changes with a modulating effect from housing condition. Monocyte number increased after infection for both groups, driven by classical monocytes (CD14 + CD16 - ), with a greater increase in socially housed animals (227%, p < .001, by day 14 compared with preinoculation time points). Platelet numbers recovered more quickly in the socially housed animals. Platelet activation (P-selectin) increased by 65% ( p = .004) and major histocompatibility complex class I surface expression by 40% ( p = .009) from preinoculation only in socially housed animals, whereas no change in these measures occurred in singly housed animals. CONCLUSIONS: Chronic psychosocial stress produced by single housing may play an immunomodulatory role in the innate immune response to acute retroviral infection. Dysregulated innate immunity could be one of the pathways by which psychosocial stress contributes to immune suppression and increased disease severity in people with HIV.
Assuntos
Infecções por HIV , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Habitação , Imunidade Inata , Macaca nemestrina , Masculino , Selectina-P/farmacologia , Estudos Retrospectivos , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Vírus da Imunodeficiência Símia/genética , Estresse PsicológicoRESUMO
BACKGROUND: Although social distancing is a key public health response during viral pandemics, psychosocial stressors, such as social isolation, have been implicated in adverse health outcomes in general [1] and in the context of infectious disease, such as human immunodeficiency virus (HIV) [2, 3]. A comprehensive understanding of the direct pathophysiologic effects of psychosocial stress on viral pathogenesis is needed to provide strategic and comprehensive care to patients with viral infection. METHODS: To determine the effect of psychosocial stress on HIV pathogenesis during acute viral infection without sociobehavioral confounders inherent in human cohorts, we compared commonly measured parameters of HIV progression between singly (nâ =â 35) and socially (nâ =â 41) housed simian immunodeficiency virus (SIV)-infected pigtailed macaques (Macaca nemestrina). RESULTS: Singly housed macaques had a higher viral load in the plasma and cerebrospinal fluid and demonstrated greater CD4 T-cell declines and more CD4 and CD8 T-cell activation compared with socially housed macaques throughout acute SIV infection. CONCLUSIONS: These data demonstrate that psychosocial stress directly impacts the pathogenesis of acute SIV infection and imply that it may act as an integral variable in the progression of HIV infection and potentially of other viral infections.
Assuntos
Infecções por HIV , HIV/patogenicidade , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Estresse Psicológico , Animais , Linfócitos T CD4-Positivos/imunologia , Humanos , Ativação Linfocitária , Macaca nemestrina , Síndrome de Imunodeficiência Adquirida dos Símios/psicologia , Carga ViralRESUMO
BACKGROUNDIdentifying a quantitative biomarker of neuropsychiatric dysfunction in people with HIV (PWH) remains a significant challenge in the neuroHIV field. The strongest evidence to date implicates the role of monocytes in central nervous system (CNS) dysfunction in HIV, yet no study has examined monocyte subsets in blood as a correlate and/or predictor of neuropsychiatric function in virally suppressed PWH.METHODSIn 2 independent cohorts of virologically suppressed women with HIV (vsWWH; n = 25 and n = 18), whole blood samples were obtained either in conjunction with neuropsychiatric assessments (neuropsychological [NP] test battery, self-report depression and stress-related symptom questionnaires) or 1 year prior to assessments. Immune cell subsets were assessed by flow cytometry.RESULTSA higher proportion of intermediate monocytes (CD14+CD16+) was associated with lower global NP function when assessing monocytes concurrently and approximately 1 year before (predictive) NP testing. The same pattern was seen for executive function (mental flexibility) and processing speed. Conversely, there were no associations with monocyte subsets and depression or stress-related symptoms. Additionally, we found that a higher proportion of classical monocytes was associated with better cognition.CONCLUSIONAlthough it is widely accepted that lentiviral infection of the CNS targets cells of monocyte-macrophage-microglial lineage and is associated with an increase in intermediate monocytes in the blood and monocyte migration into the brain, the percentage of intermediate monocytes in blood of vsWWH has not been associated with neuropsychiatric outcomes. Our findings provide evidence for a new, easily measured, blood-based cognitive biomarker in vsWWH.FUNDINGR01-MH113512, R01-MH113512-S, P30-AI094189, R01-MH112391, R01-AI127142, R00-DA044838, U01-AI35004, and P30-MH075673.
