Deep point cloud landmark localization for fringe projection profilometry.

Point clouds have been widely used due to their information being richer than images. Fringe projection profilometry (FPP) is one of the camera-based point cloud acquisition techniques that is being developed as a vision system for robotic surgery. For semi-autonomous robotic suturing, fluorescent fiducials were previously used on a target tissue as suture landmarks. This not only increases system complexity but also imposes safety concerns. To address these problems, we propose a numerical landmark localization algorithm based on a convolutional neural network (CNN) and a conditional random field (CRF). A CNN is applied to regress landmark heatmaps from the four-channel image data generated by the FPP. A CRF leveraging both local and global shape constraints is developed to better tune the landmark coordinates, reject extra landmarks, and recover missing landmarks. The robustness of the proposed method is demonstrated through ex vivo porcine intestine landmark localization experiments.

Perspectives from the Society for Pediatric Research: Probiotic use in urinary tract infections, atopic dermatitis, and antibiotic-associated diarrhea: an overview.

Probiotics have received significant attention within both the scientific and lay communities for their potential health-promoting properties, including the treatment or prevention of various conditions in children. In this article, we review the published data on use of specific probiotic strains for three common pediatric conditions: the prevention of urinary tract infections and antibiotic-associated diarrhea and the treatment of atopic dermatitis. Research into the utility of specific probiotic strains is of varying quality, and data are often derived from small studies and case series. We discuss the scientific merit of these studies, their overall findings regarding the utility of probiotics for these indications, issues in reporting of methods, and results from these clinical trials, as well as future areas of investigation.

A View from the past into our collective future: the oncofertility consortium vision statement.

PURPOSE: Today, male and female adult and pediatric cancer patients, individuals transitioning between gender identities, and other individuals facing health extending but fertility limiting treatments can look forward to a fertile future. This is, in part, due to the work of members associated with the Oncofertility Consortium. METHODS: The Oncofertility Consortium is an international, interdisciplinary initiative originally designed to explore the urgent unmet need associated with the reproductive future of cancer survivors. As the strategies for fertility management were invented, developed or applied, the individuals for who the program offered hope, similarly expanded. As a community of practice, Consortium participants share information in an open and rapid manner to addresses the complex health care and quality-of-life issues of cancer, transgender and other patients. To ensure that the organization remains contemporary to the needs of the community, the field designed a fully inclusive mechanism for strategic planning and here present the findings of this process. RESULTS: This interprofessional network of medical specialists, scientists, and scholars in the law, medical ethics, religious studies and other disciplines associated with human interventions, explore the relationships between health, disease, survivorship, treatment, gender and reproductive longevity. CONCLUSION: The goals are to continually integrate the best science in the service of the needs of patients and build a community of care that is ready for the challenges of the field in the future.

Interleukin-4 Signaling Plays a Major Role in Urogenital Schistosomiasis-Associated Bladder Pathogenesis.

Interleukin-4 (IL-4) is crucial in many helminth infections, but its role in urogenital schistosomiasis, infection with Schistosoma haematobium worms, remains poorly understood due to a historical lack of animal models. The bladder pathology of urogenital schistosomiasis is caused by immune responses to eggs deposited in the bladder wall. A range of pathology occurs, including urothelial hyperplasia and cancer, but associated mechanisms and links to IL-4 are largely unknown. We modeled urogenital schistosomiasis by injecting the bladder walls of IL-4 receptor-alpha knockout (Il4ra-/- ) and wild-type mice with S. haematobium eggs. Readouts included bladder histology and ex vivo assessments of urothelial proliferation, cell cycle, and ploidy status. We also quantified the effects of exogenous IL-4 on urothelial cell proliferation in vitro, including cell cycle status and phosphorylation patterns of major downstream regulators in the IL-4 signaling pathway. There was a significant decrease in the intensity of granulomatous responses to bladder-wall-injected S. haematobium eggs in Il4ra-/- versus wild-type mice. S. haematobium egg injection triggered significant urothelial proliferation, including evidence of urothelial hyper-diploidy and cell cycle skewing in wild-type but not Il4ra-/- mice. Urothelial exposure to IL-4 in vitro led to cell cycle polarization and increased phosphorylation of AKT. Our results show that IL-4 signaling is required for key pathogenic features of urogenital schistosomiasis and that particular aspects of this signaling pathway may exert these effects directly on the urothelium. These findings point to potential mechanisms by which urogenital schistosomiasis promotes bladder carcinogenesis.

