MAFB in macrophages regulates cold-induced neuronal density in brown adipose tissue

Transcription factor MAFB regulates various homeostatic functions of macrophages. This study explores the role of MAFB in brown adipose tissue (BAT) thermogenesis using macrophage-specific Mafb-deficient (Mafbf/f::LysM-Cre) mice. We find that Mafb deficiency in macrophages reduces thermogenesis, energy expenditure, and sympathetic neuron (SN) density in BAT under cold conditions. This phenotype features a proinflammatory environment that is characterized by macrophage/granulocyte accumulation, increases in interleukin-6 (IL-6) production, and IL-6 trans-signaling, which lead to decreases in nerve growth factor (NGF) expression and reduction in SN density in BAT. We confirm MAFB regulation of IL-6 expression using luciferase readout driven by IL-6 promoter in RAW-264.7 macrophage cell lines. Immunohistochemistry shows clustered organization of NGF-producing cells in BAT, which are primarily TRPV1+ vascular smooth muscle cells, as additionally shown using single-cell RNA sequencing and RT-qPCR of the stromal vascular fraction. Treating Mafbf/f::LysM-Cre mice with anti-IL-6 receptor antibody rescues SN density, body temperature, and energy expenditure.

IL-27-containing exosomes secreted by innate B-1a cells suppress and ameliorate uveitis

Introduction

IL-27 is a heterodimeric cytokine composed of Ebi3 and IL-27p28 and can exert proinflammatory or immune suppressive effects depending on the physiological context. Ebi3 does not contain membrane-anchoring motifs, suggesting that it is a secreted protein while IL-27p28 is poorly secreted. How IL-27p28 and Ebi3 dimerize in-vivo to form biologically active IL-27 is unknown. Major impediment to clinical use of IL-27 derives from difficulty of determining exact amount of bioavailable heterodimeric IL-27 needed for therapy.

Methods

To understand how IL-27 mediates immune suppression, we characterized an innate IL-27-producing B-1a regulatory B cell population (i27-Breg) and mechanisms i27-Bregs utilize to suppress neuroinflammation in mouse model of uveitis. We also investigated biosynthesis of IL-27 and i27-Breg immunobiology by FACS, immunohistochemical and confocal microscopy.

Results

Contrary to prevailing view that IL-27 is a soluble cytokine, we show that i27-Bregs express membrane-bound IL-27. Immunohistochemical and confocal analyses co-localized expression of IL-27p28 at the plasma membrane in association with CD81 tetraspanin, a BCR-coreceptor protein and revealed that IL-27p28 is a transmembrane protein in B cells. Most surprising, we found that i27-Bregs secrete IL-27-containing exosomes (i27-exosomes) and adoptive transfer of i27-exosomes suppressed uveitis by antagonizing Th1/Th17 cells, up-regulating inhibitory-receptors associated with T-cell exhaustion while inducing Treg expansion.

Discussion

Use of i27-exosomes thus obviates the IL-27 dosing problem, making it possible to determine bioavailable heterodimeric IL-27 needed for therapy. Moreover, as exosomes readily cross the blood-retina-barrier and no adverse effects were observed in mice treated with i27-exosome, results of this study suggest that i27-exosomes might be a promising therapeutic approach for CNS autoimmune diseases.

STAT3-Specific Single Domain Nanobody Inhibits Expansion of Pathogenic Th17 Responses and Suppresses Uveitis in Mice

