ABSTRACT
CD4 encodes a glycoprotein, located on the surface of T helper (Th) cells and regulatory T cells. Through interaction with MHC class II molecules, CD4 directs the linage development of Th cells in immune organs and activates the CD4+ T cell maturation process [1]. Thus, the transcriptional level of CD4 is directly related to T cell development [2]. In mice, CD4 transcription is controlled by several cis-acting elements including enhancers, silencers and DNA methylation [3,4]. However, the epigenetic regulation of CD4 gene in chicken and its relationship with any virus infection are still unclear.
