High throughput data analyses of the immune characteristics of Microtus fortis infected with Schistosoma japonicum

Single-cell RNA sequencing reveals a peripheral landscape of immune cells in Schistosomiasis japonica

BACKGROUND

Schistosomiasis, also known as bilharzia, is a devastating parasitic disease. This progressive and debilitating helminth disease is often associated with poverty and can lead to chronic poor health. Despite ongoing research, there is currently no effective vaccine for schistosomiasis, and praziquantel remains the only available treatment option. According to the progression of schistosomiasis, infections caused by schistosomes are classified into three distinct clinical phases: acute, chronic and advanced schistosomiasis. However, the underlying immune mechanism involved in the progression of schistosomiasis remains poorly understood.

METHODS

We employed single-cell RNA sequencing (scRNA-seq) to profile the immune landscape of Schistosomiasis japonica infection based on peripheral blood mononuclear cells (PBMCs) from a healthy control group (n = 4), chronic schistosomiasis group (n = 4) and advanced schistosomiasis group (n = 2).

RESULTS

Of 89,896 cells, 24 major cell clusters were ultimately included in our analysis. Neutrophils and NK/T cells accounted for the major proportion in the chronic group and the healthy group, and monocytes dominated in the advanced group. A preliminary study showed that NKT cells were increased in patients with schistosomiasis and that CXCR2 + NKT cells were proinflammatory cells. Plasma cells also accounted for a large proportion of B cells in the advanced group. MHC molecules in monocytes were notably lower in the advanced group than in the chronic group or the healthy control group. However, monocytes in the advanced group exhibited high expression of FOLR3 and CCR2.

CONCLUSIONS

Overall, this study enhances our understanding of the immune mechanisms involved in schistosomiasis. It provides a transcriptional atlas of peripheral immune cells that may contribute to elimination of the disease. This preliminary study suggests that the increased presence of CCR2 + monocyte and CXCR2 + NKT cells might participate in the progression of schistosomiasis.

Trained immunity: a cutting edge approach for designing novel vaccines against parasitic diseases?

The preventive situation of parasitosis, a global public health burden especially for developing countries, is not looking that good. Similar to other infections, vaccines would be the best choice for preventing and controlling parasitic infection. However, ideal antigenic molecules for vaccine development have not been identified so far, resulting from the complicated life history and enormous genomes of the parasites. Furthermore, the suppression or down-regulation of anti-infectious immunity mediated by the parasites or their derived molecules can compromise the effect of parasitic vaccines. Comparing the early immune profiles of several parasites in the permissive and non-permissive hosts, a robust innate immune response is proposed to be a critical event to eliminate the parasites. Therefore, enhancing innate immunity may be essential for designing novel and effective parasitic vaccines. The newly emerging trained immunity (also termed innate immune memory) has been increasingly recognized to provide a novel perspective for vaccine development targeting innate immunity. This article reviews the current status of parasitic vaccines and anti-infectious immunity, as well as the conception, characteristics, and mechanisms of trained immunity and its research progress in Parasitology, highlighting the possible consideration of trained immunity in designing novel vaccines against parasitic diseases.

Macrophage-mediated trogocytosis contributes to destroying human schistosomes in a non-susceptible rodent host, Microtus fortis

Schistosoma parasites, causing schistosomiasis, exhibit typical host specificity in host preference. Many mammals, including humans, are susceptible to infection, while the widely distributed rodent, Microtus fortis, exhibits natural anti-schistosome characteristics. The mechanisms of host susceptibility remain poorly understood. Comparison of schistosome infection in M. fortis with the infection in laboratory mice (highly sensitive to infection) offers a good model system to investigate these mechanisms and to gain an insight into host specificity. In this study, we showed that large numbers of leukocytes attach to the surface of human schistosomes in M. fortis but not in mice. Single-cell RNA-sequencing analyses revealed that macrophages might be involved in the cell adhesion, and we further demonstrated that M. fortis macrophages could be mediated to attach and kill schistosomula with dependence on Complement component 3 (C3) and Complement receptor 3 (CR3). Importantly, we provided direct evidence that M. fortis macrophages could destroy schistosomula by trogocytosis, a previously undescribed mode for killing helminths. This process was regulated by Ca2+/NFAT signaling. These findings not only elucidate a novel anti-schistosome mechanism in M. fortis but also provide a better understanding of host parasite interactions, host specificity and the potential generation of novel strategies for schistosomiasis control.

