Recruitment of leukocytes to sites of acute inflammation is a finely orchestrated process initiated by membrane expression and functional activation of leukocyte and endothelial cell adhesion molecules (CAMs) including selectins, integrins, and Ig-super family ligands. A set of unifying themes have emerged over the tenure of this R01 which provide molecular scale insight into how PMNs integrate force as a spatio-mechanical cue in the transition from rolling to firm arrest and transendothelial migration: 1) Selectins are endowed with mechanical and biochemical properties which allow them to function as both adhesive and signal transduction receptors;2) Shear stress and transmembrane calcium release-activated Ca2+ (CRAC) channels regulate intracellular calcium flux which functions to synchronize integrin mediated arrest and cell migration;3) 22-integrin affinity and bond mechanics in binding ICAM-1 provide a gatekeeper mechanism via regulation of outside-in signaling of transendothelial migration. In this competitive renewal we apply our innovative vascular mimetic microfluidic channels combined with real-time immunofluorescence imaging to pursue the following specific aims: 1) Examine the role of calcium release activated calcium flux in orchestration of the multistep process of neutrophil recruitment. 2) Determine how E-selectin ligands on neutrophils serve as mechano-transducers that trigger and amplify chemokine signaling of integrin activation on inflamed endothelium 3) define the molecular and mechanical mechanisms underlying LFA-1 outside-in signaling of neutrophil shape polarization. Our strategy entails the use of freshly isolated human neutrophils and murine models of inflammation with the overarching goal of identifying regulatory pathways and molecular targets for prognosis and treatment of inflammatory diseases.

Public Health Relevance

White blood cell emigration into inflamed tissue is likened to a double edged sword, it is critical to innate immune defense against bacterial infection, but if unchecked contributes to autoimmune disease and tissue destruction. We develop technologies to measure how neutrophils, the most common white cell, adhere to blood vessels and migrate to sites of inflammation in order to design more effective anti-inflammatory therapeutics.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
Project #
Application #
Study Section
Bioengineering, Technology and Surgical Sciences Study Section (BTSS)
Program Officer
Minnicozzi, Michael
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of California Davis
Biomedical Engineering
Schools of Engineering
United States
Zip Code
Skoog, Emma C; Morikis, Vasilios A; Martin, Miriam E et al. (2018) CagY-Dependent Regulation of Type IV Secretion in Helicobacter pylori Is Associated with Alterations in Integrin Binding. MBio 9:
Miller, Lloyd S; Simon, Scott I (2018) Neutrophils in hot pursuit of MRSA in the lymph nodes. Proc Natl Acad Sci U S A 115:2272-2274
Immler, Roland; Simon, Scott I; Sperandio, Markus (2018) Calcium signalling and related ion channels in neutrophil recruitment and function. Eur J Clin Invest 48 Suppl 2:e12964
Morikis, Vasilios A; Chase, Shannon; Wun, Ted et al. (2017) Selectin catch-bonds mechanotransduce integrin activation and neutrophil arrest on inflamed endothelium under shear flow. Blood 130:2101-2110
Murphy, Kaitlin C; Whitehead, Jacklyn; Falahee, Patrick C et al. (2017) Multifactorial Experimental Design to Optimize the Anti-Inflammatory and Proangiogenic Potential of Mesenchymal Stem Cell Spheroids. Stem Cells 35:1493-1504
Falahee, Patrick C; Anderson, Leif S; Reynolds, Mack B et al. (2017) ?-Toxin Regulates Local Granulocyte Expansion from Hematopoietic Stem and Progenitor Cells in Staphylococcus aureus-Infected Wounds. J Immunol 199:1772-1782
Block, Helena; Stadtmann, Anika; Riad, Daniel et al. (2016) Gnb isoforms control a signaling pathway comprising Rac1, Plc?2, and Plc?3 leading to LFA-1 activation and neutrophil arrest in vivo. Blood 127:314-24
Morikis, Vasilios A; Radecke, Chris; Jiang, Yanyan et al. (2016) Atrial natriuretic peptide down-regulates neutrophil recruitment on inflamed endothelium by reducing cell deformability and resistance to detachment force. Biorheology 53:109
Morikis, Vasilios A; Radecke, Chris; Jiang, Yanyan et al. (2015) Atrial natriuretic peptide down-regulates neutrophil recruitment on inflamed endothelium by reducing cell deformability and resistance to detachment force. Biorheology 52:447-63
Uchiyama, Satoshi; Döhrmann, Simon; Timmer, Anjuli M et al. (2015) Streptolysin O Rapidly Impairs Neutrophil Oxidative Burst and Antibacterial Responses to Group A Streptococcus. Front Immunol 6:581

Showing the most recent 10 out of 62 publications