Engineered CD8+ cytotoxic T cells with fiber-modified adenovirus-mediated TNF-α gene transfection counteract immunosuppressive interleukin-10-secreting lung metastasis and solid tumors

Abstract

T-cell suppression derived from tumor-secreted immunosuppressive interleukin (IL)-10 becomes a major barrier to CD8 þ T-cell immunotherapy of tumors. Tumor necrosis factor-alpha (TNF-a) is a multifunctional cytokine capable of activating T and dendritic cells (DCs) and counteracting IL-10-mediated DC inhibition and regulatory T-cell-mediated immune suppression. In this study, we constructed a recombinant adenovirus MF AdVTNF with fiber-gene modified by RGD insertion into the viral knob's H1 loop and a melanoma cell line B16 OVA/ILÀ10 engineered to express ovalbumin (OVA) and to secrete IL-10 (2.2 ng/ml/10 6 cells/24 h). We transfected OVA-specific CD8 þ T cells with MF AdVTNF, and found a fivefold increase in transgene human TNF-a secretion (4.3 ng/ ml/10 6 cells/24 h) by the engineered CD8 þ T TNF cells transfected with MF AdVTNF, compared to that (0.8 ng/ml/10 6 cells/24 h) by CD8 þ T cells transfected with the original AdVTNF without viral fiber modification. The engineered CD8 þ T TNF cells exhibited enhanced cytotoxicity and elongated survival in vivo after adoptive transfer. TNF-a derived from both the donor CD8 þ T cells and the host cells plays an important role in donor CD8 þ T-cell survival in vivo after adoptive transfer. We also demonstrated that the transfected B16 OVA/ILÀ10 tumor cells secreting IL-10 are more resistant to in vivo CD8 þ T-cell therapy than the original B16 OVA tumor cells without IL-10 expression. Interestingly, the engineered CD8 þ T TNF cells secreting transgene-coded TNF-a, but not the control CD8 þ T control cells without any transgene expression eradicated IL-10-secreting 12-day lung micrometastasis in all 10/10 mice and IL-10-secreting solid tumors (B5 mm in diameter) in 6/10 mice. Transfer of the engineered CD8 þ T TNF cells further induced both donor-and host-derived memory CD8 þ T cells, leading to a stronger long-term antitumor immunity against the IL-10-secreting B16 OVA/ILÀ10 tumor cell challenges. Therefore, CD8 þ T cells engineered to secrete TNF-a may be useful when designing strategies for adoptive T-cell therapy of solid tumors.

Tumor necrosis factor and cancer, buddies or foes?

“…TNF behaved as an immunoadjuvant through inducing major histocompatibility complex (MHC) class I molecules or maintaining DCs’ maturation status[141, 142]. Similarly, TNF gene-engineered CD8+ cytotoxic T cells had enhanced cytotoxicity and prolonged survival in vivo after adoptive transfer, and exerted a stronger antitumor immunity against the immunosuppressive IL-10-secreting B16 lung tumors in mice[143]. Injecting a TNF-engineered tumor vaccine into tumors strongly augmented their overall antitumor effectiveness through development of systemic antitumor immunity [144, 145].…”

Enhanced Transduction and Replication of RGD-Fiber Modified Adenovirus in Primary T Cells

“…T cell activation induced expression of α v β3 and α v β5 integrins on cell surface has already been known for quite some time [4]. Although reports of successful RGD-fiber modified virus mediated gene delivery in T cells have been reported, knowledge about viral-replication in the transduced T cells has not yet been addressed [30].…”

Platelets promote tumour metastasis via interaction between TLR4 and tumour cell-released high-mobility group box1 protein

“…These data suggest that TLR4 deficiency led to decreased platelet activation on tumour cell infusion. Recruitment of immune cells, such as T cells, NK cells, NKT cells and myeloid-derived suppressor cells (MDSCs) can affect the tumour burden in the lung [34][35][36][37] . Therefore, we determined the changes in the composition of immune cell subsets of splenocytes, blood and metastatic tumour foci in the lung in tumour-bearing mice.…”