Expression of Heat Shock Protein 70 (HSP70) and Astacin Genes of Strongyloides stercoralis as well as HSP70 and HSP17.1 Genes of S. ratti in Adult and Larval Stages of S. stercoralis

Background: Uncovering the roles and characteristics of pathogenesis-related molecules can help us develop novel management methods in parasitology. In this study, we studied the expression levels of Strongyloides stercoralis heat shock protein70 (HSP70) (Sst-hsp-70) and astacin (Sst-ast) as pathogenesis-related genes as well as the expression of S. ratti HSP70 and HSP17.1 (Sra-hsp-70, Sra-hsp-17.1) in the larvae and adult stages of S. stercoralis. Methods: A hyperinfection isolate of S. stercoralis from Gilan Province, northern Iran was cultivated on nutrient agar. After a couple of days, parasites in different stages of life were collected, and total RNA was extracted. The expression levels of astacin and HSP genes were compared by real-time PCR. Results: Statistically higher expression levels of Sst-ast, Sst-hsp-70, and Sra-hsp-70 genes in L3 larvae than in adults were observed. However, the expression level of Sra-hsp-17.1 was non-significantly lower in the larval stage than in adult worms. Conclusion: Higher expression levels of Sst-ast, Sst-hsp-70, and Sra-hsp-70 genes in the larval stages of S. stercoralis suggest the potential role of these enzymes in parasite cutaneous invasion and pathogenesis. However, higher expression of Sra-hsp-17.1 in adult forms is probably involved in resistance and survival mechanisms. The similarity in gene expression between S. stercoralis and S. ratti can provide helpful hints to better understand strongyloidiasis from various perspectives, including pathogenesis, proper diagnosis, and targeted treatment.