Two-photon microscopy investigation of brain dendritic cells in inflamed brain

Human African trypanosomiasis, also known as sleeping sickness, is a severe disease caused by the parasite Trypanosoma brucei (T.b.), in which systemic infection evolves into meningoencephalitis1. One of the most effective strategies adopted by several parasites to attack the host immune system is to interfere with dendritic cells (DCs)2, which play a key role of immune surveillance. In African trypanosomiasis, DCs have been analyzed in peripheral organs3,4 but have not been hitherto examined in the brain. We recently demonstrated that thy1GFP-M transgenic mice represent a novel tool for the study of brain DCs because they express green fluorescent protein (GFP) not only in neurons but also in DCs5. Here, we investigated in vivo, by two-photon microscopy, DCs and their interaction with T.b. in infected thy1GFP-M mice at different time points during the meningoencephalitic stage of the disease.