Host genetic backgrounds: the key to determining parasite-host adaptation

Parasitic diseases pose a significant threat to global public health, particularly in developing countries. Host genetic factors play a crucial role in determining susceptibility and resistance to infection. Recent advances in molecular and biological technologies have enabled significant breakthroughs in understanding the impact of host genes on parasite adaptation. In this comprehensive review, we analyze the host genetic factors that influence parasite adaptation, including hormones, nitric oxide, immune cells, cytokine gene polymorphisms, parasite-specific receptors, and metabolites. We also establish an interactive network to better illustrate the complex relationship between host genetic factors and parasite-host adaptation. Additionally, we discuss future directions and collaborative research priorities in the parasite-host adaptation field, including investigating the impact of host genes on the microbiome, developing more sophisticated models, identifying and characterizing parasite-specific receptors, utilizing patient-derived sera as diagnostic and therapeutic tools, and developing novel treatments and management strategies targeting specific host genetic factors. This review highlights the need for a comprehensive and systematic approach to investigating the underlying mechanisms of parasite-host adaptation, which requires interdisciplinary collaborations among biologists, geneticists, immunologists, and clinicians. By deepening our understanding of the complex interactions between host genetics and parasite adaptation, we can develop more effective and targeted interventions to prevent and treat parasitic diseases. Overall, this review provides a valuable resource for researchers and clinicians working in the parasitology field and offers insights into the future directions of this critical research area.

Pattern recognition receptor signaling and innate immune responses to schistosome infection

Schistosomiasis remains to be a significant public health problem in tropical and subtropical regions. Despite remarkable progress that has been made in the control of the disease over the past decades, its elimination remains a daunting challenge in many countries. This disease is an inflammatory response-driven, and the positive outcome after infection depends on the regulation of immune responses that efficiently clear worms and allow protective immunity to develop. The innate immune responses play a critical role in host defense against schistosome infection and pathogenesis. Initial pro-inflammatory responses are essential for clearing invading parasites by promoting appropriate cell-mediated and humoral immunity. However, elevated and prolonged inflammatory responses against the eggs trapped in the host tissues contribute to disease progression. A better understanding of the molecular mechanisms of innate immune responses is important for developing effective therapies and vaccines. Here, we update the recent advances in the definitive host innate immune response to schistosome infection, especially highlighting the critical roles of pattern recognition receptors and cytokines. The considerations for further research are also provided.

Prognostic Roles of Glucose to Lymphocyte Ratio and Modified Glasgow Prognosis Score in Patients With Non-small Cell Lung Cancer

Background

Non-small cell lung cancer (NSCLC) is among the most prevalent malignancies worldwide. Previous studies have shown that the status of inflammation, nutrition and immune are closely related to overall survival (OS) of patients with NSCLC, but little is known about their interactive and combined roles. Hence, we chose glucose to lymphocyte ratio (GLR) and modified Glasgow Prognosis Score (mGPS) as prognostic factors and assessed the prognostic values of them for patients with NSCLC.

Methods

Baseline clinicopathologic and laboratory characteristics of 862 patients with NSCLC were obtained from a multicenter prospective cohort. The Cox proportional hazard regression models were used to determine prognostic values of the clinical factors. A nomogram was also constructed integrating the clinical factors with clinical significance or independent prognostic values. Concordance index (C-index) was utilized to evaluate the prediction accuracy of the TNM stage and the nomogram.