Assuntos
Cognição , Depressão/imunologia , Infecções por HIV/imunologia , Monócitos/imunologia , Estresse Psicológico/imunologia , Adulto , Fármacos Anti-HIV/uso terapêutico , Depressão/psicologia , Função Executiva , Feminino , Citometria de Fluxo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/psicologia , Humanos , Imunofenotipagem , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estresse Psicológico/psicologia , Resposta Viral SustentadaRESUMO
The relevance of monocyte and macrophage reservoirs in virally suppressed people with HIV (vsPWH) has previously been debatable. Macrophages were assumed to have a moderate life span and lack self-renewing potential. However, recent studies have challenged this dogma and now suggest an important role of these cell as long-lived HIV reservoirs. Lentiviruses have a long-documented association with macrophages and abundant evidence exists that macrophages are important target cells for HIV in vivo. A critical understanding of HIV infection, replication, and latency in macrophages is needed in order to determine the appropriate method of measuring and eliminating this cellular reservoir. This review provides a brief discussion of the biology and acute and chronic infection of monocytes and macrophages, with a more substantial focus on replication, latency and measurement of the reservoir in cells of myeloid origin.
Assuntos
Infecções por HIV , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Linfócitos T CD4-Positivos , Humanos , Macrófagos , Monócitos , Replicação ViralRESUMO
: The current review examines the role of brain macrophages, that is perivascular macrophages and microglia, as a potential viral reservoir in antiretroviral therapy (ART) treated, simian immunodeficiency virus (SIV)-infected macaques. The role, if any, of latent viral reservoirs of HIV and SIV in the central nervous system during ART suppression is an unresolved issue. HIV and SIV infect both CD4 lymphocytes and myeloid cells in blood and tissues during acute and chronic infection. HIV spread to the brain occurs during acute infection by the infiltration of activated CD4 lymphocytes and monocytes from blood and is established in both embryonically derived resident microglia and monocyte-derived perivascular macrophages. ART controls viral replication in peripheral blood and cerebrospinal fluid in HIV-infected individuals but does not directly eliminate infected cells in blood, tissues or brain. Latently infected resting CD4 lymphocytes in blood and lymphoid tissues are a well recognized viral reservoir that can rebound once ART is withdrawn. In contrast, central nervous system resident microglia and perivascular macrophages in brain have not been examined as potential reservoirs for HIV during suppressive ART. Macrophages in tissues are long-lived cells that are HIV and SIV infected in tissues such as gut, lung, spleen, lymph node and brain and contribute to ongoing inflammation in tissues. However, their potential role in viral persistence and latency or their potential to rebound in the absence ART has not been examined. It has been shown that measurement of HIV latency by HIV DNA PCR in CD4 lymphocytes overestimates the size of the latent reservoirs of HIV that contribute to rebound that is cells containing the genomes of replicative viruses. Thus, the quantitative viral outgrowth assay has been used as a reliable measure of the number of latent cells that harbor infectious viral DNA and, may constitute a functional latent reservoir. Using quantitative viral outgrowth assays specifically designed to quantitate latently infected CD4 lymphocytes and myeloid cells in an SIV macaque model, we demonstrated that macrophages in brain harbor SIV genomes that reactivate and produce infectious virus in this assay, demonstrating that these cells have the potential to be a reservoir.
