Editorial: “You shall not pass” or “Let`s make a deal” - crosstalk between helminths and the host immune system

COPYRIGHT © 2023 Bąska, Schabussova and Zawistowska-Deniziak. This is an openaccess article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. TYPE Editorial PUBLISHED 14 July 2023 DOI 10.3389/fcimb.2023.1244429

Parasites are multicellular organisms that infect both humans and animals. They have coevolved with their hosts over millions of years. This co-evolution can be viewed as an "arms race" in which both sides have developed sophisticated attack and defense mechanisms. "Classical" immune system defense mechanisms such as phagocytosis or induced apoptosis are efficient against bacteria and viruses but usually fail to terminate a parasitic worm infection. This inefficiency has forced the development of a higher-level cooperation between immune, nervous, and endocrine systems. Through this network, gastrointestinal helminths can be expelled by increased muscle contractility and enhanced water release to gut, resulting in diarrhea (Baska and Norbury, 2022). In some cases, however, it is more beneficial to allow the infection to persist rather than to develop a strong but harmful immune response. Surprisingly, this phenomenon is not only a necessary disadvantage to prevent immunopathology, but may also be beneficial to the host by alleviating symptoms of allergies and autoimmune diseases. The host-parasite interaction is extremely complicated (Gazzinelli-Guimaraes and Nutman, 2018), and depends on the species and genetic background of both the host (Klementowicz et al., 2012) and the parasite (Baska et al., 2017) and therefore this subject was the focus of this Research Topic.
There is ample evidence that helminth infections may be beneficial for people suffering from allergies or autoimmune diseases. This topic was explored by Hou et al. and Gao et al. In both studies, molecules derived from Schistosoma japonicum were tested for their ability to alleviate the symptoms of colitis or allergic rhinitis in mouse models. Administration of attenuated S. japonicum eggs improved the severity of colitis in mice (Hou et al.), and treatment with a small molecule peptide of S. japonicum, SJMHE1, reduced the clinical symptoms of allergic rhinitis and suppressed the recruitment of inflammatory cells and  Most studies of parasite-induced modulation have been performed with laboratory parasite strains that are likely to have low genetic diversity. Previous studies have confirmed that immune responses can vary depending on the parasite isolate (Baska et al., 2017). Liu et al. showed that different Haemonchus contortus isolates exhibit different patterns in protein expression. Although the authors did not focus on the interaction of specific isolates with host immune responses, their results support the hypothesis that due to differences in protein expression, their effects on host immune responses and metabolism may differ.
The articles published in the Research Topic "You shall not pass or Let`s make a deal -Crosstalk between helminths and the host immune system" examined the interactions of E. granulosus with the host response (Hou et al.), the potential of using antigens from S. japonicum to alleviate symptoms of colitis (Hou et al.) and allergic rhinitis (Gao et al.), and the proteomics of H. contortus (Liu et al.). The contributions shed light on the intricate interactions between parasites and hosts, and we hope that the results will inspire other scientists to explore the role of parasitology in basic and applied research.

Author contributions
PB and IS wrote the MS. AZ-D reviewed manuscript. All authors contributed to the article and approved the submitted version.

Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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