Novel antiinflammatory biologics shaped by parasite-host coevolution

Excretory/secretory antigens from Trichinella spiralis muscle larvae ameliorate HFD-induced non-alcoholic steatohepatitis via driving macrophage anti-inflammatory activity

No approved effective therapy for non-alcoholic steatohepatitis (NASH) is currently available. Trichinella spiralis (T. spiralis) infection and their products have positive impact on several metabolic diseases. Considering, we firstly investigated the effects of the T. spiralis-derived Excretory-Secretory antigens (ESA) on high fat diet (HFD)-induced NASH mouse models. To further elucidate the mechanism of action, HepG2 cells were incubated with palmitic acid (PA) to construct NASH-like cell model, and then the culture medium supernatant collected from ESA-treated macrophages was applied to intervene the cell model in vitro. In NASH mouse models, ESA significantly alleviated hepatic steatosis and hepatic inflammation, as reflected by reducing pro-inflammatory cytokines and inactivating TLR4/MYD88/NF-κB pathway and NLRP3 inflammasome. Meanwhile, the HFD-induced oxidative stress was restored by ESA through lessening the level of MDA, increasing the activity of T-SOD and enhancing Nrf2 signaling-related proteins, including p-Nrf2, NQO1, HO-1, GPX4, and p-AMPK. Notably, ESA preferentially promoted macrophages polarization toward M2 anti-inflammatory phenotype in vivo and vitro. Moreover, in vitro, intervention of PA-treated HepG2 cells with medium supernatant of ESA-treated macrophages attenuated lipid accumulation, inflammation, as well as oxidative stress. In conclusion, T. spiralis-derived ESA may serve as a novel promising candidate for the treatment of NASH via its properties of driving macrophage anti-inflammatory activity.

Conducting Human Biology Research Using Invasive Clinical Samples: Methods, Strengths, and Limitations

Invasive biological samples collected during clinical care represent a valuable yet underutilized source of information about human biology. However, the challenges of working with clinical personnel and the invasive nature of sample collection in biomedical studies can hinder the acquisition of sufficiently large sample sizes for robust statistical analyses. In addition, the incorporation of demographic data from participants is crucial for ensuring the inclusiveness of representative populations, identifying at-risk groups, and addressing healthcare disparities. Drawing on both research experiences and the existing literature, this article provides recommendations for researchers aiming to undertake efficient and impactful projects involving invasive human samples. The suggested strategies include: (1) establishing productive collaborations with clinicians; (2) optimizing sample quality through meticulous collection and handling procedures; and (3) strategically implementing a retrospective model to capitalize on existing invasive sample repositories. When established, cooperative work between clinical health care workers and biological anthropologists can yield insights into human biology that have the potential to improve human health and wellbeing.

Echinococcus multilocularis serpin regulates macrophage polarization and reduces gut dysbiosis in colitis

Helminths serve as principal regulators in modulating host immune responses, and their excretory-secretory proteins are recognized as potential therapeutic agents for inflammatory bowel disease. Nevertheless, our comprehension of the mechanisms underlying immunoregulation remains restricted. This investigation delves into the immunomodulatory role of a secretory protein serpin (Emu-serpin), within the larval stage of Echinococcus multilocularis. Our observations indicate that Emu-serpin effectively alleviates dextran sulfate sodium-induced colitis, yielding a substantial reduction in immunopathology and an augmentation of anti-inflammatory cytokines. Furthermore, this suppressive regulatory effect is concomitant with the reduction of gut microbiota dysbiosis linked to colitis, as evidenced by a marked impediment to the expansion of the pathobiont taxa Enterobacteriaceae. In vivo experiments demonstrate that Emu-serpin facilitates the expansion of M2 phenotype macrophages while concurrently diminishing M1 phenotype macrophages, alongside an elevation in anti-inflammatory cytokine levels. Subsequent in vitro investigations involving RAW264.7 and bone marrow macrophages reveal that Emu-serpin induces a conversion of M2 macrophage populations from a pro-inflammatory to an anti-inflammatory phenotype through direct inhibition. Adoptive transfer experiments reveal the peritoneal macrophages induced by Emu-serpin alleviate colitis and gut microbiota dysbiosis. In summary, these findings propose that Emu-serpin holds the potential to regulate macrophage polarization and maintain gut microbiota homeostasis in colitis, establishing it as a promising candidate for developing helminth therapy for preventing inflammatory diseases.

