AIDS/HIV
Abstract
Serious non-AIDS events (SNAEs), including non-AIDS malignancies, cardiovascular disease, and hepatic complications, remain major causes of mortality in treated HIV infection. These outcomes are driven by persistent immune activation, systemic inflammation, and metabolic dysfunction despite effective viral suppression with antiretroviral therapy (ART). To investigate mechanisms underlying SNAE pathogenesis, we performed a cross-site multi-omic analysis integrating plasma proteins, plasma metabolites, and mucosal microbiomes in 82 ART-treated people with HIV (PWH) and 10 people without HIV from the United States and Mexico. Geography was the dominant source of variation, particularly across lipid classes. However, individuals at high risk for SNAEs, defined by low CD4+ T cell counts and low CD4/CD8 ratios, shared a consistent signature of systemic inflammation, mitochondrial dysfunction, and microbial dysbiosis, including elevated plasma IL-6 and ω-oxidation products (adipic and suberic acids) and depletion of short-chain fatty acid–producing commensals in the gut mucosa, including Akkermansia muciniphila, Bacteroides uniformis, and Ruminococcus. A. muciniphila abundance correlated with lower IL-6 levels, fewer HIV RNA-producing cells in lymph nodes, and higher CD4/CD8 ratios. These findings identify a shared inflammatory and metabolic phenotype in PWH and implicate A. muciniphila as a potential microbiome-based target to mitigate immune activation and SNAE risk in treated HIV.
Authors
Christopher M. Basting, Jodi Anderson, Kevin Escandón, Garritt Wieking, Candace Guerrero, Jarrett Reichel, Ross T. Cromarty, Erik Swanson, Ty Schroeder, Elaina Creagan, Maura Barrett, Fernanda Torres-Ruiz, Maribel Soto-Nava, Lady Carvajal-Ruiz, Karla Krystel Ordaz-Candelario, Olivia Briceño, Nicholas Funderburg, Melanie Graham, Peter Hunt, Santiago Avila-Rios, Gonzalo Salgado Montes de Oca, Timothy W. Schacker, Nichole R. Klatt
Microbiome-Derived Metabolites Shape CD4⁺ T-Cell Differentiation and Immune Aging in HIV-1 Infection
Abstract
The role of aromatic gut-derived bacterial metabolites (GDBMs) in shaping immune cell metabolism and function remains poorly explored. Using ex vivo metabolomic profiling of paired plasma and CD4⁺ T-cells from people living with HIV-1 (PLWH), we identified a network of aromatic GDBMs whose cell-associated abundance, rather than systemic levels, was linked to broad alterations in CD4⁺ T-cell metabolic and functional states. Among these, p-cresol sulfate (PCS) emerged as a mechanistic prototype. Ex vivo flow cytometry and single-cell RNA sequencing of CD4⁺ T-cells stratified by cell-associated PCS levels revealed dose-dependent enrichment of transcriptional programs associated with impaired differentiation, regulatory-like identity, and cellular senescence. In vitro transcriptomic and proteomic analyses of PCS-exposed CD4⁺ T cells demonstrated induction of cell-cycle arrest, mitochondrial dysfunction, and senescence-associated programs, including upregulation of p16 and p21. Integration of these immunometabolic findings with HIV-1 reservoir measurements revealed that CD4⁺ T-cell states defined by cell-associated GDBMs track with intact proviral DNA levels in vivo. These findings define a microbiome-derived axis that reshapes CD4⁺ T-cell metabolism and fate, promotes immune aging in PLWH, and may foster immunometabolic states linked to long-term HIV-1 reservoir persistence.
