In:
The Journal of Immunology, The American Association of Immunologists, Vol. 197, No. 1 ( 2016-07-01), p. 168-178
Abstract:
Tumors with the help of the surrounding environment facilitate the immune suppression in patients, and immunotherapy can counteract this inhibition. Among immunotherapeutic strategies, the immunostimulatory cytokine IL-15 could represent a serious candidate for the reactivation of antitumor immunity. However, exogenous IL-15 may have a limited impact on patients with cancer due to its dependency on IL-15Rα frequently downregulated in cancer patients. In this work, we studied the antitumor activity of the IL-15 superagonist receptor-linker–IL-15 (RLI), designed to bypass the need of endogenous IL-15Rα. RLI consists of human IL-15 covalently linked to the human IL-15Rα sushi+ domain. In a mouse model of colorectal carcinoma, RLI as a stand-alone treatment could limit tumor outgrowth only when initiated at an early time of tumor development. At a later time, RLI was not effective, coinciding with the strong accumulation of terminally exhausted programmed cell death-1 (PD-1)high T cell Ig mucin-3+ CD8+ T cells, suggesting that RLI was not able to reactivate terminally exhausted CD8+ T cells. Combination with PD-1 blocking Ab showed synergistic activity with RLI, but not with IL-15. RLI could induce a greater accumulation of memory CD8+ T cells and a stronger effector function in comparison with IL-15. Ex vivo stimulation of tumor-infiltrated lymphocytes from 16 patients with renal cell carcinoma demonstrated 56% of a strong tumor-infiltrated lymphocyte reactivation with the combination anti–PD-1/RLI compared with 43 and 6% with RLI or anti–PD-1, respectively. Altogether, this work provides evidence that the sushi–IL-15Rα/IL-15 fusion protein RLI enhances antitumor activity of anti–PD-1 treatment and is a promising approach to stimulate host immunity.
Type of Medium:
Online Resource
ISSN:
0022-1767
,
1550-6606
DOI:
10.4049/jimmunol.1600019
Language:
English
Publisher:
The American Association of Immunologists
Publication Date:
2016
detail.hit.zdb_id:
1475085-5
