TLR7 Modulated T Cell Response in the Mesenteric Lymph Node of Schistosoma japonicum-Infected C57BL6 Mice

Abstract EN

Toll-like receptors (TLRs) play an important role in regulating immune responses during pathogen infection.

However, roles of TLRs on T cells reside in the mesenteric lymph node (MLN) were not be fully elucidated in the course of S.

japonicum infection.

In this study, T lymphocytes from the mesenteric lymph node (MLN) of S.

japonicum-infected mice were isolated and the expression and roles of TLR2, TLR3, TLR4, and TLR7 on both CD4+ and CD8+ T cells were compared.

We found that the expression of TLR7 was increased in the MLN cells of S.

japonicum-infected mice, particularly in CD4+ and CD8+ T cells (P<0.05).

R848, a TLR7 agonist, could enhance the production of IFN-γ from MLN T cells of infected mice (P<0.05), especially in CD8+ T cells (P<0.01).

In TLR7 gene knockedout (KO) mice, the S.

japonicum infection caused a significant decrease (P<0.05) of the expression of CD25 and CD69, as well as the production of IFN-γ and IL-4 inducted by PMA plus ionomycin on both CD4+ and CD8+ T cells.

Furthermore, the decreased level of IFN-γ and IL-4 in the supernatants of SEA- or SWA-stimulated mesenteric lymphocytes was detected (P<0.05).

Our results indicated that S.

japonicum infection could induce the TLR7 expression on T cells in the MLN of C57BL/6 mice, and TLR7 mediates T cell response in the early phase of infection.