The Schistosomiasis SpleenOME: Unveiling the Proteomic Landscape of Splenomegaly Using Label-Free Mass Spectrometry

Changes in splenic tissue and immune response profile of Schistosoma mansoni infected mice submitted to chronic ethanol intake

In Schistosoma mansoni infection, the spleen is one of the organs affected, causing its enlargement (splenomegaly). Intake of ethanol through alcoholic beverages can cause spleen atrophy and interfere with immune activity. To gain knowledge of this association on the spleen and on the immune response profile, male mice were used as an experimental model. These animals were divided into four groups: C. control; EC. uninfected/ethanol gavage; I. infected; and IE. infected/ethanol gavage. Groups I and IE were infected with about 100 cercariae (BH strain) of S. mansoni and in the fifth week of infection, gavage 200 μL/day/animal of 18 % ethanol was started for 28 consecutive days. At the end of the gavage (9th week of infection) all animals were euthanized. The spleen was removed and longitudinally divided in two parts. After histological processing, the sections were stained with H&E and Gomori's Reticulin for histopathological and stereological analyses, white pulp morphometry and quantification of megakaryocytes. The other fragment was macerated (in laminar flow) and the cell suspension, after adjusting the concentration (2 × 106), was plated to obtain cytokines produced by spleen cells that were measured by flow cytometry (Citometric Bead Array). Histopathological and quantitative analyzes in the spleen of the IE group showed an increase in the number of trabeculae and megakaryocytes, a decrease in reticular fibers, as well as important organizational changes in the white pulp and red pulp. Due to the decrease in the levels of cytokines measured and the result of the calculation of the ratio between the IFN-y and IL-10 cytokines (p = 0.0079) of the infected groups, we suggest that ethanol decreased the inflammatory and anti-inflammatory response generated by the infection (group IE, the production of cytokines was significantly decreased (p < 0.01). These changes demonstrate that ethanol ingestion interferes with some parameters of experimental S. mansoni infection, such as changes in splenic tissue and in the pattern of cytokine production.

Liver Cirrhosis of Unknown Etiology and Its Predictors in Eastern Ethiopia

Background

The global burden of liver cirrhosis is increasing, with 2.1 million incident cases and nearly 1.5 million deaths in 2019. Despite the enormous progress in our understanding of the etiology of liver cirrhosis, significant cases of the disease have been reported in Eastern Ethiopia due to unidentified causes. Hence, this study aimed to identify predictors of liver cirrhosis of unknown etiology in Eastern Ethiopia.

Methods

A score of 7 out of 11 possible points on the ultrasound-based cirrhosis scale was used as a diagnostic criterion to include 127 liver cirrhosis patients. The study participants' demographic, dietary, lifestyle, and clinical data were gathered using a structured questionnaire and standardized reporting forms. The associations between the outcome (known and unknown etiology) and independent variables were modeled using binary logistic regression analysis.

Results

The etiology of liver cirrhosis was known in only 23% of patients and attributed to hepatitis B virus (21%), hepatitis C virus (0.8%), and alcohol abuse (0.8%). Sorghum consumption as a staple food (adjusted odds ratio (AOR) =3.8; 95% CI: 1.2, 12.5), splenomegaly (AOR = 4.0; 95% CI: 1.1, 14.4), and a family history of liver disease (AOR = 0.24; 95% CI: 0.06, 0.91) were significantly associated with liver cirrhosis of unknown etiology.

Conclusion

Sorghum consumption was found to be the determinant factor of liver cirrhosis of unknown etiology, suggesting it as a possible source of exposure to aflatoxin B1.

Profiling the serum proteome during Schistosoma mansoni infection in the BALB/c mice: A focus on the altered lipid metabolism as a key modulator of host-parasite interactions

Schistosomiasis represents a condition in which every aspect of the disease, starting from skin invasion of the cercariae to egg laying by adult worms, incites a tissue response from the vertebrate host. This response, whether acute or chronic, leads to the appearance of reporter molecules of tissue injury in bodily fluids that could be surveyed as markers for disease diagnosis, status and prognosis. In this scenario, the serum proteome associated with a schistosome infection remains poorly explored; particularly by the use of high-throughput mass spectrometric instrumentation. In this study, we aimed to comparatively examine the serum proteome of control versus infected BALB/c mice, spanning the interval between the onset of egg laying and the peak of the acute phase of infection. Compositional analysis of the sera, using one dimensional reversed-phase fractionation of tryptic peptides coupled to mass spectrometry, allowed identification of 453 constituents. Among these, over 30% (143 molecules) were differentially present comparing sera from infected and non-infected mice, as revealed by quantitative label-free shotgun approach. The majority of proteins exhibiting altered levels was categorised as belonging to immune response (acute phase-related proteins) followed by those linked to lipid transport and metabolism. Inspection of the lipid profile from control and infected individuals demonstrated more pronounced and significant alterations in triglycerides, VLDL and HDL fractions (p<0,001), attesting for a disturbance in circulating lipid molecules, and suggesting a key role in host-parasite interactions. Our findings provide a global view of the serum proteome in the context of experimental schistosomiasis during the acute phase of infection. It contributes by listing key molecules that could be monitored to inform on the associated inflammatory disease status. We hope it will shed light into uncovered aspects of the Schistosoma mansoni parasitism in the vertebrate host, particularly those related to modulation of the lipid metabolism mediating immune responses.