Authors
Amanda Cabral da Silva, Luke Flantzer, Jaclyn Weinberg, Shuya Kyu, Lisa P. Daley-Bauer, Anyce Godoy, Ana Carolina Santana, Aarthi Talla, Amber Rittgers, Sarah Welbourn, David E. Gordon, Jeffrey A. Tomalka, Vincent C. Marconi, Dean P. Jones, Souheil-Antoine Younes
Abstract
Myeloid-Derived Suppressor Cells (MDSCs) represent a heterogeneous population of immature myeloid cells with potent immunosuppressive capabilities that contribute to viral persistence in chronic infections. However, their direct impact on the latent HIV reservoir remains poorly understood. Here, we report that people with HIV (PWH) exhibit elevated levels of MDSCs with notable immunosuppressive activity. Both granulocytic (G-MDSCs) and monocytic (M-MDSCs) subsets expressing arginase 1 (ARG1) or indoleamine 2,3-dioxygenase (IDO) are increased during treated infection, with low-level viral transcription preferentially associated with the expansion of highly suppressive G-MDSCs. Functional assays revealed that G-MDSCs robustly inhibit HIV reactivation from latent reservoirs. Mechanistically, G-MDSCs mediate this inhibition through a contact-independent mechanism, primarily involving ARG1 activity. Our findings demonstrate the capacity of G-MDSCs to sustain HIV reservoirs, suggesting that targeting these cells could potentiate therapeutic strategies aimed at eliminating HIV reservoirs through viral reactivation.
Authors
Ana Gallego-Cortés, Judith Grau-Expósito, Irene Mota-Gómez, Aleix Benitez-Martinez, Josep Castellvi, Jordi Navarro, Adrian Curran, Joaquin Burgos, Paula Suanzes, Vicenç Falcó, Meritxell Genescà, Maria J. Buzon
Abstract
The estrogen receptor is hypothesized to directly influence HIV-transcription and latency but is also critical for immune signaling. However, the mechanisms of action of the estrogen receptor (ER) in immune cells in the context of HIV are limited, and relevant to HIV cure strategies, the influence of latency reversal agents (LRAs) on the ER pathway are unknown. We evaluated a) the impact of estrogen (E2) on the nuclear translocation of estrogen receptor α (ERα) in CD4+ T cells, b) the ability of Fulvestrant, a selective estrogen receptor degrader (SERD), and ARV-471, a novel, potent, PROteolysis TArgeting Chimera (PROTAC) selective ERα degrader to modulate ER and c) the impact of different classes of LRAs on ER signaling. In contrast to what has been demonstrated in oncology, E2 does not induce ERα nuclear translocation in CD4+ T cells. Similarly, neither Fulvestrant nor ARV-471 induced degradation of ERα in CD4+ T cells. LRAs significantly downregulated ERα gene and protein expression in both PBMCs and CD4+ T cells. Collectively, our results suggest that estrogen influences on HIV transcription are not likely a consequence of canonical nuclear ERα mechanisms. The consequences of LRA downregulation of ER, a protein important for immune signaling, warrants further investigation.
Authors
Cristina Ceriani, Priya Khetan, Anthony Abeyta-Lopez, Kena J. Lemu, Prachi Meher, Brigitte Allard, Katherine S. James, Anne-Marie W. Turner, David M. Margolis, Nancie M. Archin
Abstract
BACKGROUND. Despite antiretroviral therapy (ART), people with HIV (PWH) are at heightened risk for insulin resistance (IR) and type 2 diabetes (T2D). Subcutaneous adipose tissue (SAT) fibrosis contributes to metabolic disease, but its role in IR among PWH is unknown. We investigated the relationship between SAT fibrosis and IR in PWH, along with transcriptional signatures to distinguish it from SAT fibrosis due to obesity. METHODS. We analyzed body composition and SAT fibrosis (hydroxyproline) in 46 PWH and 74 people without HIV (PWoH), excluding individuals with T2D. We examined fibrosis-related gene transcription in the SAT using a targeted panel and measured plasma endotrophin, a marker of extracellular matrix (ECM) remodeling. RESULTS. PWH had substantially more SAT fibrosis than PWoH, notably in non-obese individuals. Moreover, SAT fibrosis in these PWH was strongly associated with IR, independently of prior legacy ART or ongoing integrase strand inhibitor treatment. This SAT fibrosis was highlighted by a distinct transcriptional pattern marked by upregulation of COL14A1, key immune-related genes (e.g., CCL4, NLRP3), and pathways governing ECM remodeling and immune activation, as well as downregulation of thermogenic, lipid metabolic, and insulin signaling pathways. Plasma endotrophin levels were also elevated in PWH and correlated independently with SAT fibrosis. CONCLUSION. SAT fibrosis was associated with IR independent of obesity in PWH and was mirrored by circulating endotrophin levels, offering a plausible noninvasive biomarker for early intervention. The distinct transcriptional signature of HIV-associated SAT fibrosis highlights candidate mechanisms that may underlie metabolic risk and offer therapeutic avenues in this population.
