No abstract

Circulating conventional memory CD8 T cells (i.e., the CD8 effector memory T [T] cell and CD8 central memory T [T] cell subsets) and the noncirculating CD8 tissue-resident memory T (T) cell subset play a critical role in mucosal immunity. Mucosal chemokines, including the recently discovered CXCL17, are also important in mucosal immunity because they are homeostatically expressed in mucosal tissues. However, whether the CXCL17 chemokine contributes to the mobilization of memory CD8 T cell subsets to access infected mucosal tissues remains to be elucidated. In this study, we report that after intravaginal HSV type 1 infection of B6 mice, we detected high expression levels of CXCL17 and increased numbers of CD44CD62LCD8 T and CD103CD8 T cells expressing CXCR8, the cognate receptor of CXCL17, in the vaginal mucosa (VM) of mice with reduced genital herpes infection and disease. In contrast to wild-type B6 mice, the CXCL17 mice developed 1) fewer CXCR8CD8 T and T cells associated with more virus replication in the VM and more latency established in dorsal root ganglia, and 2) reduced numbers and frequencies of functional CD8 T cells in the VM. These findings suggest that the CXCL17/CXCR8 chemokine pathway plays a crucial role in mucosal vaginal immunity by promoting the mobilization of functional protective CD8 T and CD8 T cells, within this site of acute and recurrent herpes infection.

Most blinding ocular herpetic disease is due to reactivation of herpes simplex virus 1 (HSV-1 IMPORTANCESeventy percent to 90% of adults harbor herpes simplex virus 1 (HSV-1), which establishes lifelong latency in sensory neurons of the trigeminal ganglia. This latent state sporadically switches to spontaneous reactivation, resulting in viral shedding in tears. Most blinding herpetic disease in humans is due to reactivation of HSV-1 from latency rather than to primary acute infection. To date, there is no licensed therapeutic vaccine that can effectively stop or reduce HSV-1 reactivation from latently infected sensory ganglia and the subsequent shedding in tears. In the present study, we demonstrated that topical ocular therapeutic vaccination of latently infected HLA transgenic rabbits with a lipopeptide vaccine that contains exclusively human "asymptomatic" CD8 ؉ T-cell epitopes successfully decreased spontaneous HSV-1 reactivation, as judged by a significant reduction in spontaneous shedding in tears. The findings should guide the clinical development of a safe and effective T-cell-based therapeutic herpes vaccine.

No abstract

Herpes simplex virus type 1 (HSV-1) is a prevalent human pathogen that infects over 3.72 billion individuals worldwide and can cause potentially blinding recurrent corneal herpetic disease. HSV-1 establishes latency within sensory neurons of trigeminal ganglia (TG) and TG-resident CD8+ T cells play a critical role in preventing its reactivation. The repertoire, phenotype and function of protective CD8+ T cells are unknown. Bolstering the apparent feeble numbers of CD8+ T cells in TG remains a challenge for immunotherapeutic strategies. In this study, a comprehensive panel of 467 HLA-A*0201-restricted CD8+ T cell epitopes were predicted from the entire HSV-1 genome. CD8+ T cell responses to these genome-wide epitopes were compared in HSV-1 seropositive symptomatic (SYMP) individuals (with a history of numerous episodes of recurrent herpetic disease) vs. asymptomatic (ASYMP) individuals (who are infected but never experienced any recurrent herpetic disease). Frequent polyfunctional HSV-specific effector memory IFN-γ+CD107a/b+CD44highCD62LlowCD8+ TEM cells were detected in ASYMP individuals and were mainly directed against three “ASYMP” epitopes. In contrast, SYMP individuals have more mono-functional central memory CD44highCD62LhighCD8+ TCM cells. Furthermore, therapeutic immunization with an innovative prime/pull vaccine, based on priming with multiple “ASYMP” epitopes (prime) and neurotropic TG delivery of the T-cell attracting chemokine CXCL-10 (pull), boosted the number and function of CD44highCD62LlowCD8+ TEM and tissue-resident CD103highCD8+ TRM cells in TG of latently infected HLA-A*0201 Tg mice and reduced recurrent ocular herpes following UV-B induced reactivation. These findings have profound implications in the development of T-cell-based immunotherapeutic strategies to treat blinding recurrent herpes infection and disease.