Dynamics of dendritic cells in vaginal mucosa of mice inoculated with Brucella suis.

Twenty-five mice were randomly devided into five groups of five mice each.Mice of four groups were inoculated by intravaginal administration of Brucella vaccine.The iliac lymph nodes(ILNs) were removed pose-treatment 12,24,48,and 72 h,respectively.As a control,the mice in fifth group were intravaginally instillated with phosphate-buffered saline(PBS) and ILNs were harvested.ILNs were processed routinely to obtain paraffin-embedded sections.Polyclonal rabbit anti-S100 antibody was used to detect dendritic cells(DCs) in ILNs.Peripherial blood samples were collected for ELISA assay of IFN-γ.DCs were pulsed with the Brucella vaccine in vitro and stained with Giemsa.It was shown that the numbers and distribution pattern of DCs changed dramatically in ILNs after inoculation with Brucella vaccine.The numbers of DCs in cortex of ILNs increased and concentrated in cluster from 12-48 h,and migrated from the outer cortex into the paracortical zone.The distributing area of DCs enlarged at 72 h.The level of IFN-γ in serum increased,significantly compared with control at 48 h(P0.05) and reached the peak level pose-treatment 72 h with significantly higher than that of control group(P0.01).DCs only captured a small amount of Brucella pose-treatment 4 h in vitro.The numbers of DCs captured Brucella increased constantly and reached the peak level at 12 h.It is concluded that DCs have a powerful capability to capture Brucella.The antigen-loaded DCs in vagina are capable of rapidly migrating to the draining lymph nodes,indicating that DCs in vagianl mucosa is of Brucella antigen presenting cells and initiate immune response characteristized by of release of IFN-γ.