PKM2-mediated inhibition of autophagy facilitates Tat's inducing HIV-1 transactivation.

Considerable evidence has shown that autophagy has an important role in HIV-1 infection. However, it is still unknown whether metabolism-regulated autophagy pathway is involved in Tat-mediated HIV-1 transactivation. This study demonstrated that treatment of Tat in TZM-bl cells significantly down-regulated protein levels of Beclin-1, Atg-5, Atg-7, and LC3B-II and up-regulated of p62 levels. Blockage of autophagy enhanced Tat-induced HIV-1 transactivation in TZM-bl cells. Moreover, we found that Tat activated the Akt/mTOR and inhibited AMPK signaling pathway that was related to its up-regulation of PKM2 expression. In addition, we showed that PI3K/AKT activation and AMPK inhibtion was required for the PKM2-mediated inhibition of autophagy in Tat-treated TZM-bl cells. In conclusion, our data reveals that PKM2-mediated autophagy inhibition is required for Tat-mediated HIV-1 transactivation. Metabolism-related autophagic pathway may act as a promising diagnostic and therapeutic tool for HIV-1 infection in the future.