Psychosocial Stress Alters the Immune Response and Results in Higher Viral Load During Acute SIV Infection in a Pigtailed Macaque Model of HIV.

Background While social distancing is a key public health response during viral pandemics, psychosocial stressors, such as social isolation, have been implicated in adverse health outcomes in general (1) and in the context of infectious disease, such as HIV (2,3). A comprehensive understanding of the direct pathophysiologic effects of psychosocial stress on viral pathogenesis is needed to provide strategic and comprehensive care to patients with viral infection. Methods To determine the effect of psychosocial stress on HIV pathogenesis during acute viral infection without sociobehavioral confounders inherent in human cohorts, we compared commonly measured parameters of HIV progression between singly (n=35) and socially (n=41) housed SIV-infected pigtailed macaques (Macaca nemestrina). Results Singly housed macaques had a higher viral load in the plasma and cerebrospinal fluid and demonstrated greater CD4 T cell declines and more CD4 and CD8 T cell activation compared to socially housed macaques throughout acute SIV infection. Conclusions These data demonstrate that psychosocial stress directly impacts the pathogenesis of acute SIV infection and imply that it may act as an integral variable in the progression of HIV infection and potentially of other viral infections.