Autoantigen-specific CD4+ T cells acquire an exhausted phenotype and persist in human antigen-specific autoimmune diseases.

Pro-inflammatory autoantigen-specific CD4+ T helper (auto-Th) cells are central orchestrators of autoimmune diseases (AIDs). We aimed to characterize these cells in human AIDs with defined autoantigens by combining human leukocyte antigen (HLA)-tetramer-based and activation-based multidimensional ex vivo analyses. In aquaporin4-antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) patients, auto-Th cells expressed CD154, but proliferative capacity and pro-inflammatory cytokines were strongly reduced. Instead, exhaustion-associated co-inhibitory receptors were expressed together with FOXP3, the canonical regulatory T cell (Treg) transcription factor. Auto-Th cells responded in vitro to checkpoint inhibition and provided potent B cell help. Cells with the same exhaustion-like (ThEx) phenotype were identified in soluble liver antigen (SLA)-antibody-autoimmune hepatitis and BP180-antibody-positive bullous pemphigoid, AIDs of the liver and skin, respectively. While originally described in cancer and chronic infection, our data point to T cell exhaustion as a common mechanism of adaptation to chronic (self-)stimulation across AID types and link exhausted CD4+ T cells to humoral autoimmune responses, with implications for therapeutic targeting.

CD38 promotes hematopoietic stem cell dormancy.

A subpopulation of deeply quiescent, so-called dormant hematopoietic stem cells (dHSCs) resides at the top of the hematopoietic hierarchy and serves as a reserve pool for HSCs. The state of dormancy protects the HSC pool from exhaustion throughout life; however, excessive dormancy may prevent an efficient response to hematological stresses. Despite the significance of dHSCs, the mechanisms maintaining their dormancy remain elusive. Here, we identify CD38 as a novel and broadly applicable surface marker for the enrichment of murine dHSCs. We demonstrate that cyclic adenosine diphosphate ribose (cADPR), the product of CD38 cyclase activity, regulates the expression of the transcription factor c-Fos by increasing the release of Ca2+ from the endoplasmic reticulum (ER). Subsequently, we uncover that c-Fos induces the expression of the cell cycle inhibitor p57Kip2 to drive HSC dormancy. Moreover, we found that CD38 ecto-enzymatic activity at the neighboring CD38-positive cells can promote human HSC quiescence. Together, CD38/cADPR/Ca2+/c-Fos/p57Kip2 axis maintains HSC dormancy. Pharmacological manipulations of this pathway can provide new strategies to improve the success of stem cell transplantation and blood regeneration after injury or disease.

Balancing the Nanoscale Organization in Multivalent Materials for Functional Inhibition of the Programmed Death-1 Immune Checkpoint.

Dendritic cells (DCs) regulate immune priming by expressing programmed death ligand 1 (PD-L1) and PD-L2, which interact with the inhibitory receptor PD-1 on activated T cells. PD-1 signaling regulates T cell effector functions and limits autoimmunity. Tumor cells can hijack this pathway by overexpressing PD-L1 to suppress antitumor T cell responses. Blocking this inhibitory pathway has been beneficial for the treatment of various cancer types, although only a subset of patients responds. A deepened understanding of the spatial organization and molecular interplay between PD-1 and its ligands may inform the design of more efficacious nanotherapeutics. We visualized the natural molecular PD-L1 organization on DCs by DNA-PAINT microscopy and created a template to engineer DNA-based nanoclusters presenting PD-1 at defined valencies, distances, and patterns. These multivalent nanomaterials were examined for their cellular binding and blocking ability. Our data show that PD-1 nano-organization has profound effects on ligand interaction and that the valency of PD-1 molecules modulates the effectiveness in restoring T cell function. This work highlights the power of spatially controlled functional materials to unravel the importance of multivalent patterns in the PD-1 pathway and presents alternative design strategies for immune-engineering.

Robot-assisted laparoscopic varicocelectomy in a pediatric population.

PURPOSE: To present our experience with robot-assisted laparoscopic varicocelectomy in a pediatric population. METHODS: We reviewed 49 consecutive cases performed by the same experienced surgeon. One-to-four veins were ligated at the internal ring of the inguinal canal, while the testicular artery and lymphatics were spared. Information on patient characteristics, surgical time, complications, and recurrences were collected. RESULTS: Median patient age was 14 (range 10-17) years. Forty-eight had left-sided varicoceles and one had a bilateral varicocele. Forty-five were grade 3. All patients were referred due to discomfort/pain and 20 also had reduced testicular size. The median operating time from skin incision was 48 min (31-89 min) and the median console time was 18 min (7-55 min). Forty-seven patients were discharged the same day. Two patients experienced pain and problems urinating, respectively. These issues had resolved by the first post-operative day. There were no other complications, but at 6 months, eight recurrences were noted (16%). Scrotal complaints had subsided in all patients. Catch-up growth of the affected testicles was seen in 19/20 cases. CONCLUSION: Robot-assisted laparoscopic varicocelectomy is feasible and safe in a pediatric population but with a relatively high recurrence rate.

