Comparison of Schistosoma mansoni intestinal and liver eggs

Schistosoma mansoni eggs are critical in the pathology of chronic schistosomiasis. This study investigates the difference between eggs migrating through the intestinal wall, which contribute to disease progression, and those lodged in liver tissue, which do not complete the parasite life cycle. Using transcriptomic methods, we show significant differences in gene expression associated with egg location and developmental stage. In particular, mitochondrial genes and venom allergen-like proteins are up-regulated in intestinal eggs, whereas liver eggs predominantly express immunomodulators and microexon genes. Tissue-specific expression of proteases and inhibitors further highlights these differences. Our findings provide new insights into S. mansoni egg biology and highlight the importance of considering tissue localisation in understanding host-parasite interactions. This approach challenges the historical focus on liver-caught eggs and suggests a more nuanced view of the host immune response and parasite viability.