Biology subjects

Anderson, J.

Publications and source records attributed to Anderson, J..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Genome-wide CRISPR screens identify PTGES3 as a novel AR modulator

The androgen receptor (AR) is a critical driver of prostate cancer (PCa). To study regulators of AR protein levels and oncogenic activity, we created the first live cell quantitative endogenous AR fluorescent reporters. Leveraging this novel AR reporter, we performed genome-scale CRISPRi flow cytometry sorting screens to systematically identify genes that modulate AR protein levels. We identified and validated known AR protein regulators including HOXB13 and GATA2 and also unexpected top hits including PTGES3, a poorly characterized gene in PCa. PTGES3 repression resulted in loss of AR protein, cell cycle arrest, and cell death in AR-driven PCa models. PTGES3 is not a commonly essential gene, and our data nominate it as a prime PCa therapeutic target. Clinically, analysis of PCa data demonstrate that PTGES3 expression is associated with AR-directed therapy resistance. Mechanistically, we show PTGES3 binds directly to AR, forms a protein complex with AR in the nucleus, regulates AR protein stability in vitro and in vivo and modulates AR function in the nucleus at AR target genes. PTGES3 represents a novel therapeutic target for overcoming known mechanisms of resistance to existing AR-directed therapies in PCa.

cancer biology↗

bioRxiv2024

Superresolution Imaging Reveals the Spatial Organization of CD81 Microdomains in Regulating Membrane Signaling on Jurkat T Cell Microvilli

Tetraspanin proteins are closely associated with high-curvature membrane structures and play key roles in organizing membrane domains and regulating membrane signaling in immune cells. However, their specific roles in regulating T cell membrane signaling, particularly within the microvilli often characteristic of these cells, remain poorly understood. Here, we used Jurkat T cells as a model system and investigated CD81 as a member of the tetraspanin family. Using total internal reflection fluorescence (TIRF) microscopy and structured illumination microscopy (SIM), we identified an enrichment of the tetraspanin CD81 microdomains along the actin-rich membrane microvilli. At the distal end of the microvilli, SIM images revealed the spatial colocalization of CD81 with T cell receptors (TCR) and CD63, implying a potential role for CD81 in regulating TCR signaling in conjunction with CD63. Spatial analysis of CD81 and CD63 microdomains from the dual-color SIM data revealed their preference for associating with each other. Cluster analysis of direct stochastic optical reconstruction microscopy (dSTORM) data revealed that in vitro T cell activation results in reduced domain sizes and increased domain separation of CD81. These findings provide visual evidence of the spatial organization and rearrangement of CD81 on the T cell microvilli, highlighting its potential role in signal regulation on specialized membrane protrusions.

cell biology↗

bioRxiv2024

Testicular sex cord stromal tumors in mice with constitutive activation of PI3K and loss of Pten

Testicular tumors are the most common malignancy of young men and tumors affecting the testis are caused by somatic mutations in germ or germ-like cells. The PI3K pathway is constitutively activated in about one third of testicular cancers. To investigate the role of the PI3K pathway in transforming stem-like cells in the testis, we investigated tumors derived from mice with post-natal, constitutive activation of PI3K signaling and homozygous deletion of tumor suppressor Pten, targeted to nestin expressing cells. Mice developed aggressive tumors, exhibiting heterogeneous histopathology and hemorrhaging. The tumors resemble the rare testis tumor type, testicular sex cord-stromal Leydig cell tumors. Single cell resolution spatial tissue analysis demonstrated that T-cells are the dominant tumor infiltrating immune cell type, with very few infiltrating macrophages observed in the tumor tissue, with CD8+ T-cells predominating. Further analysis showed that immune cells preferentially localize to or accumulate within stromal regions. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=114 SRC="FIGDIR/small/613175v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@657f74org.highwire.dtl.DTLVardef@192bcc7org.highwire.dtl.DTLVardef@a7c63eorg.highwire.dtl.DTLVardef@c81d17_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

The Changing Immune Landscape of Innate-like T Cells and Innate Cells Throughout Life

