1. Academic Validation
  2. CXCL1 regulates neutrophil homeostasis in pneumonia-derived sepsis caused by Streptococcus pneumoniae serotype 3

CXCL1 regulates neutrophil homeostasis in pneumonia-derived sepsis caused by Streptococcus pneumoniae serotype 3

  • Blood. 2019 Mar 21;133(12):1335-1345. doi: 10.1182/blood-2018-10-878082.
Sagar Paudel 1 Pankaj Baral 1 Laxman Ghimire 1 Scott Bergeron 1 Liliang Jin 1 Joseph A DeCorte 1 John T Le 1 Shanshan Cai 1 Samithamby Jeyaseelan 1 2
Affiliations

Affiliations

  • 1 Center for Lung Biology and Disease, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA; and.
  • 2 Section of Pulmonary and Critical Care, Department of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA.
Abstract

Neutrophil migration to the site of Bacterial infection is a critical step in host defense. Exclusively produced in the bone marrow, neutrophil release into the blood is tightly controlled. Although the chemokine CXCL1 induces neutrophil influx during Bacterial infections, its role in regulating neutrophil recruitment, granulopoiesis, and neutrophil mobilization in response to lung infection-induced sepsis is unclear. Here, we used a murine model of intrapulmonary Streptococcus pneumoniae Infection to investigate the role of CXCL1 in host defense, granulopoiesis, and neutrophil mobilization. Our results demonstrate that CXCL1 augments neutrophil influx to control Bacterial growth in the lungs, as well as Bacterial dissemination, resulting in improved host survival. This was shown in Cxcl1 -/- mice, which exhibited defective amplification of early neutrophil precursors in granulocytic compartments, and CD62L- and CD49d-dependent neutrophil release from the marrow. Administration of recombinant CXCL2 and CXCL5 after Infection rescues the impairments in neutrophil-dependent host defense in Cxcl1 -/- mice. Taken together, these findings identify CXCL1 as a central player in host defense, granulopoiesis, and mobilization of neutrophils during Gram-positive Bacterial pneumonia-induced sepsis.

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