Fate mapping of hematopoietic stem cells reveals two pathways of native thrombopoiesis.

Hematopoietic stem cells (HSCs) produce highly diverse cell lineages. Here, we chart native lineage pathways emanating from HSCs and define their physiological regulation by computationally integrating experimental approaches for fate mapping, mitotic tracking, and single-cell RNA sequencing. We find that lineages begin to split when cells leave the tip HSC population, marked by high Sca-1 and CD201 expression. Downstream, HSCs either retain high Sca-1 expression and the ability to generate lymphocytes, or irreversibly reduce Sca-1 level and enter into erythro-myelopoiesis or thrombopoiesis. Thrombopoiesis is the sum of two pathways that make comparable contributions in steady state, a long route via multipotent progenitors and CD48hi megakaryocyte progenitors (MkPs), and a short route from HSCs to developmentally distinct CD48-/lo MkPs. Enhanced thrombopoietin signaling differentially accelerates the short pathway, enabling a rapid response to increasing demand. In sum, we provide a blueprint for mapping physiological differentiation fluxes from HSCs and decipher two functionally distinct pathways of native thrombopoiesis.

Robot-Assisted vs. Open Appendicovesicostomy in Pediatric Urology: A Systematic Review and Single-Center Case Series.

Introduction: Appendicovesicostomy (APV) is the preferred choice of continent catheterizable channels in pediatric urology. The introduction of robot-assisted laparoscopic techniques has been correlated to superior cosmesis and convalescence and is now increasingly implemented for APV procedures. We aimed to perform a systematic review of the literature comparing open vs. robotic APV regarding possible differences in postoperative outcomes and to evaluate these findings with our own initial experiences with robotic APV compared to our previous open procedures. Methods: We evaluated the first five patients undergoing robotic APV at our institution and compared 1-year outcomes with a consecutive series of 12 patients undergoing open APV. In a systematic literature review, we screened studies from PubMed, EMBASE, and CENTRAL comparing open and robotic APV in pediatric urology (current to December 2021) and performed meta-analyses on postoperative outcomes comparing the two groups and evaluated the grade of evidence. Results: We found significantly shortened postoperative length of stay in the robotic group (p = 0.001) and comparable 1-year complication rates in robotic vs. open APV patients. We systematically screened 3,204 studies and ultimately included three non-randomized studies comparing postoperative outcomes of robotic and open APV for quantitative analysis. The open and robotic approaches performed equally well regarding overall postoperative complications, surgical reintervention, and stomal stenosis. Two of the included studies reported comparable stomal continence rates and shortened postoperative length of stay in the robotic group, in agreement with the findings in our own series. Conclusion: Robotic APV is equally safe to the conventional open approach with additional advantages in postoperative hospitalization length.

Isolation of macrophages from mouse skin wounds for single-cell RNA sequencing.

Understanding macrophage heterogeneity in tissue repair is a major challenge. Here, we describe a protocol that combines isolation of immune cells from skin wounds with subsequent flow-cytometry-based sorting of wound macrophages and single-cell RNA sequencing. We use a modified version of the original Smart-seq2 protocol to increase speed and accuracy. This protocol is useful for analyzing the pronounced heterogeneity of activation phenotypes in wound macrophages and might be adapted to other experimental models of skin inflammation. For complete details on the use and execution of this protocol, please refer to Willenborg et al. (2021).

A common framework of monocyte-derived macrophage activation.

Macrophages populate every organ during homeostasis and disease, displaying features of tissue imprinting and heterogeneous activation. The disconnected picture of macrophage biology that has emerged from these observations is a barrier for integration across models or with in vitro macrophage activation paradigms. We set out to contextualize macrophage heterogeneity across mouse tissues and inflammatory conditions, specifically aiming to define a common framework of macrophage activation. We built a predictive model with which we mapped the activation of macrophages across 12 tissues and 25 biological conditions, finding a notable commonality and finite number of transcriptional profiles, in particular among infiltrating macrophages, which we modeled as defined stages along four conserved activation paths. These activation paths include a "phagocytic" regulatory path, an "inflammatory" cytokine-producing path, an "oxidative stress" antimicrobial path, or a "remodeling" extracellular matrix deposition path. We verified this model with adoptive cell transfer experiments and identified transient RELMɑ expression as a feature of monocyte-derived macrophage tissue engraftment. We propose that this integrative approach of macrophage classification allows the establishment of a common predictive framework of monocyte-derived macrophage activation in inflammation and homeostasis.