Spectral flow cytometry is an advanced immunological tool that enables comprehensive analysis of the immune system by simultaneously comparing innate and adaptive immune cells. Here, using a 40-colour antibody panel we advance our knowledge of innate and innate-like T cells by investigating chemokine receptors, activation and maturation markers not usually assessed on these populations and examine age-related effects to these immune cell subsets. We characterised phenotypic changes of peripheral blood mononuclear cells (PBMC) in three age groups: newborn (cord blood), adults aged 20-30 years, and adults aged 70-80 years, focusing on innate-like T cells and innate cells, including MAIT cells, NKT cells, {gamma}{delta} T cells, ILCs, and Natural Killer (NK) cells. We identify subsets of double-negative (DN) T cells (CD4- CD8-) and CD161+ T cells that increase in an age-related manner and exhibit a phenotype similar to innate-like T cells, MAIT cells and {gamma}{delta} T cells. Innate-like T cell subsets express similar patterns of the chemokine receptors and maturation markers CCR4, CCR6, CD27, CD38, CD57 and CD45RA, and resemble memory subsets of conventional CD4+ T cells and CD8+ T cells. We could detect ILCs in all age ranges, although the frequency of ILC1, ILC2, and ILC3 subsets decreased with age. Notably, we identify the NK maturation marker, CD57, as a universal marker that defines ageing populations of innate and adaptive immune cells. This study enhances our understanding of the ontogeny of human immune cells, highlighting significant age-related changes in the frequency and phenotype of immune cells.

immunology↗

bioRxiv2024

Social and environmental predictors of gut microbiome age in wild baboons

Mammalian gut microbiomes are highly dynamic communities that shape and are shaped by host aging, including age-related changes to host immunity, metabolism, and behavior. As such, gut microbial composition may provide valuable information on host biological age. Here we test this idea by creating a microbiome-based age predictor using 13,563 gut microbial profiles from 479 wild baboons collected over 14 years. The resulting "microbiome clock" predicts host chronological age. Deviations from the clocks predictions are linked to some demographic and socio-environmental factors that predict baboon health and survival: animals who appear old-for-age tend to be male, sampled in the dry season (for females), and have high social status (both sexes). However, an individuals "microbiome age" does not predict the attainment of developmental milestones or lifespan. Hence, in our host population, gut microbiome age largely reflects current, as opposed to past, social and environmental conditions, and does not predict the pace of host development or host mortality risk. We add to a growing understanding of how age is reflected in different host phenotypes and what forces modify biological age in primates.

evolutionary biology↗

bioRxiv2024

Multi omics aided small RNA profiling of wheat rhizosphere and their potential targets in contrasting soils for Rhizoctonia solani-AG8 suppression

Next-generation sequencing helps describe microbial communities in rhizosphere environments, but understanding rhizosphere-plant interactions synergistic effects on plant traits and health outcomes remains challenging. This study analyses rhizosphere sRNAs ability to manipulate host gene targets in plants grown in suppressive (SP) and non-suppressive (NSP) soils with an integrated multi omics dataset. The results showed that rhizosphere sRNAs exhibited specific compositional features that may be important for rhizosphere-plant interaction. Small RNAs, less than 30 nt in size, were predominant in both samples, with a 5-prime bias towards cytosine enrichment, suggesting potential association with wheat specific argonauts. Mapping of sRNA reads to microbial metagenomes assembled draft genomes from SP and NSP soils showed sRNA loci were differentially expressed (DE) between the soils with contrasting disease suppressive capacities. In total, 96 and 132 non redundant rhizosphere sRNAs were abundant in SP and NSP rhizosphere communities, respectively. While 55 known bacterial sRNA loci were predicted from both SP and NSP metagenomes, 127 sRNAs originated from these loci were differentially expressed. Global wheat target prediction and functional analysis from DE rhizosphere sRNAs showed both soil type specific and common pathways. Upregulated NSP sRNAs target metabolic pathways, secondary metabolite biosynthesis, MAPK signalling, while SP sRNAs target glycerophospholipid metabolism, pathways such as polycomb repressive complex, starch/sucrose metabolism, and plant-pathogen interactions were targeted by both sets of sRNAs. This is the first study showing evidence for rhizosphere sRNAs and their corresponding plant transcripts in the context of biological disease suppression in agricultural soils. ImportanceSmall RNAs (sRNAs) have gained attention in host-microbe interactions due to their diverse roles in controlling biological processes. Studies have identified numerous sRNAs with novel functions across various organisms. Echoing growing evidence of sRNAs in different plant-microbe interaction, we show an evidence of rhizosphere sRNAs regulating wheat genes in soil disease suppression context. This understanding could significantly enhance our comprehension of gene regulation in biological functions, potentially paving the way for the development of microbiome-based methods to influence host traits. Understanding the microbiome communitys mechanisms in different environments offers opportunities to modify them for agriculture, including modifying farming practices, host genetics/immunity, and synthetic communities for disease suppression.