Results

Multivariate analyses demonstrated that GLR [Hazard ratio (HR) = 1.029, 95% confidence interval (CI) = 1.004–1.056, P = 0.023] and mGPS (score of 1: HR = 1.404, 95% CI = 1.143–1.726, P = 0.001; score of 2: HR = 1.515, 95% CI = 1.159–1.980, P = 0.002) were independent prognostic factors for patients with NSCLC. The C-indexes of the TNM stage and the nomogram were 0.642 (95% CI = 0.620–0.663) and 0.694 (95% CI = 0.671–0.717), respectively.

Conclusion

GLR and mGPS were independent prognostic factors for patients with NSCLC. Moreover, our constructed nomogram might be superior in predicting prognosis of patients with NSCLC compared with the TNM stage.

Gene expression changes in mammalian hosts during schistosomiasis: a review

Schistosomiasis affects over 250 million people worldwide with an estimated mortality of more than 200,000 deaths per year in sub-Saharan Africa. Efforts to control schistosomiasis in the affected areas have mainly relied on mass administration of praziquantel, which kills adult but not immature worms of all Schistosoma species. Mammalian hosts respond differently to Schistosoma infection with some being more susceptible than others, which is associated with risk factors such as sociodemographic, epidemiological, immunological and/or genetic. Host genetic factors play a major role in influencing molecular processes in response to schistosomiasis as shown in gene expression studies. These studies highlight gene profiles expressed at different time points of infection using model animals. Immune function related genes; cytokines (Th1 and Th17) are upregulated earlier in infection and Th2 upregulated later indicating a mixed Th1/Th2 response. However, Th1 response has been shown to be sustained in S. japonicum infection. Immune mediators such as matrix metalloproteinases (Mmps) and tissue inhibitors of matrix metalloproteinases (Timps) are expressed later in the infection and these are linked to wound healing and fibrosis. Downregulation of metabolic associated genes is recorded in later stages of infection. Most mammalian host gene expression studies have been done using rodent models, with fewer in larger hosts such as bovines and humans. The majority of these studies have focused on S. japonicum infections and less on S. haematobium and S. mansoni infections (the two species that cause most global infections). The few human schistosomiasis gene expression studies so far have focused on S. japonicum and S. haematobium infections and none on S. mansoni, as far as we are aware. This highlights a paucity of gene expression data in humans, specifically with S. mansoni infection. This data is important to understand the disease pathology, identify biomarkers, diagnostics and possible drug targets.

Transcriptional profiling of Microtus fortis responses to S. japonicum: New sight into Mf-Hsp90α resistance mechanism

AIMS

Schistosomiasis is a parasitic disease with a chronic debilitating character caused by parasitic flatworms of the genus Schistosoma. The main disease-causing species of Schistosoma in China is S. japonicum. M fortis has been proved to be a nonpermissive host of S. japonicum. Mf-HSP90α (Microtus fortis heat shock protein 90alpha), the homologue of HSP90α, display anti-schistosome effect in vitro and in vivo. In the current study, in order to investigate the mechanism of anti-schistosome effect of Mf-HSP90α, we conducted RNA-Seq to obtain the transcriptome profile of M. fortis liver infected with S. japonicum at different time points.

METHODS AND RESULTS

By mapping the differential expressed genes (DEGs) to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), we found that the JAK2/STAT1 pathway was highly enriched with an elevated level of IL-10 and HSP90α. We then checked the IL-10-JAK2/STAT1-HSP90α pathway, and found that this pathway was activated in the infected mice with S. japonicum. The expression of the molecules in this pathway was elevated on the 10^th day after infection and gradually decreased on the 20^th day.

CONCLUSIONS

The IL-10-JAK2/STAT1-HSP90α axis was associated with the anti-schistosome effect of Mf-HSP90α, and targeting IL-10-JAK2/STAT1-HSP90α axis might be a novel therapeutic strategy for developing resistance to S. japonicum infection.

