EBV EA
Description
Role in EBV Lifecycle
EBV EA is transiently expressed 1–3 days post-infection, marking the transition from latent to lytic replication. Its expression is tightly regulated by viral transactivators:
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BZLF1 (Zta) and BRLF1 (Rta) activate the EA-D promoter (BMRF1) in a cell-type-dependent manner .
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In lymphoid cells, Zta and Rta synergistically enhance EA-D promoter activity, while in epithelial cells, Zta alone suffices .
Diagnostic Significance
EBV EA serology is a cornerstone for diagnosing active EBV infections and related pathologies:
Table 1: Diagnostic Performance of EBV EA Antibodies
^1 Systemic Chronic Active EBV Disease
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EA IgG appears early in infection but persists in 20% of healthy individuals, complicating standalone interpretation .
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EA-D IgG is more specific for acute/reactivated EBV infections compared to EA-R .
Table 2: Key EBV EA Components and Functions
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Monoclonal antibodies targeting the 55/49 kDa subunits neutralize EBV DNA polymerase, highlighting their therapeutic potential .
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EA-D suppresses apoptosis via interactions with Bcl-2 homologs, promoting viral persistence .
Clinical Implications in EBV-Associated Diseases
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Prognostic marker: In systemic chronic active EBV (sCAEBV), patients with anti-EA IgG titers ≥640 exhibit lower 5-year survival rates (45% vs. 72% in low-titer groups) .
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Oncogenic role: EA-D IgG is elevated in EBV-driven malignancies (e.g., nasopharyngeal carcinoma, Burkitt lymphoma) due to sustained lytic activation .
Challenges in Serological Interpretation
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False positives: 9–18% of healthy individuals show EA-D IgG reactivity .
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Pattern variability: Only 12/32 EBV serological patterns are clinically interpretable, necessitating combinatorial testing (e.g., VCA IgM, EBNA-1 IgG) .
Future Research Directions
Product Specs
Product Science Overview
The Epstein-Barr virus (EBV), also known as human herpesvirus 4 (HHV-4), is a member of the herpesvirus family. It is one of the most common viruses in humans and is best known for causing infectious mononucleosis, commonly referred to as glandular fever . EBV is also associated with various forms of cancer, including Hodgkin’s lymphoma, Burkitt’s lymphoma, nasopharyngeal carcinoma, and central nervous system lymphomas, particularly in individuals with HIV .
The EBV early antigen (EA) is a complex of proteins expressed during the early phase of viral replication. These proteins are crucial for the virus’s ability to replicate and establish infection in host cells. The EA complex includes several components, such as the diffuse (EA-D) and restricted (EA-R) antigens .
Recombinant EBV early antigens are produced using genetic engineering techniques. These recombinant proteins are typically expressed in bacterial or mammalian cell systems and are used for various research and diagnostic purposes. For example, the recombinant EBV early antigen (a.a. 306-390) is produced in E. coli and is used in immunization protocols to generate antibodies that specifically target the protein of interest .
Recombinant EBV early antigens have several applications in research and diagnostics:
- Immunization Protocols: These antigens are used to generate specific antibodies for research and diagnostic purposes .
- ELISA Kits: Recombinant antigens are used in enzyme-linked immunosorbent assays (ELISA) to detect antibodies against EBV in patient samples .
- Vaccine Development: Research on recombinant EBV antigens contributes to the development of vaccines against EBV-related diseases .
