Innate immunity forms a critical arm of host defense in the lungs, and neutrophils are an important component. Changes in cytoskeletal structure and adhesivity are critical events in this response. The cytoskeletal changes induced by binding of mediators result in the initial sequestration of neutrophils within pulmonary capillaries. They take the form of increased cytoskeletal formation in a circumferential rim beneath the plasma membrane that leads to decreased ability to deform. Subsequent cytoskeletal rearrangements required for flattening and crawling along and between cells and through connective tissue are initiated by both ligation of adhesion molecules and binding of chemotaxic factors to their receptors. These rearrangements are dynamic and likely to result from complex interactions between signaling pathways activated by adhesion and mediator receptors. Furthermore, the release of neutrophils from the bone marrow, necessary for mobilization of neutrophils needed for host defense in the lungs, likely involves similar cytoskeletal structural and adhesive changes initiated by circulating mediators. The working hypothesis for this proposal is that the response of neutrophils to inflammatory stimuli in the lung tissue and blood is modulated by a series of cytoskeletal structural and adhesive changes.
Aim 1 determines the signaling pathways leading to cytoskeletal rearrangements following binding of mediators to receptors and the role of these rearrangements in neutrophil sequestration in vivo.
Aim 2 focuses on determining the interactions between adhesive and structural changes in neutrophils when they bind to pulmonary microvascular endothelial cells in vitro and in vivo through CD11/CD18-dependent and -independent pathways. The goal of Aim 3 is to determine the role of adhesive and structural changes in the release of neutrophils from the bone marrow.
Aim 4 determines the mechanisms through which CD44, a receptor on neutrophils for hyaluronic acid, modulates neutrophil emigration in the lungs upon ligation. Our goal is to provide information that will ultimately be used to therapeutically modulate human disease.
|Gomez, John C; Dang, Hong; Kanke, Matthew et al. (2017) Predicted effects of observed changes in the mRNA and microRNA transcriptome of lung neutrophils during S. pneumoniae pneumonia in mice. Sci Rep 7:11258|
|Gomez, John C; Dang, Hong; Martin, Jessica R et al. (2016) Nrf2 Modulates Host Defense during Streptococcus pneumoniae Pneumonia in Mice. J Immunol 197:2864-79|
|Gomez, John C; Yamada, Mitsuhiro; Martin, Jessica R et al. (2015) Mechanisms of interferon-? production by neutrophils and its function during Streptococcus pneumoniae pneumonia. Am J Respir Cell Mol Biol 52:349-64|
|Kebaier, Chahnaz; Chamberland, Robin R; Allen, Irving C et al. (2012) Staphylococcus aureus ?-hemolysin mediates virulence in a murine model of severe pneumonia through activation of the NLRP3 inflammasome. J Infect Dis 205:807-17|
|Yamada, Mitsuhiro; Gomez, John C; Chugh, Pauline E et al. (2011) Interferon-? production by neutrophils during bacterial pneumonia in mice. Am J Respir Crit Care Med 183:1391-401|
|Kang, Inkyung; Wang, Qin; Eppell, Steven J et al. (2010) Effect of neutrophil adhesion on the mechanical properties of lung microvascular endothelial cells. Am J Respir Cell Mol Biol 43:591-8|
|Gomez, John C; Doerschuk, Claire M (2010) The role of CD18 in the production and release of neutrophils from the bone marrow. Lab Invest 90:599-610|
|Gomez, John C; Soltys, Jindrich; Okano, Keiichi et al. (2008) The role of Rac2 in regulating neutrophil production in the bone marrow and circulating neutrophil counts. Am J Pathol 173:507-17|
|Kang, Inkyung; Panneerselvam, Dinesh; Panoskaltsis, Vassilis P et al. (2008) Changes in the hyperelastic properties of endothelial cells induced by tumor necrosis factor-alpha. Biophys J 94:3273-85|
|Yoshida, Kazuo; Kondo, Ryoichi; Wang, Qin et al. (2006) Neutrophil cytoskeletal rearrangements during capillary sequestration in bacterial pneumonia in rats. Am J Respir Crit Care Med 174:689-98|
Showing the most recent 10 out of 47 publications