Proteome analysis of lymphocytes after infection and transformation by the oncogenic Mareks Disease Virus.

• Applicants: Dr. Axel Karger; Professor Benedikt Bertold Kaufer, Ph.D.
• Subject Area: Veterinary Medical Science
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 258963904

Mareks disease virus (MDV) is a highly oncogenic alphaherpesvirus that infects chickens and causes high economic losses in poultry industry. In vivo, the virus infects B- and T-cells, which are the main targets for lytic replication and latency, respectively. In addition, MDV is able to transform CD4+ T-cells in susceptible chickens, resulting in deadly lymphomas. Despite many years of research, the effect of MDV and its gene productson the protein expression profile of infected lymphocytes remains unknown. This is mainly due to the short lifespan of T- and B-cells in culture and the low quantity of infected cells in thymus, spleen and bursa of Fabricius which precluded proteome studies of cells relevant to infection in vivo. We recently established cell culture conditions that not only allow prolonged cultivation, but also efficient infection of B- and T-cells in vitro. This system will for the first time provide very pure preparations of infected natural target cells of MDV, a prerequisite for efficient quantitative proteome analysis. In addition, preliminary studies using imaging mass spectrometry (IMS) not only showed that MDV-induced tumors possess highly characteristic mass signatures distinguishing them from surrounding tissue, but also revealed a certain heterogeneity of the tumor tissue itself. Based on these findings and previous publications, we hypothesize that (1) MDV infection induces changes in the T-cell proteome that result in transformation, (2) the viral oncogenes Meq and vTR modulate the T-cell proteome, (3) distinct protein expression profiles reflect different stages of transformation within MDV-induced lymphomas. We will be able to test these hypotheses by combination of our new cultivation/infection system with proteome analysis based on quantitative mass spectrometry. Three specific aims will be addressed: 1) To determine the changes in protein expression profiles of MDV infected B- and T-cells. 2) To characterize the function of the viral oncogenes Meq and vTR in the transformation of T-cells using MDV knockout mutants. 3) To identify protein biomarkers that characterize transformed T-cells in the blood and solid tumors in vivo.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Jens Peter Teifke