HLA-G/ILTs Targeted Solid Cancer Immunotherapy: Opportunities and Challenges

Area of Science:

• Immunology
• Oncology
• Cancer Immunotherapy

Background:

• Immune checkpoint inhibitors (ICIs) are a cornerstone of modern cancer therapy.
• Human leukocyte antigen-G (HLA-G) is increasingly recognized for its role in immune evasion within the tumor microenvironment.
• HLA-G functions as a novel immune checkpoint by interacting with inhibitory receptors ILT-2 and ILT-4 on immune cells.

Purpose of the Study:

• To explore the potential of targeting the HLA-G/ILT-2/-4 signaling pathway for cancer immunotherapy.
• To identify and discuss the significant challenges hindering the clinical application of anti-HLA-G strategies.

Main Methods:

• Review of existing literature on HLA-G function, its role in malignancies, and current "anti-HLA-G" therapeutic strategies.
• Analysis of the mechanisms by which HLA-G mediates immune suppression.
• Identification of key obstacles for clinical translation of HLA-G-targeted therapies.

Main Results:

• HLA-G/ILT-2/-4 signaling promotes immune suppression, tumor growth, and disease progression.
• Early clinical trials are investigating anti-HLA-G strategies for advanced solid cancers.
• Significant challenges include HLA-G isoform diversity, binding specificities, tumor heterogeneity, and lack of specific antibodies and assays.

Conclusions:

• Targeting HLA-G represents a promising avenue for cancer immunotherapy.
• Addressing the identified challenges is crucial for realizing the full clinical potential of HLA-G-targeted therapies.
• Overcoming these hurdles is essential to prevent premature or fluctuating clinical benefits in solid cancer immunotherapy.