Baharlou, H;Canete, N;Vine, EE;Hu, K;Yuan, D;Sandgren, KJ;Bertram, KM;Nasr, N;Rhodes, JW;Gosselink, MP;Di Re, A;Reza, F;Ctercteko, G;Pathma-Nathan, N;Collins, G;Toh, J;Patrick, E;Haniffa, MA;Estes, JD;Byrne, SN;Cunningham, AL;Harman, AN;
PMID: 36130503 | DOI: 10.1016/j.celrep.2022.111385
The initial immune response to HIV determines transmission. However, due to technical limitations we still do not have a comparative map of early mucosal transmission events. By combining RNAscope, cyclic immunofluorescence, and image analysis tools, we quantify HIV transmission signatures in intact human colorectal explants within 2 h of topical exposure. We map HIV enrichment to mucosal dendritic cells (DCs) and submucosal macrophages, but not CD4+ T cells, the primary targets of downstream infection. HIV+ DCs accumulate near and within lymphoid aggregates, which act as early sanctuaries of high viral titers while facilitating HIV passage to the submucosa. Finally, HIV entry induces recruitment and clustering of target cells, facilitating DC- and macrophage-mediated HIV transfer and enhanced infection of CD4+ T cells. These data demonstrate a rapid response to HIV structured to maximize the likelihood of mucosal infection and provide a framework for in situ studies of host-pathogen interactions and immune-mediated pathologies.
Human anogenital monocyte-derived dendritic cells and langerin+cDC2 are major HIV target cells
Rhodes, JW;Botting, RA;Bertram, KM;Vine, EE;Rana, H;Baharlou, H;Vegh, P;O'Neil, TR;Ashhurst, AS;Fletcher, J;Parnell, GP;Graham, JD;Nasr, N;Lim, JJK;Barnouti, L;Haertsch, P;Gosselink, MP;Di Re, A;Reza, F;Ctercteko, G;Jenkins, GJ;Brooks, AJ;Patrick, E;Byrne, SN;Hunter, E;Haniffa, MA;Cunningham, AL;Harman, AN;
PMID: 33846309 | DOI: 10.1038/s41467-021-22375-x
Tissue mononuclear phagocytes (MNP) are specialised in pathogen detection and antigen presentation. As such they deliver HIV to its primary target cells; CD4 T cells. Most MNP HIV transmission studies have focused on epithelial MNPs. However, as mucosal trauma and inflammation are now known to be strongly associated with HIV transmission, here we examine the role of sub-epithelial MNPs which are present in a diverse array of subsets. We show that HIV can penetrate the epithelial surface to interact with sub-epithelial resident MNPs in anogenital explants and define the full array of subsets that are present in the human anogenital and colorectal tissues that HIV may encounter during sexual transmission. In doing so we identify two subsets that preferentially take up HIV, become infected and transmit the virus to CD4 T cells; CD14+CD1c+ monocyte-derived dendritic cells and langerin-expressing conventional dendritic cells 2 (cDC2).
AIDS research and human retroviruses
Sanders-Beer, BE;Archin, NM;Brumme, ZL;Busch, M;Deleage, C;O'Doherty, U;Hughes, SH;Jerome, K;Jones, RB;Karn, J;Kearney, MF;Keele, B;Kulpa, D;Laird, G;Li, JZ;Lichterfeld, M;Nussenzweig, MC;Persaud, D;Yukl, S;Siliciano, RF;Mellors, JW;
PMID: 37126090 | DOI: 10.1089/AID.2022.0188
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.
Plasmacytoid dendritic cells have divergent effects on HIV infection of initial target cells and induce a pro-retention phenotype
Tong, O;Duette, G;O'Neil, TR;Royle, CM;Rana, H;Johnson, B;Popovic, N;Dervish, S;Brouwer, MAE;Baharlou, H;Patrick, E;Ctercteko, G;Palmer, S;Lee, E;Hunter, E;Harman, AN;Cunningham, AL;Nasr, N;
PMID: 33872331 | DOI: 10.1371/journal.ppat.1009522
Although HIV infection inhibits interferon responses in its target cells in vitro, interferon signatures can be detected in vivo soon after sexual transmission, mainly attributed to plasmacytoid dendritic cells (pDCs). In this study, we examined the physiological contributions of pDCs to early HIV acquisition using coculture models of pDCs with myeloid DCs, macrophages and the resting central, transitional and effector memory CD4 T cell subsets. pDCs impacted infection in a cell-specific manner. In myeloid cells, HIV infection was decreased via antiviral effects, cell maturation and downregulation of CCR5 expression. In contrast, in resting memory CD4 T cells, pDCs induced a subset-specific increase in intracellular HIV p24 protein expression without any activation or increase in CCR5 expression, as measured by flow cytometry. This increase was due to reactivation rather than enhanced viral spread, as blocking HIV entry via CCR5 did not alter the increased intracellular p24 expression. Furthermore, the load and proportion of cells expressing HIV DNA were restricted in the presence of pDCs while reverse transcriptase and p24 ELISA assays showed no increase in particle associated reverse transcriptase or extracellular p24 production. In addition, pDCs also markedly induced the expression of CD69 on infected CD4 T cells and other markers of CD4 T cell tissue retention. These phenotypic changes showed marked parallels with resident memory CD4 T cells isolated from anogenital tissue using enzymatic digestion. Production of IFNα by pDCs was the main driving factor for all these results. Thus, pDCs may reduce HIV spread during initial mucosal acquisition by inhibiting replication in myeloid cells while reactivating latent virus in resting memory CD4 T cells and retaining them for immune clearance.
