202 A CTS Team Approach to Immune Signatures of PTSD Susceptibility

OBJECTIVES/GOALS: Post-traumatic stress disorder (PTSD) develops in a subset of individuals (15-25%) exposed to trauma. We report our preliminary findings investigating underlying peripheral immune responses related to risk and resilience to PTSD. METHODS/STUDY POPULATION: Sprague-Dawley rats (half male) were exposed to predator scent stress in the form of the fox pheromone 2,5-dihydro-2,4,5-trimethylthiazoline (TMT) once for 10 minutes. Seven days later, rats were assessed for persistent anxiety-like behavior using the acoustic startle response task (ASR) and elevated plus maze (EPM). Tail blood was collected for later inflammation analysis at three time points: 1) prior to experiment start, 2) after TMT exposure, and 3) after ASR and EPM. Using a with-in subjects design, our experiment elucidates the connection between PTSD-like symptoms and baseline immune function, inflammatory stress responses, and chronic inflammatory state after stress exposure. RESULTS/ANTICIPATED RESULTS: In comparison to healthy controls, humans with PTSD show elevated blood levels of inflammatory markers. Human studies also show a relationship between baseline immune dysfunction and later PTSD development. In agreement with this literature, we anticipate PTSD-like rats will have increased blood levels of inflammation markers at all three time points compared to resilient and control rats. These findings will back-translate human findings in support of the predator scent stress preclinical model of PTSD. DISCUSSION/SIGNIFICANCE: Our findings will elucidate the temporal aspects of proinflammatory markers and PTSD development. This study will indicate if baseline peripheral immune dysfunction, inflammatory response immediately after stress exposure, and/or chronic inflammatory state predicts ptsd-like behavior in rats.