CpG Oligodeoxynucleotides Enhance the Activities of CD8+ Cytotoxic T-Lymphocytes Generated by Combined hMUC1 Vaccination and hNIS Radioiodine Gene Therapy

Abstract

Purpose The authors evaluated whether the cytotoxicity of CD8+CTLs generated by combined hMUC1 vaccination and hNIS radioiodine gene therapy was enhanced in the presence of CpG in an established tumor model. Methods CMNF cells (CT26 cells expressing hMUC1, hNIS and Firefly luciferase) were transplanted into BALB/c mice. Four and 10 days later, tumor-bearing mice were immunized intramuscularly with pcDNA3.1 or pcDNA-hMUC1 or pcDNA-hMUC1+CpG, and subsequently administered PBS or 131 I [five groups (seven mice/group): referred to as the pcDNA3.1+PBS, phMUC1+PBS, pcDNA3.1+ 131 I, phMUC1+ 131 I, and phMUC1+ 131 I+CpG groups]. The number of CD8+IFNr+ T cells of splenocytes as well as the number of CD8+IFNr+ T cells of splenocytes re-stimulated with CD11c+ cells was determined using FACS analysis. The activities of cytotoxic T cells (CTLs) from splenocytes were investigated.Results Marked tumor growth inhibition was observed in the phMUC1+ 131 I and phMUC1+ 131 I+CpG groups, but not in the other three single therapy groups. Particularly the number of CD8+IFN-γ+ T cells of splenocytes was more increased in the phMUC1+ 131 I+CpG group than in the phMUC1+ 131 I group. The number of CD8+IFN-γ+ T cells of splenocytes stimulated with CD11c+ cells was the most enhanced in the phMUC1+ 131 I+CpG group among the five groups. Concurrently, the activities of hMUC1-associated CTLs obtained from splenocytes in the phMUC1+ 131 I+CpG group were significantly greater than in the other four groups (pcDNA+PBS, phMUC1+PBS, pcDNA+ 131 I, phMUC1+ 131 I, and phMUC1+ 131 I+CpG, 16±2%, 20±1%, 30±2%, 60±2%, and 87±2%, respectively, P<0.01). Conclusion Our data suggest that adjuvant CpG ODNs can increase the killing activities of CTLs generated by combined hMUC1 DNA vaccination and hNIS radioiodine gene therapy.

Tracking of dendritic cell migration into lymph nodes using molecular imaging with sodium iodide symporter and enhanced firefly luciferase genes

“…Most importantly, these methods allow researchers to non-invasively monitor the proliferation and migration of infused cells, which are important aspects of cell-based therapy in living subjects. Similar to the luciferase and HSV1-tk genes that are extensively investigated for their use in cell tracking, the NIS gene has also been demonstrated to be an attractive reporter gene for monitoring cancer progression and therapeutic response 6 , stem cell trafficking 8 , and specific cellular events 0 in living subjects. Recently, several studies have demonstrated the possibility of using the NIS gene as a reporter for the tracking of T cells and macrophages.…”

Immunogenic properties of empty pcDNA3 plasmid against zoonotic cutaneous leishmaniasis in mice

“…Boccacio et al have demonstrated that non-coding plasmid DNA inhibits experimental allergic encephalomyelitis via the activation of IFN-γ [ 27 ]. CpG motifs have been used as an adjuvant to enhance the cellular responses in various disorders, such as cancer, and it has a significant immunostimulatory effect on the induction of cell death in cancer cells via activating cytotoxic T cells [ 49 ]. Bacterial CpG motif binds to toll-like receptor 9 (TLR-9), which is expressed by different immune system cells, such as macrophages, dendritic cells and natural killer (NK) cells.…”

“…Bacterial CpG motif binds to toll-like receptor 9 (TLR-9), which is expressed by different immune system cells, such as macrophages, dendritic cells and natural killer (NK) cells. This motif is known to activate lymphocytes and induce them to secrete a verity of cytokines, including IL-6, IL-12, and IFN-γ [ 49 ]. Quintana et al have reported that CpG motif is able to induce the expression of IFN-γ [ 24 ].…”

In Vitro Radionuclide Therapy and In Vivo Scintigraphic Imaging of Alpha-Fetoprotein-Producing Hepatocellular Carcinoma by Targeted Sodium Iodide Symporter Gene Expression

“…Also, since the NIS gene was first cloned in 1996 [26], many studies have demonstrated the efficacy of molecular imaging or radioiodide gene therapy using NIS in vitro and in vivo [16,17,[27][28][29]. NIS has a number of obvious advantages, such as, its potential use as a diagnostic gene for noninvasive imaging, the bystander effect due to crossfire by β-emitters, the lack of immune response due to its endogenous origin, its well-known physiological effects, and others [23].…”