Extracellular vesicles derived from Spirometra erinaceieuropaei plerocercoids inhibit activation of murine macrophage RAW264.7 cells

Roles of helminth extracellular vesicle-derived let-7 in host-parasite crosstalk

Helminth infections are a major public health problem as they can cause long-term chronic infections in their hosts for which there is no effective vaccine. During the long-term interaction between helminths and their hosts, helminth-derived extracellular vesicles (EVs) can participate in host immunomodulatory processes by secreting bioactive molecules (BMAs). Growing data suggests that microRNAs (miRNAs) in helminth EVs have a significant impact on the host's immune system. The let-7 family is highly conserved among helminth EVs and highly homologous in the host, and its function in host-parasite crosstalk may reflect active selection for compatibility with the host miRNA machinery. In-depth studies targeting this aspect may better elucidate the mechanism of parasite-host interactions. Hence, this review summarizes the current studies on the cross-species involvement of helminth EV-derived let-7 in host immune regulation and discusses the barriers to related research and potential applications of helminth EVs.

Pharmaceutical Potential of Remedial Plants and Helminths for Treating Inflammatory Bowel Disease

Research is increasingly revealing that inflammation significantly contributes to various diseases, particularly inflammatory bowel disease (IBD). IBD is a major medical challenge due to its chronic nature, affecting at least one in a thousand individuals in many Western countries, with rising incidence in developing nations. Historically, indigenous people have used natural products to treat ailments, including IBD. Ethnobotanically guided studies have shown that plant-derived extracts and compounds effectively modulate immune responses and reduce inflammation. Similarly, helminths and their products offer unique mechanisms to modulate host immunity and alleviate inflammatory responses. This review explored the pharmaceutical potential of Aboriginal remedial plants and helminths for treating IBD, emphasizing recent advances in discovering anti-inflammatory small-molecule drug leads. The literature from Scopus, MEDLINE Ovid, PubMed, Google Scholar, and Web of Science was retrieved using keywords such as natural product, small molecule, cytokines, remedial plants, and helminths. This review identified 55 important Aboriginal medicinal plants and 9 helminth species that have been studied for their anti-inflammatory properties using animal models and in vitro cell assays. For example, curcumin, berberine, and triptolide, which have been isolated from plants; and the excretory-secretory products and their protein, which have been collected from helminths, have demonstrated anti-inflammatory activity with lower toxicity and fewer side effects. High-throughput screening, molecular docking, artificial intelligence, and machine learning have been engaged in compound identification, while clustered regularly interspaced short palindromic repeats (CRISPR) gene editing and RNA sequencing have been employed to understand molecular interactions and regulations. While there is potential for pharmaceutical application of Aboriginal medicinal plants and gastrointestinal parasites in treating IBD, there is an urgent need to qualify these plant and helminth therapies through reproducible clinical and mechanistic studies.

Harnessing Bacterial Extracellular Vesicle Immune Effects for Cancer Therapy

There are a growing number of studies linking the composition of the human microbiome to disease states and treatment responses, especially in the context of cancer. This has raised significant interest in developing microbes and microbial products as cancer immunotherapeutics that mimic or recapitulate the beneficial effects of host-microbe interactions. Bacterial extracellular vesicles (bEVs) are nano-sized, membrane-bound particles secreted by essentially all bacteria species and contain a diverse bioactive cargo of the producing cell. They have a fundamental role in facilitating interactions among cells of the same species, different microbial species, and even with multicellular host organisms in the context of colonization (microbiome) and infection. The interaction of bEVs with the immune system has been studied extensively in the context of infection and suggests that bEV effects depend largely on the producing species. They thus provide functional diversity, while also being nonreplicative, having inherent cell-targeting qualities, and potentially overcoming natural barriers. These characteristics make them highly appealing for development as cancer immunotherapeutics. Both natively secreted and engineered bEVs are now being investigated for their application as immunotherapeutics, vaccines, drug delivery vehicles, and combinations of the above, with promising early results. This suggests that both the intrinsic immunomodulatory properties of bEVs and their ability to be modified could be harnessed for the development of next-generation microbe-inspired therapies. Nonetheless, there remain major outstanding questions regarding how the observed preclinical effectiveness will translate from murine models to primates, and humans in particular. Moreover, research into the pharmacology, toxicology, and mass manufacturing of this potential novel therapeutic platform is still at early stages. In this review, we highlight the breadth of bEV interactions with host cells, focusing on immunologic effects as the main mechanism of action of bEVs currently in preclinical development. We review the literature on ongoing efforts to develop natively secreted and engineered bEVs from a variety of bacterial species for cancer therapy and finally discuss efforts to overcome outstanding challenges that remain for clinical translation.

Proteomic differences between extracellular vesicles and extracellular vesicle-depleted excretory/secretory products of barber's pole worm

BACKGROUND

Components of excretory/secretory products (ESPs) of helminths have been proposed as vaccine targets and shown to play a role in modulating host immune responses for decades. Such research interest is further increased by the discovery of extracellular vesicles (EVs) in the ESPs of parasitic worms. Although efforts have been made to reveal the cargos of EVs, little is known about the proteomic differences between EVs and canonical ESPs released by parasitic worms from animals.

METHODS

The total ESPs of Haemonchus contortus (barber's pole worm) were obtained by short-term in vitro culturing of young adult worms, and small EVs were isolated from ESPs using an ultracentrifugation method. Data-dependent acquisition (DDA) label-free Nano-LC-MS/MS was used to quantify the proteomic difference between small EVs and EV-depleted ESPs of H. contortus. Functional annotation and enrichment of the differential proteins were performed regarding cellular components, molecular functions, pathways, and/or biological processes.

RESULTS

A total of 1697 proteins were identified in small EVs and EV-depleted ESPs of H. contortus adult worms, with 706 unique proteins detected in the former and 597 unique proteins in the latter. It was revealed that proteins in small EVs are dominantly cytoplasmic, whereas proteins in EV-depleted ESPs are mainly extracellular; canonical ESPs such as proteases and small GTPases were abundantly detected in small EVs, and SCP/TAP-, DUF-, and GLOBIN domain-containing proteins were mainly found in EV-depleted ESPs. Compared with well-characterised proteins in small EVs, about 50% of the proteins detected in EV-depleted ESPs were poorly characterised.

CONCLUSIONS

There are remarkable differences between small EVs and EV-depleted ESPs of H. contortus in terms of protein composition. Immune modulatory effects caused by nematode ESPs are possibly contributed mainly by the proteins in small EVs.