Assuntos
Encéfalo/virologia , Macrófagos/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Latência Viral , Animais , Antirretrovirais/uso terapêutico , Encéfalo/imunologia , Linfócitos T CD4-Positivos/virologia , Infecções por HIV/tratamento farmacológico , Humanos , Macaca mulatta , Células Mieloides/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/imunologia , Carga Viral , Replicação ViralRESUMO
Human immunodeficiency virus (HIV) eradication or long-term suppression in the absence of antiretroviral therapy (ART) requires an understanding of all viral reservoirs that could contribute to viral rebound after ART interruption. CD4 T cells (CD4s) are recognized as the predominant reservoir in HIV type 1 (HIV-1)-infected individuals. However, macrophages are also infected by HIV-1 and simian immunodeficiency virus (SIV) during acute infection and may persist throughout ART, contributing to the size of the latent reservoir. We sought to determine whether tissue macrophages contribute to the SIVmac251 reservoir in suppressed macaques. Using cell-specific quantitative viral outgrowth assays (CD4-QVOA and MΦ-QVOA), we measured functional latent reservoirs in CD4s and macrophages in ART-suppressed SIVmac251-infected macaques. Spleen, lung, and brain in all suppressed animals contained latently infected macrophages, undetectable or low-level SIV RNA, and detectable SIV DNA. Silent viral genomes with potential for reactivation and viral spread were also identified in blood monocytes, although these cells might not be considered reservoirs due to their short life span. Additionally, virus produced in the MΦ-QVOA was capable of infecting healthy activated CD4s. Our results strongly suggest that functional latent reservoirs in CD4s and macrophages can contribute to viral rebound and reestablishment of productive infection after ART interruption. These findings should be considered in the design and implementation of future HIV cure strategies.IMPORTANCE This study provides further evidence that the latent reservoir is comprised of both CD4+ T cells and myeloid cells. The data presented here suggest that CD4+ T cells and macrophages found throughout tissues in the body can contain replication-competent SIV and contribute to rebound of the virus after treatment interruption. Additionally, we have shown that monocytes in blood contain latent virus and, though not considered a reservoir themselves due to their short life span, could contribute to the size of the latent reservoir upon entering the tissue and differentiating into long-lived macrophages. These new insights into the size and location of the SIV reservoir using a model that is heavily studied in the HIV field could have great implications for HIV-infected individuals and should be taken into consideration with the development of future HIV cure strategies.
Assuntos
Antirretrovirais/farmacologia , Linfócitos T CD4-Positivos/virologia , Infecções por HIV/virologia , Macrófagos/virologia , Células Mieloides/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Latência Viral , Animais , Modelos Animais de Doenças , Genoma Viral , Pulmão , Macaca mulatta , Masculino , Monócitos , Vírus da Imunodeficiência Símia/genética , Baço , Carga Viral , Replicação ViralRESUMO
Evaluation of HIV cure strategies is complicated by defective proviruses that persist in ART-treated patients but are irrelevant to cure. Non-human primates (NHP) are essential for testing cure strategies. However, the persisting proviral landscape in ART-treated NHPs is uncharacterized. Here, we describe viral genomes persisting in ART-treated, simian immunodeficiency virus (SIV)-infected NHPs, simian-human immunodeficiency virus (SHIV)-infected NHPs, and humans infected with HIV-2, an SIV-related virus. The landscapes of persisting SIV, SHIV, and HIV-2 genomes are also dominated by defective sequences. However, there was a significantly higher fraction of intact SIV proviral genomes compared to ART-treated HIV-1 or HIV-2 infected humans. Compared to humans with HIV-1, SIV-infected NHPs had more hypermutated genomes, a relative paucity of clonal SIV sequences, and a lower frequency of deleted genomes. Finally, we report an assay for measuring intact SIV genomes which may have value in cure research.