Novel catheter design enables transurethral catheterization of male mice.

The male mouse is underrepresented in research of the urinary tract due to the difficulty of transurethral catheterization. As a result, there is a lack of analysis of sex differences in urinary tract research. Here, we present a novel catheter design and technique that enables urethral catheterization of male mice for bladder inoculation. Our catheterization technique uses the resistance met at the level of the external urinary sphincter and prostate to guide the retraction, positioning, and advancement of the catheter into the urinary bladder. We have shown that this method can be used to reproducibly catheterize 12 male mice with minimal urogenital trauma but cannot be used as a cystometric technique. This method will facilitate the expansion of research into sex differences in various genitourinary conditions that require transurethral catheterization of mice.

IPSE, a parasite-derived, host immunomodulatory infiltrin protein, alleviates resiniferatoxin-induced bladder pain.

The transient receptor potential cation channel subfamily V member 1 (TRPV1) receptor is an important mediator of nociception and its expression is enriched in nociceptive neurons. TRPV1 signaling has been implicated in bladder pain and is a potential analgesic target. Resiniferatoxin is the most potent known agonist of TRPV1. Acute exposure of the rat bladder to resiniferatoxin has been demonstrated to result in pain-related freezing and licking behaviors that are alleviated by virally encoded IL-4. The interleukin-4-inducing principle of Schistosoma mansoni eggs (IPSE) is a powerful inducer of IL-4 secretion, and is also known to alter host cell transcription through a nuclear localization sequence-based mechanism. We previously reported that IPSE ameliorates ifosfamide-induced bladder pain in an IL-4- and nuclear localization sequence-dependent manner. We hypothesized that pre-administration of IPSE to resiniferatoxin-challenged mice would dampen pain-related behaviors. IPSE indeed lessened resiniferatoxin-triggered freezing behaviors in mice. This was a nuclear localization sequence-dependent phenomenon, since administration of a nuclear localization sequence mutant version of IPSE abrogated IPSE's analgesic effect. In contrast, IPSE's analgesic effect did not seem IL-4-dependent, since use of anti-IL-4 antibody in mice given both IPSE and resiniferatoxin did not significantly affect freezing behaviors. RNA-Seq analysis of resiniferatoxin- and IPSE-exposed bladders revealed differential expression of TNF/NF-κb-related signaling pathway genes. In vitro testing of IPSE uptake by urothelial cells and TRPV1-expressing neuronal cells showed uptake by both cell types. Thus, IPSE's nuclear localization sequence-dependent therapeutic effects on TRPV1-mediated bladder pain may act on TRPV1-expressing neurons and/or may rely upon urothelial mechanisms.

IPSE, a parasite-derived host immunomodulatory protein, is a potential therapeutic for hemorrhagic cystitis.

Chemotherapy-induced hemorrhagic cystitis is characterized by bladder pain and voiding dysfunction caused by hemorrhage and inflammation. Novel therapeutic options to treat hemorrhagic cystitis are needed. We previously reported that systemic administration of the Schistosomiasis hematobium-derived protein H-IPSEH06 (IL-4-inducing principle from Schistosoma mansoni eggs) is superior to three doses of MESNA in alleviating hemorrhagic cystitis (Mbanefo EC, Le L, Pennington LF, Odegaard JI, Jardetzky TS, Alouffi A, Falcone FH, Hsieh MH. FASEB J 32: 4408-4419, 2018). Based on prior reports by others on S. mansoni IPSE (M-IPSE) and additional work by our group, we reasoned that H-IPSE mediates its effects on hemorrhagic cystitis by binding IgE on basophils and inducing IL-4 expression, promoting urothelial proliferation, and translocating to the nucleus to modulate expression of genes implicated in relieving bladder dysfunction. We speculated that local bladder injection of the S. hematobium IPSE ortholog IPSEH03, hereafter called H-IPSEH03, might be more efficacious in preventing hemorrhagic cystitis compared with systemic administration of IPSEH06. We report that H-IPSEH03, like M-IPSE and H-IPSEH06, activates IgE-bearing basophils in a nuclear factor of activated T-cells reporter assay, indicating activation of the cytokine pathway. Furthermore, H-IPSEH03 attenuates ifosfamide-induced increases in bladder wet weight in an IL-4-dependent fashion. H-IPSEH03 relieves hemorrhagic cystitis-associated allodynia and modulates voiding patterns in mice. Finally, H-IPSEH03 drives increased urothelial cell proliferation, suggesting that IPSE induces bladder repair mechanisms. Taken together, H-IPSEH03 may be a potential novel therapeutic to treat hemorrhagic cystitis by basophil activation, attenuation of allodynia, and promotion of urothelial cell proliferation.

