Targeting the "PVR-TIGIT axis" with immune checkpoint therapies

Area of Science:

• Immunology
• Oncology
• Molecular Biology

Background:

• Current cancer immunotherapies like checkpoint inhibitors (anti-CTLA-4, anti-PD1, anti-PDL-1) show variable efficacy across different tumors.
• Tumor microenvironment, immune infiltrate, and target molecule expression influence immunotherapy response.
• Identifying novel immune checkpoint targets is critical for improving cancer treatment.

Purpose of the Study:

• To review recent advances in understanding the PVR-TIGIT axis in immune regulation.
• To discuss the potential of targeting the PVR-TIGIT axis for novel cancer immunotherapies.
• To highlight the need for further research into the mechanisms of this axis, particularly in humans.

Main Methods:

• Literature review of studies on PVR-like molecules and their interactions with immune cells.
• Analysis of PVR, Nectin-2, TIGIT, CD96, and DNAM-1 expression in tumors and immune cells.
• Examination of the functional consequences of these molecular interactions on immune responses.

Main Results:

• PVR-like molecules play regulatory roles in immune cell function and are upregulated in malignancies.
• The PVR-TIGIT axis involves interactions between PVR, Nectin-2, TIGIT, CD96, and DNAM-1.
• Distinct immune responses, including activation and suppression, are mediated by these interactions, with varying effects in murine models versus humans for CD96.

Conclusions:

• The PVR-TIGIT axis presents a promising target for developing new immune checkpoint therapies.
• Further research is needed to elucidate the precise mechanisms of the PVR-TIGIT synapse, especially concerning human CD96 and Nectin-2.
• Targeting this axis could overcome limitations of current immunotherapies and improve cancer treatment outcomes.