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

TL;DR

This study shows that HIV uses specific cell channels and signaling to cluster receptors and enter cells.

Contribution

The study reveals a novel mechanism where Pannexin-1 channels and ATP signaling are essential for HIV receptor clustering and entry.

Findings

HIV or gp120 induces Panx-1 channel opening and ATP secretion.

Blocking Panx-1 or ATP signaling prevents HIV entry and replication.

Purinergic signaling is required for CCR5/CXCR4 clustering and HIV infection.

Abstract

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.

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

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.

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.

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