STAT3 activates transcription of genes that regulate cell growth, differentiation, and survival of mammalian cells. Genetic deletion of Stat3 in T cells has been shown to abrogate Th17 differentiation, suggesting that STAT3 is a potential therapeutic target for Th17-mediated diseases. However, a major impediment to therapeutic targeting of intracellular proteins such as STAT3 is the lack of efficient methods for delivering STAT3 inhibitors into cells. In this study, we developed a novel antibody (SBT-100) comprised of the variable (V) region of a STAT3-specific heavy chain molecule and demonstrate that this 15 kDa STAT3-specific nanobody enters human and mouse cells, and induced suppression of STAT3 activation and lymphocyte proliferation in a concentration-dependent manner. To investigate whether SBT-100 would be effective in suppressing inflammation in vivo, we induced experimental autoimmune uveitis (EAU) in C57BL/6J mice by active immunization with peptide from the ocular autoantigen, interphotoreceptor retinoid binding protein (IRBP_651-670). Analysis of the retina by fundoscopy, histological examination, or optical coherence tomography showed that treatment of the mice with SBT-100 suppressed uveitis by inhibiting expansion of pathogenic Th17 cells that mediate EAU. Electroretinographic (ERG) recordings of dark and light adapted a- and b-waves showed that SBT-100 treatment rescued mice from developing significant visual impairment observed in untreated EAU mice. Adoptive transfer of activated IRBP-specific T cells from untreated EAU mice induced EAU, while EAU was significantly attenuated in mice that received IRBP-specific T cells from SBT-100 treated mice. Taken together, these results demonstrate efficacy of SBT-100 in mice and suggests its therapeutic potential for human autoimmune diseases.

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.

Multilevel modelling of the risk of malaria among children aged under five years in Nigeria

BACKGROUND

Malaria is still a major cause of morbidity and mortality among children aged <5 y (U5s). This study assessed individual, household and community risk factors for malaria in Nigerian U5s.

METHODS

Data from the Nigerian Malaria Health Indicator Survey 2015 were pooled for analyses. This comprised a national survey of 329 clusters. Children aged 6-59 mo who were tested for malaria using microscopy were retained. Multilevel logit model accounting for sampling design was used to assess individual, household and community factors associated with malaria parasitaemia.

RESULTS

A total of 5742 children were assessed for malaria parasitaemia with an overall prevalence of 27% (95% CI 26 to 28%). Plasmodium falciparum constituted 98% of the Plasmodium species. There was no significant difference in parasitaemia between older children and those aged ≤12 mo. In adjusted analyses, rural living, northwest region, a household size of >7, dependence on river and rainwater as primary water source were associated with higher odds of parasitaemia, while higher wealth index, all U5s who slept under a bed net and dependence on packaged water were associated with lower odds of parasitaemia.

CONCLUSION

Despite sustained investment in malaria control and prevention, a quarter of the overall study population of U5s have malaria. Across the six geopolitical zones, the highest burden was in children living in the poorest rural households.

Uveitis: Molecular Pathogenesis and Emerging Therapies

The profound impact that vision loss has on human activities and quality of life necessitates understanding the etiology of potentially blinding diseases and their clinical management. The unique anatomic features of the eye and its sequestration from peripheral immune system also provides a framework for studying other diseases in immune privileged sites and validating basic immunological principles. Thus, early studies of intraocular inflammatory diseases (uveitis) were at the forefront of research on organ transplantation. These studies laid the groundwork for foundational discoveries on how immune system distinguishes self from non-self and established current concepts of acquired immune tolerance and autoimmunity. Our charge in this review is to examine how advances in molecular cell biology and immunology over the past 3 decades have contributed to the understanding of mechanisms that underlie immunopathogenesis of uveitis. Particular emphasis is on how advances in biotechnology have been leveraged in developing biologics and cell-based immunotherapies for uveitis and other neuroinflammatory diseases.

IPSE, a urogenital parasite-derived immunomodulatory molecule, suppresses bladder pathogenesis and anti-microbial peptide gene expression in bacterial urinary tract infection

BACKGROUND

Parasitic infections can increase susceptibility to bacterial co-infections. This may be true for urogenital schistosomiasis and bacterial urinary tract co-infections (UTI). We previously reported that this co-infection is facilitated by S. haematobium eggs triggering interleukin-4 (IL-4) production and sought to dissect the underlying mechanisms. The interleukin-4-inducing principle from Schistosoma mansoni eggs (IPSE) is one of the most abundant schistosome egg-secreted proteins and binds to IgE on the surface of basophils and mast cells to trigger IL-4 release. IPSE can also translocate into host nuclei using a nuclear localization sequence (NLS) to modulate host transcription. We hypothesized that IPSE is the factor responsible for the ability of S. haematobium eggs to worsen UTI pathogenesis.

