Autophagy regulates T lymphocyte proliferation through selective degradation of the cell-cycle inhibitor CDKN1B/p27Kip1

作者：Jia Wei; He Ming Xiao; McLeod Ian X; Guo Jian; Ji Dong; He You Wen^*

来源：Autophagy, 2015, 11(12): 2335-2345.

DOI：10.1080/15548627.2015.1110666

• ATG3
• ATG7
• autophagy
• CDKN1B
• proliferation
• T lymphocytes

The highly conserved cellular degradation pathway, macroautophagy, regulates the homeostasis of organelles and promotes the survival of T lymphocytes. Previous results indicate that Atg3-, Atg5-, or Pik3c3/Vps34-deficient T cells cannot proliferate efficiently. Here we demonstrate that the proliferation of Atg7-deficient T cells is defective. By using an adoptive transfer and Listeria monocytogenes (LM) mouse infection model, we found that the primary immune response against LM is intrinsically impaired in autophagy-deficient CD8(+) T cells because the cell population cannot expand after infection. Autophagy-deficient T cells fail to enter into S-phase after TCR stimulation. The major negative regulator of the cell cycle in T lymphocytes, CDKN1B, is accumulated in autophagy-deficient naive T cells and CDKN1B cannot be degraded after TCR stimulation. Furthermore, our results indicate that genetic deletion of one allele of CDKN1B in autophagy-deficient T cells restores proliferative capability and the cells can enter into S-phase after TCR stimulation. Finally, we found that natural CDKN1B forms polymers and is physiologically associated with the autophagy receptor protein SQSTM1/p62 (sequestosome 1). Collectively, autophagy is required for maintaining the expression level of CDKN1B in naive T cells and selectively degrades CDKN1B after TCR stimulation.

• 出版日期2015-12