Revisiting the Schistosoma japonicum life cycle transcriptome for new insights into lung schistosomula development

Application of microphysiological systems to unravel the mechanisms of schistosomiasis egg extravasation

Despite decades of control efforts, the prevalence of schistosomiasis remains high in many endemic regions, posing significant challenges to global health. One of the key factors contributing to the persistence of the disease is the complex life cycle of the Schistosoma parasite, the causative agent, which involves multiple stages of development and intricate interactions with its mammalian hosts and snails. Among the various stages of the parasite lifecycle, the deposition of eggs and their migration through host tissues is significant, as they initiate the onset of the disease pathology by inducing inflammatory reactions and tissue damage. However, our understanding of the mechanisms underlying Schistosoma egg extravasation remains limited, hindering efforts to develop effective interventions. Microphysiological systems, particularly organ-on-a-chip systems, offer a promising approach to study this phenomenon in a controlled experimental setting because they allow the replication of physiological microenvironments in vitro. This review provides an overview of schistosomiasis, introduces the concept of organ-on-a-chip technology, and discusses its potential applications in the field of schistosomiasis research.

The mRNA Vaccine Technology Era and the Future Control of Parasitic Infections

Despite intensive long-term efforts, with very few exceptions, the development of effective vaccines against parasitic infections has presented considerable challenges, given the complexity of parasite life cycles, the interplay between parasites and their hosts, and their capacity to escape the host immune system and to regulate host immune responses. For many parasitic diseases, conventional vaccine platforms have generally proven ill suited, considering the complex manufacturing processes involved and the costs they incur, the inability to posttranslationally modify cloned target antigens, and the absence of long-lasting protective immunity induced by these antigens. An effective antiparasite vaccine platform is required to assess the effectiveness of novel vaccine candidates at high throughput. By exploiting the approach that has recently been used successfully to produce highly protective COVID mRNA vaccines, we anticipate a new wave of research to advance the use of mRNA vaccines to prevent parasitic infections in the near future. This article considers the characteristics that are required to develop a potent antiparasite vaccine and provides a conceptual foundation to promote the development of parasite mRNA-based vaccines. We review the recent advances and challenges encountered in developing antiparasite vaccines and evaluate the potential of developing mRNA vaccines against parasites, including those causing diseases such as malaria and schistosomiasis, against which vaccines are currently suboptimal or not yet available.

Glyceraldehyde-3-phosphate dehydrogenase affects the growth of Schistosoma japonicum schistosomula

This study was conducted to evaluate the effect of glyceraldehyde-3-phosphate dehydrogenase from Schistosoma japonicum (SjGAPDH) on the growth of schistosomula. Quantitative reverse transcription PCR and immunohistochemical analysis were performed to analyze the mRNA levels and immune localization of SjGAPDH. RNA interference experiments were conducted to further examine the role of SjGAPDH in the schistosomula growth of S. japonicum. The results demonstrated that SjGAPDH mRNA was expressed during all stages of S. japonicum development, with its expression gradually increasing over time. SjGAPDH was mainly distributed on the surface and in some parenchymal cells of S. japonicum. Double-stranded RNA-mediated GAPDH knockdown reduced SjGAPDH expression by approximately 59%. Light microscopic observations revealed that the size, length, width, volume, and area of schistosomula in the SjGAPDH interference group were significantly lower than those in the enhanced green fluorescent protein control group. These findings indicate that SjGAPDH may affect the growth of S. japonicum schistosomula and could be a useful target for treating schistosomiasis.

Involvement of the fatty acid-binding protein in the growth of Schistosoma japonicum schistosomula

This study aimed to explore the effect and mechanism underlying the role of the Schistosoma japonicum antigen of fatty acid-binding protein (SjFABP) on the growth of the schistosomula. SjFABP levels were evaluated by quantitative real-time polymerase chain reaction of samples of mice infected with S. japonicum; SjFABP was expressed and its levels gradually increased during all stages of S. japonicum schistosomula, including on 3, 10, 14, and 21 days of the growth process. Immunohistochemistry results demonstrated that SjFABP was distributed in the parenchyma, especially in the digestive tract of the S. japonicum schistosomula. RNA interference resulted in more than 60% knockdown of SjFABP leading to a reduction in length, volume, width, and area of the schistosomula as compared to control samples, as determined by light microscopy. Terminal deoxynucleotidyl transferase dUTP nick-end labeling detection further suggested that SjFABP knockdown resulted in increased apoptosis of schistosomes. Taken together, these results suggest that SjFABP may be related to the growth and survival of S. japonicum schistosomula, thereby representing a potential target for the treatment of schistosomiasis.

The Search for a Schistosomiasis Vaccine: Australia's Contribution

Schistosomiasis, a neglected tropical disease caused by parasitic flatworms of the genus Schistosoma, results in considerable human morbidity in sub-Saharan Africa, in particular, but also parts of the Middle East, South America, and Southeast Asia. The anti-schistosome drug praziquantel is efficacious and safe against the adult parasites of all Schistosoma species infecting humans; however, it does not prevent reinfection and the development of drug resistance is a constant concern. The need to develop an effective vaccine is of great importance if the health of many in the developing world is to be improved. Indeed, vaccination, in combination with other public health measures, can provide an invaluable tool to achieve lasting control, leading to schistosomiasis elimination. Australia has played a leading role in schistosomiasis vaccine research over many years and this review presents an overview of some of the significant contributions made by Australian scientists in this important area.