Mechanisms of Immune Modulation by Fasciola Hepatica: The Impact of Innate Immune Cells on the Developing Adaptive Immune Response
Pp. 51-67 (17)
Sandra M. O’Neill and Sheila Donnelly
Fasciola (F.) hepatica lives for prolonged periods within its host due to its
ability to modulate host immune responses. Unlike other helminths, within hours postinfection
it drives antigen specific Th2/Treg responses. This polarisation of the host
immune response continues throughout all developmental stages within the definitive
host. Central to the parasite’s ability to produce such an immune outcome is the
secretion of a plethora of molecules that interact with innate immune cells impairing
their ability to promote Th1/Th17 responses. This firmly establishes F. hepatica as an
important model to examine the anti-inflammatory properties of helminths. In this
chapter, we specifically examine the communication between the secreted and shed
molecules from F. hepatica and dendritic cells, macrophages and mast cells. In
particular, we aim to highlight the impact that this interaction has on the development of
Th1/Th17 immune responses. This chapter examines the diverse range of F. hepatica
molecules that utilise different immune mechanisms to achieve the same overall
outcome, thus ensuring redundancy in the development of Th2/Treg immune responses
associated with F. hepatica infection.
Fasciola hepatica, Th1, Th2, Treg, dendritic cells, macrophages, mast
cells, IL-4, IL-10, IL-5, excretory-secretory molecules, tegumental antigens,
cathepsin L, peroxredoxin, human defence molecule, sigma Class Glutathione
transferase, immune modulatory molecules.
School of Biotechnology, Faculty of Science and Health, Dublin, Ireland, and the i3 Institute, University of Technology Sydney, Ultimo, New South Wales, Australia.