Human cytomegalovirus immediate-early 2 protein (IE2) (IE2)

Human cytomegalovirus (HCMV) immediate-early 2 (IE2) protein, encoded by the UL122 gene, is a master regulatory protein essential for the initiation of the viral lytic cycle and the progression of viral replication [UniProt: P04439]. As a potent transcription factor, IE2 auto-regulates its own expression and activates the transcription of early and late viral genes while simultaneously modulating host cell pathways such as the cell cycle and innate immune signaling [PubMed: 25653451]. In clinical development, IE2 is a primary antigenic payload for next-generation vaccines and immunotherapies because it is one of the first proteins expressed upon viral entry or reactivation and is a major target for the host's cellular immune response [PubMed: 31534001]. Therapeutic strategies, including mRNA vaccines like mRNA-1647 and viral vector platforms like Triplex, utilize IE2 to prime the immune system to recognize and destroy infected cells early in the replication cycle [ClinicalTrials.gov: NCT05085301]. This approach is particularly critical for preventing congenital CMV transmission and managing life-threatening CMV reactivation in hematopoietic stem cell and solid organ transplant recipients. By inducing robust CD8+ and CD4+ T-cell responses, these therapies aim to establish long-term immunological surveillance against the virus [PubMed: 31534001].

Other names

UL122IE86Immediate-early protein 2HCMV IE2Regulatory protein IE2

Induction of adaptive immune responses, specifically CD8+ and CD4+ T-cell activation, to recognize and eliminate CMV-infected cells expressing the IE2 protein during the early stages of viral replication [PubMed: 31534001, ClinicalTrials.gov: NCT05085301].