Parasite

Parasites are highly adapted organisms that depend on host-derived resources for survival, growth, and transmission, making host-parasite interactions a central biological process in infectious disease biology[1]. Mechanistically, successful parasitism relies on the ability of parasites to invade host tissues, acquire nutrients, persist within host environments, and evade or manipulate immune defenses that would otherwise eliminate infection[2][3]. Immune evasion represents a key pathway underlying parasite persistence, and diverse parasites employ molecular strategies such as antigenic variation, immune modulation, and interference with host signaling pathways to maintain long-term survival within hosts[2][4]. These processes not only facilitate infection but also influence parasite transmission, virulence, and disease progression across a wide range of human and animal diseases[1][3]. In disease models, the dynamic interaction between parasite adaptation and host immunity has provided important experimental systems for investigating infection biology, immune regulation, and evolutionary coadaptation[5][6]. Host-parasite relationships further drive reciprocal selective pressures that shape genetic diversity and biological traits in both organisms, making coevolution a fundamental component of parasite biology[5]. Compared with related pathogenic microorganisms that primarily rely on rapid replication, many parasites establish prolonged host associations through sophisticated immune-evasion mechanisms and complex life-cycle strategies involving one or multiple hosts[2][7]. For experimental applications, investigations of parasite invasion, persistence, and immune-subversion pathways continue to support the identification of therapeutic targets and the development of improved antiparasitic intervention strategies[3][4].