Authors
Diana L. Alba, Alaa Abdellatif, Moon K. Choi, Stephen M. Brown Mayfield, Thuy An T. Pham, David I. Berrios, Antonio E. Rodriguez, Marin Ewing, Tony R. Figueroa, Judy Gonzalez-Vargas, Ningyan Zhang, Zhiqiang An, Dawei Bu, Steven G. Deeks, Philipp E. Scherer, Peter W. Hunt, Suneil K. Koliwad
Abstract
Virally suppressed people with HIV (PWH) remain at risk for developing comorbidities due to chronic inflammation with one potential contributor being the HIV reservoir. Associations between the CD4-reservoir and inflammation have been extensively characterized, while the role the monocyte-reservoir is poorly understood despite evidence that inflammatory monocytes play a role in HIV-associated comorbidities. Additionally, most studies focus on a single cellular reservoir, while it is highly likely that these reservoirs are interdependent. In a cohort of 164 PWH, we used the intact proviral DNA assay to quantify cell-specific reservoirs, applied unsupervised clustering to identify reservoir phenotypes, and then determined if reservoir phenotypes were associated with distinct immune signatures compared to people without HIV. Five unique reservoir clusters emerged driven primarily by variability in the monocyte reservoir, and each associated with a distinct immune landscape. These included profiles characterized by systemic inflammation, leukocyte–vascular activation, T cell activation with vascular and neuronal injury, enhanced CD8 activation and NK cell recovery, and altered monocyte survival, activation, and migration. This multidimensional approach provides a framework to identify reservoir-immune profiles that may explain heterogeneity in inflammation despite viral suppression and may inform strategies to mitigate HIV-associated comorbidities.
Authors
Ruoyu Wang, Aparna B. Bhattacharyya, Lily Pohlenz, Erin N. Shirk, Hayley S. Romero, Katherine Haas, Jennifer M. Coughlin, Raha M. Dastgheyb, Leah H. Rubin, Rebecca T. Veenhuis
Abstract
HLA-E-restricted HIV-specific T cells offer exciting possibilities for immunotherapy. However, HLA-E binding peptides are rare. A recent study showed that in HLA-B*57:01 people living with HIV (PLWH), the peptide that dominates the T cell response, KAFSPEVIPMF (KF11), also stimulates HLA-E-restricted T cells, even though direct binding of this peptide to HLA-E could not be demonstrated. We therefore changed position 2 alanine for methionine in the peptide (referred to as KMF11) which greatly enhanced binding to HLA-E. This enabled the generation of stabilised HLA-E-KMF11 tetramers which were used to select and then grow specific T cell clones from T cells of HLA-B*57:01 negative blood donors primed with this peptide in vitro. Approximately 20% of these T cell clones reacted with HLA-E positive cells presenting the native KF11 peptide. Furthermore, these T cells inhibited replication of HIV-1 NL4-3 in CD4 T cells in vitro. Therefore, this native peptide can be presented by HLA-E to CD8 T cells, although priming in vivo may depend on cross reactivities to classical MHC Ia types. Nevertheless, such T cells could be exploitable for immunotherapy given the conservation of this HIV1 peptide epitope and the non-polymorphism in HLA-E.
Authors
Hong Sun, Hongbing Yang, Max N. Quastel, Simon Brackenridge, Wanlin He, Anna E. Kliszczak, Margarida Rei, Persephone Borrow, Geraldine M. Gillespie, Andrew J. McMichael
Abstract
TB (Tuberculosis) and HIV co-infection remains a major global health challenge, with limited understanding of how these pathogens impact local immune responses in the lungs. This study is the first to investigate the modulation of IL-21 during LTBI and Mycobacterium tuberculosis (Mtb)/ Simian Immunodeficiency Virus (SIV) co-infection in non-human primates (NHP). We show that IL-21 expression, predominantly derived from CD4⁺ T cells, is significantly reduced in lungs of Mtb/SIV co-infected macaques, especially in the absence of cART. Although cART and cART with 3HP partially restore IL-21-producing CD4⁺ T cells, levels remain below those in LTBI, indicating ongoing immune impairment. Spatial transcriptomic analysis suggests localized alterations in immune signaling, including differences in STAT1- and STAT3-associated transcriptional profiles and reduced Mtb-specific IFN-γ responses in co-infected animals. Together, our findings indicate that IL-21-producing CD4⁺ T cells are selectively and persistently impaired in the lungs during Mtb/SIV co-infection despite antimicrobial and antiviral therapy. These results highlight a compartment-specific deficit in immune reconstitution and suggest that IL-21-associated pathways may warrant further investigation as potential targets for host-directed therapeutic strategies.