Bioactive Earthworm Peptides Produced by Novel Protease-Producing Bacillus velezensis PM 35 and Its Bioactivities on Liver Cancer Cell Death via Apoptosis, Antioxidant Activity, Protection Against Oxidative Stress, and Immune Cell Activation

Earthworms have long been used as traditional medicine. The purposes of this research were to create bioactive peptides from the unique Amynthas arenulus earthworm (PAAEs) and test their potentials on liver cancer bioprophylactic activity, antioxidant, oxidative stress protection, and immune cell activation. This earthworm had a high protein content ratio, at 55.39%. Besides, PM 35 is one out of 58 bacteria isolated from the earthworm carcasses that exhibited the highest protease and yield protein production which was chosen as the protease-producing bacteria to hydrolyze the protein. The genera were identified by 16S rRNA and 16S–23S rRNA comparison and confirmed as Bacillus velezensis PM 35. The response surface methodology was applied to optimize these hydrolysis parameters, i.e., the enzyme/substrate (E/S) concentration ratio [1%–3% (v/v)] and time (1–3 h) of the hydrolyzing earthworm’s proteins. The optimal hydrolyzing conditions were 3% (v/v) of E/S concentration ratio and 3 h of hydrolysis time, which found protein-hydrolysate yield (24.62%) and degree of hydrolysis (85.45%) as the highest. After being challenged in the gastrointestinal tract-resistant model, these PAAEs (MW <3 and 3–5 kDa) induced liver cancer cell (HepG2) death via apoptotic action modes (cell morphological change and DNA fragmentation). The PAAEs (MW <3 kDa) exhibited significant antioxidant activity via DPPH, ABTS, and FRAP with IC₅₀ values of 0.94, 0.44, and 6.34 mg/ml, respectively. The PAAEs (MW < 3 kDa) were non-cytotoxic and protected the mouse fibroblast cells (L929) against oxidative stress. These PAAEs (MW < 3 kDa, 0.2 mg/ml) stimulated the B lymphocytes (122.3%), and T lymphocytes (126.7%) proliferation. This research suggests that PAAEs can be used in a variety of applications, especially in the food and pharmaceutical industries.

HIV protease inhibitor nelfinavir is a potent drug candidate against echinococcosis by targeting Ddi1-like protein

Background

Alveolar echinococcosis (AE), which is caused by larval Echinococcus multilocularis, is one of the world's most dangerous neglected diseases. Currently, no fully effective treatments are available to cure this disease.

Methods

In vitro protoscolicidal assay along with in vivo murine models was applied in repurposing drugs against AE. Genome-wide identification and homology-based modeling were used for predicting drug targets. RNAi, enzyme assay, and RNA-Seq analyses were utilized for investigating the roles in parasite survival and validations for the drug target.

Findings

We identified nelfinavir as the most effective HIV protease inhibitor against larval E. multilocularis. Once-daily oral administration of nelfinavir for 28 days resulted in a remarkable reduction in parasite infection in either immune-competent or immunocompromised mice. E. multilocularis DNA damage-inducible 1 protein (EmuDdi1) is predicted as a target candidate for nelfinavir. We proved that EmuDdi1 is essential for parasite survival and protein excretion and acts as a functionally active protease for this helminth. We found nelfinavir is able to inhibit the proteolytic activity of recombinant EmuDdi1 and block the EmuDdi1-related pathways for protein export. With other evidence of drug efficacy comparison, our results suggest that inhibition of EmuDdi1 is a mechanism by which this HIV proteinase inhibitor mediates its antiparasitic action on echinococcosis.

Interpretation

This study demonstrates that nelfinavir is a promising candidate for treating echinococcosis. This drug repurposing study proves that the widely prescribed drug for AIDS treatment is potent in combating E. multilocularis infection and thus provides valuable insights into the development of single-drug therapy for highly prevalent co-infection between HIV and helminth diseases.

