Identification and characterization of L. major T cell epitopes based on quantitative proteomics

• Applicants: Professorin Dr. Ruth Esther von Stebut-Borschitz; Professor Dr. Stefan Tenzer
• Subject Area: Immunology
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 214563342

Leishmaniasis is a disease observed after inoculation of a protozoan parasite into the skin inducing symptoms ranging from local, self-limiting lesions to life-threatening visceralisation. Protective immunity against Leishmania is mediated by antigen specific CD8+ and CD4+ T cells which are primed by dendritic cells infected with the amastigote life form. As currently no vaccine exists, identification of protective T cell epitopes is essential, but so far only two CD4 epitopes have been characterized. Therefore, we aim to identify and characterize potential protective T cell epitopes derived from Leishmania major. Towards this purpose, we will partition the proteome of L. major promastigote and amastigote life forms by chromatographic and ultracentrifugation techniques. Using label-free quantitative mass spectrometry, we will identify abundant and/or stage-specific proteins constituting potential sources for T cell epitopes. We will then select epitope candidates applying in silico predictions for MHC binding affinity or by peptide library screening. Candidates will then be assayed for immunoreactivity both in vitro (binding affinity to MHC class I and II, induction of cytokine release and proliferation of T cells), and in vivo (immunizations) followed by detailed analyses of immunodominance, mechanisms of antigen uptake, processing of parasite life form-specific epitopes, and potential immune evasion mechanisms.

• DFG Programme: Research Grants