METHODS

Mice were intravenously administered a single 25 μg dose of recombinant S. haematobium-derived IPSE, an NLS mutant of IPSE or PBS. Following IPSE exposure, mice were serially weighed and organs analyzed by histology to assess for toxicity. Twenty-four hours after IPSE administration, mice were challenged with the uropathogenic E. coli strain UTI89 by urethral catheterization. Bacterial CFU were measured using urine. Bladders were examined histologically for UTI-triggered pathogenesis and by PCR for antimicrobial peptide and pattern recognition receptor expression.

RESULTS

Unexpectedly, IPSE administration did not result in significant differences in urine bacterial CFU. However, IPSE administration did lead to a significant reduction in UTI-induced bladder pathogenesis and the expression of anti-microbial peptides in the bladder. Despite the profound effect of IPSE on UTI-triggered bladder pathogenesis and anti-microbial peptide production, mice did not demonstrate systemic ill effects from IPSE exposure.

CONCLUSIONS

Our data show that IPSE may play a major role in S. haematobium-associated urinary tract co-infection, albeit in an unexpected fashion. These findings also indicate that IPSE either works in concert with other IL-4-inducing factors to increase susceptibility of S. haematobium-infected hosts to bacterial co-infection or does not contribute to enhancing vulnerability to this co-infection.

IPSE, an abundant egg-secreted protein of the carcinogenic helminth Schistosoma haematobium, promotes proliferation of bladder cancer cells and angiogenesis

BACKGROUND

Schistosoma haematobium, the helminth causing urogenital schistosomiasis, is a known bladder carcinogen. Despite the causal link between S. haematobium and bladder cancer, the underlying mechanisms are poorly understood. S. haematobium oviposition in the bladder is associated with angiogenesis and urothelial hyperplasia. These changes may be pre-carcinogenic events in the bladder. We hypothesized that the Interleukin-4-inducing principle of Schistosoma mansoni eggs (IPSE), an S. haematobium egg-secreted "infiltrin" protein that enters host cell nuclei to alter cellular activity, is sufficient to induce angiogenesis and urothelial hyperplasia. Methods: Mouse bladders injected with S. haematobium eggs were analyzed via microscopy for angiogenesis and urothelial hyperplasia. Endothelial and urothelial cell lines were incubated with recombinant IPSE protein or an IPSE mutant protein that lacks the native nuclear localization sequence (NLS-) and proliferation measured using CFSE staining and real-time monitoring of cell growth. IPSE's effects on urothelial cell cycle status was assayed through propidium iodide staining. Endothelial and urothelial cell uptake of fluorophore-labeled IPSE was measured. Findings: Injection of S. haematobium eggs into the bladder triggers angiogenesis, enhances leakiness of bladder blood vessels, and drives urothelial hyperplasia. Wild type IPSE, but not NLS-, increases proliferation of endothelial and urothelial cells and skews urothelial cells towards S phase. Finally, IPSE is internalized by both endothelial and urothelial cells. Interpretation: IPSE drives endothelial and urothelial proliferation, which may depend on internalization of the molecule. The urothelial effects of IPSE depend upon its NLS. Thus, IPSE is a candidate pro-carcinogenic molecule of S. haematobium.

SUMMARY

Schistosoma haematobium acts as a bladder carcinogen through unclear mechanisms. The S. haematobium homolog of IPSE, a secreted schistosome egg immunomodulatory molecule, enhances angiogenesis and urothelial proliferation, hallmarks of pre-carcinogenesis, suggesting IPSE is a key pro-oncogenic molecule of S. haematobium.

