Subcutaneous Mycobacterium vaccae promotes resilience in a mouse model of chronic psychosocial stress when administered prior to or during psychosocial stress

Publication date: Available online 27 December 2019Source: Brain, Behavior, and ImmunityAuthor(s): Mattia Amoroso, Alexandra Böttcher, Christopher A. Lowry, Dominik Langgartner, Stefan O. ReberAbstractChronic psychosocial stress is a risk factor for many mental disorders, including affective disorders, anxiety disorders, and trauma- and stressor-related disorders (i.e. posttraumatic stress disorder, PTSD). As these disorders are associated with an overreactive immune system and chronic low-grade inflammation, immunoregulatory approaches counterbalancing basal and/or stress-induced immune activation should be protective in this context. In support of this hypothesis, we recently demonstrated that repeated subcutaneous (s.c) preimmunization with a heat-killed preparation of the immunoregulatory bacterium Mycobacterium vaccae (M. vaccae; National Collection of Type Culture (NCTC) 11659) promoted proactive stress coping and protected against stress-induced anxiety and intestinal pathology in a mouse model of chronic psychosocial stress. To induce development of a chronic anxiety-like state, the chronic subordinate colony housing (CSC) paradigm was used. Here we employed the CSC paradigm (start day 1) to confirm the stress-protective effects of repeated s.c. M. vaccae administrations prior to CSC exposure (days -21, -14, and -7) and to extend these findings to the stress-protective role of M. vaccae when administered repeatedly during CSC exposure (days 2, 8 and 15). As readouts ...
Source: Brain, Behavior, and Immunity - Category: Neurology Source Type: research