Generation of complex bone marrow organoids from human induced pluripotent stem cells

The human bone marrow (BM) niche sustains hematopoiesis throughout life. We present a method for generating complex BM-like organoids (BMOs) from human induced pluripotent stem cells (iPSCs). BMOs consist of key cell types that self-organize into spatially defined three-dimensional structures mimicking cellular, structural and molecular characteristics of the hematopoietic microenvironment. Functional properties of BMOs include the presence of an in vivo-like vascular network, the presence of multipotent mesenchymal stem/progenitor cells, the support of neutrophil differentiation and responsiveness to inflammatory stimuli. Single-cell RNA sequencing revealed a heterocellular composition including the presence of a hematopoietic stem/progenitor (HSPC) cluster expressing genes of fetal HSCs. BMO-derived HSPCs also exhibited lymphoid potential and a subset demonstrated transient engraftment potential upon xenotransplantation in mice. We show that the BMOs could enable the modeling of hematopoietic developmental aspects and inborn errors of hematopoiesis, as shown for human VPS45 deficiency. Thus, iPSC-derived BMOs serve as a physiologically relevant in vitro model of the human BM microenvironment to study hematopoietic development and BM diseases.

A microfluidic platform integrating functional vascularized organoids-on-chip

The development of vascular networks in microfluidic chips is crucial for the long-term culture of three-dimensional cell aggregates such as spheroids, organoids, tumoroids, or tissue explants. Despite rapid advancement in microvascular network systems and organoid technologies, vascularizing organoids-on-chips remains a challenge in tissue engineering. Most existing microfluidic devices poorly reflect the complexity of in vivo flows and require complex technical set-ups. Considering these constraints, we develop a platform to establish and monitor the formation of endothelial networks around mesenchymal and pancreatic islet spheroids, as well as blood vessel organoids generated from pluripotent stem cells, cultured for up to 30 days on-chip. We show that these networks establish functional connections with the endothelium-rich spheroids and vascular organoids, as they successfully provide intravascular perfusion to these structures. We find that organoid growth, maturation, and function are enhanced when cultured on-chip using our vascularization method. This microphysiological system represents a viable organ-on-chip model to vascularize diverse biological 3D tissues and sets the stage to establish organoid perfusions using advanced microfluidics.

Identification of CCZ1 as an essential lysosomal trafficking regulator in Marburg and Ebola virus infections

Marburg and Ebola filoviruses are two of the deadliest infectious agents and several outbreaks have occurred in the last decades. Although several receptors and co-receptors have been reported for Ebola virus, key host factors remain to be elucidated. In this study, using a haploid cell screening platform, we identify the guanine nucleotide exchange factor CCZ1 as a key host factor in the early stage of filovirus replication. The critical role of CCZ1 for filovirus infections is validated in 3D primary human hepatocyte cultures and human blood-vessel organoids, both critical target sites for Ebola and Marburg virus tropism. Mechanistically, CCZ1 controls early to late endosomal trafficking of these viruses. In addition, we report that CCZ1 has a role in the endosomal trafficking of endocytosis-dependent SARS-CoV-2 infections, but not in infections by Lassa virus, which enters endo-lysosomal trafficking at the late endosome stage. Thus, we have identified an essential host pathway for filovirus infections in cell lines and engineered human target tissues. Inhibition of CCZ1 nearly completely abolishes Marburg and Ebola infections. Thus, targeting CCZ1 could potentially serve as a promising drug target for controlling infections caused by various viruses, such as SARS-CoV-2, Marburg, and Ebola.

NKG2D Fine-Tunes the Local Inflammatory Response in Colorectal Cancer

Treating colorectal cancer (CRC) is a major challenge due to the heterogeneous immunological, clinical and pathological landscapes. Immunotherapy has so far only proven effective in a very limited subgroup of CRC patients. To better define the immune landscape, we examined the immune gene expression profile in various subsets of CRC patients and used a mouse model of intestinal tumors to dissect immune functions. We found that the NK cell receptor, natural-killer group 2 member D (NKG2D, encoded by KLRK1) and NKG2D ligand gene expression is elevated in the most immunogenic subset of CRC patients. High level of KLRK1 positively correlated with the mRNA expression of IFNG and associated with a poor survival of CRC patients. We further show that NKG2D deficiency in the Apcmin/+ mouse model of intestinal tumorigenesis led to reduced intratumoral IFNγ production, reduced tumorigenesis and enhanced survival, suggesting that the high levels of IFNγ observed in the tumors of CRC patients may be a consequence of NKG2D engagement. The mechanisms governing the contribution of NKG2D to CRC progression highlighted in this study will fuel discussions about (i) the benefit of targeting NKG2D in CRC patients and (ii) the need to define the predictive value of NKG2D and NKG2D ligand expression across tumor types.

