Abrogation of TNFα Production during Cancer Immunotherapy Is Crucial for Suppressing Side Effects Due to the Systemic Expression of IL-12

Abstract

For more than a decade, the cytokine interleukin-12 (IL-12) has been utilized, either alone or in combination with other drugs, as a treatment for cancer. The numerous anti-tumor properties of IL-12 still generate interest in the clinical use of this cytokine, even though it has demonstrated toxicity when administrated systemically. As an approach to overcome this toxicity, numerous laboratories have attempted to induce IL-12 expression at the site of the tumor. However for tumors that are difficult to remove surgically or for the treatment of disseminated metastases, systemic expression of this cytokine still remains as the most efficient method of administration. Nevertheless, finding alternative approaches for the use of IL-12 in the treatment of cancer and unraveling the basis of IL-12-side effects remain a challenge. In the present work we demonstrate that systemic expression of IL-12 through hydrodynamic injection of IL-12 cDNA is able to induce different types of liver lesions associated with a toxic pathology. However we report here that hepatic toxicity is diminished and survival of mice enhanced in the absence of tumor necrosis factor alpha (TNFα). This observation is in contrast to several murine models and clinical trials that postulate interferon gamma (IFNγ) as the main cytokine responsible for IL-12 toxicity. Moreover, our work demonstrates that when IL-12 cDNA is co-injected with IL-18 cDNA or when mice are pre-treated with a low dose of IL-12 cDNA prior to receiving a high dose of IL-12 cDNA, systemic levels of TNFα are almost completely abrogated, resulting in improved survival and less hepatic damage. Importantly, abrogation of TNFα signaling does not affect the strong anti-tumor activity of IL-12. Thus, neutralizing TNFα with antagonists already approved for human use offers a promising approach to abrogate IL-12 side effects during the use of this cytokine for the treatment of cancer.

Intra-tumoral production of IL18, but not IL12, by TCR-engineered T cells is non-toxic and counteracts immune evasion of solid tumors

“…The detection of IFNγ and TNFα in plasma is considered a consequence of IL-12-mediated productions of these cytokines by tumor-infiltrating immune cells. 34 IFNγ is most likely derived from administered T cells following infiltration and activation in the tumor tissue. This notion is strengthened by our observation that CD335-positive NK cells, as an alternative source of IFNγ, were only present at low frequency within the tumors of treated mice.…”

“…Collectively, our findings extend previous clinical studies, where systemic administration of recombinant protein or cDNA encoding IL-12 was reported to result in enhanced production of IFNγ and TNFα, changes in blood vessel wall permeability, edema and even sepsis-like symptoms. 34,35 In fact, a recent study demonstrated that treatment of melanoma patients with iIL-12-transduced TILs was accompanied by liver dysfunction, high fever, and hemodynamic instability. 36 To further assess the observed toxicities, we also treated mice without tumor-implant with TCR+iIL-12 T cells and still observed enhanced weight loss when compared to mice treated with TCR T cells (see supplementary figure 3).…”

Systemic sterile induced-co-expression of IL-12 and IL-18 drives IFN-γ-dependent activation of microglia and recruitment of MHC-II-expressing inflammatory monocytes into the brain

“…Accordingly, it has been previously shown that an increase in IL-10 correlates with a protective role mediated by this cytokine, limiting an exacerbated inflammation induced by pro-inflammatory cytokines such as IL-12 (26) and IFN- (39). Besides, TNF-α was associated with hepatic toxicity and diminished mice survival when IL-12 cDNA was injected alone (32). Thus, this coordinated Th1/Th2 balance is critical to shape a well-controlled peripheral immune response against systemic inflammatory events, which could in turn lead to neuroinflammation.…”

“…The hydrodynamic gene transfer procedure was adapted according to Liu F et al (31) and routinely used in our laboratory (26,27,32,33). Briefly, through this technique, the large volume and high injection rate used, forces the flow of cDNA solution into tissues directly linked to the inferior vena cava.…”

Preclinical validation: LV/IL-12 transduction of patient leukemia cells for immunotherapy of AML

“…11–14 Side products including interferon-γ (IFN-γ) and tumor necrosis factor alpha (TNFα) were believed to contribute to such toxicities. 15,16 …”