An Examination of Th1- / Th2- Type Immune Response to Infection with the Helminth Trichuris muris

Abstract

Two billion people—almost a third of the world’s entire population—are infected with parasitic worms. However, despite its enormous global burden on health and wellbeing, helminth infection receives a disproportionately small amount of research funding and attention. The global campaigns addressing helminth infection focus primarily on distributing anthelminthic drugs to children to completely deworm them. While helminth infection has decidedly negative effects on the host, including malnutrition and iron deficiency, it is irresponsible to simply deworm communities without first understanding the complex role of the pathogen in regular immune functioning. Research has shown that helminths incite a complex combination of both Th1- and Th2-type immune responses in hosts. This study aims to more carefully examine the dynamics of Th1-/Th2- immune response and how it is affected by environment and immune system ability. C57BL/6 and Stat6 knockout mice in either a sterile quarantine facility or a semi-natural facility were infected with 200 eggs of the helminth Trichuris muris. Fecal samples were collected over the course of approximately three weeks and were analyzed for concentrations of calprotectin, a Th1-indicated protein, and mucin 5ac, a Th2- indicated protein. Final mouse worm burdens were collected at the end of the experiment. Results show that final mouse worm burden is significantly correlated with both fecal calprotectin and fecal mucin 5ac. Results also indicate a significant difference in protein concentrations between mice in the sterile quarantine facility and mice in the semi-natural conditions, indicating the importance of recognition in the scientific community of environmental-dependent effects and reduced generalizability of laboratory results. This study also proves the feasibility of examining Th1-/Th2-type immune responses over the course of an infection and offers future experimentation ideas at the Stony Ford Center for Ecological Studies.