Characterizing the role of cancer-associated U2AF mutations in immune dysregulation

PROJECT SUMMARY This project aims to define the role of cancer-associated U2AF mutations in immune dysregulation. Splicing, the process by which intronic sequences are removed from mRNA precursors, is coordinated by machinery called the spliceosome. Mutations in components of the spliceosome and associated proteins have been linked to a wide range of pathologies, but are particularly prevalent in myeloid neoplasms, where they have been identified as drivers of abnormal hematopoiesis and of cancer progression. Several of these mutations occur in U2 Small Nuclear RNA Auxiliary Factor 1 and 2 (U2AF1 and U2AF2), which together play a key role in intron recognition. U2AF1 is one of the most commonly mutated splicing factors in the context of cancer, whereas mutations in U2AF2 are less common, but have been associated with more aggressive disease. Hyperinflammation and susceptibility to infection are also hallmarks of blood cancers. Notably, the risk of severe sepsis among those with hematological malignancies is 15 times higher than the general population. Under the current paradigm, dysregulated inflammatory immune pathways are linked to pathogenesis of hematological malignancies, but the mechanistic connection between mutations in splicing factors and dysregulated immune responses is poorly understood. Based on my preliminary data, I hypothesize that mutations in the U2AF heterodimer contribute to hyperinflammation through changes in splicing of immune transcripts. My proposal will characterize how cancer-associated mutations in U2AF1 and 2 lead to dysregulation of the innate immune response in ex vivo and in vivo models of sepsis. In Aim 1, I will identify and compare the consequences of disease-relevant mutations in U2AF1 and U2AF2 on the macrophage inflammatory response to lipopolysaccharide. In Aim 2, I will define how U2AF mutations impact inflammatory outcomes to sepsis in a mouse model. Training in long-read RNA-seq, CLIP-seq, and a variety of other molecular biology techniques will not only ensure the success of this proposal, but will also provide me with the skills necessary to one day lead a research program focused on understanding how the dysregulation of RNA processing contributes to human disease.