Assuntos
Antirretrovirais/uso terapêutico , Variação Genética , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , HIV-2/efeitos dos fármacos , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Animais , Vírus Defeituosos/genética , Genoma Viral , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/genética , HIV-2/classificação , HIV-2/genética , Humanos , Macaca mulatta , Provírus/genética , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/classificação , Vírus da Imunodeficiência Símia/genéticaRESUMO
Understanding the cellular and anatomical sites of latent virus that contribute to human immunodeficiency virus (HIV) rebound is essential for eradication. In HIV-positive patients, CD4+ T lymphocytes comprise a well-defined functional latent reservoir, defined as cells containing transcriptionally silent genomes able to produce infectious virus once reactivated. However, the persistence of infectious latent virus in CD4+ T cells in compartments other than blood and lymph nodes is unclear. Macrophages (MÏ) are infected by HIV/simian immunodeficiency virus (SIV) and are likely to carry latent viral genomes during antiretroviral therapy (ART), contributing to the reservoir. Currently, the gold standard assay used to measure reservoirs containing replication-competent virus is the quantitative viral outgrowth assay (QVOA). Using an SIV-macaque model, the CD4+ T cell and MÏ functional latent reservoirs were measured in various tissues using cell-specific QVOAs. Our results showed that blood, spleen, and lung in the majority of suppressed animals contain latently infected MÏs. Surprisingly, the numbers of CD4+ T cells, monocytes, and MÏs carrying infectious genomes in blood and spleen were at comparable frequencies (â¼1 infected cell per million). We also demonstrate that ex vivo viruses produced in the MÏ QVOA are capable of infecting activated CD4+ T cells. These results strongly suggest that latently infected tissue MÏs can reestablish productive infection upon treatment interruption. This study provides the first comparison of CD4+ T cell and MÏ functional reservoirs in a macaque model. It is the first confirmation of the persistence of latent genomes in monocytes in blood and MÏs in the spleen and lung of SIV-infected ART-suppressed macaques. Our results demonstrate that transcriptionally silent genomes in MÏs can contribute to viral rebound after ART interruption and should be considered in future HIV cure strategies.IMPORTANCE This study suggests that CD4+ T cells found throughout tissues in the body can contain replication-competent SIV and contribute to rebound of the virus after treatment interruption. In addition, this study demonstrates that macrophages in tissues are another cellular reservoir for SIV and may contribute to viral rebound after treatment interruption. This new insight into the size and location of the SIV reservoir could have great implications for HIV-infected individuals and should be taken into consideration for the development of future HIV cure strategies.
Assuntos
Antirretrovirais/administração & dosagem , Linfócitos T CD4-Positivos/virologia , Macrófagos/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Latência Viral , Animais , Células Sanguíneas/virologia , Células Cultivadas , Pulmão/virologia , Macaca , Vírus da Imunodeficiência Símia/isolamento & purificação , Baço/virologiaRESUMO
PURPOSE OF REVIEW: In addition to preventive protocols and antiretroviral therapy, HIV-1 eradication has been considered as an additional strategy to help fight the AIDS epidemic. With the support of multiple funding agencies, research groups worldwide have been developing protocols to achieve either a sterilizing or a functional cure for HIV-infection. RECENT FINDINGS: Most of the studies focus on the elimination or suppression of circulating CD4+ T cells, the best characterized HIV-1 latent reservoir. The role of the central nervous system (CNS) as a latent reservoir is still controversial. Although brain macrophages and astrocytes are susceptible to HIV-1 infection, it has not been ascertained whether the CNS carries latent HIV-1 during cART and, if so, whether the virus can be reactivated and spread to other compartments after ART interruption. Here, we examine the implications of HIV-1 eradication strategies on the CNS, regardless of whether it is a true latent reservoir and, if so, whether it is present in all patients.
Assuntos
Encéfalo/virologia , Linfócitos T CD4-Positivos/virologia , Erradicação de Doenças/métodos , Infecções por HIV/tratamento farmacológico , HIV-1/fisiologia , Latência Viral/fisiologia , Astrócitos/virologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Reservatórios de Doenças/virologia , HIV-1/efeitos dos fármacos , Humanos , Macrófagos/virologia , Latência Viral/efeitos dos fármacosRESUMO
An integral component of the antiviral response, type I IFNs require regulation to modulate immune activation. We identify ß-arrestin 2 as a key modulator of type I IFN in primary human macrophages, an essential component of the innate immune response. ß-Arrestin 2 was selectively activated by CCL2/CCR2 signaling, which induced a decrease in IFN-α, but not IFN-ß expression. Small interfering RNA knockdown of ß-arrestin 2 demonstrated its role in IFNAR1 internalization, as well as STAT1 and IRF3 activation. As a result, cytokine responses were not propagated following HIV infection and TLR3 activation. However, remnants of IFN signaling remained intact, despite ß-arrestin 2 activation, as IFN-ß, IFN-γ, IFN-λ1, IRF7, TRAIL, and MxA expression were sustained. Similar effects of ß-arrestin 2 on IFN signaling occurred in hepatocytes, suggesting that arrestins may broadly modulate IFN responses in multiple cell types. In summary, we identify a novel role of ß-arrestin 2 as an integral regulator of type I IFN through its internalization of IFNAR1 and a subsequent selective loss of downstream IFN signaling.
