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Tuong, Z. K.

Publications and source records attributed to Tuong, Z. K..

15 recordsLinked to original sources

CXCL9-Dependent Immune Networks of Spontaneous Tertiary Lymphoid Structures in a Murine Subcutaneous Tumor Model

Recent discoveries have identified human tumor tertiary lymphoid structures (TLS) as organized clusters of innate and adaptive immune cells and stromal cells. Cancer-associated TLS can promote tumor clearance and enhance responses to immune checkpoint blockade (ICB) immunotherapy. However, the absence of TLS in conventional mouse tumor models, particularly subcutaneous transplant models, limits experimental manipulation and study of TLS development. By tuning tumor antigen expression, we have generated a subcutaneous tumor model that naturally forms TLS within the immune-hot, vasculature-rich peritumoral adipose tissue. These TLS were identified as clusters of B and T cells in close proximity to high endothelial venules. TLS organization was underpinned by spatially compartmentalized chemokine expression, with CCL21 produced in the T cell zone of perivascular TLS and CXCL13 present in the B cell region. Single cell transcriptomic sequencing showed that the immune composition in the TLS forming peritumoral tissue resembled human cancer TLS signatures. Upon anti-PD-L1 ICB treatment, TLS underwent expansion, which was associated with increased interferon responses in macrophages and coincided with tumor clearance. We further identified the interferon-inducible chemokine CXCL9 as a key regulator of the TLS microenvironment. CXCL9-expressing macrophages populated TLS, interacting with B cells following ICB treatment. CXCL9 deficiency reduced B cell recruitment to peritumoral tissue and TLS formation. Further T and B cell receptor sequencing indicated a CXCL9-dependent promotion of antigen-specific responses within the tumor and TLS niche. Combined, these findings establish a tractable subcutaneous model of naturally arising tumor TLS and define the cellular and molecular networks that regulate their formation and function. This provides a platform to dissect how TLS develop and test strategies that promote TLS formation to enhance cancer therapy.

immunology↗

Mapping immune cellular landscapes and vaccine responses across a spectrum of health and immunodeficiency.

Immune responses to infection and vaccination exhibit diversity between individuals that can be shaped by differences in their immune cell landscapes and the signalling, transcriptional, and genetic mechanisms that coordinate immune cell function. Specific antibody deficiency (SAD) and common variable immunodeficiency (CVID) are common forms of predominantly antibody deficiencies that result in poor responses to vaccination. While molecular and cellular causes of the immune dysfunction and poor vaccination responses for individuals with CVID have been reported, immune cell or molecular defects have not yet been identified in SAD. Here, we have used single-cell multi-omics to define the cellular landscapes, transcriptional states, adaptive immune repertoires and protein expression of patients with SAD and CVID before and after polysaccharide vaccination. We discovered that while SAD and CVID exhibit overlapping immune defects, including accumulation of exhausted NK memory cells and dysregulated expression of genes that mediate lipopolysaccharide sensing and clearance by monocytes, individuals with SAD have a unique expansion of cytotoxic CD4+ T cells that correlates with reduced regulatory T cells. In response to vaccination, we observed rapid changes in gene expression associated with lipopolysaccharide responses by monocytes and NF-kB pathway activation in B cells, and an apparent expansion of a CD95+ class-switched memory B cell population that does not occur in patients with lower antigen-specific responses. Together, our findings reveal cellular and molecular factors that underpin variability in vaccine responses and define SAD in a broader spectrum of immune dysfunction.

immunology↗

Resolving cDC2 heterogeneity across human cancer atlases

Dendritic cells (DCs) are vital in driving effective anti-tumour immune responses. Multiple DC subpopulations have been identified in human tumours, however their alignment, phenotype and function across tumour types have not been comprehensively addressed. Here, we curated single-cell RNA sequencing datasets to generate an extensive integrated atlas of myeloid antigen presenting cells (APCs) across different human cancer types. We confirm that cDC1, cDC2 and mregDC represent the major DC populations present in human tumours, and that these populations are highly conserved regardless of cancer type. A distinct DC3 population was not identified within the atlas, suggesting these cells are less distinguishable in tumour tissue. The cDC2 compartment resolved into two subpopulations, a minor population that aligned tumour associated CD207+CD1A+ cDC2 with splenic cDC2A, and a predominate subset aligning with cDC2B. This integrated atlas serves as a powerful resource enabling deeper investigation into the functions of tumour-associated DC diversity, phenotype and function, across a range of human cancer types.

immunology↗

Intestinal challenges shape the polarisation of protective dural memory CD4 T cells

