Microsporidia infection impacts the host cell's cycle and reduces host cell apoptosis

Area of Science:

• * Parasitology
• * Molecular Biology
• * Apiculture

Background:

• * Microsporidia are obligate intracellular fungal parasites dependent on host cells for survival.
• * Honey bees are globally affected by Nosema apis and Nosema ceranae, which infect ventricular epithelial cells.
• * Previous research on microsporidian host cell manipulation primarily focused on morphological changes.

Purpose of the Study:

• * To investigate the molecular mechanisms of host cell manipulation by Nosema apis and Nosema ceranae.
• * To analyze gene expression changes related to apoptosis and the cell cycle in honey bee cells post-infection.
• * To elucidate parasite-host interaction pathways at the molecular level.

Main Methods:

• * Quantitative gene expression analysis.
• * Histological examination of infected honey bee tissues.
• * Comparative analysis of molecular responses to N. apis and N. ceranae infections.

Main Results:

• * Both N. apis and N. ceranae infections induced significant gene expression changes in apoptosis and cell cycle pathways.
• * Upregulation of "buffy" and BIRC5 genes suggests inhibition of host cell apoptosis by both parasites.
• * Distinct alterations in cell cycle regulation were observed: N. apis upregulated cyclin B1, dacapo, and E2F2, while N. ceranae upregulated cyclin E, both promoting G1/S phase transition.

Conclusions:

• * Microsporidia actively manipulate host cell molecular pathways to facilitate their survival.
• * Inhibition of apoptosis and promotion of cell cycle progression are key strategies employed by Nosema species.
• * This study provides the first molecular insights into Nosema-honey bee interactions, revealing parasite-driven manipulation of host cellular processes.