The Epstein-Barr virus (EBV) is a double-stranded DNA virus that infects human B-lymphocytes and epithelial cells. EBV has been implicated in several human cancers such as Burkitt lymphoma, nasopharyngeal carcinoma, post-transplant lymphoproliferative disease, and Hodgkin lymphoma. EBV is transmitted orally through saliva and can also spread through blood or transplanted organs. It evades the immune system and causes cells to proliferate uncontrollably, leading to cancer development. Diagnosis involves antibody testing for EBV, while prevention focuses on avoiding contact with saliva and maintaining clean conditions.

1. EPSTEIN-BARR VIRUS
Structure
 Double stranded DNA virus
 Enveloped
 EBV has a toroid-shaped DNA core in
a nucleocapsid
 External glycoprotein spikes, and a
protein tegument between the
nucleocapsid and envelope

2. EPSTEIN-BARR VIRUS (EBV)
 EBV infects human B-lymphocytes and epithelial cells and long-term infection
stimulates them to proliferate and develop into malignancies of corresponding
cells. EBV is implicated in the following human tumours:
i. Burkitt lymphoma
ii. Anaplastic nasopharyngeal carcinoma
iii. Post-transplant lymphoproliferative disease
iv. Primary CNS lymphoma in AIDS patients
v. Hodgkin lymphoma

3. Mode of Transmission
 Oral secretion : Kissing
 Blood products
 Transplanted Organ

4. EBV-induced oncogenesis
B lymphocyte
(EBV-infected)
Cell proliferation
dysegulated
(CD40-like effect)
LMP1 expressed Activates BCL2
Growth signalling
Prevents apoptosis
Epithelial cell
(EBV-infected)
Elaborates EBNA-2
(via NF-kB, JAK/stat pathway)
Activates cyclin D and
SRC family
Stimulates B-cell
proliferation
Burkitt Lymphoma
Nasopharyngeal
carcinoma

5.  In immunocompetent individuals, LMP1 is kept under control by the body`s
immune system. Therefore, in these individuals lymphoma cells appear only after
another characterstic mutation t(8;14) activates growth promoting MYC oncogene.

7. Burkitt Lymphoma
 Burkitt lymphoma was initially noticed in African children by Burkitt in 1958 but is now
known to occur in 2 forms.
• African endemic form
• Sporadic form (seen else where in world)
 It usually occurs in children in between the age of 3-14 years.
 It responds favorably to chemotherapy.
 The association between Burkitt lymphoma and EBV is observed from the following
features.
• Over 90% of Burkitt lymphomas are EBV-positive in which the tumour cells carry the viral DNA.
• 100% cases of Burkitt lymphoma show elevated levels of antibody titres to various EBV
antigens.
• EBV has strong tropism for B lymphocytes. EBV-infected B cells grown in cultures are
immortalized, i.e. they continue to develop further along B-cell-line to propagate their
progeny in the altered form.

8. Anaplastic nasopharyngeal carcinoma
 This is the other tumour having involvement of EBV infection.
 The tumour is prevalent in South-East Asia, especially in the Chinese, and in
Eskimos.
 The evidence linking EBV infection with this tumour is as follows:
i. 100% cases of nasopharyngeal carcinoma carry DNA of EBV in nuclei of tumour cells.
ii. Individuals with this tumour have titres of antibodies to various EBV antigens.

9. Diagnosis
 Heterophile anti body test
 EBV- specific anti-bodies test
 Culture of EBV requires 4 to 6 weeks
 Real time PCR - expensive and not commonly used.

10. Prevention
 Avoid contact with saliva
 Do not kiss children on the mouth.
 Maintain clean conditions
 Vaccines : not available currently