The meninges house several innate and adaptive immune cell populations1-3. These predominantly localise within the dura mater and include gut-derived IgA-secreting plasma cells4. Whether T cell adaptive memory in the dura is similarly linked to the gut is currently unknown. Here we show that dural CD4 T cell polarisation to a T helper (Th) 1, Th2 and Th17 state is determined by the nature of the immunological challenge encountered in the gastrointestinal tract. We find that intestinally polarised CD4 T cells seed to the dura in a CXCR6-CXCL16-dependent manner, express tissue-residency markers and are long-lived. Functionally, these orally-primed dural CD4 T are capable of a rapid antigen-specific recall response that limits pathogen spread into the brain following intravenous re-challenge. Our work reveals how linked intestinal and dural immunity enables the central nervous system to accrue immunological memory of gut microbes, the most likely source of life-threatening bloodborne pathogens.

immunology↗

dandelionR: Single-cell immune repertoire trajectory analysis in R

Integration of single-cell RNA-sequencing (scRNA-seq) and adaptive immune receptor (AIR) sequencing (scVDJ-seq) is extremely powerful in studying lymphocyte development. A python-based package, Dandelion, introduced VDJ-feature space method, which addresses the challenge in integration of single-cell AIR data with gene expression data and enhanced the trajectory analysis results. However, no R-based equivalent or similar methods currently exist. To fill this gap, we present dandelionR, an R implementation of Dandelions trajectory analysis workflow, bringing the VDJ feature space construction and trajectory analysis using diffusion map and absorbing Markov chain to R, offering a new option for scRNA-seq and scVDJ-seq analysis to R language users.

bioinformatics↗

Temporally overlapping mechanisms diversify clonal B cell responses in vivo.

Naive B cells amplify and diversify their responses when activated by cognate antigen, via Myc-dependent clonal expansion, immunoglobulin class switch recombination (CSR), phenotypic variation, and somatic hypermutation (SHM). Whether these mechanisms act combinatorially in vivo to diversify clonal responses to a single pathogen remains unclear. Since diversity in the antigenic targets, functional classes, and production kinetics of parasite-specific antibodies influences immunity to malaria, we test here whether individual B cell clones diversify over time during Plasmodium infection and treatment. During the first week of infection, amid widespread Type I Interferon (IFN)-mediated bystander activation, CSR initiates soon after Myc up-regulation, and overlaps partially with clonal expansion, resulting in isotype variegation amongst clones. During the second week of infection, expanded clones that seed germinal centres (GC) bifurcate into extra-follicular plasmablasts, exhibit isotype variegation, and initiate SHM, revealing substantial intra-clonal diversification. Over the following month, GC clones exhibit SHM at approximately four mutations per week, with IgG mutational diversity and IgM+ cells also preserved in GCs over time. Anti-malarial intervention does not impede SHM, but instead exerts quantitative limits on GC size, plasma cell emergence, circulating IgG levels, and protection against re-infection. Finally, contemporaneous B cell development relocates from bone marrow to spleen during infection and treatment. Thus, multiple temporally overlapping mechanisms combine in vivo to amplify, diversify, and safeguard humoral immune responses. We present this data as a temporal, multi-parameter atlas of B cell differentiation in vivo: https://bcell-dynamics.science.unimelb.edu.au Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/628863v2_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@c57890org.highwire.dtl.DTLVardef@6e5936org.highwire.dtl.DTLVardef@a2e872org.highwire.dtl.DTLVardef@14abbac_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIPartial temporal overlap of CSR with clonal expansion leads to isotype variegation in clones. C_LIO_LIClones seeding GCs bifurcate into plasmablasts and exhibit isotype variegation. C_LIO_LIGC B cells accrue [~]4 mutations/week, a rate unaffected by anti-malarials. C_LIO_LIPlasmodium infection triggers antigen-independent Type I IFN-mediated bystander activation. C_LIO_LIB cell development is preserved in malaria by shifting from bone marrow to spleen. C_LI

immunology↗

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↗

Temporal profiling of human lymphoid tissues reveals coordinated defence to viral challenge

Adaptive immunity is generated in lymphoid organs, but how these structures defend themselves during infection in humans is unknown. The nasal epithelium is a major site of viral entry, with adenoid nasal-associated lymphoid tissue (NALT) generating early adaptive responses. Here, using a nasopharyngeal biopsy, we examined longitudinal immune responses in NALT following viral challenge, using SARS-CoV-2 infection as a natural experimental model. In acute infection, infiltrating monocytes formed a subepithelial and peri-follicular shield, recruiting NET-forming neutrophils, whilst tissue macrophages expressed pro-repair molecules during convalescence to promote the restoration of tissue integrity. Germinal centre B cells expressed anti-viral transcripts that inversely correlated with fate-defining transcription factors. Among T cells, tissue-resident memory CD8 T cells alone showed clonal expansion and maintained cytotoxic transcriptional programmes into convalescence. Together our study provides a unique insight into how human nasal adaptive immune responses are generated and sustained in the face of viral challenge.

