Cytomegalovirus and Autophagy

Autophagy is a well-described vacuolar degradative pathway which contributes to the homeostasis of the cell and to the response to environmental stresses. An increasing number of studies describe the modulation of autophagy by a large subset of viruses, either to avoid a host defense mechanism (potentially degrading viral particles before they can escape the host cell) or to hijack the autophagic machinery for their own benefit. Human cytomegalovirus (HCMV) has the capacity to fine tune the autophagic process during its own life cycle, and finally block the autophagic flux to promote its own replication and presumably avoid the degradation of cytoplasmic viral components. At least two anti-autophagic viral proteins encoded by HCMV have been described, but future studies may reveal new viral modulators. The purpose of this chapter is to discuss the significance of these findings in the light of the general knowledge on the autophagic pathway and the interplay between the viruses and this conserved homeostatic pathway. The importance of such information is supported by the recent publication of the 12-volume series (Elsevier) discussing autophagy.