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

Obesity and inflammation: colorectal cancer engines

The prevalence of obesity continues to increase to the extent that it became a worldwide pandemic. An accumulating body of evidence has associated obesity with the development of different types of cancer, including colorectal cancer, which is a notorious disease with a high mortality rate. At the molecular level, colorectal cancer is a heterogenous disease characterized by a myriad of genetic and epigenetic alterations associated with various forms of genomic instability (detailed in Supplementary Materials). Recently, the microenvironment has emerged as a major factor in carcinogenesis. Our aim is to define the different molecular alterations leading to the development of colorectal cancer in obese patients with a focus on the role of the microenvironment in carcinogenesis. We also highlight all existent molecules in clinical trials that target the activated pathways in obesity-associated colorectal cancer, whether used as single treatments or in combination. Obesity predisposes to colorectal cancer via creating a state of chronic inflammation with dysregulated adipokines, inflammatory mediators, and other factors such as immune cell infiltration. A unifying theme in obesity-mediated colorectal cancer is the activation of the PI3K/AKT, mTOR/MAPK, and STAT3 signaling pathways. Different inhibitory molecules towards these pathways exist, increasing the therapeutic choice of obesity-associated colon cancer. However, obese patients are more likely to suffer from chemotherapy overdosing. Preventing obesity through maintaining a healthy and active lifestyle remains to be the best remedy.

Harnessing Tumor Necrosis Factor Alpha to Achieve Effective Cancer Immunotherapy

Tumor necrosis factor alpha (TNFα) is a pleiotropic cytokine known to have contradictory roles in oncoimmunology. Indeed, TNFα has a central role in the onset of the immune response, inducing both activation and the effector function of macrophages, dendritic cells, natural killer (NK) cells, and B and T lymphocytes. Within the tumor microenvironment, however, TNFα is one of the main mediators of cancer-related inflammation. It is involved in the recruitment and differentiation of immune suppressor cells, leading to evasion of tumor immune surveillance. These characteristics turn TNFα into an attractive target to overcome therapy resistance and tackle cancer. This review focuses on the diverse molecular mechanisms that place TNFα as a source of resistance to immunotherapy such as monoclonal antibodies against cancer cells or immune checkpoints and adoptive cell therapy. We also expose the benefits of TNFα blocking strategies in combination with immunotherapy to improve the antitumor effect and prevent or treat adverse immune-related effects.

Efficient gene transfer into T lymphocytes by fiber-modified human adenovirus 5

Background

The gene transduction efficiency of adenovirus to hematopoietic cells, especially T lymphocytes, is needed to be improved. The purpose of this study is to improve the transduction efficiency of T lymphocytes by using fiber-modified human adenovirus 5 (HAdV-5) vectors.

Results

Four fiber-modified human adenovirus 5 (HAdV-5) vectors were investigated to transduce hematopoietic cells. F35-EG or F11p-EG were HAdV-35 or HAdV-11p fiber pseudotyped HAdV-5, and HR-EG or CR-EG vectors were generated by incorporating RGD motif to the HI loop or to the C-terminus of F11p-EG fiber. All vectors could transduce more than 90% of K562 or Jurkat cells at an multiplicity of infection (MOI) of 500 viral particle per cell (vp/cell). All vectors except HR-EG could transduce nearly 90% cord blood CD34+ cells or 80% primary human T cells at the MOI of 1000, and F11p-EG showed slight superiority to F35-EG and CR-EG. Adenoviral vectors transduced CD4+ T cells a little more efficiently than they did to CD8+ T cells. These vectors showed no cytotoxicity at an MOI as high as 1000 vp/cell because the infected and uninfected T cells retained the same CD4/CD8 ratio and cell growth rate.

Conclusions

HAdV-11p fiber pseudotyped HAdV-5 could effectively transduce human T cells when human EF1a promoter was used to control the expression of transgene, suggesting its possible application in T cell immunocellular therapy.

