Effector T lymphocytes present in demyelinating lesions induced by Theiler's virus

Area of Science:

• Neuroimmunology
• Virology
• Demyelinating Diseases

Background:

• Theiler's virus infection in SJL/J mice causes chronic demyelination and viral persistence.
• Investigating local immune responses in the central nervous system is crucial for understanding persistent viral infections.

Purpose of the Study:

• To assess the effector functions of T lymphocytes within inflammatory brain lesions during Theiler's virus persistence.
• To determine if local immune dysfunction contributes to viral persistence.

Main Methods:

• Isolation of T lymphocytes from inflammatory brain lesions in infected SJL/J mice.
• In vitro assessment of CD4+ T cell function (B-lymphocyte proliferation, antibody secretion).
• In vitro assessment of CD8+ T cell function (cytolytic activity).

Main Results:

• CD4+ T cells isolated from lesions effectively induced B-lymphocyte proliferation and antibody secretion.
• CD8+ T cells isolated from lesions exhibited significant cytolytic activity.
• These findings demonstrate functional T cell responses within the affected brain tissue.

Conclusions:

• Theiler's virus persistence in SJL/J mice is not characterized by local immune unresponsiveness.
• Immune cells within the brain lesions maintain effector functions, suggesting an ongoing immune response.
• The study challenges the notion of immune evasion solely through local immune suppression.