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PUMA and the innate immune response during pneumococcal infection in the lung

Background: The p53-up-regulated modulator of apoptosis (PUMA) protein is a pro-apoptotic, BH3-only member of the BCL2 family of effector proteins responsible for promoting organized cell death. PUMA is required for resolution of pneumococcal pneumonia in mice, as mice deficient of PUMA exhibit greater numbers of S. pneumoniae CFU within tissues and higher mortality rates than observed in Puma+/+ mice. Methods: Puma+/+ and Puma-/- mice were intranasally challenged with TIGR4 pneumococcus and sacrificed 24 h post-infection. Differences in cytokine levels from blood and whole lung tissue were detected by MILLIPLEX MAP Mouse Cytokine/Chemokine Magnetic Bead Panel. Lung transcriptomes from Puma+/+ and Puma-/- mice were prepared from total lung RNA using NEBNext Poly(A) mRNA Magnetic Isolation Module and NEBNext Ultra RNA Library Prep Kit for Illumina. Libraries were read by Illumina NovaSeq and transcript reads were referenced to Mus musculus. Results: Puma-/- mice exhibited significant differences in G-CSF, GM-CSF, IFN-gamma, IL-1-alpha and -beta, -6, -9, -10, -12 (p40 and p70), -13, and -17, IP-10, KC, MCP-1, MIP- iv 1alpha and -beta, MIP-2, RANTES, and TNF-alpha compared to Puma+/+ mice. Puma-/- lungs exhibited higher levels of IL-12, IFN-gamma, and IP-10. Loss of PUMA also resulted in expression of the pro-angiogenic genes Adam19 and Neurexin2. Additionally, Puma+/+ and Puma-/- mice displayed similar levels of colonization, but Puma-/- mice were more susceptible to subsequent dissemination to the lungs and blood. Conclusion: Polymorphonuclear cells (PMNs) were previously demonstrated to be one of the innate cell types responsible for Puma-dependent resolution of pneumococcal pneumonia in mice. Observations reported here suggest that this resolution is propelled by suppressing the inflammatory response via the inhibition of IL-12/IFN-gamma/IP-10 pro-inflammatory axis. Pulmonary tissue transcriptomic analysis also suggests PUMA-dependent positive regulation of homeostatic control of pulmonary vasculature, smooth muscle innervation, and maintenance of the interstitium. Gene ontological analysis further demonstrated Puma's modulatory role in Type I and II IFN signaling. For the first time, we report Puma's regulatory effects on pro-inflammatory cytokine signaling and gene expression during pneumococcal pneumonia.

Identiferoai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-6196
Date06 August 2021
CreatorsKennedy, Daniel Edward, II
PublisherScholars Junction
Source SetsMississippi State University
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceTheses and Dissertations

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