Viral Antigens

EBV has a linear double-stranded DNA genome of approximately 184 kilobases, encoding around 100 proteins . The virus primarily infects B lymphocytes and epithelial cells . EBV is highly prevalent, with over 90% of the adult population worldwide having been infected . The virus can establish a latent infection, allowing it to persist in the host for a lifetime . EBV is mainly transmitted through saliva but can also spread through other bodily fluids .

EBV plays a significant role in immune responses and pathogen recognition. It infects and replicates in epithelial cells and B cells in the oral cavity, leading to the shedding of the virus in the oropharynx and the entry of infected B cells into the bloodstream . The virus can evade the immune system, allowing it to establish a latent infection . EBV is associated with various diseases, including infectious mononucleosis, chronic active EBV infection, EBV-associated autoimmune diseases, and EBV-associated tumors .

EBV infects B cells and epithelial cells through different glycoproteins. Glycoprotein gp350/220 binds to complement receptor type 2 (CR2/CD21) on B cells, facilitating viral attachment . The virus activates growth transformation programs to drive the proliferation and differentiation of infected B cells into memory B cells . EBV also interacts with antigen-presenting cells, which present antigenic substances to T cells .

The regulation of EBV latency involves various mechanisms, including epigenetic and immune regulation . EBV latency is maintained through the expression of different latent genes at various stages. For example, in latent phase 0, EBV microRNA and EBV-encoded RNA are primarily expressed . In type I latency, EBV-encoded nuclear antigens (EBNA1) and noncoding RNAs are expressed . Type II latency involves the expression of EBNA1, latent membrane proteins (LMP1 and LMP2), and noncoding RNAs . Type III latency occurs in immortalized lymphoblastoid cell lines and involves the expression of all latent proteins .

EBV has several applications in biomedical research, diagnostic tools, and therapeutic strategies. In research, EBV is used to study viral oncogenesis and immune evasion mechanisms . Diagnostic tools for EBV include serological tests for EBV-specific antibodies and polymerase chain reaction (PCR) for detecting viral DNA . Therapeutic strategies for EBV-associated diseases include antiviral drugs, immunotherapy, and targeted therapies .

EBV has a discrete life cycle that includes primary infection, latency, and lytic reactivation . During primary infection, the virus infects epithelial cells and B lymphocytes, leading to the establishment of latency in memory B cells . The virus can remain dormant in the host for a lifetime. Reactivation of the virus can occur under certain conditions, leading to the production of new virions and the potential development of EBV-associated diseases . EBV plays a role in various stages of life, from childhood infections to the development of certain cancers in adulthood .