Hookworm genomics: dusk or dawn?

Hookworms are parasites, closely related to the model nematode Caenorhabditis elegans, that are a major economic and health burden worldwide. Primarily three hookworm species (Necator americanus, Ancylostoma duodenale, and Ancylostoma ceylanicum) infect humans. Another 100 hookworm species from 19 genera infect primates, ruminants, and carnivores. Genetic data exist for only seven of these species. Genome sequences are available from only four of these species in two genera, leaving 96 others (particularly those parasitizing wildlife) without any genomic data. The most recent hookworm genomes were published 5 years ago, leaving the field in a dusk. However, assembling genomes from single hookworms may bring a new dawn. Here we summarize advances, challenges, and opportunities for studying these neglected but important parasitic nematodes.

Immunosuppressive Ability of Trichinella spiralis Adults Can Ameliorate Type 2 Inflammation in a Murine Allergy Model

BACKGROUND

There is an increase in the global incidence of allergies. The hygiene hypothesis and the old friend hypothesis reveal that helminths are associated with the prevalence of allergic diseases. The therapeutic potential of Trichinella spiralis is recognized; however, the stage at which it exerts its immunomodulatory effect is unclear.

METHODS

We evaluated the differentiation of bone marrow-derived macrophages stimulated with T spiralis excretory-secretory products. Based on an ovalbumin-induced murine model, T spiralis was introduced during 3 allergy phases. Cytokine levels and immune cell subsets in the lung, spleen, and peritoneal cavity were assessed.

RESULTS

We found that T spiralis infection reduced lung inflammation, increased anti-inflammatory cytokines, and decreased Th2 cytokines and alarms. Recruitment of eosinophils, CD11b+ dendritic cells, and interstitial macrophages to the lung was significantly suppressed, whereas Treg cells and alternatively activated macrophages increased in T spiralis infection groups vs the ovalbumin group. Notably, when T spiralis was infected prior to ovalbumin challenge, intestinal adults promoted proportions of CD103+ dendritic cells and alveolar macrophages.

CONCLUSIONS

T spiralis strongly suppressed type 2 inflammation, and adults maintained lung immune homeostasis.

Development of Lyophilized Eukaryotic Cell-Free Protein Expression System Based on Leishmania tarentolae

Eukaryotic cell-free protein expression systems enable rapid production of recombinant multidomain proteins in their functional form. A cell-free system based on the rapidly growing protozoan Leishmania tarentolae (LTE) has been extensively used for protein engineering and analysis of protein interaction networks. However, like other eukaryotic cell-free systems, LTE deteriorates at ambient temperatures and requires deep freezing for transport and storage. In this study, we report the development of a lyophilized version of LTE. Use of lyoprotectants such as poly(ethylene glycol) and trehalose during the drying process allows retention of 76% of protein expression activity versus nonlyophilized controls. Lyophilized LTE is capable of withstanding storage at room temperature for over 2 weeks. We demonstrated that upon reconstitution the lyophilized LTE could be used for in vitro expression of active enzymes, analysis of protein-protein interactions by AlphaLISA assay, and functional analysis of protein biosensors. Development of lyophilized LTE lowers the barriers to its distribution and opens the door to its application in remote areas.

