Host cell manipulation by microsporidia secreted effectors: Insights into intracellular pathogenesis

Microsporidia are prolific producers of effector molecules, encompassing both proteins and nonproteinaceous effectors, such as toxins, small RNAs, and small peptides. These secreted effectors play a pivotal role in the pathogenicity of microsporidia, enabling them to subvert the host's innate immunity and co-opt metabolic pathways to fuel their own growth and proliferation. However, the genomes of microsporidia, despite falling within the size range of bacteria, exhibit significant reductions in both structural and physiological features, thereby affecting the repertoire of secretory effectors to varying extents. This review focuses on recent advances in understanding how microsporidia modulate host cells through the secretion of effectors, highlighting current challenges and proposed solutions in deciphering the complexities of microsporidial secretory effectors.