The expression of Foxp3 protein by retroviral vector-mediated gene transfer of Foxp3 in C57BL/6 mice / 대한수의학회지

The maintenance of peripheral immune tolerance and prevention of chronic inflammation and autoimmune disease require CD4+CD25+ T cells (regulatory T cells). The transcription factor Foxp3 is essential for the development of functional, regulatory T cells, which plays a prominent role in self-tolerance. Retroviral vectors can confer high level of gene transfer and transgene expression in a variety of cell types. Here we observed that following retroviral vector-mediated gene transfer of Foxp3, transductional Foxp3 expression was increased in the liver, lung, brain, heart, muscle, spinal cord, kidney and spleen. One day after vector administration, high levels of transgene and gene expression were observed in liver and lung. At 2 days after injection, transductional Foxp3 expression level was increased in brain, heart, muscle and spinal cord, but kidney and spleen exhibited a consistent low level. This finding was inconsistent with the increase in both CD4+CD25+ T cell and CD4+Foxp3+ T cell frequencies observed in peripheral immune cells by fluorescence-activated cell-sorting (FACS) analysis. Retroviral vector-mediated gene transfer of Foxp3 did not lead to increased numbers of CD4+CD25+ T cell and CD4+Foxp3+ T cell. These results demonstrate the level and duration of transductional Foxp3 gene expression in various tissues. A better understanding of Foxp3 regulation can be useful in dissecting the cause of regulatory T cells dysfunction in several autoimmune diseases and raise the possibility of enhancing suppressive functions of regulatory T cells for therapeutic purposes.

Glatiramer acetate inhibits the activation of NFkappaB in the CNS of experimental autoimmune encephalomyelitis / 대한수의학회지

Glatiramer acetate (GA; Copaxone) has been shown to be effective in preventing and suppressing experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). It has been recently shown that GA-reactive T cells migrate through the blood-brain barrier, accumulate in the central nervous system (CNS), secrete antiinflammatory cytokines and suppress production of proinflammatory cytokines of EAE and MS. Development of EAE requires coordinated expression of a number of genes involved in the activation and effector functions of inflammatory cells. Activation of inflammatory cells is regulated at the transcriptional level by several families of transcription factors. One of these is the nuclear factor kappa B (NFkappaB) family which is present in a variety of cell types and involved in the activation of immune-relative genes during inflammatory process. Since it is highly activated at site of inflammation, NFkappaB activation is also implicated in the pathogenesis of EAE. In this study, we examined whether the inhibition of NFkappaB activation induced by GA can have suppressive therapeutic effects in EAE mice. We observed the expression of NFkappaB and phospho-IkappaB proteins increased in GA-treated EAE mice compared to EAE control groups. The immunoreactivity in inflammatory cells and glial cells of NFkappaB and phospho-IkappaB significantly decreased at the GA-treated EAE mice. These results suggest that treatment of GA in EAE inhibits the activation of NFkappaB and phophorylation of IkappaB in the CNS. Subsequently, the inhibition of NFkappaB activation and IkappaB phosphorylation leads to the anti-inflammatory effects thereby to reduce the progression and severity of EAE.