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REVIEW article

Front. Immunol.

Sec. Cancer Immunity and Immunotherapy

Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1499663

This article is part of the Research Topic Immune-Checkpoint Inhibitors and Immunometabolic Reprogramming in Cancer Immunotherapy View all 10 articles

Revealing the Mechanisms and Therapeutic Potential of Immune Checkpoint Proteins Across Diverse Protein Families

Provisionally accepted
  • Beijing University of Chinese Medicine, Beijing, China

The final, formatted version of the article will be published soon.

    Host immune responses to antigens are tightly regulated through the activation and inhibition of synergistic signaling networks that maintain homeostasis. Stimulatory checkpoint molecules initiate attacks on infected or tumor cells, while inhibitory molecules halt the immune response to prevent overreaction and self-injury. Multiple immune checkpoint proteins are grouped into families based on common structural domains or origins, yet the variability within and between these families remains largely unexplored. In this review, we discuss the current understanding of the mechanisms underlying the co-suppressive functions of CTLA-4, PD-1, and other prominent immune checkpoint pathways. Additionally, we examine the IgSF, PVR, TIM, SIRP, and TNF families, including key members such as TIGIT, LAG-3, VISTA, TIM-3, SIRPα, and OX40. We also highlight the unique dual role of VISTA and SIRPα in modulating immune responses under specific conditions, and explore potential immunotherapeutic pathways tailored to the distinct characteristics of different immune checkpoint proteins. These insights into the unique advantages of checkpoint proteins provide new directions for drug discovery, emphasizing that emerging immune checkpoint molecules could serve as targets for novel therapies in cancer, autoimmune diseases, infectious diseases, and transplant rejection.

    Keywords: Immunotherapy, Immune checkpoint proteins, Tumor microenvironment specificity, Co-suppressive pathways, Protein Families

    Received: 21 Sep 2024; Accepted: 28 Mar 2025.

    Copyright: © 2025 Liu, Jiang, Yuting, Dong, Gai and Wei. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Cong Gai, Beijing University of Chinese Medicine, Beijing, China
    Peng Wei, Beijing University of Chinese Medicine, Beijing, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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