immunology↗

Rapid establishment of a tumor-retained state curtails the contribution of conventional NK cells to anti-tumor immunity in solid cancers

Immune cell dysfunction within the tumor microenvironment undermines the control of cancer progression. NK cells play critical roles in limiting early tumor growth and metastatic disease, however, established cancers contain a phenotypically distinct, tumor-specific NK cell compartment. The temporal dynamics, mechanistic underpinning and functional significance of this tumor NK pool remains incompletely understood. To address this, we exploited photo-labeling, combined with longitudinal transcriptomic and cellular analyses, to interrogate the fate of NK cells after tumor entry. In multiple murine cancer models we reveal that conventional NK cells are continuously recruited into tumors, but rapidly adopt a distinct phenotypic state with features associated with tissue-residency and complete loss of effector functions (including chemokine and cytokine production and cytotoxicity), within 48-72 hrs of entering the tumor. Depletion of NK cells from established tumors did not alter tumor growth, indicating that intratumoral NK cells cease to actively contribute to anti- tumor responses. Furthermore, comparable NK populations were identified in human colorectal cancers, confirming translational relevance and raising the possibility that interventions to reactivate NK cells within tissues may boost anti-tumor immunity in established cancers. Indeed, administration of IL-15:IL-15Ra complexes prevented the loss of NK cell function and improved tumor control, generating intratumoral NK cells with both enhanced tissue-residency characteristics and effector function. Collectively, our data reveals the fate of cNK cells after recruitment into tumors and provides insight into how intratumoral NK cell functions may be revived. SummaryConventional NK cells recruited from the circulation rapidly establish a tissue-resident phenotype defined by impaired cytotoxicity and chemokine production after tumor entry; administration of IL- 15:IL-15R complexes further promotes this tissue-residency programme but maintains core NK cell effector functions within the tumor.

immunology↗

Time-, tissue- and treatment-associated heterogeneity in tumour-residing migratory DCs

Tumour dendritic cells (DCs) internalise antigen and upregulate CCR7, which directs their migration to tumour-draining lymph nodes (dLN). CCR7 expression is coupled to a maturation programme enriched in regulatory molecule expression, including PD-L1, termed mRegDC. However, the spatio- temporal dynamics and role of mRegDCs in anti-tumour immune responses remain unclear. Using photoconvertible mice to precisely track DC migration, we found that mRegDCs were the dominant DC population arriving in the dLN, but a subset remained tumour-resident despite CCR7 expression. These tumour-retained mRegDCs were phenotypically and transcriptionally distinct from their dLN counterparts and were heterogeneous. Specifically, they demonstrated a progressive reduction in the expression of antigen presentation and pro-inflammatory transcripts with more prolonged tumour dwell-time. Tumour mRegDCs spatially co-localised with PD-1+CD8+ T cells in human and murine solid tumours. Following anti-PD-L1 treatment, tumour-residing mRegDCs adopted a state enriched in lymphocyte stimulatory molecules, including OX40L, which was capable of augmenting anti- tumour cytolytic activity. Altogether, these data uncover previously unappreciated heterogeneity in mRegDCs that may underpin a variable capacity to support intratumoural cytotoxic T cells, and provide insights into their role in cancer immunotherapy.

immunology↗

Early human lung immune cell development and its role in epithelial cell fate

During human development, lungs develop their roles of gas exchange and barrier function. Recent single cell studies have focused on epithelial and mesenchymal cell types, but much less is known about the developing lung immune cells, although the airways are a major site of mucosal immunity after birth. An open question is whether tissue-resident immune cells play a role in shaping the tissue as it develops in utero. In order to address this, we profiled lung immune cells using scRNAseq, smFISH and immunohistochemistry. At the embryonic stage, we observed an early wave of innate immune cells, including ILCs, NK, myeloid cells and lineage progenitors. By the canalicular stage, we detected naive T lymphocytes high in cytotoxicity genes, and mature B lymphocytes, including B1 cells. Our analysis suggests that fetal lungs provide a niche for full B cell maturation. Given the abundance of immune cells, we investigated their possible effect on epithelial maturation and found that IL-1{beta} drives epithelial progenitor exit from self-renewal and differentiation to basal cells in vitro. In vivo, IL-1{beta}-producing myeloid cells were found adjacent to epithelial tips, suggesting that immune cells may direct the developing lung epithelium.