molecular biology↗

bioRxiv2024

Comprehensive multi-site profiling of the malignant pleural mesothelioma micro-environment identifies candidate molecular determinants of histopathologic type

Pleural mesothelioma (PM) comprises sarcomatoid, epithelioid and biphasic histologic subtypes. Bulk PM RNA-sequencing identifies a histology-associated molecular gradient with features of epithelial-mesenchymal (EM) transition but cannot parse malignant, stromal, and immune tumor components. The mechanisms driving PM malignant cell phenotype and associated histology is not well-characterized. Here, we use single-cell RNA-sequencing (scRNA-seq) paired with exome, bulk RNA-sequencing, and histologic analysis of adjacent samples to characterize malignant cell EM state, parse the tumor microenvironment (TME), and identify candidate drivers of PM cell fate. We observe EM variation in malignant cells analogous to bulk samples. We characterize epithelioid and sarcomatoid malignant cell programs and identify a new uncommitted malignant cell EM phenotype enriched in biphasic histology samples. Using inferred CNVs we observe that single individual PM clones consist of cells exhibiting all three EM cell states. We find that distinct non-malignant microenvironments associated with tumors consisting of mostly cells in each state, and identify WNT inhibition, GAS6-AXL, and HBEGF-EGFR signaling as pathways associated with distinct EM cell states. These findings provide deeper insight into the molecular drivers of PM malignant cells and identify non-malignant cell signals as potential EMT and growth drivers in PM.

cancer biology↗

bioRxiv2024

Blocking MIF secretion enhances CAR T-cell efficacy against neuroblastoma

While chimeric antigen receptor (CAR) T-cell therapies are showing highly promising first results in neuroblastoma, immunosuppressive tumor microenvironments (TME) limit T cell persistence and durable clinical efficacy. To improve CAR T-cell efficacy further, we applied a multi-omics approach including single-cell RNA sequencing and proteomics, which identified 13 targetable immunosuppressive factors in neuroblastoma. Of these, macrophage migration inhibitory factor (MIF) and midkine (MDK) were validated across multiple published RNA datasets. Moreover, they were secreted in high abundance by neuroblastoma tumoroids. Functional validation experiments revealed MIF as a potent inhibitor of CAR T-cells, in vitro and in vivo. Degradation of MIF by PROTAC technology significantly enhanced CAR T-cell activation targeting GPC2 and B7-H3, providing a potential intervention against MIF. By defining the immunosuppressive effects of neuroblastomas TME on CAR T-cell efficacy, particularly the pivotal role of MIF, we provide a therapeutic strategy for improving adoptive cell therapies for this pediatric malignancy.

cancer biology↗

bioRxiv2024

Quantitative Superresolution Imaging of F-Actin in the Cell Body and Cytoskeletal Protrusions Using Phalloidin-Based Single-Molecule Labeling and Localization Microscopy

We present single-molecule labeling and localization microscopy (SMLLM) using dye-conjugated phalloidin to achieve enhanced superresolution imaging of filamentous actin (F-actin). We demonstrate that the intrinsic phalloidin dissociation enables SMLLM in an imaging buffer containing low concentrations of dye-conjugated phalloidin. We further show enhanced single-molecule labeling by chemically promoting phalloidin dissociation. Two benefits of phalloidin-based SMLLM are better preservation of cellular structures sensitive to mechanical and shear forces during standard sample preparation and more consistent F-actin quantification at the nanoscale. In a proof-of-concept study, we employed SMLLM to super-resolve F-actin structures in U2OS and dendritic cells (DCs) and demonstrate more consistent F-actin quantification in the cell body and structurally delicate cytoskeletal proportions, which we termed membrane fibers, of DCs compared to direct stochastic optical reconstruction microscopy (dSTORM). Using DC2.4 mouse dendritic cells as the model system, we show F-actin redistribution from podosomes to actin filaments and altered prevalence of F-actin-associated membrane fibers on the culture glass surface after lipopolysaccharide exposure. While our work demonstrates SMLLM for F-actin, the concept opens new possibilities for protein-specific single-molecule labeling and localization in the same step using commercially available reagents.

