The Secretome of Adult Murine Hookworms Is Shaped by Host Expression of STAT6

Co-evolutionary adaptation of hookworms with their mammalian hosts has been selected for immunoregulatory excretory/secretory (E/S) products. However, it is not known whether, or if so, how host immunological status impacts the secreted profile of hematophagous adult worms. This study interrogated the impact of host Signal transducer and activator of transcription 6 (STAT6) expression during the experimental evolution of hookworms through the sequential passage of the life cycle in either STAT6 deficient or WT C57BL/6 mice. Proteomic analysis of E/S products by LC-MS showed increased abundance of 15 proteins, including myosin-3, related to muscle function, and aconitate hydratase, related to iron homeostasis. However, most E/S proteins (174 of 337 unique identities) were decreased, including those in the Ancylostoma-secreted protein (ASP) category, and metallopeptidases. Several identified proteins are established immune-modulators such as fatty acid-binding protein homologue, cystatin, and acetylcholinesterase. Enrichment analysis of InterPro functional categories showed down-regulation of Cysteine-rich secretory proteins, Antigen 5, and Pathogenesis-related 1 proteins (CAP), Astacin-like metallopeptidase, Glycoside hydrolase, and Transthyretin-like protein groups in STAT6 KO-adapted worms. Taken together, these data indicate that in an environment lacking Type 2 immunity, hookworms alter their secretome by reducing immune evasion proteins- and increasing locomotor- and feeding-associated proteins.