Experimental Murine Fascioliasis Derives Early Immune Suppression with Increased Levels of TGF-β and IL-4

Abstract

In fascioliasis, T-helper 2 (Th2) responses predominate, while little is known regarding early immune phenomenon. We herein analyzed early immunophenotype changes of BALB/c, C57BL/6, and C3H/He mice experimentally infected with 5 Fasciola hepatica metacercariae. A remarkable expansion of CD19+ B cells was observed as early as week 1 post-infection while CD4+/CD8+ T cells were down-regulated. Accumulation of Mac1+ cells with time after infection correlated well with splenomegaly of all mice strains tested. The expression of tumor necrosis factor (TNF)-α mRNA in splenocytes significantly decreased while that of IL-4 up-regulated. IL-1β expression was down-modulated in BALB/c and C57BL/6 mice, but not in C3H/He. Serum levels of transforming growth factor (TGF)-β were considerably elevated in all mice during 3 weeks of infection period. These collective results suggest that experimental murine fascioliasis might derive immune suppression with elevated levels of TGF-β and IL-4 during the early stages of infection.

Immunization of Goats with Recombinant Protein 14-3-3 Isoform 2(rHcftt-2) Induced Moderate Protection against Haemonchus contortus Challenge

“…TGF-β is secreted by regulatory T(Treg) cells, down-regulating the immune system after activation in response to allergens and pathogens [39]. In a previous study, mice serum levels of TGF-β were found to be increased after infection of Fasciola hepatica [40]. In this study, the concentrations of serum IL-4 and TGF-β in the immunized group and the infection group were both increased after L3 challenge, the concentrations in the nonimmunized and uninfected group (group 3) were still lower even when they were injected with adjuvant.…”

Fasciola and fasciolosis in ruminants in Europe: Identifying research needs

“…The kinetics of B‐cells in both infected and vaccinated animals would suggest that they play a role in providing protection. Chung, Bae, Yun, Yang, and Kong () noted an accumulation of splenic CD19 + B‐cells post‐infection in mice. Zafra et al.…”

Characterization of dendritic cells and follicular dendritic cells in the hepatic lymph nodes and liver of sheep experimentally infected with Fasciola hepatica

“…They play a crucial role in B-cell activation and have the unique capacity to bind and retain native antigen in B-cell follicles for long periods of time [13,14]. In previous papers, it has been reported that F. hepatica is able to downregulate the Th1 immune response and upregulate the Th2 response at early stages of infection in sheep [15] and mice [16], as well as in chronic stages in cattle [17]. This imbalance towards a Th2 immune profile is mediated through regulatory cytokines and cells, such as DC, that modulate and/or suppress inflammatory responses.…”