The Protective Role of Monocytes in Stroke-Associated Pneumonia

Linda Ma*, Kelly L. Monaghan, Wen Zheng, Shokofeh Rahimpour, and Edwin Wan
Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV 26505

Presentation No.: 84

Assigned Category (Presentation Format): Health Sciences (Poster Presentations)

Student’s Major: Immunology and Medical Microbiology

Ischemic stroke leads to increased susceptibility to bacterial infection in the lungs, resulting in stroke-associated pneumonia (SAP). Monocytes are innate immune cells with critical roles in stroke-mediated inflammation and defense against bacterial infection; however, their role in SAP is not known. After inducing ischemic stroke in mice, our lab reported a significant increase of monocytes in the brain, not the lungs, despite monocyte chemoattractant CCL2 increasing in the lungs. We hypothesize that ischemic stroke alters monocyte distribution--monocytes are directed into the brain instead of migrating to the lungs, causing increased susceptibility to bacterial infection. We administered CD45.1+ monocytes into CD45.2+ mice infected with S. pneumoniae with/without stroke induction and determined the migration of CD45.1+ monocytes by antibody staining and flow cytometric analysis. Our data show that CD45.1+ monocytes were found only in the brains of the stroke mice. CD45.1+ monocytes in the lungs were reduced in mice with ischemic stroke induction compared to mice without stroke induction. Moving forward, we will determine whether direct administration of monocytes into the lungs facilitates bacterial clearance following stroke.

Funding: NIH, GM109098

Program/mechanism supporting research/creative efforts: the WVU IMMB Undergraduate Research Internship Program (Jennifer Franko)