Authors
Vinay Shivanna, Renee D. Escalona, Colin Chuba, Shashi Prakash Singh, Ahmed A. Moustafa, J. Quincy Brown, Chenyao Xiao, Sangkyu Kim, Edward J. Dick Jr., Smriti Mehra, Mirko Paiardini, Riti Sharan
Abstract
Inhibiting the mammalian target of rapamycin (mTOR) during acute viral infection generates highly functional memory CD8 T cells. We investigated the effects of inhibiting mTOR by using rapamycin during the effector and contraction phases of the immune response to a DNA prime and Modified Vaccinia Ankara (MVA) boost SIV vaccination in rhesus macaques. Rapamycin administered either during MVA boosts alone (DMR) or during both primes and boosts (DRMR) reduced the contraction of effector CD8 T cells, resulting in higher frequencies of SIV-specific memory CD8 T cells with enhanced quality as indicated by expression of Bcl-2 and CD127. Additionally, rapamycin reduced the frequency of proliferating CCR5+ CD4 T cells in the blood following the MVA boost. Post SIV251 infection, rapamycin-treated macaques demonstrated marked expansion of SIV-specific CD8 T cells (reaching up to 50% in blood and 25% in gut). The heightened expansion of SIV-specific CD8 T cells in the DMR group was associated with markedly lower (2-logs compared to unvaccinated and 1-log compared to DM) peak viral load in the gut and set-point viremia, along with improved survival post infection. Thus, inhibiting the mTOR pathway during MVA boosts of a DNA/MVA vaccine enhances vaccine efficacy by improving memory CD4 and CD8 T cell function.
Authors
Shanmugalakshmi Sadagopal, Kasey Stokdyk, Suefen Kwa, Rahul Basu, Sailaja Gangadhara, Rafi Ahmed, Smita S. Iyer, Koichi Araki, Rama Rao Amara
Abstract
Antiretroviral therapy (ART) has prolonged the life expectancy of persons living with HIV, the majority of whom are now older than 50 years. Aging people with HIV are at increased risk for cardiovascular events driven by HIV-related inflammation and hypercoagulation. Apixaban is a factor Xa inhibitor that reduces cardiovascular risks and treats stroke, deep vein thrombosis, and pulmonary embolism. We assessed apixaban’s impact on key parameters of HIV/SIV pathogenesis in SIV-infected, aged rhesus macaques (RMs) receiving ART. Inflammation, coagulation, T cell subsets, B cells, and macrophages and their immune activation status were monitored throughout the study. We found no significant differences between the apixaban-treated and control groups for virus replication or CD4+ T cell recovery in blood and tissues after ART. Apixaban did not significantly affect D-dimer, immune activation, or inflammation of SIV-infected, ART-treated RMs. Apixaban-treated RMs experienced multiple bleeding episodes, tissue hemorrhages, and myocardial infarctions, as demonstrated by pathological examination of necropsy-collected tissues. Given apixaban’s lack of effect on immune activation, CD4+ T cell restoration, and inflammation, along with increased risk of hemorrhage, factor Xa inhibition may not be an efficient or safe option to target and prevent cardiovascular events in aging people with HIV.
Authors
Cuiling Xu, Haritha Annapureddy, Lilly Carson, Vansh Khurana, Ranjit Sivanandham, Sindhuja Sivanandham, Tianyu He, Kevin D. Raehtz, Janet Kim, Christie Biber, Norma Arbujas-Silva, Mohammed Daira, Sudhapriya Kandasamy, Matthew J. Feinstein, Irini Sereti, Cristian Apetrei, Ivona Pandrea
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