Assuntos
Infecções por HIV/imunologia , HIV-1/fisiologia , Hepatócitos/fisiologia , Interferon-alfa/metabolismo , Macrófagos/imunologia , Receptor de Interferon alfa e beta/metabolismo , beta-Arrestina 2/metabolismo , Células Cultivadas , Quimiocina CCL2/metabolismo , Humanos , Imunidade Inata , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Interferon Tipo I/imunologia , Cultura Primária de Células , RNA Interferente Pequeno/genética , Receptores CCR2/metabolismo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais , Receptor 3 Toll-Like/metabolismo , Ativação Transcricional , beta-Arrestina 2/genéticaRESUMO
Lentiviruses are retroviruses that primarily infect myeloid cells, leading to acute inflammatory infections in many tissues particularly, lung, joints and the central nervous system (CNS). Acute infection by lentiviruses is followed by persistent/latent infections that are not cleared by the host immune system. HIV and SIV are lentiviruses that also infect CD4+ lymphocytes as well as myeloid cells in blood and multiple tissues. HIV infection of myeloid cells in brain, lung and heart cause tissue specific diseases as well as infect cells in gut, lymph nodes and spleen. AIDS dementia and other tissue specific disease are observed when infected individuals are immunosuppressed and the number of circulating CD4+ T cells declines to low levels. Antiretroviral therapy (ART) controls viral spread and dramatically changes the course of immunodeficiency and AIDS dementia. However, ART does not eliminate virus-infected cells. Brain macrophages contain HIV DNA and may represent a latent reservoir that persists. HIV latency in CD4+ lymphocytes is the main focus of current research and concern in efforts to eradicate HIV. However, a number of studies have demonstrated that myeloid cells in blood and tissues of ART suppressed individuals harbor HIV DNA. The resident macrophages in tissues such as brain (microglia), spleen (red pulp macrophages) and alveolar macrophages in lung are derived from the yolk sac and can self renew. The question of the latent myeloid reservoir in HIV has not been rigorously examined and its potential as a barrier to eradication been considered. Using a well characterized SIV ART suppressed, non-human primate (NHP) model, our laboratory developed the first quantitative viral outgrowth assay (QVOA) designed to evaluate latently infected CD4+ lymphocytes and more recently developed a similar protocol for the assessment of latently infected myeloid cells in blood and brain. Using an SIV ART model, it was demonstrated that myeloid cells in blood and brain harbor latent SIV that can be reactivated and produce infectious virus in vitro. These studies demonstrate for the first time that myeloid cells have the potential to be a latent reservoir of HIV that produces infectious virus that can be reactivated in the absence of ART and during HIV eradication strategies. Graphical Abstract.
Assuntos
Encéfalo/virologia , Infecções por HIV/virologia , Macrófagos/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Latência Viral/fisiologia , Animais , HIV/fisiologia , Humanos , Vírus da Imunodeficiência Símia/fisiologiaRESUMO
HIV-associated neurocognitive disorders (HAND) occur in ~50% of HIV infected individuals despite combined antiretroviral therapy. Transmigration into the CNS of CD14+CD16+ monocytes, particularly those that are HIV infected and express increased surface chemokine receptor CCR2, contributes to neuroinflammation and HAND. To examine whether in HIV infected individuals CCR2 on CD14+CD16+ monocytes serves as a potential peripheral blood biomarker of HAND, we examined a cohort of 45 HIV infected people. We correlated CCR2 on CD14+CD16+ monocytes with cognitive status, proton magnetic resonance spectroscopy (1H-MRS) measured neurometabolite levels, and peripheral blood mononuclear cell (PBMC) HIV DNA copies. We determined that CCR2 was increased specifically on CD14+CD16+ monocytes from people with HAND (median [interquartile range (IQR)]) (63.3 [51.6, 79.0]), compared to those who were not cognitively impaired (38.8 [26.7, 56.4]) or those with neuropsychological impairment due to causes other than HIV (39.8 [30.2, 46.5]). CCR2 was associated with neuronal damage, based on the inverse correlation of CCR2 on CD14+CD16+ monocytes with total N-Acetyl Aspartate (tNAA)/total Creatine (tCr) (r2 = 0.348, p = 0.01) and Glutamine-Glutamate (Glx)/tCr (r2 = 0.356, p = 0.01) in the right and left caudate nucleus, respectively. CCR2 on CD14+CD16+ monocytes also correlated with PBMC HIV DNA copies (ρ = 0.618, p = 0.02) that has previously been associated with HAND. These findings suggest that CCR2 on CD14+CD16+ monocytes may be a peripheral blood biomarker of HAND, indicative of increased HIV infected CD14+CD16+ monocyte entry into the CNS that possibly increases the macrophage viral reservoir and contributes to HAND.