cell biology↗

bioRxiv2024

Functional avidity of anti-B7H3 CAR-T constructs predicts antigen density thresholds for triggering effector function

Chimeric Antigen receptor T cell (CAR-T) treatments for solid cancers have been compromised by limited expansion and survival in the tumor microenvironment following interaction with antigen-expressing target cells. Using B7H3 as a model antigen with broad clinical applicability, we evaluated the relationship between the antibody/antigen affinity of three clinical candidate binders and the three following functional characteristics: functional avidity, prolonged cytotoxicity in tumoroid re-stimulation assays, and in vivo anti-tumoral responses. BEHAV3D video-microscopy assessed distinct CAR-T cell behaviors at single cell resolution. T cell exhaustion did not dictate effector function. Rather, we demonstrated a threshold avidity of CAR-T / tumor cell interaction, characterized by longer cumulative CD8+ CAR-T / tumor target interaction times, and required for adequate CAR-T cell expansion to result in sustained tumor control upon re-challenge. These results provide new insights into design of CAR-T cells for antigen-dim cell targeting, and avoidance of antigen-dim tumor relapse.

bioengineering↗

bioRxiv2024

Preservation of memory B cell homeostasis in an individual producing broadly neutralising antibodies against HIV-1

Immunological determinants favouring emergence of broadly neutralising antibodies are crucial to the development of HIV-1 vaccination strategies. Here, we combined RNAseq and B cell cloning approaches to isolate a broadly neutralising antibody (bnAb) ELC07 from an individual living with untreated HIV-1. Using single particle cryogenic electron microscopy (cryo-EM), we show that the antibody recognises a conformational epitope at the gp120-gp41 interface. ELC07 binds the closed state of the viral glycoprotein causing considerable perturbations to the gp41 trimer core structure. Phenotypic analysis of memory B cell subsets from the ELC07 bnAb donor revealed a lack of expected HIV-1-associated dysfunction, specifically no increase in CD21-/CD27- cells was observed whilst the resting memory (CD21+/CD27+) population appeared preserved despite uncontrolled HIV-1 viraemia. Moreover, single cell transcriptomes of memory B cells from this bnAb donor showed a resting memory phenotype irrespective of the epitope they targeted or their ability to neutralise diverse strains of HIV-1. Strikingly, single memory B cells from the ELC07 bnAb donor were transcriptionally similar to memory B cells from HIV-negative individuals. Our results demonstrate that potent bnAbs can arise without the HIV-1-induced dysregulation of the memory B cell compartment and suggest that sufficient levels of antigenic stimulation with a strategically designed immunogen could be effective in HIV-negative vaccine recipients.

microbiology↗

bioRxiv2023

UV damage induces production of mitochondrial DNA fragments with specific length profiles

UV light is a potent mutagen that induces bulky DNA damage in the form of cyclobutane pyrimidine dimers (CPDs). In eukaryotic cells, photodamage and other bulky lesions occurring in nuclear genomes (nucDNAs) can be repaired through nucleotide excision repair (NER), where dual incisions on both sides of a damaged site precede the removal of a single-stranded oligonucleotide containing the damage. Mitochondrial genomes (mtDNAs) are also susceptible to damage from UV light, but current views hold that the only way to eliminate bulky DNA damage in mtDNAs is through mtDNA degradation. Damage-containing oligonucleotides excised during NER can be captured with anti-damage antibodies and sequenced (XR-seq) to produce high resolution maps of active repair locations following UV exposure. We analyzed previously published datasets from Arabidopsis thaliana, Saccharomyces cerevisiae, and Drosophila melanogaster to identify reads originating from the mtDNA (and plastid genome in A. thaliana). In A. thaliana and S. cerevisiae, the mtDNA-mapping reads have unique length distributions compared to the nuclear-mapping reads. The dominant fragment size was 26 nt in S. cerevisiae and 28 nt in A. thaliana with distinct secondary peaks occurring in 2-nt (S. cerevisiae) or 4-nt (A. thaliana) intervals. These reads also show a nonrandom distribution of di-pyrimidines (the substrate for CPD formation) with TT enrichment at positions 7-8 of the reads. Therefore, UV damage to mtDNA appears to result in production of DNA fragments of characteristic lengths and positions relative to the damaged location. We hypothesize that these fragments may reflect the outcome of a previously uncharacterized mechanism of NER-like repair in mitochondria or a programmed mtDNA degradation pathway.