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

Increasing evidence suggests that TLR4 expression by tumour cells promotes tumour progression, but it is unclear whether TLR4 is involved in metastasis. Here we show that TLR4 deficiency significantly diminishes experimental lung metastasis without affecting primary tumour growth. Bone marrow transplantation experiment and application of antiplatelet agents in mice demonstrate that TLR4 on platelets plays an important role in metastasis. TLR4 is critical for platelet-tumour cell interaction in vitro. Furthermore, high-mobility group box1 (HMGB1) neutralization attenuates platelet-tumour cell interaction in vitro and metastasis in vivo in a TLR4-dependent manner, indicating that tumour cell-released HMGB1 is the key factor that interacts with TLR4 on platelets and mediates platelet-tumour cell interaction, which promotes metastasis. These findings demonstrate a mechanism by which platelets promote tumour cell metastasis and suggest TLR4, and its endogenous ligand HMGB1 as targets for antimetastatic therapies.

Chapter six--Adenovirus-based immunotherapy of cancer: promises to keep

Progress in vector design and an increased knowledge of mechanisms underlying tumor-induced immune suppression have led to a new and promising generation of Adenovirus (Ad)-based immunotherapies, which are discussed in this review. As vaccine vehicles Ad vectors (AdVs) have been clinically evaluated and proven safe, but a major limitation of the commonly used Ad5 serotype is neutralization by preexistent or rapidly induced immune responses. Genetic modifications in the Ad capsid can reduce intrinsic immunogenicity and facilitate escape from antibody-mediated neutralization. Further modification of the Ad hexon and fiber allows for liver and scavenger detargeting and selective targeting of, for example, dendritic cells. These next-generation Ad vaccines with enhanced efficacy are now becoming available for testing as tumor vaccines. In addition, AdVs encoding immune-modulating products may be used to convert the tumor microenvironment from immune-suppressive and proinvasive to proinflammatory, thus facilitating cell-mediated effector functions that can keep tumor growth and invasion in check. Oncolytic AdVs, that selectively replicate in tumor cells and induce an immunogenic form of cell death, can also be armed with immune-activating transgenes to amplify primed antitumor immune responses. These novel immunotherapy strategies, employing highly efficacious AdVs in optimized configurations, show great promise and warrant clinical exploration.

Diminished metastasis in tetraspanin CD151-knockout mice

Tetraspanin protein CD151 on tumor cells supports invasion and metastasis. In the present study, we show that host animal CD151 also plays a critical role. CD151-null mice showed markedly diminished experimental lung metastasis after injection of Lewis lung carcinoma or B16F10 melanoma cells. Diminished tumor cell residence in the lungs was evident 6-24 hours after injection. Consistent with an endothelial cell deficiency, isolated CD151-null mouse lung endothelial cells showed diminished support for B16F10 adhesion and transendothelial migration, diminished B16F10-induced permeability, and diminished B16F10 adhesion to extracellular matrix deposited by CD151-null mouse lung endothelial cells. However, CD151 deletion did not affect the size of metastatic foci or subcutaneous primary B16F10 tumors, tumor aggregation, tumor clearance from the blood, or tumor-induced immune cell activation and recruitment. Therefore, the effects of host CD151 on metastasis do not involve altered local tumor growth or immune surveillance. VEGF-induced endothelial cell signaling through Src and Akt was diminished in CD151-null endothelial cells. However, deficient signaling was not accompanied by reduced endothelial permeability either in vitro (monolayer permeability assay) or in vivo (VEGF-stimulated Miles assay). In summary, diminished metastasis in CD151-null host animals may be due to impaired tumor-endothelial interactions, with underlying defects in mouse lung endothelial cell extracellular matrix production.

Enhanced transduction and replication of RGD-fiber modified adenovirus in primary T cells

Background

Adenoviruses are often used as vehicles to mediate gene delivery for therapeutic purposes, but their research scope in hematological cells remains limited due to a narrow choice of host cells that express the adenoviral receptor (CAR). T cells, which are attractive targets for gene therapy of numerous diseases, remain resistant to adenoviral infection because of the absence of CAR expression. Here, we demonstrate that this resistance can be overcome when murine or human T cells are transduced with an adenovirus incorporating the RGD-fiber modification (Ad-RGD).

