Sulfur mustard (SM), a vesicant that is one of the most lethal chemical warfare agents, remains
as a great threat in modern times. Exposure to SM and its mono-functional analog 2-chloroethyl
ethyl sulfide (CEES) induces deleterious effects on the lung. Oxidative stress and uncontrolled
inflammation are considered as the major mechanisms of SM toxicity on the lung. Currently, there
are no effective medical countermeasures to mitigate the vesicant induced lung damage.
Therefore, it is essential to expand our understanding of the molecular mechanisms and to identify
effective measures, including pharmacological interventions, to alleviate the inflammation and
oxidative stress induced by SM. Cannabinoid-2 receptors (CB2R), expressed mainly in the
immune cells, have shown promising anti-inflammatory and anti-injury potential without any
adverse psychotic effects. Our preliminary findings indicated a significant reduction of CEES-
induced acute lung injury and immune cell infiltration by pharmacological activation of CB2R,
while the genetic deletion of CB2R worsened the lung injury. Moreover, CB2R ligands show
marked functional selectivity, suggesting CB2R can be a good target for developing counter
measures to CEES. Given these promising indications, this project aims to further investigate how
CB2R activation attenuates CEES-induced acute lung injury, using pharmacological activation
and genetic deletion approach in the following specific aims: 1) To determine the extent to which
CB2R regulates the CEES-induced acute lung injury, inflammatory response, and oxidative
stress. 2) To delineate the mechanism of the protective role of CB2R in CEES-induced lung injury,
inflammatory response, and oxidative stress. These efforts will reveal a novel mechanism of
endocannabinoid signaling through CB2R in CEES-induced lung injury and would assist in
translational strategies for the development of therapeutic agent against vesicant-induced lung
damage.