1. Academic Validation
  2. Complement c5a receptor facilitates cancer metastasis by altering T-cell responses in the metastatic niche

Complement c5a receptor facilitates cancer metastasis by altering T-cell responses in the metastatic niche

  • Cancer Res. 2014 Jul 1;74(13):3454-65. doi: 10.1158/0008-5472.CAN-14-0157.
Surya Kumari Vadrevu 1 Navin K Chintala 1 Sharad K Sharma 1 Priya Sharma 1 Clayton Cleveland 1 Linley Riediger 1 Sasikanth Manne 1 David P Fairlie 2 Wojciech Gorczyca 3 Othon Almanza 4 Magdalena Karbowniczek 1 Maciej M Markiewski 5
Affiliations

Affiliations

  • 1 Authors' Affiliations: Department of Immunotherapeutics and Biotechnology, School of Pharmacy, Texas Tech University Health Science Center;
  • 2 Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, University of Queensland, Queensland, Australia.
  • 3 Bioreference Laboratories, Elmwood Park; Regional Cancer Care Associates, Hackensack, New Jersey; and.
  • 4 Clinical Pathology Associates, Abilene, Texas;
  • 5 Authors' Affiliations: Department of Immunotherapeutics and Biotechnology, School of Pharmacy, Texas Tech University Health Science Center; maciej.markiewski@ttuhsc.edu.
Abstract

The impact of complement on Cancer metastasis has not been well studied. In this report, we demonstrate in a preclinical mouse model of breast Cancer that the complement anaphylatoxin C5a receptor (C5aR) facilitates metastasis by suppressing effector CD8(+) and CD4(+) T-cell responses in the lungs. Mechanisms of this suppression involve recruitment of immature myeloid cells to the lungs and regulation of TGFβ and IL10 production in these cells. TGFβ and IL10 favored generation of T regulatory cells (Treg) and Th2-oriented responses that rendered CD8(+) T cells dysfunctional. Importantly, pharmacologic blockade of C5aR or its genetic ablation in C5aR-deficient mice were sufficient to reduce lung metastases. Depletion of CD8(+) T cells abolished this beneficial effect, suggesting that CD8(+) T cells were responsible for the effects of C5aR inhibition. In contrast to previous findings, we observed that C5aR signaling promoted Treg generation and suppressed T-cell responses in organs where metastases arose. Overall, our findings indicated that the immunomodulatory functions of C5aR are highly context dependent. Furthermore, they offered proof-of-concept for complement-based immunotherapies to prevent or reduce Cancer metastasis.

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