PMC

Mice exposed to social stress prior to TMEV infection have elevated CNS viral load (titer) on day 8 post-infection compared to non-stressed controls (asterisk denotes significance).

SDR exposure significantly reduced TMEV-induced CD4 and CD8 mRNA expression in samples of cortex and meninges (cortical/meningeal combined samples) at day 8 post-infection. Panel A. CD4 mRNA expression was significantly elevated as a result of TMEV infection (denoted by asterisk). This effect was attenuated by exposure to SDR prior to infection (asterisk denotes significant difference between SDR/Infected and NON-SDR/Infected conditions). Panel B. CD8 mRNA expression was significantly elevated as a result of TMEV infection (denoted by asterisk). SDR exposure attenuated the TMEV-induced elevation in CD8 mRNA (asterisk denotes significant difference between SDR/Infected and NON-SDR/Infected conditions).

SDR prior to TMEV infection exacerbated body weight loss and anhedonia. Panel A. Infection resulted in a significant reduction in body weight at day 1 post-infection (denoted by asterisk). SDR exposure prior to TMEV infection exacerbated body weight loss on day 1 post-infection (significant difference between NON-SDR/Infected and SDR/Infected conditions denoted by asterisk). The SDR/Infected condition exhibited greater reduction in body weight (-1.8 g, 10.1%) than NON-SDR/Infected (-0.676, g, 3.1%), NON-SDR/Uninfected (-.258 g, 1.6%) and SDR/Uninfected (-0.225 g, 1.4%) conditions. Panel B. Sucrose preference was reduced as a result of infection (asterisk denotes significant difference). SDR/Infected mice consumed significantly less sucrose compared to all other conditions (denoted by asterisk). The horizontal line indicates the minimum sucrose consumption indicative of sucrose preference.

Data are presented as mean number of spot forming cells (SFCs) detected with IFN-γ detection antibodies (mean ± SEM) after SDR (or NON) and infection. Infection significantly increased the number of virus-specific CD4+ T cells (see Panel A) and virus-specific CD8⁺ T cells (see Panel B) detected in isolated CNS infiltrating lymphocytes (CNS-ILs; denoted by asterisk) while SDR exposure prior to infection prevented this increase (asterisk denotes significant difference between NON-SDR/Infected and SDR/Infected conditions). Infection significantly increased the number of virus-specific CD4⁺ T cells (see Panel C) and virus-specific CD8+ T cells (see Panel D) at day 8 post-infection (denoted by asterisk). SDR exposure did not significantly attenuate the elevation in either CD4+ or CD8+ T cells resulting from infection.