Khanal, S;Cao, D;Zhang, J;Zhang, Y;Schank, M;Dang, X;Nguyen, LNT;Wu, XY;Jiang, Y;Ning, S;Zhao, J;Wang, L;Gazzar, ME;Moorman, JP;Yao, ZQ;
PMID: 36146709 | DOI: 10.3390/v14091902
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.
Journal of Virus Eradication
Collins, D;Hitschfel, J;Walker, B;
| DOI: 10.1016/j.jve.2022.100202
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
The Contributions of Clinical Pharmacology to HIV Cure Research
Clinical pharmacology and therapeutics
Fletcher, CV;Dyavar, SR;Acharya, A;Byrareddy, SN;
PMID: 33763860 | DOI: 10.1002/cpt.2237
Combination antiretroviral therapy (ART) can suppress plasma HIV-RNA to < 50 copies/mL, decrease HIV transmission, reduce mortality, and improve quality of life for people living with HIV. ART cannot, however, eliminate HIV from an infected individual. The primary barrier to cure HIV infection is the multiple reservoir sites, including adipose tissue, bone marrow, central nervous system, liver, lungs, male and female reproductive system, secondary lymph nodes, and gut-associated lymphoid tissue, established 1 to 2 weeks after acquisition of HIV. Additional challenges include understanding the mechanism(s) by which HIV is maintained at low or undetectable levels and developing treatments that will eradicate or produce a sustained suppression of virus without ART. To date, the most extensive clinical investigations of cure strategies have been the shock-and-kill approach using histone deacetylase inhibitors (HDACis) to induce reactivation of latent HIV. Despite evidence for HIV latency reversal, HDACis alone have not decreased the size of the latent reservoir. Clinical pharmacologic explanations for these results include a low inhibitory quotient (i.e., low potency) within the reservoir sites and intrinsic (e.g., sex differences and reservoir size) and extrinsic (physiochemical and pharmacokinetic drug characteristics) factors. We offer an outline of desired clinical pharmacologic attributes for therapeutics intended for clinical HIV cure research and call for research teams to have early and ongoing involvement of clinical pharmacologists. We believe such a collective effort will provide a solid scientific basis and hope for reaching the goal of a cure for HIV infection.
Journal of leukocyte biology
Joseph, J;Daley, W;Lawrence, D;Lorenzo, E;Perrin, P;Rao, VR;Tsai, SY;Varthakavi, V;
PMID: 36073341 | DOI: 10.1002/JLB.4MR0722-619R
Macrophages play a significant role in HIV infection and contribute to pathogenesis of comorbidities as well as establishment of the viral reservoir in people living with HIV. While CD4+ T cells are considered the main targets of HIV infection, infected macrophages resist the cytopathic effects of infection, contributing to the persistent HIV reservoir. Furthermore, activated macrophages drive inflammation and contribute to the development of comorbidities, including HIV-associated CNS dysfunction. Better understanding the role of macrophages in HIV infection, persistence, and comorbidities can lead to development of innovative therapeutic strategies to address HIV-related outcomes in people living with HIV. In October 2021, the National Institute of Mental Health and the Ragon Institute of MGH, MIT, and Harvard conducted a virtual meeting on role of macrophages in HIV infection, pathogenesis, and cure. This review article captures the key highlights from this meeting and provides an overview of interests and activities of various NIH institutes involved in supporting research on macrophages and HIV.Published 2022. This article is a U.S. Government work and is in the public domain in the USA.