Mast cell-derived BH4 is a critical mediator of postoperative pain

Postoperative pain affects most patients after major surgery and can transition to chronic pain. Here, we discovered that postoperative pain hypersensitivity correlated with markedly increased local levels of the metabolite BH4. Gene transcription and reporter mouse analyses after skin injury identified neutrophils, macrophages and mast cells as primary postoperative sources of GTP cyclohydrolase-1 (Gch1) expression, the rate-limiting enzyme in BH4 production. While specific Gch1 deficiency in neutrophils or macrophages had no effect, mice deficient in mast cells or mast cell-specific Gch1 showed drastically decreased postoperative pain after surgery. Skin injury induced the nociceptive neuropeptide substance P, which directly triggers the release of BH4-dependent serotonin in mouse and human mast cells. Substance P receptor blockade substantially ameliorated postoperative pain. Our findings underline the unique position of mast cells at the neuro-immune interface and highlight substance P-driven mast cell BH4 production as promising therapeutic targets for the treatment of postoperative pain.

NKG2D signaling regulates IL-17A-producing γδT cells in mice to promote cancer progression

γδT cells are unconventional T cells particularly abundant in mucosal tissues that play an important role in tissue surveillance, homeostasis, and cancer. γδT cells recognize stressed cells or cancer cells through the NKG2D receptor to kill these cells and maintain normality. Contrary to the well-established anti-tumor function of these NKG2D-expressing γδT cells, we show here that, in mice, NKG2D regulates a population of pro-tumor γδT cells capable of producing IL-17A. Germline deletion of Klrk1, the gene encoding NKG2D, reduced the frequency of γδT cells in the tumor microenvironment and delayed tumor progression. We further show that blocking NKG2D reduced the capability of γδT cells to produce IL-17A in the pre-metastatic lung and that co-culture of lung T cells with NKG2D ligand-expressing tumor cells specifically increased the frequency of γδT cells. Together, these data support the hypothesis that, in a tumor microenvironment where NKG2D ligands are constitutively expressed, γδT cells accumulate in an NKG2D-dependent manner and drive tumor progression by secreting pro-inflammatory cytokines, such as IL-17A.

The ubiquitin ligase HOIL-1L regulates immune responses by interacting with linear ubiquitin chains

The Linear Ubiquitin Chain Assembly Complex (LUBAC), composed of HOIP, HOIL-1L, and SHARPIN, promotes tumor necrosis factor (TNF)-dependent NF-κB signaling in diverse cell types. HOIL-1L contains an Npl4 Zinc Finger (NZF) domain that specifically recognizes linear ubiquitin chains, but its physiological role in vivo has remained unclear. Here, we demonstrate that the HOIL-1L NZF domain has important regulatory functions in inflammation and immune responses in mice. We generated knockin mice (Hoil-1l^{T201A;R208A/T201A;R208A}) expressing a HOIL-1L NZF mutant and observed attenuated responses to TNF- and LPS-induced shock, including prolonged survival, stabilized body temperature, reduced cytokine production, and liver damage markers. Cells derived from Hoil-1l^{T201A;R208A/T201A;R208A} mice show reduced TNF-dependent NF-κB activation and incomplete recruitment of HOIL-1L into TNF Receptor (TNFR) Complex I. We further show that HOIL-1L NZF cooperates with SHARPIN to prevent TNFR-dependent skin inflammation. Collectively, our data suggest that linear ubiquitin-chain binding by HOIL-1L regulates immune responses and inflammation in vivo.

