One of the major non-infectious risks from blood transfusions is the development of transfusion-related acute lung injury (TRALI), which is the number one cause of transfusion-related mortality in the United States. We have previously shown in a mouse model of TRALI that neutrophils and platelets are both required to produce acute lung endothelial injury, protein permeability, and pulmonary edema. However, the mechanisms by which neutrophils and platelets potentially interact and ultimately lead to lung injury are not known. In this application, we will test potential mechanisms in three scientific aims.
In Aim 1, we will test for the presence of neutrophil-platelet aggregates in TRALI and determine the molecular mechanisms responsible for the aggregates by using bone marrow chimeras and in vitro studies with cells isolated from MHC Class I-null mice and Fcg receptor knockouts. We will also test pharmacologic inhibitors of platelets and the mechanisms by which these inhibitors may ameliorate lung injury.
In Aim 2, we will determine how neutrophils lead to lung endothelial injury by using mice with loss of function mutations in neutrophil proteases and ROS production. We hypothesize that neutrophil extracellular traps (NETs) will be formed in TRALI in a platelet-dependent process that exposes extracellular histones leading to lung endothelial injury.
In Aim 3, we will use a new application of two-photon microscopy in the live, mouse lung to image the temporal sequence of neutrophil and platelet recruitment in our mouse model of TRALI. Using intravital microscopy, we will also determine the spatial relationships between neutrophils and platelets in the injured lung and how this influences NET formation in the lung microvasculature. The results from this investigation will elucidate the mechanisms of lung injury in TRALI, and by focusing on the roles of platelet activation and NET formation it may be possible to identify novel pharmacologic approaches to treating acute lung injury.

Public Health Relevance

Blood transfusions may acutely injure the lungs in a process termed transfusion-related acute lung injury (TRALI). Using a mouse model of TRALI, we have discovered that neutrophils and platelets are responsible for this injury. In this proposal, we will determine how neutrophils and platelets interact with each other in the lung microcirculation to ultimately produce lung injury.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL107386-04
Application #
8646984
Study Section
Special Emphasis Panel (ZRG1-VH-F (50))
Program Officer
Mondoro, Traci
Project Start
2011-04-01
Project End
2016-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
4
Fiscal Year
2014
Total Cost
$400,459
Indirect Cost
$141,262
Name
University of California San Francisco
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Toy, Pearl; Bacchetti, Peter; Grimes, Barbara et al. (2015) Recipient clinical risk factors predominate in possible transfusion-related acute lung injury. Transfusion 55:947-52
Greenland, John R; Xu, Xiang; Sayah, David M et al. (2014) Mast cells in a murine lung ischemia-reperfusion model of primary graft dysfunction. Respir Res 15:95
Ortiz-Muñoz, Guadalupe; Mallavia, Beñat; Bins, Adriaan et al. (2014) Aspirin-triggered 15-epi-lipoxin A4 regulates neutrophil-platelet aggregation and attenuates acute lung injury in mice. Blood 124:2625-34
Looney, Mark R; Roubinian, Nareg; Gajic, Ognjen et al. (2014) Prospective study on the clinical course and outcomes in transfusion-related acute lung injury*. Crit Care Med 42:1676-87
Looney, Mark R; Bhattacharya, Jahar (2014) Live imaging of the lung. Annu Rev Physiol 76:431-45
Gilliss, Brian M; Looney, Mark R; Gropper, Michael A (2011) Reducing noninfectious risks of blood transfusion. Anesthesiology 115:635-49