Assuntos
Complexo AIDS Demência/sangue , Complexo AIDS Demência/virologia , Biomarcadores/sangue , Monócitos/virologia , Receptores CCR2/sangue , Adulto , Idoso , DNA Viral/análise , Feminino , Proteínas Ligadas por GPI/metabolismo , Humanos , Receptores de Lipopolissacarídeos/metabolismo , Masculino , Pessoa de Meia-Idade , Receptores de IgG/metabolismoRESUMO
Lentiviruses infect myeloid cells, leading to acute infection followed by persistent/latent infections not cleared by the host immune system. HIV and SIV are lentiviruses that infect CD4+ lymphocytes in addition to myeloid cells in blood and tissues. HIV infection of myeloid cells in brain, lung, and heart causes tissue-specific diseases that are mostly observed during severe immunosuppression, when the number of circulating CD4+ T cells declines to exceeding low levels. Antiretroviral therapy (ART) controls viral replication but does not successfully eliminate latent virus, which leads to viral rebound once ART is interrupted. HIV latency in CD4+ lymphocytes is the main focus of research and concern when HIV eradication efforts are considered. However, myeloid cells in tissues are long-lived and have not been routinely examined as a potential reservoir. Based on a quantitative viral outgrowth assay (QVOA) designed to evaluate latently infected CD4+ lymphocytes, a similar protocol was developed for the assessment of latently infected myeloid cells in blood and tissues. Using an SIV ART model, it was demonstrated that myeloid cells in blood and brain harbor latent SIV that can be reactivated and produce infectious virus in vitro, demonstrating that myeloid cells have the potential to be an additional latent reservoir of HIV that should be considered during HIV eradication strategies.
Assuntos
Sistema Nervoso Central/virologia , Modelos Animais de Doenças , Macaca mulatta/virologia , Macrófagos/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Latência Viral , Animais , Linfócitos T CD4-Positivos/virologia , Infecções por HIV/virologia , Humanos , Carga ViralRESUMO
Simian immunodeficiency virus (SIV) infection of pigtailed macaques is a highly representative and well-characterized animal model for HIV neuropathogenesis studies that provides an excellent opportunity to study and develop prognostic markers of HIV-associated neurocognitive disorders (HAND) for HIV-infected individuals. SIV studies can be performed in a controlled setting that enhances reproducibility and offers high-translational value. Similar to observations in HIV-infected patients receiving antiretroviral therapy (ART), ongoing neurodegeneration and inflammation are present in SIV-infected pigtailed macaques treated with suppressive ART. By developing quantitative viral outgrowth assays that measure both CD4+ T cells and macrophages harboring replication competent SIV as well as a highly sensitive mouse-based viral outgrowth assay, we have positioned the SIV/pigtailed macaque model to advance our understanding of latent cellular reservoirs, including potential CNS reservoirs, to promote HIV cure. In addition to contributing to our understanding of the pathogenesis of HAND, the SIV/pigtailed macaque model also provides an excellent opportunity to test innovative approaches to eliminate the latent HIV reservoir in the brain.
