Development of New, More Sensitive MR-Reporter Genes for Stem Cell Tracking and Gene Therapy Imaging

Letterio Salvatore Politi¹, Sara Pizzi¹, Anna Cozzi², Mario Amendola³, Andrea Falini¹, Luigi Naldini³, Sonia Levi², Alessandra Biffi³, Giuseppe Scotti¹

MR-reporter genes might allow sustained and stable intracellular contrast accumulation for long-term stem cell (SC) tracking studies and gene therapy applications. Since sensitivity of previously described MR-reporter genes, such as intracellular ferritin, is low, we are exploiting potentially stronger reporters in combination with late generation lentivirial vectors. A new mutated form of human ferritin L-chain (mhL-Fer) that aggregates and stores great iron quantities was tested and compared to wild type H and L human ferritin chains and human tyrosinase. The mhL-Fer turned out to be the strongest reporter gene and allowed sustained and sensitive detection of SC also at 3T.