Immunometabolism: Towards a Better Understanding the Mechanism of Parasitic Infection and Immunity

As a relatively successful pathogen, several parasites can establish long-term infection in host. This “harmonious symbiosis” status relies on the “precise” manipulation of host immunity and metabolism, however, the underlying mechanism is still largely elusive. Immunometabolism is an emerging crossed subject in recent years. It mainly discusses the regulatory mechanism of metabolic changes on reprogramming the key transcriptional and post-transcriptional events related to immune cell activation and effect, which provides a novel insight for understanding how parasites regulate the infection and immunity in hosts. The present study reviewed the current research progress on metabolic reprogramming mechanism exploited by parasites to modulate the function in various immune cells, highlighting the future exploitation of key metabolites or metabolic events to clarify the underlying mechanism of anti-parasite immunity and design novel intervention strategies against parasitic infection.

Genome assembly and transcriptome analysis provide insights into the antischistosome mechanism of Microtus fortis

Microtus fortis is the only mammalian host that exhibits intrinsic resistance against Schistosoma japonicum infection. However, the underlying molecular mechanisms of this resistance are not yet known. Here, we perform the first de novo genome assembly of M. fortis, comprehensive gene annotation analysis, and evolution analysis. Furthermore, we compare the recovery rate of schistosomes, pathological changes, and liver transcriptomes between M. fortis and mice at different time points after infection. We observe that the time and type of immune response in M. fortis are different from those in mice. M. fortis activates immune and inflammatory responses on the 10th day post infection, such as leukocyte extravasation, antibody activation, Fc-gamma receptor-mediated phagocytosis, and the interferon signaling cascade, which play important roles in preventing the development of schistosomes. In contrast, an intense immune response occurrs in mice at the late stages of infection and could not eliminate schistosomes. Infected mice suffer severe pathological injury and continuous decreases in cell cycle, lipid metabolism, and other functions. Our findings offer new insights into the intrinsic resistance mechanism of M. fortis against schistosome infection. The genome sequence also provides the basis for future studies of other important traits in M. fortis.

Hepatic transcriptome study of Taenia asiatica infection in suckling pigs

Taenia asiatica is a crucial Taenia that is prevalent in East and Southeast Asia. Domestic pigs and wild boars are essential intermediate hosts for Taenia. Cysticercus larvae are mainly parasitic in the liver of domestic pigs. The Taenia asiatica was collected from Liangmu Township, Duyun City, Guizhou Province. Twelve Yorkshire Suckling pigs of 20 days of age were randomly divided into an experimental and control group of 6 pigs each. RNA sequencing (RNA-seq) technology was used to detect the expression differences of the mRNA transcriptomes in the liver of the experimental and control group at different infection times. Differential genes were analyzed by bioinformatics and verified by Real Time-PCR(RT-PCR). On the 15th and 75th days after infection, 152 and 558 differentially expressed genes were detected in the liver of the experimental group, respectively, accounting for 0.85% and 3.12% of all identified transcribed RNA genes, respectively. Through GO and KEGG related bioinformatics analysis, it was found that these differentially expressed genes are involved in the immune response, material metabolism, fibrosis, and tissue proliferation and repair of suckling pig liver, and related to MHC antigen processing and presentation, cytochrome P450, transforming growth factor-beta (TGF-β) signaling pathway and so on. Cysticercus asiatica parasites cause significant differential gene expression in the liver of suckling pigs. Specific differentially expressed genes are involved in biological processes such as liver metabolism, immune response, and tissue repair or regeneration in suckling pigs. The immune evasion is related to the immuno-suppressive response of the intermediate host.

