Herpes simplex virus 2-specific T-cell receptor (HSV-2-specific TCR)

Herpes simplex virus 2-specific T-cell receptors (HSV-2-specific TCRs) are specialized antigen receptors found on the surface of CD8+ and CD4+ T lymphocytes that mediate the adaptive immune response against HSV-2. These receptors specifically recognize viral peptide fragments, such as those from the tegument protein VP11/12 or envelope glycoproteins gD and gB, when presented by human leukocyte antigen (HLA) molecules on infected cells. Upon recognition, the TCR initiates a signaling pathway that activates the T cell to destroy the infected host cell and produce proinflammatory cytokines, which are crucial for controlling viral replication and reducing the frequency of symptomatic outbreaks. In the context of drug development, these TCRs are the primary targets of therapeutic vaccines (like HSV529) designed to expand the repertoire of protective tissue-resident memory T cells at sites of viral reactivation. Furthermore, they are being explored in adoptive cell therapies, where patient T cells are engineered to express high-affinity HSV-2-specific TCRs to provide robust immunity in immunocompromised individuals or those with severe recurrent disease. A significant challenge in targeting these receptors is the virus's ability to evade detection by downregulating MHC expression through proteins like ICP47, as well as the inherent HLA restriction that requires therapies to be tailored to specific patient genotypes.

Other names

T-cell receptors recognizing HSV-2 peptide–MHC complexesHSV-2 pMHC-specific T-cell receptorHerpes simplex virus type 2-specific TCRHSV-2-reactive T-cell receptor

T-cell receptors (TCRs) recognize specific viral peptides derived from HSV-2 proteins (such as gD, gB, or VP11/12) presented by Major Histocompatibility Complex (MHC/HLA) molecules on the surface of infected cells. This binding triggers a signaling cascade involving LCK and ZAP-70, leading to T-cell proliferation, the release of cytotoxic granules (perforin/granzyme), and the secretion of antiviral cytokines like IFN-gamma and TNF-alpha to eliminate the virus-infected cells.