Continuous mitotic activity of primitive hematopoietic stem cells in adult mice.

The proliferative activity of aging hematopoietic stem cells (HSCs) is controversially discussed. Inducible fluorescent histone 2B fusion protein (H2B-FP) transgenic mice are important tools for tracking the mitotic history of murine HSCs in label dilution experiments. A recent study proposed that primitive HSCs symmetrically divide only four times to then enter permanent quiescence. We observed that background fluorescence due to leaky H2B-FP expression, occurring in all H2B-FP transgenes independent of label induction, accumulated with age in HSCs with high repopulation potential. We argue that this background had been misinterpreted as stable retention of induced label. We found cell division-independent half-lives of H2B-FPs to be short, which had led to overestimation of HSC divisional activity. Our data do not support abrupt entry of HSCs into permanent quiescence or sudden loss of regeneration potential after four divisions, but show that primitive HSCs of adult mice continue to cycle rarely.

C/EBPß-Dependent Epigenetic Memory Induces Trained Immunity in Hematopoietic Stem Cells.

Hematopoietic stem cells (HSCs) maintain life-long production of immune cells and can directly respond to infection, but sustained effects on the immune response remain unclear. We show that acute immune stimulation with lipopolysaccharide (LPS) induced only transient changes in HSC abundance, composition, progeny, and gene expression, but persistent alterations in accessibility of specific myeloid lineage enhancers occurred, which increased responsiveness of associated immune genes to secondary stimulation. Functionally, this was associated with increased myelopoiesis of pre-exposed HSCs and improved innate immunity against the gram-negative bacterium P. aeruginosa. The accessible myeloid enhancers were enriched for C/EBPß targets, and C/EBPß deletion erased the long-term inscription of LPS-induced epigenetic marks and gene expression. Thus, short-term immune signaling can induce C/EBPß-dependent chromatin accessibility, resulting in HSC-trained immunity, during secondary infection. This establishes a mechanism for how infection history can be epigenetically inscribed in HSCs as an integral memory function of innate immunity.

Gene Expression-Based Identification of Antigen-Responsive CD8+ T Cells on a Single-Cell Level.

CD8+ T cells are important effectors of adaptive immunity against pathogens, tumors, and self antigens. Here, we asked how human cognate antigen-responsive CD8+ T cells and their receptors could be identified in unselected single-cell gene expression data. Single-cell RNA sequencing and qPCR of dye-labeled antigen-specific cells identified large gene sets that were congruently up- or downregulated in virus-responsive CD8+ T cells under different antigen presentation conditions. Combined expression of TNFRSF9, XCL1, XCL2, and CRTAM was the most distinct marker of virus-responsive cells on a single-cell level. Using transcriptomic data, we developed a machine learning-based classifier that provides sensitive and specific detection of virus-responsive CD8+ T cells from unselected populations. Gene response profiles of CD8+ T cells specific for the autoantigen islet-specific glucose-6-phosphatase catalytic subunit-related protein differed markedly from virus-specific cells. These findings provide single-cell gene expression parameters for comprehensive identification of rare antigen-responsive cells and T cell receptors.

Aldh1b1 expression defines progenitor cells in the adult pancreas and is required for Kras-induced pancreatic cancer.

The presence of progenitor or stem cells in the adult pancreas and their potential involvement in homeostasis and cancer development remain unresolved issues. Here, we show that mouse centroacinar cells can be identified and isolated by virtue of the mitochondrial enzyme Aldh1b1 that they uniquely express. These cells are necessary and sufficient for the formation of self-renewing adult pancreatic organoids in an Aldh1b1-dependent manner. Aldh1b1-expressing centroacinar cells are largely quiescent, self-renew, and, as shown by genetic lineage tracing, contribute to all 3 pancreatic lineages in the adult organ under homeostatic conditions. Single-cell RNA sequencing analysis of these cells identified a progenitor cell population, established its molecular signature, and determined distinct differentiation pathways to early progenitors. A distinct feature of these progenitor cells is the preferential expression of small GTPases, including Kras, suggesting that they might be susceptible to Kras-driven oncogenic transformation. This finding and the overexpression of Aldh1b1 in human and mouse pancreatic cancers, driven by activated Kras, prompted us to examine the involvement of Aldh1b1 in oncogenesis. We demonstrated genetically that ablation of Aldh1b1 completely abrogates tumor development in a mouse model of KrasG12D-induced pancreatic cancer.