Alterations of Gut Microbiome and Metabolite Profiling in Mice Infected by Schistosoma japonicum

Schistosoma japonicum (S. japonicum) is one of the etiological agents of schistosomiasis, a widespread zoonotic parasitic disease. However, the mechanism of the balanced co-existence between the host immune system and S. japonicum as well as their complex interaction remains unclear. In this study, 16S rRNA gene sequencing, combined with metagenomic sequencing approach as well as ultraperformance liquid chromatography–mass spectrometry metabolic profiling, was applied to demonstrate changes in the gut microbiome community structure during schistosomiasis progression, the functional interactions between the gut bacteria and S. japonicum infection in BALB/c mice, and the dynamic metabolite changes of the host. The results showed that both gut microbiome and the metabolites were significantly altered at different time points after the infection. Decrease in richness and diversity as well as differed composition of the gut microbiota was observed in the infected status when compared with the uninfected status. At the phylum level, the gut microbial communities in all samples were dominated by Firmicutes, Bacteroidetes, Proteobacteria, and Deferribacteres, while at the genus level, Lactobacillus, Lachnospiraceae NK4A136 group, Bacteroides, Staphylococcus, and Alloprevotella were the most abundant. After exposure, Roseburia, and Ruminococcaceae UCG-014 decreased, while Staphylococcus, Alistipes, and Parabacteroides increased, which could raise the risk of infections. Furthermore, LEfSe demonstrated several bacterial taxa that could discriminate between each time point of S. japonicum infection. Besides that, metagenomic analysis illuminated that the AMP-activated protein kinase (AMPK) signaling pathway and the chemokine signaling pathway were significantly perturbed after the infection. Phosphatidylcholine and colfosceril palmitate in serum as well as xanthurenic acid, naphthalenesulfonic acid, and pimelylcarnitine in urine might be metabolic biomarkers due to their promising diagnostic potential at the early stage of the infection. Alterations of glycerophospholipid and purine metabolism were also discovered in the infection. The present study might provide further understanding of the mechanisms during schistosome infection in aspects of gut microbiome and metabolites, and facilitate the discovery of new targets for early diagnosis and prognostic purposes. Further validations of potential biomarkers in human populations are necessary, and the exploration of interactions among S. japonicum, gut microbiome, and metabolites is to be deepened in the future.

Mechanisms of Resistance to Schistosoma japonicum Infection in Microtus fortis, the Natural Non-permissive Host

Human schistosomiasis, which is caused by schistosomes, is a zoonosis that is difficult to control because of the many reservoir hosts. However, Microtus fortis is the only mammal that is naturally resistant to Schistosoma japonicum infection known in China, in which S. japonicum growth and development were arrested on day 12, and the worms eliminated on day 20 post-infection. In this review, we present an overview of the established and purported mechanisms of resistance to S. japonicum infection in M. fortis in comparison to Rattus norvegicus, a semi-permissive host. Clarifying the mechanism of this efficient resistance can help us to better understand host-parasite interaction and to provide better methods to control schistosomiasis.

Zinc oxide nanoparticles and L-carnitine effects on neuro-schistosomiasis mansoni induced in mice

Neuro-schistosomiasis can induce neurological symptoms and severe disability. Since the resistance against the chemotherapy "praziquantel" was reported, the aim of the present study was investigating the anti-neuro-schistosomal effects of ZnO nanoparticles and/or L-carnitine (as free radicals scavenger) on schistosome-infected mice, where technology of nanoparticles has come to the forefront in the medical diagnosis and therapeutic drug delivery. In the human body, nanoscale-sized particles can move freely and reveal unique biological, mechanical, electrical, and chemical properties. In the present study, mice were divided into five groups. The first group served as the non-infected control group. Groups II, III, IV, and V were infected with cercariae of Schistosoma mansoni. Mice of groups III and IV were treated with ZnO nanoparticles (5.6 mg/kg b. wt.) and L-carnitine (500 mg/kg b. wt.), respectively, after 47 days post-infection. Finally, mice of the fifth group were injected with ZnO nanoparticles and after 1 h, the mice were intraperitoneally injected with L-carnitine once daily for 5 days. On day 52, post-infection mice of all groups were cervically decapitated. The treatment of ZnO nanoparticles and/or L-carnitine to schistosome-infected mice decreased brain oxidative stress parameters, where glutathione level and catalase activity were significantly increased as compared to schistosome-infected group. On the contrary, the treatment decreased nitrite/nitrate, malondialdehyde, and reactive oxygen species levels significantly. In addition, ZnO nanoparticles and/or L-carnitine treatment restored DNA laddering profile and improved the brain histopathological impairments resulting from neuro-schistosomiasis. Finally, the ZnO nanoparticle treatment and the co-treatment of ZnO nanoparticles and L-carnitine revealed anti-neuro-schistosomal effects on the infected mice.

