Potential role of toll-like receptor 3 in a murine model of polyinosinic-polycytidylic acid-induced embryo resorption.

OBJECTIVE

To investigate the potential role that toll-like receptor 3 (TLR3) may play in a murine model of polyinosinic-polycytidylic acid (polyIC)-induced embryo resorption.

DESIGN

An animal model-based study on induced embryo resorption.

SETTING

University animal laboratory.

ANIMAL(S): Pathogen-free animals housed under barrier conditions and monitored for health status. Pregnant BALB/c mouse mated by C57BL/6 male was used as a model of allogeneic gestation.

INTERVENTION(S): The administration of polyIC was performed to establish a murine model of induced embryo resorption, with or without TLR3 blocking by multiple injection of mAb against this receptor.

MAIN OUTCOME MEASURE(S): Flow cytometric analysis was performed to detect the percentage of CD45(+)DX5+ and DX5(+)CD69+ cell subsets, with the DX5 antigen used as a common natural killer (NK) cell marker, and CD69 as a marker for activated NK cells, respectively.

RESULT(S): In the allogeneic mating model, BALB/cxC57BL/6, both the CD45(+)DX5+ and DX5(+)CD69+ cell percentages were significantly elevated upon polyIC stimulation at the absence of anti-TLR3 administration but were kept unchanged if the female mice were pretreated with anti-TLR3 monoclonal antibody. Accordingly, the resorption rate of embryos was boosted by polyIC administration, but this effect could be abrogated by pretreatment of anti-TLR3 mAb.

CONCLUSION(S): The engagement of polyIC with TLR3 may be critical to the activation of NK cells infiltrated at the feto-maternal interface, subsequently resulting in an increase in embryo resorption.