genetics↗

bioRxiv2023

A high-cholesterol zebrafish diet promotes hypercholesterolemia and fasting-associated liver triglycerides accumulation

Zebrafish are an ideal model organism to study lipid metabolism and to elucidate the molecular underpinnings of human lipid-associated disorders. In this study, we provide an improved protocol to assay the impact of a high-cholesterol diet (HCD) on zebrafish lipid deposition and lipoprotein regulation. Fish fed HCD developed hypercholesterolemia as indicated by significantly elevated ApoB-containing lipoproteins (ApoB-LP) and increased plasma levels of cholesterol and cholesterol esters. Feeding of the HCD to larvae (8 days followed by a 1 day fast) and adult female fish (2 weeks, followed by 3 days of fasting) was also associated with a fatty liver phenotype that presented as severe hepatic steatosis. The HCD feeding paradigm doubled the levels of liver triacylglycerol (TG), which was striking because our HCD was only supplemented with cholesterol. The accumulated liver TG was unlikely due to increased de novo lipogenesis or inhibited {beta}-oxidation since no differentially expressed genes in these pathways were found between the livers of fish fed the HCD versus control diets. However, fasted HCD fish had significantly increased lipogenesis gene fasn in adipose tissue and higher free fatty acids (FFA) in plasma. This suggested that elevated dietary cholesterol resulted in lipid accumulation in adipocytes, which supplied more FFA during fasting, promoting hepatic steatosis. In conclusion, our HCD zebrafish protocol represents an effective and reliable approach for studying the temporal characteristics of the physiological and biochemical responses to high levels of dietary cholesterol and provides insights into the mechanisms that may underlie fatty liver disease.

physiology↗

bioRxiv2023

Human assembloids reveal the consequences of CACNA1G gene variants in the thalamocortical pathway

Abnormalities in crosstalk between the thalamus and the cerebral cortex are thought to lead to severe neuropsychiatric disorders, such as epilepsy and psychotic disorders. Pathogenic variants in the CACNA1G gene, which encodes the 1G subunit of the thalamus-enriched T-type voltage-gated calcium channel CaV3.1, are associated with absence seizures, intellectual disability, and schizophrenia, but the cellular and circuit level consequences of these genetic variants in humans remain unknown. Here, we developed an in vitro human assembloid model of the thalamocortical pathway to systematically dissect the contribution of genetic variants in T-type calcium channels. We discovered that a CACNA1G variant (M1531V) associated with seizures led to changes in T-type currents in human thalamic neurons, as well as correlated hyperactivity of thalamic and cortical neurons in thalamo-cortical assembloids. In contrast, CACNA1G loss, which has been associated with risk of schizophrenia, resulted in abnormal thalamocortical connectivity that was related to both increased spontaneous thalamic activity and aberrant thalamic axonal projections. Taken together, these results illustrate the utility of organoid and assembloid systems for interrogating human genetic disease risk variants at both cellular and circuit level.

neuroscience↗

bioRxiv2023

Chromosome-specific maturation of the epigenome in the Drosophila male germline

Spermatogenesis in the Drosophila male germline proceeds through a unique transcriptional program controlled both by germline-specific transcription factors and by testis-specific versions of core transcriptional machinery. This program includes the activation of genes on the heterochromatic Y chromosome, and reduced transcription from the X chromosome, but how expression from these sex chromosomes is regulated has not been defined. To resolve this, we profiled active chromatin features in the testes from wildtype and meiotic arrest mutants and integrate this with single-cell gene expression data from the Fly Cell Atlas. These data assign the timing of promoter activation for genes with germline-enriched expression throughout spermatogenesis, and general alterations of promoter regulation in germline cells. By profiling both active RNA polymerase II and histone modifications in isolated spermatocytes, we detail widespread patterns associated with regulation of the sex chromosomes. Our results demonstrate that the X chromosome is not enriched for silencing histone modifications, implying that sex chromosome inactivation does not occur in the Drosophila male germline. Instead, a lack of dosage compensation in spermatocytes accounts for the reduced expression from this chromosome. Finally, profiling uncovers dramatic ubiquitinylation of histone H2A and lysine-16 acetylation of histone H4 across the Y chromosome in spermatocytes that may contribute to the activation of this heterochromatic chromosome.

developmental biology↗

bioRxiv2022

A generalizable epigenetic clock captures aging in two nonhuman primates.