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An RBR-type E3 ligase HOIL-1L decodes linear ubiquitin chains via the NZF domain

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HOIL-1L NZF is essential for proper responses to LPS and TNF-induced shock in mice

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Intact HOIL-1L NZF is required for activating the TNF-induced NF-kB pathway

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HOIL-1L NZF cooperates with SHARPIN to control inflammation in mice

A summary of current NKG2D-based CAR clinical trials

Cancer immunotherapies have significantly improved patient survival and treatment options in recent years. Nonetheless, the success of immunotherapy is limited to certain cancer types and specific subgroups of patients, making the development of new therapeutic approaches a topic of ongoing research. Chimeric antigen receptor (CAR) cells are engineered immune cells that are programmed to specifically eliminate cancer cells. Ideally, a CAR recognizes antigens that are restricted to tumor cells to avoid off-target effects. NKG2D is an activating immunoreceptor and an important player in anti-tumor immunity due to its ability to recognize tumor cells and initiate an anti-tumor immune response. Ligands for NKG2D are expressed on malignant or stressed cells and typically absent from healthy tissue, making it a promising CAR candidate. Here, we provide a summary of past and ongoing NKG2D-based CAR clinical trials and comment on potential pitfalls.

Identification of lectin receptors for conserved SARS-CoV-2 glycosylation sites

New SARS‐CoV‐2 variants are continuously emerging with critical implications for therapies or vaccinations. The 22 N‐glycan sites of Spike remain highly conserved among SARS‐CoV‐2 variants, opening an avenue for robust therapeutic intervention. Here we used a comprehensive library of mammalian carbohydrate‐binding proteins (lectins) to probe critical sugar residues on the full‐length trimeric Spike and the receptor binding domain (RBD) of SARS‐CoV‐2. Two lectins, Clec4g and CD209c, were identified to strongly bind to Spike. Clec4g and CD209c binding to Spike was dissected and visualized in real time and at single‐molecule resolution using atomic force microscopy. 3D modelling showed that both lectins can bind to a glycan within the RBD‐ACE2 interface and thus interferes with Spike binding to cell surfaces. Importantly, Clec4g and CD209c significantly reduced SARS‐CoV‐2 infections. These data report the first extensive map and 3D structural modelling of lectin‐Spike interactions and uncovers candidate receptors involved in Spike binding and SARS‐CoV‐2 infections. The capacity of CLEC4G and mCD209c lectins to block SARS‐CoV‐2 viral entry holds promise for pan‐variant therapeutic interventions.

A crucial role for Jagunal homolog 1 in humoral immunity and antibody glycosylation in mice and humans

Jagunal homolog 1 (JAGN1) has been identified as a critical regulator of neutrophil biology in mutant mice and rare-disease patients carrying JAGN1 mutations. Here, we report that Jagn1 deficiency results in alterations in the endoplasmic reticulum (ER) of antibody-producing cells as well as decreased antibody production and secretion. Consequently, mice lacking Jagn1 in B cells exhibit reduced serum immunoglobulin (Ig) levels at steady state and fail to mount an efficient humoral immune response upon immunization with specific antigens or when challenged with viral infections. We also demonstrate that Jagn1 deficiency in B cells results in aberrant IgG N-glycosylation leading to enhanced Fc receptor binding. Jagn1 deficiency in particular affects fucosylation of IgG subtypes in mice as well as rare-disease patients with loss-of-function mutations in JAGN1. Moreover, we show that ER stress affects antibody glycosylation. Our data uncover a novel and key role for JAGN1 and ER stress in antibody glycosylation and humoral immunity in mice and humans.

Antagonistic Inflammatory Phenotypes Dictate Tumor Fate and Response to Immune Checkpoint Blockade

Inflammation can support or restrain cancer progression and the response to therapy. Here, we searched for primary regulators of cancer-inhibitory inflammation through deep profiling of inflammatory tumor microenvironments (TMEs) linked to immune-dependent control in mice. We found that early intratumoral accumulation of interferon gamma (IFN-γ)-producing natural killer (NK) cells induced a profound remodeling of the TME and unleashed cytotoxic T cell (CTL)-mediated tumor eradication. Mechanistically, tumor-derived prostaglandin E2 (PGE2) acted selectively on EP2 and EP4 receptors on NK cells, hampered the TME switch, and enabled immune evasion. Analysis of patient datasets across human cancers revealed distinct inflammatory TME phenotypes resembling those associated with cancer immune control versus escape in mice. This allowed us to generate a gene-expression signature that integrated opposing inflammatory factors and predicted patient survival and response to immune checkpoint blockade. Our findings identify features of the tumor inflammatory milieu associated with immune control of cancer and establish a strategy to predict immunotherapy outcomes.

