An Effector Phenotype of CD8+ T Cells at the Junction Epithelium during Clinical Quiescence of Herpes Simplex Virus 2 Infection

Herpes simplex virus 2 infection is characterized by cycles of viral quiescence and reactivation. CD8(+) T cells persist at the site of viral reactivation, at the genital dermal-epidermal junction contiguous to neuronal endings of sensory neurons, for several months after herpes lesion resolution. To evaluate whether these resident CD8(+) T cells frequently encounter HSV antigen even during times of asymptomatic viral infection, we analyzed the transcriptional output of CD8(+) T cells captured by laser microdissection from human genital skin biopsy specimens during the clinically quiescent period of 8 weeks after lesion resolution. These CD8(+) T cells expressed a characteristic set of genes distinct from those of three separate control cell populations, and network and pathway analyses revealed that these T cells significantly upregulated antiviral genes such as GZMB, PRF1, INFG, IL-32, and LTA, carbohydrate and lipid metabolism-related genes such as GLUT-1, and chemotaxis and recruitment genes such as CCL5 and CCR1, suggesting a possible feedback mechanism for the recruitment of CD8(+) T cells to the site of infection. Many of these transcripts are known to have half-lives of <48 h, suggesting that cognate antigen is released frequently into the mucosa and that resident CD8(+) T cells act as functional effectors in controlling viral spread.