Pannexin-1 channels, extracellular ATP, and purinergic receptors are essential for CCR5/CXCR4 clustering and HIV entry.

Abstract

Objective: The Human Immunodeficiency Virus-1 (HIV) cell entry has been well characterized with the identification of CD4 as the main receptor and CXCR4 and CCR5 as co-receptors for the virus. However, how the virus uses the cell machinery for entry and infection is still a work-in-progress. Previously, we identified that the Pannexin-1 (Panx-1) channel, extracellular ATP, and purinergic receptors axis are essential for HIV entry and replication in macrophages, but the mechanisms were not fully explored.

Methods: Electrophysiology, ATP quantifications, confocal, HIV entry and replication experiments were used to determine the role of Panx-1 channels in HIV entry.

Results: Here, we identified that HIV or gp120 induces Panx-1 channel opening in association with ATP secretion, purinergic activation, and CCR5/CXCR4/actin clustering to enable HIV entry. Blocking Panx-1 channel opening, ATP secretion, or purinergic signaling prevented co-receptor clustering, HIV entry, and subsequent replication in multiple cell types.

Conclusion: We conclude that gp120 binding to the cell induces Panx-1 opening to promote the clustering of CCR5 or CXCR4 to the site of CD4-gp120 contact to aid viral entry.