African Sleeping Sickness (humans) and Nagana (cattle) is induced by infection with extracellular hemoprotozoan parasties, African trypanosomes. These single-cell parasites, transmitted through tsetse fly salivary gland reservoirs, survive in the bloodstream of the mammalian host and, without treatment, can be fatal. There are 36 African countries inhabited by the tsetse fly, which puts 55 million humans and 30% of African cattle at risk of infection. This project examines the splenic proteome profiles of resistant and susceptible mice to T. congolense at various time points to identify proteins involved in the immune response using 2D SDS-PAGE and mass spectrometry.