Utility of DNA Next-Generation Sequencing and Expanded Quantitative Urine Culture in Diagnosis and Management of Chronic or Persistent Lower Urinary Tract Symptoms.

Many patients suffer from chronic, irritative lower urinary tract symptoms (LUTS). The evaluation and management of these patients have proven difficult with the use of standard diagnostic tools, including urinalysis and urine culture. The growing body of literature on the urinary microbiome has looked at the possible implications of the bladder microbiome and dysbiosis, or perturbations in the microbiome, in conditions associated with chronic LUTS. Disorders such as recurrent urinary tract infections (UTIs) and interstitial cystitis have been studied utilizing 16S rRNA rapid next-generation gene sequencing (NGS) and expanded quantitative urine culture (EQUC). In this article, we first present a brief review of the literature describing the current understanding of the urinary microbiome and the features and applications of NGS and EQUC. Next, we discuss the conditions most commonly associated with chronic, persistent LUTS and present the limitations of current diagnostic practices utilized in this patient population. We then review the limited data available surrounding treatment efficacy and clinical outcomes in patients who have been managed based on results provided by these two recently established diagnostic tools (DNA NGS and/or EQUC). Finally, we propose a variety of clinical scenarios in which the use of these two techniques may affect patients' clinical outcomes.

Therapeutic exploitation of IPSE, a urogenital parasite-derived host modulatory protein, for chemotherapy-induced hemorrhagic cystitis.

Chemotherapy-induced hemorrhagic cystitis (CHC) can be difficult to manage. Prior work suggests that IL-4 alleviates ifosfamide-induced hemorrhagic cystitis (IHC), but systemically administered IL-4 causes significant side effects. We hypothesized that the Schistosoma hematobium homolog of IL-4-inducing principle from Schistosoma mansoni eggs (H-IPSE), would reduce IHC and associated bladder pathology. IPSE binds IgE on basophils and mast cells, triggering IL-4 secretion by these cells. IPSE is also an "infiltrin," translocating into the host nucleus to modulate gene transcription. Mice were administered IL-4, H-IPSE protein or its nuclear localization sequence (NLS) mutant, with or without neutralizing anti-IL-4 antibody, or 2-mercaptoethane sulfonate sodium (MESNA; a drug used to prevent IHC), followed by ifosfamide. Bladder tissue damage and hemoglobin content were measured. Spontaneous and evoked pain, urinary frequency, and bladdergene expression analysis were assessed. Pain behaviors were interpreted in a blinded fashion. One dose of H-IPSE was superior to MESNA and IL-4 in suppressing bladder hemorrhage in an IL-4-dependent fashion and comparable with MESNA in dampening ifosfamide-triggered pain behaviors in an NLS-dependent manner. H-IPSE also accelerated urothelial repair following IHC. Our work represents the first therapeutic exploitation of a uropathogen-derived host modulatory molecule in a clinically relevant bladder disease model and indicates that IPSE may be an alternative to MESNA for mitigating CHC.-Mbanefo, E. C., Le, L., Pennington, L. F., Odegaard, J. I., Jardetzky, T. S., Alouffi, A., Falcone, F. H., Hsieh, M. H. Therapeutic exploitation of IPSE, a urogenital parasite-derived host modulatory protein, for chemotherapy-induced hemorrhagic cystitis.

Schistosoma haematobium cercarial infection alters subsequent systemic immune responses to eggs but has minimal impact on immune responses to egg injection of the bladder.

