Early Childhood Stress is Associated With Elevated Antibody Levels to Herpes Simplex Virus Type 1 in Adolescence
A study published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) indicates that a stressful early childhood history affects the long-term functioning of the immune system, specifically evidenced by a secretion of higher levels of herpes simplex virus (HSV)-antibodies into saliva.
The link between psychological stress and reactivation of latent herpes simplex virus, and the manifestation of clinical symptoms such the cold sores is well-known. A recent meta-analysis confirmed the presence of a robust connection between psychosocial stress and symptomatic HSV recurrence. Interestingly, psychosocial stress tended to be more strongly associated with oral than genital herpes recurrence.
Recently, stress has been linked to an early onset and delayed resolution of herpetic lesions, reduced viral clearance at the site of infection and draining popliteal lymph nodes (PLNs), and impaired functions of HSV-specific CD8(+) T cells in PLNs. Of note, in mice, these impaired CD8(+) T cell functions are not due to direct effects of stress/corticosterone on the T cells, but the ability of PLN-derived dendritic cells to prime HSV-1-specific CD8(+) T cells is functionally impaired.
In the PNAS article Elizabeth Shirtcliff, Christopher Coe and Seth Pollak studied two different types or groups of adverse childhood experiences. First, a group of postinstitutionalized adolescents who had experienced early caregiving deprivation before adoption into a more normative family context, and second, a sample of adolescents who had experienced substantiated physical abuse and were still residing within their families of origin.
Across 4 school and home days, the authors found that the HSV antibody was higher in both postinstitutionalized and physically-abused adolescents when compared with control participants. These data revealed that a profile of high HSV antibody serves as a sentinel marker of a history of adverse experience during formative development.
The findings are particularly noteworthy because of the clear demonstration that these effects linger even after the resolution of the period of childhood adversity.
The present study is unique in demonstrating these effects with a pediatric population. In the case of the postinstitutionalized adolescents, they had been adopted into more benevolent family conditions by 2.8 years of age on average.
Thus, for many, the period of adversity had been over for nearly a decade before the current assessment. The authors conclude that the susceptibility of the immune system to early caregiving experiences reveals an important aspect of developmental plasticity.
Source: Proc Natl Acad Sci USA 2009, 106:2963
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