Methodology/Principal Finding

A luciferase-expressing replication-deficient Ad-RGD infected 3-fold higher number of activated primary T cells than an adenovirus lacking the RGD-fiber modification in vitro. Infection with replication-competent Ad-RGD virus also caused increased cell cycling, higher E1A copy number and enriched hexon antigen expression in both human and murine T cells. Transduction with oncolytic Ad-RGD also resulted in higher titers of progeny virus and enhanced the killing of T cells. In vivo, 35–45% of splenic T cells were transduced by Ad-RGD.

Conclusions

Collectively, our results prove that a fiber modified Ad-RGD successfully transduces and replicates in primary T cells of both murine and human origin.

Transgene expression of alpha tumor necrosis factor with mutations D142N and A144R under control of human telomerase reverse transcriptase promoter eradicates well-established tumors and induces long-term antitumor immunity

Recombinant adenoviral vectors (AdVTNF-alpha) expressing alpha tumor necrosis factor (TNF-alpha) under control of cytomegalovirus (CMV) promoter have been used in cancer gene therapy. To reduce its cytotoxicity, we constructed a recombinant AdV(TERT)mTNF-alpha expressing a mutant TNF-alpha (mTNF-alpha) with mutations at D142N and A144R under control of human telomerase reverse transcriptase (hTERT) promoter for treatment of well-established ovalbumin (OVA)-expressing murine B16 melanoma (BL6-10(OVA)) (6 mm in diameter). We demonstrated that the mTNF-alpha with mutations at D142N and A144R has less in vitro cytotoxicity, but maintains its functional effect in the stimulation of T-cell proliferation. The in vitro and in vivo transgene expressions under control of hTERT promoter are highly restricted in tumor cells compared with those under the control of the CMV promoter. AdV(TERT)mTNF-alpha gene therapy by intratumoral injection of AdV(TERT)mTNF-alpha vector (2 x 10(9) PFU) expressing the mutant mTNF-alpha under control of hTERT promoter reduces its in vivo toxicity, eradicates well-established BL6-10(OVA) tumors in 4/10 tumor-bearing mice, and induces OVA-specific CD8(+) T-cell-mediated long-term antitumor immunity. Therefore, AdV(TERT)mTNF-alpha gene therapy may be very useful in the immunotherapy of cancer.

Tumor necrosis factor and cancer, buddies or foes?

Tumor necrosis factor (TNF) is a multifunctional cytokine that plays important roles in diverse cellular events such as cell survival, proliferation, differentiation, and death. As a pro-inflammatory cytokine, TNF is secreted by inflammatory cells, which may be involved in inflammation-associated carcinogenesis. TNF exerts its biological functions through activating distinct signaling pathways such as nuclear factor-kappaB (NF-kappaB) and c-Jun N-terminal kinase (JNK). NF-kappaB is a major cell survival signal that is anti-apoptotic, whereas sustained JNK activation contributes to cell death. The crosstalk between the NF-kappaB and JNK is involved in determining cellular outcomes in response to TNF. In regard to cancer, TNF is a double-dealer. On one hand, TNF could be an endogenous tumor promoter, because TNF stimulates the growth, proliferation, invasion and metastasis, and tumor angiogenesis of cancer cells. On the other hand, TNF could be a cancer killer. The property of TNF in inducing cancer cell death renders it a potential cancer therapeutic, although much work is needed to reduce its toxicity for systematic TNF administration. Recent studies have focused on sensitizing cancer cells to TNF-induced apoptosis through inhibiting survival signals such as NF-kappaB, by combined therapy. In this article we provide an overview of the roles of TNF-induced signaling pathways in cancer biology with specific emphasis on carcinogenesis and cancer therapy.