AIMS: Mouse bladder wall injection with Schistosoma haematobium eggs has been used to overcome limitations in animal models of urogenital schistosomiasis. However, the effect of the absence of cercarial infection on immune responses to eggs in this model is unknown. We hypothesized that cercarial infection would alter local bladder and systemic immune responses to eggs in this model. METHODS AND RESULTS: Mice were infected or not infected with S haematobium cercariae, and then, their bladder walls injected with S haematobium eggs or vehicle 5 weeks following cercarial infection. Three weeks later, mice were bled, sacrificed, perfused and their bladders harvested. Parasitological parameters and gross bladder pathology were not changed in egg-injected bladders by cercarial exposure. Figure S1 shows no changes in either granulomas or fibrosis. The only bladder cytokine upregulated in egg-injected bladders by cercarial exposure (vs no exposure) was leptin. Cercarial exposure, compared to no exposure, resulted in increased serum, IL-1α, IL-13 and TGF-ß in bladder egg-injected mice. CONCLUSION: Cercarial exposure altered systemic responses of several cytokines in bladder egg-injected mice, but surprisingly, only modified leptin expression in bladder tissue. This suggests that depending on the specific application, cercarial exposure may not be strictly necessary to model local immune responses in the bladder wall egg injection mouse model of urogenital schistosomiasis.

Role of urinary tract infection in bladder cancer: a systematic review and meta-analysis.

PURPOSE: We sought to examine the literature reporting the effect of urinary tract infection (UTI) on non-schistosomiasis-related UBC (UBCNS) through a systematic review and meta-analysis. METHODS: A predefined study protocol was developed according to PRISMA. Medline and Scopus were searched for all studies investigating exposure to UTI with UBCNS as the primary outcome. Potential studies were screened against eligibility criteria. Clinical heterogeneity was assessed and groups with more than two studies were evaluated by random effect meta-analysis. Study-level bias was assessed with the Newcastle-Ottawa Scale (NOS). In cases of substantial between study heterogeneity (I2 > 50%), predefined sensitivity and subgroup analyses were performed. RESULTS: Of 16 eligible studies, eight case-control studies spanning four decades and five countries were suitable for quantitative analysis. Main analysis favored exposure to UTI increasing risk of subsequent UBCNS (RR 1.33 [95% CI 1.14-1.55]). This effect was no longer statistically significant after excluding studies published prior to year 2000 and at high risk of bias. Between study heterogeneity was considerable for nearly all analyses and not reduced by predefined sensitivity or subgroup analyses. CONCLUSION: Exposure to UTI favors increased risk for UBCNS, particularly in men, but these effects were statistically insignificant when pooling data from the most recent and highest quality studies. These data do not support findings of previously published studies, that report on heterogenous populations with poor definitions of UTI and minimal control for important confounders. Results from previous studies should be viewed as hypothesis generating. This review highlights the need for higher quality investigation.

Reduced transmission of human schistosomiasis after restoration of a native river prawn that preys on the snail intermediate host.

Eliminating human parasitic disease often requires interrupting complex transmission pathways. Even when drugs to treat people are available, disease control can be difficult if the parasite can persist in nonhuman hosts. Here, we show that restoration of a natural predator of a parasite's intermediate hosts may enhance drug-based schistosomiasis control. Our study site was the Senegal River Basin, where villagers suffered a massive outbreak and persistent epidemic after the 1986 completion of the Diama Dam. The dam blocked the annual migration of native river prawns (Macrobrachium vollenhoveni) that are voracious predators of the snail intermediate hosts for schistosomiasis. We tested schistosomiasis control by reintroduced river prawns in a before-after-control-impact field experiment that tracked parasitism in snails and people at two matched villages after prawns were stocked at one village's river access point. The abundance of infected snails was 80% lower at that village, presumably because prawn predation reduced the abundance and average life span of latently infected snails. As expected from a reduction in infected snails, human schistosomiasis prevalence was 18 ± 5% lower and egg burden was 50 ± 8% lower at the prawn-stocking village compared with the control village. In a mathematical model of the system, stocking prawns, coupled with infrequent mass drug treatment, eliminates schistosomiasis from high-transmission sites. We conclude that restoring river prawns could be a novel contribution to controlling, or eliminating, schistosomiasis.

