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

Abstract

Editorial on the Research Topic "You shall not pass" or "Let`s make a deal" -crosstalk between helminths and the host immune system 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 Frontiers in Cellular and Infection Microbiology frontiersin.org 01