immunology↗

Single cell antigen receptor analysis reveals lymphocyte developmental origins

Assessment of single-cell gene expression (scRNA-seq) and adaptive immune receptor sequencing (scVDJ-seq) has been invaluable in studying lymphocyte biology. Here, we introduce Dandelion, a computational pipeline for scVDJ-seq analysis. It enables the application of standard V(D)J analysis workflows to single-cell datasets, delivering improved V(D)J contig annotation and the identification of non-productive and partially spliced contigs. We devised a novel strategy to create an adaptive immune receptor feature space that can be used for both differential V(D)J usage analysis and pseudotime trajectory inference. The application of Dandelion improved the alignment of human thymic development trajectories of double positive T cells to mature single-positive CD4/CD8 T cells, with important new predictions of factors regulating lineage commitment. Dandelion analysis of other cell compartments provided novel insights into the origins of human B1 cells and ILC/NK cell development, illustrating the power of our approach. Dandelion is an open access resource (https://www.github.com/zktuong/dandelion) that will enable future discoveries.

immunology↗

Obesity associated with attenuated tissue immune cell responses in COVID-19

Obesity is common and associated with more severe COVID-19, proposed to be in part related to an adipokine-driven pro-inflammatory state. Here we analysed single cell transcriptomes from bronchiolar lavage in three adult cohorts, comparing obese (Ob, body mass index (BMI) >30m2) and non-obese (N-Ob, BMI <30m2). Surprisingly, we found that Ob subjects had attenuated lung immune/inflammatory responses in SARS-CoV-2 infection, with decreased expression of interferon (IFN), IFN{gamma} and tumour necrosis factor (TNF) alpha response gene signatures in almost all lung epithelial and immune cell subsets, and lower expression of IFNG and TNF in specific lung immune cells. Analysis of peripheral blood immune cells in an independent adult cohort showed a similar, but less marked, reduction in type I IFN and IFN{gamma} response genes, as well as decreased serum IFN, in Ob patients with SARS-CoV-2. Nasal immune cells from Ob children with COVID-19 also showed reduced enrichment of IFN and IFN{gamma} response genes. Altogether, these findings show blunted tissue immune responses in Ob COVID-19 patients, with clinical implications.

immunology↗

Mapping the developing human immune system across organs

Recent advances in single cell genomics technologies have facilitated studies on the developing immune system at unprecedented scale and resolution. However, these studies have focused on one or a few organs and were thus limited in understanding the developing immune system as a distributed network across tissues. Here, we profiled prenatal haematopoietic organs, lymphoid organs and non-lymphoid tissues using a combination of single-cell RNA sequencing, paired antigen-receptor sequencing and spatial transcriptomics to reconstruct the developing human immune system. Our analysis revealed the acquisition of immune effector transcriptome profiles in macrophages, mast cells and NK cells from the second trimester, and the transcriptomic changes accompanying the late-stage maturation of developing monocytes and T cells that extended from their organ of origin to peripheral tissues. We uncovered system-wide blood and immune cell development beyond the conventional primary haematopoietic organs. We further identified, extensively characterised and functionally validated the human prenatal B1 cells. Finally, we provide evidence for thymocyte-thymocyte selection origin for {beta}TCR- expressing unconventional T cells based on TCR gene usage and an in vitro artificial thymic organoid culture model. Our comprehensive atlas of the developing human immune system provides both valuable data resources and biological insights that will facilitate cell engineering, regenerative medicine and disease understanding. One-Sentence SummaryBy performing a comprehensive single-cell RNA sequencing atlas of human developing immune system together with antigen-receptor sequencing and spatial transcriptomics, we explored the cross-gestation and cross-organ variability in immune cells, discovered system-wide blood and immune cell development, identified, characterised and functionally validated the properties of human prenatal B1 cells and the origin of unconventional T cells.

immunology↗

Spatial analysis of ligand-receptor interactions in skin cancer at genome-wide and single-cell resolution

The ability to study cancer-immune cell communication across the whole tumor section without tissue dissociation is needed for cancer immunotherapies, to understand molecular mechanisms and to discover potential druggable targets. In this work, we developed a powerful experimental and analytical toolbox to enable genome-wide scale discovery and targeted validation of cellular communication. We assessed the utilities of five sequencing and imaging technologies to study cancer tissue, including single-cell RNA sequencing and Spatial Transcriptomic (measuring over >20,000 genes), RNA In Situ Hybridization (multiplex 4-12 genes), digital droplet PCR, and Opal multiplex protein staining (4-9 proteins). To spatially integrate multimodal data, we developed a computational method called STRISH that can automatically scan across the whole tissue section for local expression of gene and/or protein markers to recapitulate an interaction landscape across the whole tissue. We evaluated the unique ability of this toolbox to discover and validate cell-cell interaction in situ through in-depth analysis of two types of cancer, basal cell carcinoma and squamous cell carcinoma, which account for over 70% of cancer cases. We expect that the approach described here will be widely applied to discover and validate ligand receptor interaction in different types of solid cancer tumors.

cancer biology↗