Fasciola hepatica
infection is associated with T helper 2/T regulatory immune responses and increased mast cell numbers. The aim of this study was to examine the interaction between F. hepatica tegumental coat
antigen and mast cells in vivo and in vitro. Firstly, BALB/C, C57BL/6 or STAT6(-/-) mice were infected with F. hepatica metacercarie or mice were treated with F. hepatica tegumental coat
antigen and then mast cells numbers in the peritoneal cavity and/or the liver were quantified. Also, the proliferation, chemotaxis, degranulation and
cytokine secretion of mast cells from bone marrow or from peritoneal exudate cells stimulated with F. hepatica tegumental coat
antigen were measured. Finally, we tested whether F. hepatica tegumental coat
antigen inhibits degranulation of mast cells in vivo in a passive cutaneous and systemic
anaphylaxis mouse model. Mast cell numbers increased in the peritoneal cavity and liver of F. hepatica infected mice, and this was mimicked by injection of F. hepatica tegumental coat
antigen in a STAT6(-/-) independent manner. The increase in mast cell number was not the result of F. hepatica tegumental coat
antigen-induced proliferation; rather F. hepatica tegumental coat
antigen indirectly induces mast cell migration by dendritic cell-derived
chemokines. Fasciola hepatica tegumental coat
antigen interactions with mast cells do not drive T helper 2 or T regulatory immune responses. These studies on mast cell and F. hepatica tegumental coat
antigen interaction may help us to understand the function of mast cells in immunity against F. hepatica and the immunomodulatory effect of F. hepatica tegumental coat
antigen on these cells.