Hematopoietic stem cell response to acute thrombocytopenia requires signaling through distinct receptor tyrosine kinases.

Although bone marrow niche cells are essential for hematopoietic stem cell (HSC) maintenance, their interaction in response to stress is not well defined. Here, we used a mouse model of acute thrombocytopenia to investigate the cross talk between HSCs and niche cells during restoration of the thrombocyte pool. This process required membrane-localized stem cell factor (m-SCF) in megakaryocytes, which was regulated, in turn, by vascular endothelial growth factor A (VEGF-A) and platelet-derived growth factor-BB (PDGF-BB). HSCs and multipotent progenitors type 2 (MPP2), but not MPP3/4, were subsequently activated by a dual-receptor tyrosine kinase (RTK)-dependent signaling event, m-SCF/c-Kit and VEGF-A/vascular endothelial growth factor receptor 2 (VEGFR-2), contributing to their selective and early proliferation. Our findings describe a dynamic network of signals in response to the acute loss of a single blood cell type and reveal the important role of 3 RTKs and their ligands in orchestrating the selective activation of hematopoietic stem and progenitor cells (HSPCs) in thrombocytopenia.

Postnatal Germ Cell Development in the Cryptorchid Testis: The Key to Explain Why Early Surgery Decreases the Risk of Malignancy.

PURPOSE: Cryptorchidism is a risk factor for testicular malignancy and surgical treatment lowers this risk. This study aimed to investigate the germ cell behavior in prepubertal cryptorchid testes using immunohistochemical markers for germ cell malignancy to understand how early orchiopexy may possibly prevent cancer developing. MATERIALS AND METHODS: Histology sections from 1,521 consecutive testicular biopsies from 1,134 boys aged 1 month to 16.5 years operated for cryptorchidism were incubated with antibodies including antiplacental-like alkaline phosphatase (PLAP), anti-Oct3/4, anti-C-kit, and anti-D2-40. RESULTS: Oct3/4 and D2-40-positive germ cells are found throughout the first 2 years of life, with declining frequency thereafter. After 2 years, they should have disappeared and may indicate neoplasia. PLAP-positive cells were seen in 57 to 82% and C-kit-positive cells in 5 to 21% of cryptorchid testes between 4 and 13 years. Not until puberty did PLAP and C-kit-positive undifferentiated spermatogonial stem cells vanish. Only 0.3% of the present material had obvious prepubertal intratubular germ cell neoplasia (ITGCN) and they all had syndromic cryptorchidism. An additional three boys (0.3%) older than 2 years had weak Oct3/4 expression in undescended testes, but all cases were D2-40 negative. CONCLUSION: Prepubertal ITGCN was rare and mostly seen in syndromic cryptorchidism. In nonsyndromic cryptorchidism PLAP-positive undifferentiated spermatogonial stem cells persisted in a significant proportion of nontreated undescended testes and they will be especially sensitive to long-lasting abnormally high temperature that may be the single most important cause facilitating the accumulation of mutations during cell replication and the development of ITGCN to be prevented by orchiopexy.

Robotic surgery start-up with a fellow as the console surgeon.

OBJECTIVE: Owing to the encouraging data on fellowship training in robotic pyeloplasty and the documented benefits of robotic pyeloplasty, the aim of this study was to test the feasibility of starting up pediatric urological robotic surgery in a center with a limited case volume. MATERIALS AND METHODS: The operative parameters and clinical outcome of the first 25 robotic pyeloplasties performed were compared to data on open and laparoscopic procedures from the previous 5 year period. The fellow was the only console surgeon. An experienced non-robotic pediatric urologist was supervising at the patient site. RESULTS: The learning curve was in accordance with previously published data on fellows. The median operating time in robotic surgery was 182 min and was significantly shorter than in laparoscopic surgery (median 250 min) and the postoperative inpatient length of stay was significantly shorter after robotic surgery (median 1 day) than after both laparoscopic (median 2 days) and open surgery (median 3.5 days). For robotic cases, postoperative renography showed either stable or increased function of the hydronephrotic kidney. The only complication was in one case with ureteral orifice edema after JJ-stent removal, requiring nephrostomy for 6 weeks. CONCLUSIONS: The benefits of overall shorter postoperative hospital stay after robotic pyeloplasty and faster operating time compared to the laparoscopic procedure are clearly in accordance with data from the recent literature. The fast learning curve for robotic pyeloplasty will allow pediatric urology fellowship programs to be integrated in the start-up phase of a pediatric robotic program even though the case material is limited. Operative success rates were in accordance with the gold standard of open surgery.