H-IPSE Is a Pathogen-Secreted Host Nucleus-Infiltrating Protein (Infiltrin) Expressed Exclusively by the Schistosoma haematobium Egg Stage.

Urogenital schistosomiasis, caused by the parasitic trematode Schistosoma haematobium, affects over 112 million people worldwide. As with Schistosoma mansoni infections, the pathology of urogenital schistosomiasis is related mainly to the egg stage, which induces granulomatous inflammation of affected tissues. Schistosoma eggs and their secretions have been studied extensively for the related organism S. mansoni, which is more amenable to laboratory studies. Indeed, we have shown that IPSE/alpha-1 (here M-IPSE), a major protein secreted from S. mansoni eggs, can infiltrate host cells. Although the function of M-IPSE is unknown, its ability to translocate to the nuclei of host cells and bind DNA suggests a possible role in immune modulation of host cell tissues. Whether IPSE homologs are expressed in other schistosome species has not been investigated. Here, we describe the cloning of two paralog genes, H03-IPSE and H06-IPSE, which are orthologs of M-IPSE, from egg cDNA of S. haematobium Using PCR and immunodetection, we confirmed that the expression of these genes is restricted to the egg stage and female adult worms, while the H-IPSE protein is detectable only in mature eggs and not adults. We show that both H03-IPSE and H06-IPSE proteins can infiltrate HTB-9 bladder cells when added exogenously to culture medium. Monopartite C-terminal nuclear localization sequence (NLS) motifs conserved in H03-IPSE, SKRRRKY, and H06-IPSE SKRGRKY, are responsible for targeting the proteins to the nucleus of HTB-9 cells, as demonstrated by site-directed mutagenesis and green fluorescent protein (GFP) tagging. Thus, S. haematobium eggs express IPSE homologs that appear to perform similar functions in infiltrating host cells.

Redefining Healthy Urine: A Cross-Sectional Exploratory Metagenomic Study of People With and Without Bladder Dysfunction.

PURPOSE: We used the PathoScope platform to perform species level analyses of publicly available, 16S rRNA pyrosequenced, asymptomatic urine data to determine relationships between microbiomes, and clinical and functional phenotypes. MATERIALS AND METHODS: We reanalyzed previously reported, cross-sectionally acquired urine samples from 47 asymptomatic subjects, including 23 controls and 24 subjects with neuropathic bladder. Urine was originally collected by the usual method of bladder drainage and analyzed by urinalysis, culture and pyrosequencing. Urinalysis and culture values were stratified as leukocyte esterase (0, or 1 or greater), nitrite (positive or negative), pyuria (fewer than 5, or 5 or greater white blood cells per high power field), cloudy urine (positive or negative) and urine culture bacterial growth (less than 50,000, or 50,000 or greater cfu/ml). PathoScope was used for next generation sequencing alignment, bacterial classification and microbial diversity characterization. RESULTS: Subjects with neuropathic bladder were significantly more likely to have positive leukocyte esterase and pyuria, cloudy urine and bacterial growth. Of 47 samples 23 showed bacterial growth on culture and in all samples bacteria were identified by pyrosequencing. Nonneuropathic bladder urine microbiomes included greater proportions of Lactobacillus crispatus in females and Staphylococcus haemolyticus in males. The Lactobacillus community differed significantly among females depending on bladder function. Irrespective of gender the subjects with neuropathic bladder had greater proportions of Enterococcus faecalis, Proteus mirabilis and Klebsiella pneumonia. In 4 subjects with neuropathic bladder Actinobaculum sp. was detected by sequencing and by PathoScope but not by cultivation and in all cases it was associated with pyuria. CONCLUSIONS: Using PathoScope plus 16S pyrosequencing we were able to identify unique, phenotype dependent, species level microbes. Novel findings included absent L. crispatus in the urine of females with neuropathic bladder and the presence of Actinobaculum only in subjects with neuropathic bladder.

Macrophages are required for host survival in experimental urogenital schistosomiasis.

