[Dynamic changes in professional and non-professional antigen presenting cells in the spleen from mice infected with Schistosoma japonicum].

ABSTRACT

UNLABELLED OBJECTIVE; To observe the changes in various dendritic cell (DC) subsets, macrophages, basophils, eosinophils and mast cells in mouse spleen before and after Schistosoma japonicum infection induced Th2 response. METHODS: C57BL6 mice were infected with 20 S. japonicum cercariae via abdominal skin. Before infection and at 2, 4, and 6 weeks post-infection, the mice were sacrificed and spleen was removed. The frequencies of non-T, non-B basophils (NTNB), eosinophils, mast cells, subsets of DC and macrophages in the spleen were measured by flow cytometry. RESULTS: At 4 weeks after infection, when Th2 cells started to occur, the proportion of CD11c+CD8+DC and CD11c+CD4+DC in B220CD11c+DC increased from 7.4% and 7.9% before infection to 17.1% and 12.0%, respectively. During the infection, CD11c+CD4-CD8-DC, the majority of B220CD11c+DC, remained on a nearly constant level (70%); the percentage of B220+ CD11c+ DC in NTNB decreased. The macrophages were subdivided into two subsets F4/80+CD11b(int) and F4/80+CD11b(high). The percentage of F4/80+CD11b(int) and F4/80+CD11b(high) in NTNB dropped from 15.4% and 13.7% before infection to 2.7% and 8.6% at 4 weeks post-infection. The proportion of CD11b high macrophages in F4/80+ cells significantly increased from 47.1% before infection to 75.5% at 4 weeks after infection. During S. japonicum infection, eosinophil percentage in the spleen gradually increased, while the frequency of basophils and mast cells in NTNB greatly decreased. CONCLUSION: At the time when Th2 response starts to occur, the frequency of CD11c+CD8+DC and CD11c+CD4+DC in CD11c+ dendritic cells increases. Once Th2 immune response established, the eosinophil frequency increases.