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.

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-IPSE^H06 (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 IPSE^H03, hereafter called H-IPSE^H03, might be more efficacious in preventing hemorrhagic cystitis compared with systemic administration of IPSE^H06. We report that H-IPSE^H03, like M-IPSE and H-IPSE^H06, activates IgE-bearing basophils in a nuclear factor of activated T-cells reporter assay, indicating activation of the cytokine pathway. Furthermore, H-IPSE^H03 attenuates ifosfamide-induced increases in bladder wet weight in an IL-4-dependent fashion. H-IPSE^H03 relieves hemorrhagic cystitis-associated allodynia and modulates voiding patterns in mice. Finally, H-IPSE^H03 drives increased urothelial cell proliferation, suggesting that IPSE induces bladder repair mechanisms. Taken together, H-IPSE^H03 may be a potential novel therapeutic to treat hemorrhagic cystitis by basophil activation, attenuation of allodynia, and promotion of urothelial cell proliferation.

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-β 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.

Defining the Pathways of Urogenital Schistosomiasis-Associated Urothelial Carcinogenesis through Transgenic and Bladder Wall Egg Injection Models

Urogenital schistosomiasis (infection with Schistosoma haematobium) is a major cause of bladder carcinogenesis. However, the exact mechanisms of the sequelae leading up to the development of bladder cancer are poorly understood, mainly because of a dearth of tractable mouse models. We developed a mouse model of urogenital schistosomiasis through intramural injection of parasite eggs into the bladder wall to mimic the trapping of parasite eggs in the bladder. This approach recapitulates many of the sequelae observed in infected humans. Here, we describe procedures for utilizing this surgical technique in combination with well-established transgenic mouse strains to dissect the role of cancer-related genes in the initiation and establishment of bladder carcinogenesis. The described method utilizes CRE-mediated flox activity to render mice p53 haploinsufficient before challenging them with bladder wall egg injection. These techniques are potentially amenable to studying the role of other pro-carcinogenic and cancer suppressor gene(s) in urogenital schistosomiasis-associated urothelial carcinogenesis.

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.

Onchocerciasis in Anambra State, Southeast Nigeria: clinical and psychological aspects and sustainability of community directed treatment with ivermectin (CDTI)

BACKGROUND

A cross-sectional study was performed to determine the psychological impact of onchocerciasis, and assess sustainability of the decade-old community directed treatment with ivermectin (CDTI) in Ayamelum Local Council, Anambra State, Southeast Nigeria.

METHODS

Skin manifestations assessed using the rapid assessment method (RAM) in 894 subjects from 13 communities selected by multi-stage sampling were classified based on the anatomical sites affected. Focus group discussions and in-depth interviews were used to obtain information on the psychological impacts and sustainability of the CDTI programme. Qualitative data were summarised while quantitative data generated were analysed using charts and tables.

RESULTS

Anatomical distribution showed a preponderance of onchodermatitis on the limbs (the most exposed parts of the body) and buttocks (an area considered 'private'), thus revealing some reasons for the psychological impacts of the skin disease and the psychosocial inclination of the victims. Itching (40%) and onchocercal skin manifestations (OSDs) (34.3%) were identified as the most troublesome signs and symptoms, while the most worrisome consequence of onchocerciasis was social seclusion (or stigmatisation) (34.3%). Focus group responses revealed the persistence of psychological impacts on the victims, affecting almost all facets of their lives. The CDTI programme has performed creditably well when assessed using the sustainability indicators, yet there are still challenges in the areas of coverage, monitoring, resources, and participation. A 'quick-win' was identified whereby the CDTI chain could be utilised to deliver other health interventions.

CONCLUSION

It is recommended that onchocerciasis control programmes should include aspects that would address its psychosocial impacts and threats to the sustainability of the CDTI programme.