Integrating yoga with psychological group-treatment for mixed depression and anxiety in primary healthcare: An explorative pilot study

BACKGROUND AND PURPOSE

Yoga has shown promise as a treatment for depression and anxiety. The present pilot study investigated the feasibility of an eight-week grouptreatment integrating emotion-focused psychoeducation, compassion-focused therapy, and Virya yoga for depression and anxiety in primary healthcare.

MATERIALS AND METHODS

Patients seeking treatment for depression and anxiety in a primary healthcare centre completed either an integrative group-treatment (N = 14) or treatment as usual (TAU, N = 17). Outcome measures were analysed pre- and posttreatment. Correlations in the intervention group were investigated between treatment outcomes and amount of yoga practice between sessions.

RESULTS

Large within-group effect sizes on all outcome measures were found at posttreatment. Symptom reduction did not differ between groups (p = 0.155). Improvement in alexithymia correlated significantly (p < 0.05) with amount of yoga practice between sessions.

CONCLUSION

Integrating yoga with a psychological group-treatment is a somewhat feasible approach to treatment for depression and anxiety in primary healthcare.

Malondialdehyde and advanced oxidation protein products are not increased in psoriasis: a controlled study

This study investigated oxidative stress in patients with psoriasis of low and medium disease activity. We measured advanced oxidation protein products (AOPP) and malondialdehyde (MDA) in plasma using UV-spectrophotometry and high performance liquid chromatography connected to a fluorescence detector in 84 patients and 84 matched healthy subjects. AOPP is a marker of protein oxidation due to inflammation, whereas MDA is a hydroxyl radical initiated lipid peroxidation product. Clinico-demographic variables including age, gender, disease severity, and fatigue were assessed in relation to AOPP and MDA. Disease severity was evaluated with the Psoriasis Area and Severity Index and the Dermatology Life Quality Index. Median (interquartile range, IQR) AOPP concentrations were 66 µmol/l (IQR 54-102) in patients and 69 µmol/l (IQR 55-87) in healthy subjects (P = 0.75). Median plasma MDA concentrations were significantly lower in patients than in healthy subjects (0.68 µM, IQR 0.54-0.85 vs. 0.76 µM, IQR 0.60-0.97; P = 0.03). Plasma levels of AOPP and MDA did not indicate oxidative stress in patients with mild psoriasis. Higher AOPP concentrations were associated with male gender, high body mass index, and high hemoglobin values. Elevated MDA concentrations were associated with advanced age and male gender. No associations with disease severity were detected. Although, the two selected biomarkers do not provide a complete measure of oxidative damage, our study demonstrates that a number of physiological and methodological factors influence the levels of MDA and AOPP. Such methodological issues are important to consider when interpreting results using these biomarkers in patients with psoriasis.

Fatigue in psoriasis: a controlled study

BACKGROUND

Fatigue is associated with various chronic inflammatory diseases, but few studies have focused on its occurrence in psoriasis.

OBJECTIVES

To describe fatigue prevalence and degree among patients with chronic plaque psoriasis vs. age- and sex-matched healthy subjects, and to examine how fatigue is influenced by essential clinical and demographic factors.

METHODS

In 84 patients and 84 healthy subjects, fatigue severity was assessed using three different generic fatigue instruments: the fatigue Visual Analogue Scale (fVAS), the Fatigue Severity Scale (FSS) and the Short Form 36 (SF-36) Vitality scale. Cut-off scores for clinically important fatigue were defined as ≥ 4 for FSS, ≥ 50 for fVAS and ≤ 35 for the SF-36 Vitality scale. Disease activity was evaluated using the Psoriasis Area and Severity Index (PASI), and the impact on quality of life with the Dermatology Life Quality Index (DLQI).

RESULTS

Patients and healthy control subjects, respectively, showed median fVAS scores of 51 [interquartile range (IQR) 21-67] and 11 (IQR 3-20); FSS scores of 4 (IQR 2·5-5·3) and 1·6 (IQR 1·1-2·2); and SF-36 Vitality scores of 43 (IQR 25-85) and 73 (IQR 65-85). The rates of clinically important fatigue among patients vs. healthy controls, respectively, were 51% vs. 4% (fVAS); 52% vs. 4% (FSS); and 42% vs. 2% (SF-36 Vitality) (P < 0·001 for all differences). Fatigue was associated with DLQI scores, but not PASI scores, in univariate analysis but not in multivariate analysis.

CONCLUSIONS

Nearly 50% of patients with psoriasis suffered from substantial fatigue. Fatigue severity was associated with smoking, pain and depression, but not with psoriasis severity.