Abstract
ABSTRACT
Background
Recurrent ocular herpetic disease is a leading infectious cause of corneal blindness and is associated with psychological distress, anxiety, and social withdrawal. No ocular herpes vaccine or immunotherapy currently exists.
Hypothesis
A prime/pull/keep (PPK) T-cell immunotherapy, built on HSV-1 epitopes preferentially recognized by CD8
+
/CD4
+
T cells from naturally protected asymptomatic (ASYMP) individuals, would reduce viral reactivation, shedding, recurrent corneal disease, and associated neurobehavioral deficits.
Methods
Immunodominant HLA-restricted CD8+/CD4+ epitopes from HSV-1 gD/gB, tegument proteins VP11/12/VP13/14, and helicase UL9 were delivered via topical ocular AAV8 vector (prime) to latently infected HLA-A*0201/DRB1 mice, combined with chemokine CXCL11 (pull) and IL-2/IL-15 cytokines to sustain TRM cells (keep), then UVB-exposed to trigger reactivation and recurrent corneal disease.
Results
PPK immunotherapy conferred robust, near-complete protection against recurrent HSV-1 disease and improved survival after UVB-induced reactivation, unlike its individual components. This protection was associated with site-specific accumulation of HSV-1-specific CD8
+
/CD4
+
T
RM
cells in the cornea and trigeminal ganglia (TG), but not in the spleen, with peak retention from combined IL-2/IL-15, alongside durable central/effector memory populations. PPK-induced T cells showed enhanced polyfunctionality (cytokine production, cytotoxicity, proliferation), reduced exhaustion markers, and a TCF-1+ self-renewing phenotype. PPK also elicited robust, Th1-biased HSV-1-specific IgG responses complementing mucosal immunity, and restored spatial memory, reduced depression-like behavior, and reversed social withdrawal in mice with recurrent ocular herpes.
Conclusion
PPK immunotherapy induces potent, durable antiviral T
RM
cells at primary sites of HSV-1 latency and reactivation, protecting against recurrent ocular herpetic disease and alleviating associated neurobehavioral deficits, supporting its translational potential in humans.
IMPORTANCE
Recurring ocular herpes caused by HSV-1 is a major cause of blindness worldwide, and living with repeated flare-ups also takes a serious emotional toll, contributing to anxiety, low mood, and social withdrawal. Despite how common and damaging this condition is, no vaccine or treatment currently exists to prevent these outbreaks. This study tested a new three-part immune therapy designed to boost the body’s defenses against the virus, using viral pieces the immune system recognizes especially well in people who carry it without ever getting sick. In mice carrying human-like immune genes, this therapy trained immune cells to gather and stay active at the exact sites where the virus hides and can reawaken: the eye and nearby nerve tissue. Treated mice showed better protection from repeat outbreaks and improved survival after UV light triggered reactivation, compared to mice given only partial versions of the therapy. Treated mice also produced strong antibody responses and showed noticeable improvements in memory, mood, and social behavior after infection, suggesting the therapy protected the brain and behavior as well as the eye. These findings suggest this new therapy could offer meaningful protection against both the physical and emotional burden of recurrent ocular herpes in the clinic.