Epigenetic clocks generated from DNA methylation array data provide important insights into biological aging, disease susceptibility, and mortality risk. However, these clocks cannot be applied to high-throughput, sequence-based datasets more commonly used to study nonhuman animals. Here, we built a generalizable epigenetic clock using genome-wide DNA methylation data from 493 free-ranging rhesus macaques. Using a sliding-window approach that maximizes generalizability across datasets and species, this model predicted age with high accuracy ({+/-} 1.42 years) in held-out test samples, as well as in two independent test sets: rhesus macaques from a captive population (n=43) and wild baboons in Kenya (n=271). Our model can also be used to generate insight into the factors hypothesized to alter epigenetic aging, including social status and exposure to traumatic events. Our results thus provide a flexible tool for predicting age in other populations and species and illustrate how connecting behavioral data with the epigenetic clock can uncover social influences on biological age.

evolutionary biology↗

bioRxiv2022

OPS-γδ: allogeneic opsonin-secreting γδT cell immunotherapy for solid tumours mediates direct and bystander immunity

T cell-based cancer immunotherapy has typically relied on membrane-bound cytotoxicity enhancers such as chimeric antigen receptors expressed in autologous {beta}T cells. These approaches are limited by tonic signalling of synthetic constructs and costs associated with manufacture of bespoke patient products. {gamma}{delta}T cells are an emerging alternative chassis for cellular therapy, possessing innate anti-tumour activity, potent antibody-dependent cytotoxicity (ADCC) and minimal alloreactivity. We present an immunotherapeutic platform technology built around the V{gamma}9V{delta}2 {gamma}{delta}T cell chassis, harnessing specific characteristics of this cell type and offering an allo-compatible means of delivering cellular therapy that recruits bystander immunity. We engineered {gamma}{delta}T cells to secrete synthetic opsonins and stabilized IL15 (stIL15). Using GD2 as a model antigen we show how opsonin-secreting V{gamma}9V{delta}2 (OPS-{gamma}{delta}) have enhanced cytotoxicity and also confer this benefit on lymphoid and myeloid bystander cells. Reflecting the secreted nature of the engineered efficacy modules, the entire product rather than just the gene-modified fraction exhibited enhanced activation and cytotoxic profiles, superior persistence and proliferative capacity even upon repeated tumour challenge. Secretion of stIL15 abrogated the need for exogenous cytokine supplementation during expansion and further mediated functional licensing of bystander NK cells. Compared to unmodified {gamma}{delta}T cells, stIL15-OPS-{gamma}{delta} cells exhibited superior in-vivo control of subcutaneous tumour and persistence in the blood. stIL15-OPS-{gamma}{delta} cells were further efficacious in 3D patient-derived osteosarcoma models, where efficacy could be boosted with the addition of immunomodulatory aminobisphosphonate drug, zoledronic acid. Together the data identify stIL15-OPS-{gamma}{delta} cells as a novel allogeneic platform combining direct cytolysis with bystander activation to effect solid tumour control. One Sentence SummaryArmoured, opsonin-secreting OPS-{gamma}{delta} cell immunotherapy is built on the innate strengths of the V{gamma}9V{delta}2 cell chassis for allogeneic solid tumour targeting.

immunology↗

bioRxiv2022

Productive and latent HIV infections originate in resting CD4+ T cells

Productively and latently HIV-infected cells are the source of virus that respectively establishes and sustains systemic infections and the reservoir in which HIV persists and rebounds when anti-retroviral therapy (ART) is interrupted. While infected activated CD4+ T cells are thought to be the principal source of HIV production, and reversion of activated infected cells to a resting state as the major pathway to establishment of the latently infected cell reservoir, we now show that in the earliest stages of detectable HIV infection in the lymphoid tissue reservoir, infection of resting CD4+ T cells establishes the first populations of both productively and latently infected cells. We further show that the early infection of resting T cells reflects their predominance in lymphoid tissues and the expression of pTEFb in vivo in resting T cells to support their infection. The immediate establishment of productively and latently infected cell populations enable HIV to propagate and persist, and generates reservoirs from which infection can rebound despite instituting ART at the earliest stage of detectable infection.

immunology↗