Pathogenic Microbiology Commons^™

Immunomodulatory Effects Of Resolvin D2 In A Model Of Infection, Prem Yugandhar Kadiyam Sundarasivarao

Graduate School of Biomedical Sciences Theses and Dissertations

Dysregulated hyperinflammatory host immune response to underlying bacterial infections is a characteristic of sepsis. In sepsis, bacteria often trigger abnormal hyperinflammatory responses which can cause multiple organ failure and if sustained can lead to an immunosuppressive phase where the host is susceptible to secondary infections caused by opportunistic bacteria like Pseudomonas aeruginosa (P. aeruginosa). In our studies, we used a 2-hit model of cecal ligation and puncture (CLP) followed by P. aeruginosa secondary lung infection to investigate cellular and molecular mechanisms in the beneficial action of resolvin D2 (RvD2). Resolvins of the D-series are a group of fatty acids known …

The Effects Of Specialized Pro-Resolving Mediator Lipoxin A4 On Pseudomonas Aeruginosa Biofilms And Interactions With Monocytes, Julianne M. Thornton

Graduate School of Biomedical Sciences Theses and Dissertations

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen known as a major cause of hospital-acquired secondary infections, commonly causing chronic respiratory infections in immunocompromised individuals, especially those with cystic fibrosis, and often found in wound infections. P. aeruginosa uses the quorum sensing pathway to readily form protective biofilms, which reduce the efficacy of antibiotics and access by host immune cells to eradicate the pathogen. Specialized pro-resolving mediators (SPMs) are lipids endogenously produced by the host immune response to infection to aid in infection resolution. One SPM, Lipoxin A4 (LxA4), has been shown to be a robust quorum sensing inhibitor.

The …

The Effects Of Lipoxin A4 (Lxa4) On Neutrophil Biology In Sepsis, Benedict Wu

Graduate School of Biomedical Sciences Theses and Dissertations

During sepsis, neutrophils are inappropriately activated and have prolonged lifespans, thus becoming dysfunctional. Excessive neutrophil activation can lead to tissue injury while neutrophil dysfunction can lead to decreased free radical production and reduced phagocytosis, preventing the host from clearing preexisting infections. Lipoxin A4 (LXA4) is a specialized pro-resolution mediator which reduces neutrophil migration and expression of proinflammatory mediators. Intact neutrophil functions are critical for the host to efficiently clear invading pathogens. The effects of LXA4 on neutrophil function in sepsis have not been established. Using the cecal ligation and puncture (CLP) model of sepsis, LXA4 administered 1 h after sepsis …