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Wang J, Hu H, Pang S, Yin X, Cao B, Huang J, Xu X, Weng Q, Hu Q. Destruxin A inhibits the hemocytin-mediated hemolymph immunity of host insects to facilitate Metarhizium infection. Cell Rep 2024; 43:113686. [PMID: 38219149 DOI: 10.1016/j.celrep.2024.113686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/07/2023] [Accepted: 01/02/2024] [Indexed: 01/16/2024] Open
Abstract
Insects have an effective innate immune system to protect themselves against fungal invasion. Metarhizium employs a toxin-based strategy using a nonribosomal peptide called destruxin A (DA) to counteract the host immune response. However, the mechanism by which DA inhibits insect immunity is still unclear. Here, we identified 48 DA-binding proteins in silkworm hemolymph, with the binding affinity (KD) ranging from 2 to 420 μM. Among these proteins, hemocytin, an important immune factor, was determined to be the strongest DA-binding protein. DA binds to hemocytin and regulates its conformation in a multisite manner. Furthermore, DA exerts a significant inhibitory effect on hemocytin-mediated hemocyte aggregation. By disrupting the interaction between hemocytin, actin A3, and gelsolin, DA prevents the transformation of granules into vesicles in hemocytes. These vesicles are responsible for storing, maturing, and exocytosing hemocytin. Therefore, hemocytin secretion is reduced, and the formation of structures that promote aggregation in outer hemocytes is inhibited.
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Affiliation(s)
- Jingjing Wang
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China; College of Horticulture, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Hongwang Hu
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Suyun Pang
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Xuyu Yin
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Bihao Cao
- College of Horticulture, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Jilei Huang
- Instrumental Analytical and Research Center, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Xiaoli Xu
- Instrumental Analytical and Research Center, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Qunfang Weng
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Qiongbo Hu
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China.
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Hu H, Hu Q, Weng Q, Wang J. Hemocytin, the special aggregation factor connecting insect hemolymph immunity, a potential target of insecticidal immunosuppresant. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 198:105704. [PMID: 38225099 DOI: 10.1016/j.pestbp.2023.105704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 01/17/2024]
Abstract
Insects possess an effective innate immunity that enables them to adapt to their intricate living environment and fend off various pathogens (or parasites). This innate immunity comprises both humoral and cellular immunity, which synergistically orchestrate immune responses. Hemocytin, a lectin with a distinctive structure, plays a crucial role in insect hemolymph immunity. Hemocytin is involved in the early immune response, facilitating processes such as coagulation, nodulation, and encapsulation in the hemolymph. It prevents hemolymph overflow and microbial pathogens invasion resulting from epidermal damage, and also aids in the recognition and elimination of invaders. However, the research on hemocytin is still limited. Our previous findings demonstrated that destruxin A effectively inhibits insect hemolymph immunity by interacting with hemocytin, suggesting that hemocytin could be a potential target for insecticides development. Therefore, it is crucial to gain a deeper understanding of hemocytin. This review integrates recent advancements in the study of the structure and function of insect hemocytin and also explores the potential of hemocytin as a target for insecticides. This review aims to enhance our comprehension of insect innate immunity and provide innovative ideas for the development of environmentally friendly pesticides.
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Affiliation(s)
- Hongwang Hu
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Qiongbo Hu
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Qunfang Weng
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Jingjing Wang
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
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