Urogenital schistosomiasis, Schistosoma haematobium worm infection, afflicts millions of people with egg-triggered, fibrotic bladder granulomata. Despite the significant global impact of urogenital schistosomiasis, the mechanisms of bladder granulomogenesis and fibrosis are ill defined due to the prior lack of tractable animal models. We combined a mouse model of urogenital schistosomiasis with macrophage-depleting liposomal clodronate (LC) to define how macrophages mediate bladder granulomogenesis and fibrosis. Mice were injected with eggs purified from infected hamsters or vehicle prepared from uninfected hamster tissues (xenoantigen and injection trauma control). Empty liposomes were controls for LC: 1) LC treatment resulted in fewer bladder egg granuloma-infiltrating macrophages, eosinophils, and T and B cells, lower bladder and serum levels of eotaxin, and higher bladder concentrations of IL-1α and chemokines (in a time-dependent fashion), confirming that macrophages orchestrate leukocyte infiltration of the egg-exposed bladder; 2) macrophage-depleted mice exhibited greater weight loss and bladder hemorrhage postegg injection; 3) early LC treatment postegg injection resulted in profound decreases in bladder fibrosis, suggesting differing roles for macrophages in fibrosis over time; and 4) LC treatment also led to egg dose-dependent mortality, indicating that macrophages prevent death from urogenital schistosomiasis. Thus, macrophages are a potential therapeutic target for preventing or treating the bladder sequelae of urogenital schistosomiasis.

New research tools for urogenital schistosomiasis.

Approximately 200,000,000 people have schistosomiasis (schistosome infection). Among the schistosomes, Schistosoma haematobium is responsible for the most infections, which are present in 110 million people globally, mostly in sub-Saharan Africa. This pathogen causes an astonishing breadth of sequelae: hematuria, anemia, dysuria, stunting, uremia, bladder cancer, urosepsis, and human immunodeficiency virus coinfection. Refined estimates of the impact of schistosomiasis on quality of life suggest that it rivals malaria. Despite S. haematobium's importance, relevant research has lagged. Here, we review advances that will deepen knowledge of S. haematobium. Three sets of breakthroughs will accelerate discoveries in the pathogenesis of urogenital schistosomiasis (UGS): (1) comparative genomics, (2) the development of functional genomic tools, and (3) the use of animal models to explore S. haematobium-host interactions. Comparative genomics for S. haematobium is feasible, given the sequencing of multiple schistosome genomes. Features of the S. haematobium genome that are conserved among platyhelminth species and others that are unique to S. haematobium may provide novel diagnostic and drug targets for UGS. Although there are technical hurdles, the integrated use of these approaches can elucidate host-pathogen interactions during this infection and can inform the development of techniques for investigating schistosomes in their human and snail hosts and the development of therapeutics and vaccines for the control of UGS.

Schistosoma haematobium egg-induced bladder urothelial abnormalities dependent on p53 are modulated by host sex.

INTRODUCTION AND OBJECTIVE: The bladder urothelium changes dramatically during Schistosoma haematobium infection (urogenital schistosomiasis). These alterations include hyperplasia, ulceration, dysplasia, squamous metaplasia and frank carcinogenesis. Defining the pathways underpinning these urothelial responses will contribute to a deeper understanding of how S. haematobium egg expulsion, hematuria, and bladder cancer develop in humans. The tumor suppressor gene p53 is of particular interest, given its role in many cancers, including bladder cancer generally and schistosomal bladder cancer specifically. METHODS: Transgenic mice featuring tamoxifen-inducible Cre recombinase activity in cells expressing the urothelial-specific gene uroplakin-3a (Upk3a-GCE mice) were crossed with either TdTomato-floxed-EGFP reporter or p53-floxed mice. Mice were administered tamoxifen or vehicle control to induce excision of floxed genes. TdTomato-EGFP reporter mice were sacrificed and their bladders harvested, sectioned, and imaged by fluorescence microscopy. p53-floxed mice underwent bladder wall injection with S. haematobium eggs or vehicle controls. Three months later, mice were sacrificed and their bladders subjected to histological analysis (H&E staining). RESULTS: We first confirmed the phenotypic fidelity of Upk3a-GCE mice by crossing them with TdTomato-floxed-EGFP reporter mice and administering tamoxifen to their progeny. As expected, these progeny switched from TdTomato to EGFP expression in their bladder urothelium. Having confirmed the phenotype of Upk3a-GCE mice, we next crossed them to p53-floxed mice. The resulting progeny were given tamoxifen or vehicle control to render them urothelial p53-haploinsufficient or -intact, respectively. Then, we injected S. haematobium eggs or control vehicle into the bladder walls of these mice. Male p53-intact, egg-injected mice exhibited similar histological changes as their p53-haploinsufficient counterparts, including urothelial hyperplasia and ulceration. In contrast, female p53-intact, egg-injected mice featured no urothelial ulceration, whereas their p53-haploinsufficient counterparts often had significant ulceration. CONCLUSIONS: Urothelial p53 signaling indeed seems to affect urothelial homeostasis during S. haematobium infection, albeit in a sex-specific manner. Ongoing work seeks to determine whether p53 mediates associated alterations in urothelial cell cycle status and frank carcinogenesis in the setting of urogenital schistosomiasis.

