How does the immune system of aquatic organisms like fish adapt to their unique environment? The latest research from Huazhong Agricultural University provides interesting insights into this issue. It focuses on an immune system sensor called Toll-like receptor 7 (TLR7), and has discovered significant evolutionary adaptability in fish. Unlike their land-based peers, these aquatic animals have a version of TLR7 that can detect not only one, but also two types of genetic material from the virus. This is an alert system for the threat of the virus, illuminating the complexity of life in the water and opening the door to understand how immune responses develop between different species.
Fish and similar organisms were found in this pioneering study led by Professor Jiang Su, including Dr. Rui Jiang, Dr. Wenao Zhu, Dr. Wenao Liao and Dr. Chunrong Yang from Huazhong Agricultural University. Their research, published in the journal Iscience, reveals that fish have a unique version of TLR7. This receptor can detect single- and double-stranded genetic material from the virus, thus playing a crucial role in triggering defense against viral and bacterial infections.
Lead researcher Professor Jianguo Su emphasized the importance of TLR7 in their study: “TLR7 is crucial for detecting single-stranded genetic material of the virus and starting an immune response. Surprisingly, we found that in fish, TLR7 also responds to double-stranded genetic material. However, how TLR7 manages to identify such double-stranded material remains a mystery. “This insight emphasizes the novelty of their research, exploring the mechanisms of immune response in aquatic forms Unknown aspects.
This study uses innovative approaches to study these mechanisms. They first examined the receptors of a fish called teleost. By conducting experiments, the team showed that both single-stranded and double-stranded genetic materials could bind to CITLR7, triggering an immune response. This finding is important because it shows that CITLR7 can recognize and respond to a wider range of viral signals than previously known.
Professor Su further elucidated their findings: “Our study shows that CITLR7 can detect single- and double-stranded genetic material, thereby triggering an immune response. This suggests that CITLR7 has antiviral function.” This simple and effective experiment is for the receptor The dual role provides certain evidence.
The team studied specific regions in CITLR7 that bind to double-stranded genetic material. Through advanced modeling and subsequent mutation analysis, they identified two key sites L29 and L811, which are crucial for the identification of double-stranded genetic material. Professor SU explained this: “CITLR7-L29 and CITLR7-L811 are crucial for binding to double-stranded genetic material. CITLR7 detects viral genetic material, triggering antiviral defenses, thereby protecting cells from viral infection.” This finding is crucial to understanding the precise interaction of CITLR7 with different types of genetic material, a key step in revealing the immune response in fish.
In exploring evolution, the team compared TLR7 from a variety of vertebrates, including fish and taller tetrapods, to understand the evolutionary development of the receptor. Their findings suggest that the ability to bind double-stranded genetic material is unique to bidermoids and is not present in tetrapod vertebrates. This finding suggests an evolutionary adaptability in which TLR7 senses the ability of double-stranded genetic material developed in low vertebrates and is lost in higher vertebrates.
This study not only enhances our understanding of the immune system in non-tetrapod vertebrates, but also opens new avenues to explore the evolutionary complexity of the immune response mechanisms in different species. Further research is needed to further explore the protein modification and regulatory mechanisms of TLR7, which may have important implications for the fields of immunology and evolutionary biology.
In summary, research conducted by Professor Jiang Guasu and his team at Huazong Agricultural University illuminates key aspects of the immune system of non-tetrapod vertebrates. It reveals the unique ability of PISCIForme TLR7 to detect single- and double-stranded genetic material from viruses. This finding has profound implications for our understanding of the evolution and function of the immune system in aquatic vertebrates.
Journal Reference
Rui Jiang et al. “TLR7 is newly functionalized to sense dsRNA and trigger antiviral and antibacterial immunity in non-tetrapod vertebrates.” Iscience, 2023. doi: https://doi.org/10.1016/j.isci.2023.108315
About the Author
Jianguo suprofessor of Fisheries College of China Gas Agricultural University. His research topic is ejaculation immunology. He engages in antiviral and antibacterial mechanisms in fish, oral vaccines and biological agents. He focuses on Toll-like receptor family, Rig-I-like receptor family, cytokines and novel antimicrobial peptides in grass carp. He is a member of the Executive Committee of the Asian Association for Development and Comparative Immunology, the Professional Committee on Aquatic Animal Immunology, the Chinese Fisheries Society, the Professional Fish Diseases Committee, and the Chinese Fisheries Society. Comparative Immunology Report, he is the editorial board of developmental and comparative immunology. His publications include Cellular and Molecular Immunology, Science Chinese Life Sciences, EMBO Report, Journal of Immunology, Journal of Virology, Journal of Biochemistry, Aquaculture Review, ISCIENCE, ISCIENCE, etc.