Isnard, S;Fombuena, B;Ouyang, J;Royston, L;Lin, J;Bu, S;Sheehan, N;Lakatos, PL;Bessissow, T;Chomont, N;Klein, M;Lebouché, B;Costiniuk, CT;Routy, B;Marette, A;Routy, JP;Camu Camu Study Group, ;
PMID: 35039291 | DOI: 10.1136/bmjopen-2021-053081
Despite the success of antiretroviral therapy (ART) in transforming HIV disease into a chronic infection, people living with HIV (PLWH) remain at risk for various non-AIDS inflammatory comorbidities. Risk of non-AIDS comorbidities is associated with gut dysbiosis, epithelial gut damage and subsequent microbial translocation, and increased activation of both circulating CD4+ and CD8+ T-cells. Therefore, in addition to ART, novel gut microbiota-modulating therapies could aid in reducing inflammation and immune activation, gut damage, and microbial translocation. Among various gut-modulation strategies under investigation, the Amazonian fruit Camu Camu (CC) presents itself as a prebiotic candidate based on its anti-inflammatory and antioxidant properties in animal models and tobacco smokers.A total of 22 PLWH on ART for more than 2 years, with a viral load <50 copies/mL, a CD4 +count >200 and a CD4+/CD8 +ratio <1 (suggesting increased inflammation and risk for non-AIDS comorbidities), will be recruited in a single arm, non-randomised, interventional pilot trial. We will assess tolerance and effect of supplementation with CC in ART-treated PLWH on reducing gut damage, microbial translocation, inflammation and HIV latent reservoir by various assays.The Canadian Institutes of Health Research (CIHR)/Canadian HIV Trials Network (CTN) pilot trial protocol CTNPT032 was approved by the Natural and Non-prescription Health Products Directorate of Health Canada and the research ethics board of the McGill university Health Centre committee (number 2020-5903). Results will be made available as free access through publications in peer-reviewed journals and through the CIHR/CTN website.NCT04058392.
Guo, YT;Guo, XY;Fan, LN;Wang, ZR;Qu, MM;Zhang, C;Fan, X;Song, JW;Yang, BP;Zhang, JY;Xu, R;Jiao, YM;Ma, P;Chen, YK;Wang, FS;
PMID: 37184871 | DOI: 10.1089/vim.2023.0017
Studies assessing the gut mucosal immune balance in HIV-infected patients using intestinal samples are scarce. In this study, we used intestinal mucosal specimens from the ileocecal region of seven immunological nonresponders (INRs), nine immunological responders (IRs), and six HIV-negative controls. We investigated T helper 17 (Th17) and T regulatory (Treg) cell counts and their ratio, zonula occludens-1 (ZO-1), intestinal fatty acid-binding protein (I-FABP), tumor necrosis factor-α, CD4+ T cell counts, HIV DNA, and cell-associated HIV RNA. The results showed that INRs had lower Th17 and higher Treg cell counts than IR, resulting in a significant difference in the Th17/Treg ratio between IRs and INRs. In addition, INRs had lower ZO-1 and higher I-FABP levels than IRs. The Th17/Treg ratio was positively associated with ZO-1 and negatively associated with I-FABP levels. There was a positive correlation between Th17/Treg ratio and CD4+ T cell counts and a negative correlation between the Th17/Treg ratio and HIV DNA in the intestine. Our study suggests that the imbalance of Th17/Treg in the intestine is a characteristic of incomplete immune reconstitution to antiretroviral therapy and is associated with intestinal damage.
The Journal of infectious diseases
Kroon, E;Chottanapund, S;Buranapraditkun, S;Sacdalan, C;Colby, DJ;Chomchey, N;Prueksakaew, P;Pinyakorn, S;Trichavaroj, R;Vasan, S;Manasnayakorn, S;Reilly, C;Helgeson, E;Anderson, J;David, C;Zulk, J;de Souza, M;Tovanabutra, S;Schuetz, A;Robb, ML;Douek, DC;Phanuphak, N;Haase, A;Ananworanich, J;Schacker, TW;
PMID: 35275599 | DOI: 10.1093/infdis/jiac089
Starting antiretroviral therapy (ART) in Fiebig 1 acute HIV infection limits the size of viral reservoirs in lymphoid tissues, but does not impact time to virus rebound during a treatment interruption. To better understand why the reduced reservoir size did not increase the time to rebound we measured the frequency and location of HIV RNA+ cells in lymph nodes from participants in the RV254 acute infection cohort. HIV vRNA+ cells were detected more frequently and in greater numbers when ART was initiated in Fiebig 1 compared to later Fiebig stages and were localized to the T cell zone compared to the B cell follicle with treatment in later Fiebig stages. Variability of virus production in people treated during acute infection suggests that the balance between virus producing cells and the immune response to clear infected cells rapidly evolves during the earliest stages of infection.
Journal of Virus Eradication
Hernandez, C;Eugenin, E;
| DOI: 10.1016/j.jve.2022.100212
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.