Intratracheal administration of recombinant adenovirus containing IL-18 gene in treatment of experimental metastatic lung carcinoma

Objective: To study the treatment of experimental metastatic lung carcinoma by intratracheal injection of IL-l8 gene recombinant adenovirus. Methods: (1)The mouse IL-18 mRNA was detected by RT-PCR, and the concentration of IL-18 and associated cytokines in lung lavages and blood were determined by ELISA at different time points after intratracheal injection of IL-18 recombinant adenovirus. (2)The lung metastasis nodes, mouse survival periods and survival rates were evaluated. NK activity and CTL activity were determined by 51Cr 4 h release method. Results: (1) IL-18 mRNA was detectable in lung tissue 6 h after intratracheal use of IL-18 recombinant adenovirus. and the concentration of IL-18 in lung lavage was higher than that in peripheral blood. Neither IL-18 mRNA nor IL-18 was detectable in control group. (2) Intratracheal use of IL-18 recombinant adenovirus resulted in increased CTL and NK activity, longer survival time and higher survival rates compared with the control group, showing significant therapeutic effect on expermental lung metastasis. Conclusion: Intratracheal use of adenovirus vector containing IL- 18 gene has therapeutic effect on the lung metastasis, denoting that gene therapy of lung diseases could be applied through airway directly with recombinant adenovirus.

In vivo anti-tumor activity of murine hematopoietic stem cells expressing a p185HER2-specific chimeric T-cell receptor gene

We have confirmed efficient anti-tumor activities of the peripheral lymphocytes transduced with a p185HEH2-specific chimeric T-cell receptor gene both in murine and in human in our previous studies. To further test the feasibility of chimeric T-cell receptor in a bone marrow transplantation model, we first, made two routine tumor cell lines： MT901 and MCA-205, to express human p185HER2 by retroviral gene transduction. Murine bone marrow cells were retrovirally transduced to express the chimeric T-cell receptor and gene-modified bone marrow cells were transplanted into lethally irradiated mouse. Six months post transplantation, p185HER2-positive tumor ceils： MT-901/HER2 or MCA-205/ HER2 was subcutaneously or intravenously injected to make mouse models simulating primary breast cancer or pulmonary metastasis. The in vivo anti-tumor effects were monitored by the size of the subcutaneous tumor or counting the tumor nodules in the lungs after India ink staining. The size of the subcutaneous tumor was significantly inhibited and the number of pulmonary nodules were significantly decreased in mouse recipients transplanted with chimeric T-cell receptor modified bone marrow cells compared with the control group. Our results suggest the efficient in vivo anti-tumor activities of chimeric T-cell receptor gene modified bone marrow cells.

Construction of the recombinant expression vector for CD80-IgG fusion gene and its expression in Chinese hamster ovary cells

To construct the recombinant expression functionally in Chinese hamster ovary cells in order vector for CD80-IgG fusion gene and to express it to be used as an effective method to eliminate the immune escape of leukemic cells, the cDNA encoding the signal and extracellular domains of murine CD80 was generated by PCR amplification from plasmid pcDNMB7 containing the full length cDNA of murine CD80 and those of murine IgG1, in which the Fc fragment was obtained through RT-PCR amplification from murine spleen cells. These two cDNAs were then cloned in tandem into eukaryotic expression vector pcDNA3.0 and the resultant recombinant plasmid pcDNA/CD80-IgG was then transfected to Chinese hamster ovary cells with liposome transfection reagent. The cell clones constitutively expressing CD80-IgG fusion protein were obtained by G418 screening. Western blotting and dot ELISA assay were used to detect the expression of the fusion protein in the supernatants of these cells. Meanwhile, the fusion protein expressed was then purified with affinity chromatography, and its biological activity was demonstrated by flow cytometry, MTr colorimetry and ELISA assay. The experimental resuits showed that these two inserts were successfully cloned into plasmid pcDNA3.0, and the highly purified fusion protein was obtained. This fusion protein was proved to be able to upregulate the density of CD80 on leukemic cells, deliberately promote the proliferative reactions of mouse allogenic lymphocytes and increase the killing activity against WEHI-3 cells from 49.7 % up to 84.6 %. In addition, this fusion protein could also enhance the IL-2 secretion from allogenic lymphocytes activated by tumorspecific antigens. It is concluded that the recombinant vector constructed can be functionally expressed in the mammalian cells, thus providing a solid foundation for the further investigation on the mechanism to eliminate the immune escape of leukemic cells in vivo.

Tumor Antigen Specific Activation of Primary Human T-Cells Expressing a Virally Encoded Chimeric T-Cell Receptor Specific for p185HER2

We have developed and tested chimeric T-cell receptors (TCR) specific for p185HER2. In these experiments, retroviral vectors expressing the N29γ or N29ζ receptors were constructed in pRET6. Amphotropic viral producer cells were established in the GALV-based PG13 packaging cell line. Ficoll purified human peripheral blood lymphocytes (PBL) were virally transduced using an optimized protocol incorporating activation with immobilized anti-CD3/anti-CD28 monoclonal anti- bodies, followed by viral infection in the presence of fibronectin fragment CH296. Transduced cells were co-cultured with human tumor cell lines that overexpress (SK-OV-3) or underexpress (MCF7) p185HER2 to assay for antigen specific im- mune responses. Both CM+ and CD8+ T-cells transduced with the N29γ or N29ζ chTCR demonstrated HER2-specific anti- gen responses, as determined by release of Th1 like cytokines, and cellular cytotoxicity assays. Our results support the fea- sibility of adoptive immunotherapy with genetically modified T-cells expressing a chTCR specific for p185HER2.

Breast Cancer Immunotherapy

Breast cancer is a leading cause of cancer-related deaths in women worldwide.Although tumorectomy, radiotherapy,chemotherapy and hormone replacement therapy have been used for the treatment of breast cancer,there is no effective therapy for patients with invasive and metastatic breast cancer.Immunotherapy may be proved effective in treating patients with advanced breast cancer.Breast cancer immunotherapy includes antibody based immunotherapy,cancer vaccine immunotherapy,adoptive T cell transfer immunotherapy and T cell receptor gene transfer immunotherapy.Antibody based immunotherapy such as the monoclonal antibody against HER-2/neu (trastuzumab) is successfully used in the treatment of breast cancer patients with over-expressed HER-2/neu,however,HER-2/neu is over-expressed only in 25-30% of breast cancer patients.Cancer vaccine immunotherapy is a promising method to treat cancer patients.Cancer vaccines can be used to induce specific anti-tumor immunity in breast cancer patients,but cannot induce objective tumor regression.Adoptive T cell transfer immunotherapy is an effective method in the treatment of melanoma patients.Recent advances in anti-tumor T cell generation ex vivo and limited clinical trial data have made the feasibility of adoptive T cell transfer immunotherapy in the treatment of breast cancer patients.T cell receptor gene transfer can redirect the specificity of T cells.Chimeric receptor,scFv(anti-HER-2/neu)/zeta receptor,was successfully used to redirect cytotoxic T lymphocyte hybridoma cells to obtain anti-HER-2/neu positive tumor cells,suggesting the feasibility of treatment of breast cancer patients with T cell receptor gene transfer immunotherapy.Clinical trials will approve that immunotherapy is an effective method to cure breast cancer disease in the near future.Cellular & Molecular Immunology.2004;1(4):247-255.