Norah Judge
Pronouns: (she/her)
Research Mentor(s): Mary O’Riordan
Research Mentor School/College/Department: Microbiology & Immunology / Medicine
Program: UROP
Session: Session 5 (2:40pm – 3:30pm)
Authors:
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA), is a gram-negative bacteria and opportunistic pathogen that is estimated to be the cause of at least 100,000 infection-associated hospitalizations a year. MRSA infection triggers the production of a class of proinflammatory cytokines called Type 1 interferons (T1 IFNs) in macrophages, which are a critical component of innate immunity during bacterial infection. Cytosolic DNA sensing by immune receptor cyclic G-AMP synthase (cGAS) and is critical for IFN production. While bacterial or mitochondrial DNA (mtDNA) could activate T1 IFN production during MRSA infection, the relative contributions of each type are poorly understood. We hypothesize that mtDNA is the major activator of the cGAS-STING pathway to produce T1 IFN during MRSA infection. To test this hypothesis, we have generated bone marrow-derived macrophages (BMDMs) from mice with the gene-encoding Mitochondrial Transcription Factor A (TFAM) floxed. This allows for inducible ablation of TFAM transcription through the expression of CRE recombinase by lentiviral transduction, which will lead to the depletion of mitochondrial DNA. We will validate this cell line by measuring TFAM depletion at the protein level by Western blot and then measure mitochondrial DNA depletion by qPCR. We will then infect these BMDM with MRSA and measure the amount of IFN-ß present in TFAM knockout compared to control cells through an ELISA (enzyme-linked immunosorbent assay). After testing if mitochondrial DNA is mediating cGAS activation this will contribute to our understanding of host innate immunity during MRSA infection.
