Investigation into the role of DNA damage and repair during influenza infection and inflammation

The DNA in every cell accrues nearly 100,000 lesions daily from both endogenous and exogenous sources. The accumulated damage, e.g. strand breaks and base lesions, can lead to mutations, cell death, and cancer if not repaired efficiently. To protect genome integrity, organisms have evolved multiple DNA repair processes. A deeper comprehension of DNA damage and repair during disease pathogenesis can aid the development of novel therapeutics to reduce the damage and ameliorate the disease. Here, we studied DNA damage and repair in two inflammatory contexts. First, we investigated the role of DNA damage and repair during influenza infection, a common viral respiratory disease with an active inflammatory response. Second, we examined the effects of S-nitrosation, a post-translational modification that is common in inflammatory regions, on repair of alkylation damage. Influenza induces an excessive inflammatory response in the host and a reduction in inflammation reduces morbidity. While inflammation can cause DNA damage and induce DNA repair in other inflammatory contexts, there has been minimal analysis on the existence and function of DNA damage and repair during influenza infection. Utilizing immuno-fluorescent analysis of double strand break markers, we observed an increase in strand breaks both in vitro and in vivo. Influenza infected mice also displayed a significant increase in homologous recombination (HR) gene and protein expression during the recovery phase of infection in multiple virus and mouse backgrounds. Moreover, influenza infected mice deficient in DNA repair proteins AAG, ALKBH2, and ALKBH3, displayed increased morbidity and HR protein expression when compared to wild type. Together, these results raise the possibility of a role for DNA repair and more specifically HR during influenza infection. To study the effects of inflammation on DNA repair protein function, we analyzed the capacity of cells treated with S-nitrosoglutathione (GSNO), a nitrosating agent, to repair alkylation damage. GSNO-exposed cells displayed dysregulation in the activities base excision repair (BER) proteins. Following challenge with an alkylating agent, GSNO-exposed cells had an increase in repair intermediates and reduced viability, suggesting that GSNO exposure inhibits BER completion. The knowledge gained from these studies lays the groundwork for new prevention strategies and novel therapeutics.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Biological Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2017

Author dc:creator

• Parrish, Marcus Curtis

Advisor dc:contributor.advisor

• Bevin P. Engelward.

• Biological Engineering.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/109666

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/109666