Glutamine is a crucial source of energy during HIV latent infection and has detrimental effect. IDO expression is increased during HIV and EBV infections and its blockade lead to kill infected macrophages. Role of Arginine metabolism is depending of the phase infection and can be beneficial or detrimental. mTOR is largely modulated by viruses to promote cellular infection. This evidence concerns the gene IDO1 and disease arising from reactivation of latent virus.