The diagnostic impact of testicular biopsies for intratubular germ cell neoplasia in cryptorchid boys and the subsequent risk of testicular cancer in men with prepubertal surgery for syndromic or non-syndromic cryptorchidism.

INTRODUCTION: Cryptorchidism is a risk factor for testicular cancer in adult life. It remains unclear how prepubertal surgery for cryptorchidism impacts later development of adult testicular cancer. The aim of study was to investigate tools to identify the cryptorchid boys who later develop testicular cancer. METHODS: The study cohort consisted of 1403 men operated prepubertally/pubertally for undescended testis between 1971 and 2003. At surgery testicular biopsies were taken from the cryptorchid testes. The boys were followed for occurrence of testicular cancer. The testicular cancer risk was compared to the risk in the Danish Population. Testicular biopsies from the boys who developed testicular cancer during follow-up underwent histological examination with specific diagnostic immunohistochemical markers for germ cell neoplasia. RESULTS: The cohort was followed for 33,627 person years at risk. We identified 16 cases with testicular cancer in adulthood. The standardized incidence ratio was 2.66 (95% CI: 1.52-4.32). At time of primary surgery in prepubertal/pubertal age Intratubular Germ Cell Neoplasia (ITGCN) was diagnosed in 5 cases and the boys were unilaterally orchiectomized. At follow-up new immunohistochemical staining indicated ITGCN in two of the 16 cancer cases at reevaluation of the original biopsies from time of prepubertal/pubertal surgery. One had syndromic cryptorchid and developed seminoma, and another showed nonsyndromic cryptorchidism and developed embryonic teratocarcinoma. Totally, ITGCN was diagnosed in 0.5% (7/1403) of prepubertal cryptorchid boys, whereof 57% (4/7) in syndromic-cryptorchidism. DISCUSSION: ITGCN is predominantly observed prepubertally in boys with syndromic-cryptorchidism. In nonsyndromic cryptorchidism testicular cancer develops postpubertally, generally not based on dormant germ cells of ITGCN caused by an early fetal maldevelopment. LEVELS OF EVIDENCE: LEVEL I.

Genetic, Maternal, and Environmental Risk Factors for Cryptorchidism: An Update.

Unilateral or bilateral cryptorchidism is an isolated anomaly in the majority of cases, with evidence to date suggesting that it is a complex disorder resulting from interactions between genetic and environmental factors. Population, family, and limited genome-wide association data suggest moderate genetic risk, multiple susceptibility loci, and a role for the maternal environment. Epidemiologic studies have identified low birth weight or intrauterine growth retardation as factors most strongly associated with cryptorchidism, with additional evidence suggesting that maternal smoking and gestational diabetes increase risk. Animal studies have shown that the testis regulates its own descent by secretion of hormones that stimulate differentiation of the gubernaculum, and that endocrine-disrupting chemicals (EDCs) exhibit antiandrogenic and/or estrogenic activity that alters testicular function or gubernacular response to hormonal stimulation. However, we have yet to determine the degree to which EDCs contribute to cryptorchidism risk in humans, in part due to the varying methodology used in epidemiological and exposure studies. Large populations will be required to define the gene-environment interactions that predispose to cryptorchidism, in view of multiple small effect genetic susceptibility loci, ubiquitous exposure to mixtures of EDCs, and possible epigenetic effects. The present review provides an update of potential genetic and environmental risk factors for cryptorchidism, and future work required to better understand the etiology of this common and complex disease.

[Bladder pain and urinary tract symptoms as a consequence of ketamine abuse]. / Blæresmerter og vandladningsforstyrrelser som følge af ketaminmisbrug.

A recent study has shown that ketamine has become popular among Danish clubgoers. The drug can induce psychedelic effects but it also has serious urological side effects, such as frequency and urgency in relation to voiding as well as pain from the bladder and haematuria. Ketamine can also induce histological bladder changes. Mild changes are reversible on cessation of ketamine abuse but long-term abuse can cause fibrosis of the bladder and may necessitate cystectomy. Therefore, physicians should ask young patients with bladder symptoms of unknown pathology about ketamine abuse.