Assuntos
Antivirais/farmacologia , Sistema Nervoso Central/efeitos dos fármacos , Disfunção Cognitiva/tratamento farmacológico , Modelos Animais de Doenças , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Latência Viral/efeitos dos fármacos , Complexo AIDS Demência/tratamento farmacológico , Complexo AIDS Demência/imunologia , Complexo AIDS Demência/fisiopatologia , Complexo AIDS Demência/virologia , Animais , Terapia Antirretroviral de Alta Atividade , Sistema Nervoso Central/virologia , Disfunção Cognitiva/imunologia , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/virologia , Humanos , Macaca nemestrina , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/fisiopatologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/patogenicidade , Vírus da Imunodeficiência Símia/fisiologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/virologia , Carga Viral/efeitos dos fármacos , Latência Viral/fisiologiaRESUMO
A retrospective neuropathologic review of 30 SIV-infected pigtailed macaques receiving combination antiretroviral therapy (cART) was conducted. Seventeen animals with lymphocyte-dominant inflammation in the brain and/or meninges that clearly was morphologically distinct from prototypic SIV encephalitis and human immunodeficiency virus encephalitis were identified. Central nervous system (CNS) infiltrates in cART-treated macaques primarily comprised CD20+ B cells and CD3+ T cells with fewer CD68+ macrophages. Inflammation was associated with low levels of SIV RNA in the brain as shown by in situ hybridization, and generally was observed in animals with episodes of cerebrospinal fluid (CSF) viral rebound or sustained plasma and CSF viremia during treatment. Although the lymphocytic CNS inflammation in these macaques shared morphologic characteristics with uncommon immune-mediated neurologic disorders reported in treated HIV patients, including CNS immune reconstitution inflammatory syndrome and neurosymptomatic CSF escape, the high prevalence of CNS lesions in macaques suggests that persistent adaptive immune responses in the CNS also may develop in neuroasymptomatic or mildly impaired HIV patients yet remain unrecognized given the lack of access to CNS tissue for histopathologic evaluation. Continued investigation into the mechanisms and outcomes of CNS inflammation in cART-treated, SIV-infected macaques will advance our understanding of the consequences of residual CNS HIV replication in patients on cART, including the possible contribution of adaptive immune responses to HIV-associated neurocognitive disorders.
Assuntos
Antirretrovirais/uso terapêutico , Encéfalo/patologia , Encefalite/patologia , Linfócitos/patologia , Meningite/patologia , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Animais , Encefalite/complicações , Inflamação/patologia , Macaca nemestrina , Masculino , Meningite/complicações , Síndrome de Imunodeficiência Adquirida dos Símios/complicações , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Vírus da Imunodeficiência Símia , Carga ViralRESUMO
HIV reservoirs persist despite antiretroviral therapy (ART) and are established within a few days after infection. Infected myeloid cells in the central nervous system (CNS) may contribute to the establishment of a CNS viral reservoir. The mature CD14+ CD16+ monocyte subset enters the CNS in response to chemokines, including CCL2. Entry of infected CD14+ CD16+ monocytes may lead to infection of other CNS cells, including macrophages or microglia and astrocytes, and to release of neurotoxic early viral proteins and additional cytokines. This contributes to neuroinflammation and neuronal damage leading to HIV-associated neurocognitive disorders (HAND) in ~50% of HIV-infected individuals despite ART. We examined the mechanisms of monocyte entry in the context of HIV infection and report for the first time that HIV+ CD14+ CD16+ monocytes preferentially transmigrate across the blood-brain barrier (BBB). The junctional proteins JAM-A and ALCAM and the chemokine receptor CCR2 are essential to their preferential transmigration across the BBB to CCL2. We show here that JAM-A and ALCAM are increased on HIV+ CD14+ CD16+ monocytes compared to their expression on HIVexp CD14+ CD16+ monocytes-cells that are uninfected but exposed to HIV, viral proteins, and inflammatory mediators. Antibodies against JAM-A and ALCAM and the novel CCR2/CCR5 dual inhibitor cenicriviroc prevented or significantly reduced preferential transmigration of HIV+ CD14+ CD16+ monocytes. This indicates that JAM-A, ALCAM, and CCR2 may be potential therapeutic targets to block entry of these infected cells into the brain and prevent or reduce the establishment and replenishment of viral reservoirs within the CNS.IMPORTANCE HIV infects different tissue compartments of the body, including the central nervous system (CNS). This leads to establishment of viral reservoirs within the CNS that mediate neuroinflammation and neuronal damage, contributing to cognitive impairment. Our goal was to examine the mechanisms of transmigration of cells that contribute to HIV infection of the CNS and to continued replenishment of CNS viral reservoirs, to establish potential therapeutic targets. We found that an HIV-infected subset of monocytes, mature HIV+ CD14+ CD16+ monocytes, preferentially transmigrates across the blood-brain barrier. This was mediated, in part, by increased junctional proteins JAM-A and ALCAM and chemokine receptor CCR2. We show that the CCR2/CCR5 dual inhibitor cenicriviroc and blocking antibodies against the junctional proteins significantly reduce, and often completely block, the transmigration of HIV+ CD14+ CD16+ monocytes. This suggests new opportunities to eliminate infection and seeding or reseeding of viral reservoirs within the CNS, thus reducing neuroinflammation, neuronal damage, and cognitive impairment.