Comparative serum metabolomics between SCID mice and BALB/c mice with or without Schistosoma japonicum infection: Clues to the abnormal growth and development of schistosome in SCID mice

The small blood flukes of genus Schistosoma, which cause one of the most prevalent and serious parasitic zoonosis schistosomiasis, are dependent on immune-related factors of their mammalian host to facilitate their growth and development, and the formation of granulomatous pathology caused by eggs deposited in host's liver and intestinal wall. Schistosome development is hampered in the mice lacking just T cells, and is even more heavily retarded in the severe combined immunodeficient (SCID) mice lacking both T and B lymphocytes. Nevertheless, it's still not clear about the underlying regulatory molecular mechanisms of schistosome growth and development by host's immune system. This study, therefore, detected and compared the serum metabolic profiles between the immunodeficient mice and immunocompetent mice (SCID mice vs. BALB/c mice) before and after S. japonicum infection (on the thirty-fifth day post infection using liquid chromatography-mass spectrometry (LC-MS). Totally, 705 ion features in electrospray ionization in positive-ion mode (ESI+) and 242 ion features in ESI- mode were identified, respectively. First, distinct serum metabolic profiles were identified between SCID mice and BALB/c mice without S. japonicum worms infection. Second, uniquely perturbed serum metabolites and their enriched pathways were also obtained between SCID mice and BALB/c mice after S. japonicum infection, which included differential metabolites due to both species differences and differential responses to S. japonicum infection. The metabolic pathways analysis revealed that arachidonic acid metabolism, biosynthesis of unsaturated fatty acids, linoleic acid metabolism, glycosylphosphatidylinositol (GPI)-anchor biosynthesis, alpha-linolenic acid metabolism, glycerophospholipid metabolism, sphingolipid metabolism and purine metabolism were enriched based on the differential serum metabolites between SCID mice and BALB/c mice after S. japonicum infection, which was addressed to be related to the retarded growth and development of S. japonicum in SCID mice. These findings provide new clues to the underlying molecular events of host's systemic metabolic changes on the growth and development of S. japonicum worms, and also provide quite promising candidates for exploitation of drugs or vaccines against schistosome and schistosomiasis.

A comparison of next-generation sequencing analysis methods for cancer xenograft samples

The application of next-generation sequencing (NGS) technology in cancer is influenced by the quality and purity of tissue samples. This issue is especially critical for patient-derived xenograft (PDX) models, which have proven to be by far the best preclinical tool for investigating human tumor biology, because the sensitivity and specificity of NGS analysis in xenograft samples would be compromised by the contamination of mouse DNA and RNA. This definitely affects downstream analyses by causing inaccurate mutation calling and gene expression estimates. The reliability of NGS data analysis for cancer xenograft samples is therefore highly dependent on whether the sequencing reads derived from the xenograft could be distinguished from those originated from the host. That is, each sequence read needs to be accurately assigned to its original species. Here, we review currently available methodologies in this field, including Xenome, Disambiguate, bamcmp and pdxBlacklist, and provide guidelines for users.