The Antitumor Efficacy of IL2/IL21-Cultured Polyfunctional Neu-Specific T Cells Is TNFα/IL17 Dependent

Abstract

Purpose Infusion of HER2 specific T-cells, derived from vaccine-primed patients and expanded with IL-2/IL-12, has induced tumor regression in a minority of patients with metastatic treatment-refractory HER2+ breast cancer. We questioned whether alteration of cytokine growth factors used to culture vaccine-primed T-cells could improve anti-tumor activity. Experimental Design Using the TgMMTV-neu murine mammary tumor model we cultured T-cells derived from mice immunized with a previously defined neu class II peptide, p98–114 (neu p98), and evaluated different cytokine combinations for expansion. Results Infusion of neu p98 specific T-cell lines derived from all cytokine conditions evaluated resulted in significant anti-tumor activity compared to infused naïve splenocytes (p<0.05). T-cells cultured with IL-2/IL-21 could uniquely mediate complete regression of spontaneous mammary tumors. IL-2/IL-21 cultured neu specific T-cells demonstrated a different cytokine secretion pattern as compared to other cultured T-cells; secreting high levels of TNF-alpha and IL-17 (p<0.05). Moreover, tumor infiltrating CD8+ cells were significantly increased after the infusion of IL-2/IL-21 cultured T-cells as compared to tumors treated with T-cells expanded under other cytokine conditions (p<0.001). The anti-tumor effect of the infusion of IL-2/IL-21 cultured cells was mediated by CD8 T-cells. Depletion of TNF-alpha or IL-17, but not IFN-gamma, abrogated the tumor growth inhibition induced by the IL-2/IL-21 T-cells and markedly decreased the influx of CD8 into tumors. Finally, IL-2/IL-21 cultured human antigen specific T-cells also displayed a similar polyfunctional Th1/Th17 phenotype. Conclusion Expansion of HER2 vaccine-primed T-cells with IL-2/IL-21 may have the potential to effectively mediate tumor regression when used in adoptive transfer.

Adoptive immunotherapy via CD4+ versus CD8+ T cells

“…In a TgMMTV-neu murine mammary tumor model, infusion of neu p98-specific T cell lines derived from IL2/IL21 culture led to a different cytokine secretion pattern, including significantly higher production of TNF-α and IL17 (p<0.5). Following infusion of IL2/IL21 cultured T cells, tumor-infiltrating CD8+ cells were significantly increased (Phan-Lai et al, 2015). Moreover, results with IL2/IL21 cultured human antigen-specific T cells were similar to those of murine T cells.…”

“…RORγt deficiency diminishes Th17 activity (Dong, 2008). Recently, human Th1/Th17 cells could be induced by culture in IL-2 and IL-21 (an autocrine growth factor for Th17) (Korn et al, 2009;Phan-Lai et al, 2015). Moreover, gene expression of Th17 transcription factor, RORc, and IFN-γ regulatory factor, IRF-4, was significantly enhanced after IL-2/IL-21 culture.…”

“…Comparative investigations on the role of cytokine growth factors (used in combination with IL-2) to induce optimal T cell immunity are limited and unclear. Recent data suggest that IL2/IL21 may be optimal cytokines to mediate robust T cell immunity and elicit tumor regression (Phan-Lai et al, 2015). In a TgMMTV-neu murine mammary tumor model, infusion of neu p98-specific T cell lines derived from IL2/IL21 culture led to a different cytokine secretion pattern, including significantly higher production of TNF-α and IL17 (p<0.5).…”

“…Thus, cytokine growth factors used in ex vivo expansion of vaccine-primed CD4+ T cells can significantly improve antitumor immune responses. The choice of cytokine growth factor, therefore, is critical (Meng et al, 2016a;Phan-Lai et al, 2015). Specifically, IL2/IL21 (perhaps also in combination with other cytokines) can give rise to Th1/Th17 polyfunctional T cells and induce durable responses in mice and patients (Phan-Lai et al, 2015).…”

“…Today, there are a variety of approaches to elicit antitumor immunity. These approaches include therapeutic cancer vaccines (Cherryholmes et al, 2015;Guo et al, 2013;Knutson and Mittendorf, 2015), antitumor antibodies (Antonioli et al, 2016;Meng et al, 2016b), immune checkpoint blockade (Kakavand et al, 2016;Tang et al, 2016), and adoptive T cell therapy (ACT) (Phan-Lai et al, 2015;Restifo et al, 2012;Yee et al, 2002). In this review only ACT will be discussed.…”