Funding

This work was supported by the National Natural Science Foundation of China (31802179), the Natural Science Foundation of Gansu Province, China (No. 21JR7RA027), and the State Key Laboratory of Veterinary Etiological Biology (No. SKLVEB2021YQRC01).

Sex-Specific Modulation of the Host Transcriptome in the Spleen of Schistosoma mansoni-Infected Mice

Background

Schistosomiasis is a severe parasitic disease that is primarily driven by the host’s immune response to schistosome eggs trapped in tissue and by the granulomatous inflammatory and fibrotic reaction they cause. Despite significant progress in understanding the complex immunological processes involved in the relationship between schistosomes and their host, neither an effective vaccine against the infection nor anti-fibrotic drugs currently exists, making the search for new targets for schistosome drugs and vaccine candidates even more important. In order to identify new molecular targets for defense against or elimination of the parasite, we investigate herein the interplay between the host and male or female schistosomes, clearly separating this from the action of the parasite eggs.

Methods

For this purpose, we infected 6–8-week-old female NMRI mice with 100 male (M), female (F), or both (MF) S. mansoni cercariae and performed a comparative transcriptomic and flow cytometric analysis of their spleens.

Results

Principal component analysis of a total of 22,207 transcripts showed a clear clustering of the experimental groups. We identified a total of 1,293 genes in group M, 512 genes in group F, and 4,062 genes in group MF that were differentially expressed compared to naive controls. The highest percentage of regulated genes (2,972; 65.9%) was found in group MF alone, but there was a large overlap between groups M and MF (798; 17.7%) and a small overlap between groups F and MF (91; 2.0%). Only 4.5% of genes (201) were revealed to be regulated in all experimental groups (M/F/MF). In addition, we were able to show that both worm sexes trigger immune responses in an egg-independent manner (non-polarized Th1 and Th2 response), with female worms exerting less regulatory influence than males.

Conclusion

Our data show that adult schistosomes trigger sex-specific, egg-independent immune responses. The lists of genes regulated by adult female or male worms presented here may be useful in deciphering host–parasite interactions to identify targets for schistosome elimination.

Proteomic Profiling of the Liver, Hepatic Lymph Nodes, and Spleen of Buffaloes Infected with Fasciola gigantica

In the present study, we used an isobaric tag for relative and absolute quantitation (iTRAQ) proteomics technology to characterize the differentially expressed proteins (DEPs) in the liver, hepatic lymph nodes (hLNs), and spleen of buffaloes infected with Fasciola gigantica (F. gigantica). We also used the parallel reaction monitoring (PRM) method to verify the expression levels of the DEPs in the three infected tissues. At three days post-infection (dpi), 225, 1821, and 364 DEPs were detected in the liver, hLNs, and spleen, respectively. At 42 dpi, 384, 252, and 214 DEPs were detected in the liver, hLNs, and spleen, respectively. At 70 dpi, 125, 829, and 247 DEPs were detected in the liver, hLNs, and spleen, respectively. Downregulation of metabolism was prominent in infected livers at all time points, and upregulation of immune responses was marked in the hLNs during early infection (three dpi); however, no changes in the immune response were detected at the late stages of infection (42 and 70 dpi). Compared to the hLNs, there was no significant upregulation in the levels of immune responses in the infected spleen. All the identified DEPs were used to predict the subcellular localization of the proteins, which were related to extracellular space and membrane and were involved in host immune responses. Further PRM analysis confirmed the expression of 18 proteins. These data provide the first simultaneous proteomic profiles of multiple organs of buffaloes experimentally infected with F. gigantica.

Schistosome and intestinal helminth modulation of macrophage immunometabolism

Macrophages are fundamental to sustain physiological equilibrium and to regulate the pathogenesis of parasitic and metabolic processes. The functional heterogeneity and immune responses of macrophages are shaped by cellular metabolism in response to the host's intrinsic factors, environmental cues and other stimuli during disease. Parasite infections induce a complex cascade of cytokines and metabolites that profoundly remodel the metabolic status of macrophages. In particular, helminths polarize macrophages to an M2 state and induce a metabolic shift towards reliance on oxidative phosphorylation, lipid oxidation and amino acid metabolism. Accumulating data indicate that helminth-induced activation and metabolic reprogramming of macrophages underlie improvement in overall whole-body metabolism, denoted by improved insulin sensitivity, body mass in response to high-fat diet and atherogenic index in mammals. This review aims to highlight the metabolic changes that occur in human and murine-derived macrophages in response to helminth infections and helminth products, with particular interest in schistosomiasis and soil-transmitted helminths.