Frontiers in Oncology (Jul 2022)

Controversial Role of the Immune Checkpoint OX40L Expression on Platelets in Breast Cancer Progression

  • Susanne M. Rittig,
  • Susanne M. Rittig,
  • Martina S. Lutz,
  • Martina S. Lutz,
  • Kim L. Clar,
  • Kim L. Clar,
  • Yanjun Zhou,
  • Yanjun Zhou,
  • Korbinian N. Kropp,
  • André Koch,
  • Andreas D. Hartkopf,
  • Andreas D. Hartkopf,
  • Martina Hinterleitner,
  • Martina Hinterleitner,
  • Lars Zender,
  • Lars Zender,
  • Lars Zender,
  • Helmut R. Salih,
  • Helmut R. Salih,
  • Stefanie Maurer,
  • Stefanie Maurer,
  • Stefanie Maurer,
  • Clemens Hinterleitner,
  • Clemens Hinterleitner,
  • Clemens Hinterleitner

DOI
https://doi.org/10.3389/fonc.2022.917834
Journal volume & issue
Vol. 12

Abstract

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In conventional T cells, OX40 has been identified as a major costimulating receptor augmenting survival and clonal expansion of effector and memory T cell populations. In regulatory T cells, (Treg) OX40 signaling suppresses cellular activity and differentiation. However, clinical trials investigating OX40 agonists to enhance anti-tumor immunity, showed only limited success so far. Here we show that platelets from breast cancer patients express relevant levels of OX40L and platelet OX40L (pOX40L) inversely correlates with platelet-expressed immune checkpoint molecules GITRL (pGITRL) and TACI (pTACI). While high expression of pOX40L correlates with T and NK cell activation, elevated pOX40L levels identify patients with higher tumor grades, the occurrence of metastases, and shorter recurrence-free survival (RFS). Of note, OX40 mRNA levels in breast cancer correlate with enhanced expression of anti-apoptotic, immune-suppressive, and tumor-promoting mRNA gene signatures. Our data suggest that OX40L on platelets might play counteracting roles in cancer and anti-tumor immunity. Since pOX40L reflects disease relapse better than the routinely used predictive markers CA15-3, CEA, and LDH, it could serve as a novel biomarker for refractory disease in breast cancer.

Keywords