Assuntos
Sistema Nervoso Central/virologia , Infecções por HIV/virologia , Monócitos/imunologia , Monócitos/virologia , Transtornos Neurocognitivos/virologia , Antígenos CD/genética , Barreira Hematoencefálica/imunologia , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular Neuronais/genética , Sistema Nervoso Central/imunologia , Proteínas Fetais/genética , Proteínas Ligadas por GPI/imunologia , Infecções por HIV/complicações , Humanos , Receptores de Lipopolissacarídeos/imunologia , Monócitos/fisiologia , Transtornos Neurocognitivos/imunologia , Transtornos Neurocognitivos/fisiopatologia , Receptores CCR2/genética , Receptores CCR2/imunologia , Receptores de Superfície Celular/genética , Receptores de IgG/imunologiaRESUMO
A human immunodeficiency virus (HIV) infection cure requires an understanding of the cellular and anatomical sites harboring virus that contribute to viral rebound upon treatment interruption. Despite antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) are reported in HIV-infected individuals on ART. Biomarkers for macrophage activation and neuronal damage in cerebrospinal fluid (CSF) of HIV-infected individuals demonstrate continued effects of HIV in brain and suggest that the central nervous system (CNS) may serve as a viral reservoir. Using a simian immunodeficiency virus (SIV)/macaque model for HIV encephalitis and AIDS, we evaluated whether infected cells persist in brain despite ART. Eight SIV-infected pig-tailed macaques were virally suppressed with ART, and plasma and CSF viremia levels were analyzed longitudinally. To assess whether virus persisted in brain macrophages (BrMΦ) in these macaques, we used a macrophage quantitative viral outgrowth assay (MΦ-QVOA), PCR, and in situ hybridization (ISH) to measure the frequency of infected cells and the levels of viral RNA and DNA in brain. Viral RNA in brain tissue of suppressed macaques was undetectable, although viral DNA was detected in all animals. The MΦ-QVOA demonstrated that the majority of suppressed animals contained latently infected BrMΦ. We also showed that virus produced in the MΦ-QVOAs was replication competent, suggesting that latently infected BrMΦ are capable of reestablishing productive infection upon treatment interruption. This report provides the first confirmation of the presence of replication-competent SIV in BrMΦ of ART-suppressed macaques and suggests that the highly debated issue of viral latency in macrophages, at least in brain, has been addressed in SIV-infected macaques treated with ART.IMPORTANCE Resting CD4+ T cells are currently the only cells that fit the definition of a latent reservoir. However, recent evidence suggests that HIV/SIV-infected macrophages persist despite ART. Markers of macrophage activation and neuronal damage are observed in the CSF of HIV-infected individuals and of SIV-infected macaques on suppressive ART regimens, suggesting that the CNS has continued virus infection and latent infection. A controversy exists as to whether brain macrophages represent a latent source of replication-competent virus capable of reestablishing infection upon treatment interruption. In this study, we demonstrated the presence of the latent macrophage reservoir in brains of SIV-infected ART-treated macaques and analyzed the reservoir using our established outgrowth assay to quantitate macrophages harboring replication-competent SIV genomes. Our results support the idea of the existence of other latent reservoirs in addition to resting CD4+ T cells and underscore the importance of macrophages in developing strategies to eradicate HIV.