Lymphocryptovirus

Lymphocryptovirus is a genus of herpesviruses in the family Herpesviridae, subfamily Gammaherpesvirinae. The best known member is Epstein-Barr virus (EBV), or human herpesvirus 4. The genus also comprises several related primate lymphocryptoviruses. Lymphocryptoviruses primarily infect lymphocytes and establish lifelong latent infections, with cycles of lytic replication in permissive tissues such as epithelial cells. Non-human primate lymphocryptoviruses have also been described, enabling comparative studies of latency and oncogenesis.

Genomes are large, linear double-stranded DNA. After primary infection, EBV targets B cells via the CD21 receptor, establishing latency programs expressing latent genes (EBNA1-3, LMP1, LMP2) and noncoding RNAs (EBERs). Reactivation can occur, particularly during immunosuppression, enabling production of infectious virions.

Epidemiology and transmission: EBV infection is highly prevalent worldwide; most infections occur in childhood in developing countries and adolescence in developed regions. Primary infection may be asymptomatic or cause infectious mononucleosis. Transmission is mainly through saliva; the virus can also be transmitted via blood or organ transplantation.

Clinical significance: EBV is associated with several malignancies and lymphoproliferative disorders, including Burkitt lymphoma, nasopharyngeal carcinoma, and Hodgkin lymphoma, as well as post-transplant lymphoproliferative disorder. In immunocompromised individuals, latent infection can reactivate and drive disease. Diagnosis relies on serology for EBV antibodies and detection of viral DNA by PCR; treatment is disease-specific and may include antiviral therapy, chemotherapy, radiotherapy, immunotherapy, or reduction of immunosuppression.