Perveen Nighat, Kishore Uday, Al Aiyan Ahmad, Willingham Arve Lee, Mohteshamuddin Khaja
Department of Biology, College of Science, United Arab Emirates University, Al-Ain, UAE.
Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al-Ain, UAE.
Adv Exp Med Biol. 2025;1476:411-423. doi: 10.1007/978-3-031-85340-1_16.
Innate immunity in invertebrates represents the first line of defense against invading pathogens. The host's response to invading pathogens is a vital physiological reaction across all living organisms, and various defense mechanisms have evolved to preserve cellular integrity, homeostasis, and survival. Invertebrates possess cellular receptors that bind to foreign elements, enabling them to distinguish between self and non-self. In multicellular animals, this function is linked to phagocytes-known by different names like amebocytes, hemocytes, and coelomocytes-in diverse groups of invertebrates. These phagocytes are equipped with pathogen recognition receptors (PRRs) that detect pathogen-associated molecular patterns (PAMPs), which are conserved across various pathogens such as viruses, bacteria, fungi, protozoans, and helminths. Prominent PRRs include Toll-like receptors (TLRs), Nod-like receptors (NLRs), and scavenger receptors. Upon binding to a pathogen, these receptors trigger a cascade of cellular reactions that lead to the production of effector molecules. Cytokines are crucial in coordinating these responses, even in lower invertebrates, ultimately leading to the removal of the pathogen. The key effector molecules include reactive oxygen and nitrogen species, antimicrobial peptides, lectins, fibrinogen-related peptides, leucine-rich repeats (LRRs), and complement-related proteins. Antimicrobial peptides (AMPs) are crucial to invertebrate defense as they can penetrate microbial pathogens membranes, causing cell death and effectively preventing infections. In this chapter, we explore the immune mechanisms of invertebrates, which differ significantly in their modes of action. We aim to understand how these mechanisms function and investigate whether they can be harnessed to benefit agriculture or combat pathogens.
无脊椎动物的先天免疫是抵御入侵病原体的第一道防线。宿主对入侵病原体的反应是所有生物都至关重要的生理反应，并且已经进化出各种防御机制来维持细胞完整性、内环境稳定和生存。无脊椎动物拥有能与外来元素结合的细胞受体，使它们能够区分自我和非自我。在多细胞动物中，这一功能与吞噬细胞相关，在不同类群的无脊椎动物中，吞噬细胞有不同的名称，如变形细胞、血细胞和体腔细胞。这些吞噬细胞配备有病原体识别受体（PRR），可检测病原体相关分子模式（PAMP），这些模式在各种病原体如病毒、细菌、真菌、原生动物和蠕虫中都是保守的。重要的PRR包括Toll样受体（TLR）、Nod样受体（NLR）和清道夫受体。这些受体与病原体结合后，会触发一系列细胞反应，导致效应分子的产生。细胞因子在协调这些反应中至关重要，即使在低等无脊椎动物中也是如此，最终导致病原体的清除。关键的效应分子包括活性氧和氮物质、抗菌肽、凝集素、纤维蛋白原相关肽、富含亮氨酸重复序列（LRR）和补体相关蛋白。抗菌肽（AMP）对无脊椎动物的防御至关重要，因为它们可以穿透微生物病原体的膜，导致细胞死亡并有效预防感染。在本章中，我们将探讨无脊椎动物的免疫机制，它们的作用方式有很大差异。我们旨在了解这些机制如何发挥作用，并研究是否可以利用它们来造福农业或对抗病原体。
