Myelin basic protein-specific T lymphocytes proliferation and programmed cell death in demyelinating diseases.

A dynamic equilibrium between proliferation and programmed cell death (PCD) of auto-reactive T lymphocytes plays a pivotal role in the prevention of autoimmune diseases. We analyzed T lymphocytes myelin basic protein (MBP)-specific PCD and proliferation in demyelinating diseases. Results showed that MBP-specific PCD was significantly decreased in CD4+ and CD8+ T lymphocytes of progressive multifocal leukoencephalopathy (PML), not determined leukoencephalopathy (NDLE), and acute MS (AMS) patients compared to patients with stable MS (SMS) and healthy controls. MBP-specific proliferation/PCD rates were high in CD4+ T lymphocytes of PML, NDLE, and AMS patients, and in CD8+ T cells of PML and AMS individuals alone. Alterations of the balance between MBP-specific proliferation and PCD are present in demyelinating diseases and could play a major role in the pathogenesis of these diseases.