Epstein-Barr virus-encoded dUTPase modulates immune function and induces sickness behavior in mice

Area of Science:

• Virology
• Immunology
• Molecular Biology

Background:

• Epstein-Barr virus (EBV) causes infectious mononucleosis and is linked to nasopharyngeal carcinoma and Burkitt's Lymphoma.
• Antibodies to EBV early antigens (EA) are common in NPC and BL patients, but the role of EBV proteins in disease etiology is unclear.
• The EBV EA complex includes deoxyuridine triphosphate nucleotidohydrolase (dUTPase), which may modulate immune cell activation.

Purpose of the Study:

• To investigate the in vivo effects of EBV-encoded dUTPase on immune function and sickness behaviors.
• To determine if EBV dUTPase influences lymphocyte replication and cytokine production.
• To assess the impact of EBV dUTPase administration on animal physiology and behavior.

Main Methods:

• Mice were injected with purified EBV dUTPase.
• Immune function, including mitogen-stimulated lymphocyte replication and interferon-gamma synthesis, was measured.
• Sickness behaviors such as body mass, body temperature, and locomotor activity were assessed.

Main Results:

• EBV dUTPase treatment inhibited the replication of mitogen-stimulated lymphocytes from treated mice.
• Lymphocytes from dUTPase-treated mice showed reduced interferon-gamma synthesis upon re-stimulation.
• Dutpase-treated mice exhibited sickness behaviors, including weight loss, elevated body temperature, and decreased activity.

Conclusions:

• EBV dUTPase modulates immune function in vivo by inhibiting lymphocyte proliferation and cytokine production.
• EBV dUTPase induces sickness behaviors, indicating a direct role in viral pathophysiology.
• Individual viral proteins, such as EBV dUTPase, may contribute to the development of EBV-associated diseases.