The Impact of Intestinal Inflammation on Nematode's Excretory-Secretory Proteome

Parasitic nematodes and their products are promising candidates for therapeutics against inflammatory bowel diseases (IBD). Two species of nematodes, the hookworm Necator americanus and the whipworm Trichuis suis, are being used in clinical treatment trials of IBD referred to as "helminth therapy". Heligmosomoides polygyrus is a well-known model for human hookworm infections. Excretory-secretory (ES) products of H. polygyrus L4 stage that developed during colitis show a different immunomodulatory effect compared to the ES of H. polgyrus from healthy mice. The aim of the study was to evaluate excretory-secretory proteins produced by H. polygyrus L4 stage males and females that developed in the colitic milieu. Mass spectrometry was used to identify proteins. Blast2GO was used to investigate the functions of the discovered proteins. A total of 387 proteins were identified in the ES of H. polygyrus L4 males (HpC males), and 330 proteins were identified in the ES of L4 females that developed in the colitic milieu (HpC females). In contrast, only 200 proteins were identified in the ES of L4 males (Hp males) and 218 in the ES of L4 females (Hp females) that developed in control conditions. Most of the proteins (123) were detected in all groups. Unique proteins identified in the ES of HpC females included annexin, lysozyme-2, apyrase, and galectin. Venom allergen/Ancylostoma-secreted protein-like, transthyretin-like family proteins, and galectins were found in the secretome of HpC males but not in the secretome of control males. These molecules may be responsible for the therapeutic effects of nematodes in DSS-induced colitis.

A target-based discovery from a parasitic helminth as a novel therapeutic approach for autoimmune diseases

BACKGROUND

Regulatory T cells (Tregs) can alleviate the development of autoimmune and inflammatory diseases, thereby proposing their role as a new therapeutic strategy. Parasitic helminths have co-evolved with hosts to generate immunological privilege and immune tolerance through inducing Tregs. Thus, constructing a "Tregs-induction"-based discovery pipeline from parasitic helminth is a promising strategy to control autoimmune and inflammatory diseases.

METHODS

The gel filtration chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC) were used to isolate immunomodulatory components from the egg extracts of Schistosoma japonicum. The extracted peptides were evaluated for their effects on Tregs suppressive functions using flow cytometry, ELISA and T cell suppression assay. Finally, we carried out colitis and psoriasis models to evaluate the function of Tregs induced by helminth-derived peptide in vivo.

FINDINGS

Here, based on target-driven discovery strategy, we successfully identified a small 3 kDa peptide (SjDX5-53) from egg extracts of schistosome, which promoted both human and murine Tregs production. SjDX5-53 presented immunosuppressive function by arresting dendritic cells (DCs) at an immature state and augmenting the proportion and suppressive capacity of Tregs. In mouse models, SjDX5-53 protected mice against autoimmune-related colitis and psoriasis through inducing Tregs and inhibiting inflammatory T-helper (Th) 1 and Th17 responses.

INTERPRETATION

SjDX5-53 exhibited the promising therapeutic effects in alleviating the phenotype of immune-related colitis and psoriasis. This study displayed a screening and validation pipeline of the inducer of Tregs from helminth eggs, highlighting the discovery of new biologics inspired by co-evolution of hosts and their parasites.

FUNDING

This study was supported by the Natural Science Foundation of China (82272368) and Natural Science Foundation of Jiangsu Province (BK20211586).

Excretory/Secretory Proteome of Females and Males of the Hookworm Ancylostoma ceylanicum

The dynamic host-parasite mechanisms underlying hookworm infection establishment and maintenance in mammalian hosts remain poorly understood but are primarily mediated by hookworm's excretory/secretory products (ESPs), which have a wide spectrum of biological functions. We used ultra-high performance mass spectrometry to comprehensively profile and compare female and male ESPs from the zoonotic human hookworm Ancylostoma ceylanicum, which is a natural parasite of dogs, cats, and humans. We improved the genome annotation, decreasing the number of protein-coding genes by 49% while improving completeness from 92 to 96%. Compared to the previous genome annotation, we detected 11% and 10% more spectra in female and male ESPs, respectively, using this improved version, identifying a total of 795 ESPs (70% in both sexes, with the remaining sex-specific). Using functional databases (KEGG, GO and Interpro), common and sex-specific enriched functions were identified. Comparisons with the exclusively human-infective hookworm Necator americanus identified species-specific and conserved ESPs. This is the first study identifying ESPs from female and male A. ceylanicum. The findings provide a deeper understanding of hookworm protein functions that assure long-term host survival and facilitate future engineering of transgenic hookworms and analysis of regulatory elements mediating the high-level expression of ESPs. Furthermore, the findings expand the list of potential vaccine and diagnostic targets and identify biologics that can be explored for anti-inflammatory potential.