Helminth-induced interleukin-4 abrogates invariant natural killer T cell activation-associated clearance of bacterial infection.

Helminth infections affect 1 billion people worldwide and render these individuals susceptible to bacterial coinfection through incompletely understood mechanisms. This includes urinary tract coinfection by bacteria and Schistosoma haematobium worms, the etiologic agent of urogenital schistosomiasis. To study the mechanisms of S. haematobium-bacterial urinary tract coinfections, we combined the first tractable model of urogenital schistosomiasis with an established mouse model of bacterial urinary tract infection (UTI). A single bladder exposure to S. haematobium eggs triggers interleukin-4 (IL-4) production and makes BALB/c mice susceptible to bacterial UTI when they are otherwise resistant. Ablation of IL-4 receptor alpha (IL-4Rα) signaling restored the baseline resistance of BALB/c mice to bacterial UTI despite prior exposure to S. haematobium eggs. Interestingly, numbers of NKT cells were decreased in coexposed versus bacterially monoinfected bladders. Given that schistosome-induced, non-natural killer T (NKT) cell leukocyte infiltration may dilute NKT cell numbers in the bladders of coexposed mice without exerting a specific functional effect on these cells, we next examined NKT cell biology on a per-cell basis. Invariant NKT (iNKT) cells from coexposed mice expressed less gamma interferon (IFN-γ) per cell than did those from mice with UTI alone. Moreover, coexposure resulted in lower CD1d expression in bladder antigen-presenting cells (APC) than did bacterial UTI alone in an IL-4Rα-dependent fashion. Finally, coexposed mice were protected from prolonged bacterial infection by administration of α-galactosylceramide, an iNKT cell agonist. Our findings point to a previously unappreciated role for helminth-induced IL-4 in impairment of iNKT cell-mediated clearance of bacterial coexposure.

A novel mouse model of Schistosoma haematobium egg-induced immunopathology.

Schistosoma haematobium is the etiologic agent for urogenital schistosomiasis, a major source of morbidity and mortality for more than 112 million people worldwide. Infection with S. haematobium results in a variety of immunopathologic sequelae caused by parasite oviposition within the urinary tract, which drives inflammation, hematuria, fibrosis, bladder dysfunction, and increased susceptibility to urothelial carcinoma. While humans readily develop urogenital schistosomiasis, the lack of an experimentally-tractable model has greatly impaired our understanding of the mechanisms that underlie this important disease. We have developed an improved mouse model of S. haematobium urinary tract infection that recapitulates several aspects of human urogenital schistosomiasis. Following microinjection of purified S. haematobium eggs into the bladder wall, mice consistently develop macrophage-rich granulomata that persist for at least 3 months and pass eggs in their urine. Importantly, egg-injected mice also develop urinary tract fibrosis, bladder dysfunction, and various urothelial changes morphologically reminiscent of human urogenital schistosomiasis. As expected, S. haematobium egg-induced immune responses in the immediate microenvironment, draining lymph nodes, and systemic circulation are associated with a Type 2-dominant inflammatory response, characterized by high levels of interleukin-4, eosinophils, and IgE. Taken together, our novel mouse model may help facilitate a better understanding of the unique pathophysiological mechanisms of epithelial dysfunction, tissue fibrosis, and oncogenesis associated with urogenital schistosomiasis.