Transduction of rIL-2 expanded CD4+ and CD8+ ovarian TIL-derived T cell lines with the G1Na (neor) replication-deficient retroviral vector

Development of an Efficient Gene Editing Tool in Schizochytrium sp. and Improving Its Lipid and Terpenoid Biosynthesis

Schizochytrium sp. HX-308 is a marine microalga with fast growth and high lipid content, which has potential as microbial cell factories for lipid compound biosynthesis. It is significant to develop efficient genetic editing tool and discover molecular target in Schizochytrium sp. HX-308 for lipid compound biosynthesis. In this study, we developed an efficient gene editing tool in HX-308 which was mediated by Agrobacterium tumefaciens AGL-1. Results showed that the random integration efficiency reached 100%, and the homologous recombination efficiency reached about 30%. Furthermore, the metabolic pathway of lipid and terpenoid biosynthesis were engineered. Firstly, the acetyl-CoA c-acetyltransferase was overexpressed in HX-308 with a strong constitutive promoter. With the overexpression of acetyl-CoA c-acetyltransferase, more acetyl-CoA was used to synthesize terpenoids, and the production of squalene, β-carotene and astaxanthin was increased 5.4, 1.8, and 2.4 times, respectively. Interestingly, the production of saturated fatty acids and polyunsaturated fatty acids also changed. Moreover, three Acyl-CoA oxidase genes which catalyze the first step of β-oxidation were knocked out using homologous recombination. Results showed that the production of lipids increased in the three knock-out strains. Our results demonstrated that the A. tumefaciens-mediated transformation method will be of great use for the study of function genes, as well as developing Schizochytrium sp. as a strong cell factory for producing high value products.

Synthetic TILs: Engineered Tumor-Infiltrating Lymphocytes With Improved Therapeutic Potential

Immunotherapy has emerged as an effective and life-changing approach for several types of cancers, both liquid and solid tumors. In combination with traditional treatments such as radiotherapy and/or chemotherapy, immune checkpoints inhibitors have improved prognosis and overall survival of patients with advanced melanoma and many other cancers. Among adoptive cell therapies (ACT), while chimeric antigen receptor T cell therapies have demonstrated remarkable efficacy in some hematologic malignancies, such as B cell leukemias, their success in solid tumors remains scarce due to the characteristics of the tumor microenvironment. On the other hand, ACT using tumor-infiltrating lymphocytes (TILs) is arguably the most effective treatment for metastatic melanoma patients, but even if their isolation has been achieved in epithelial tumors, their success beyond melanoma remains limited. Here, we review several aspects impacting TIL- and gene-modified “synthetic” TIL-based therapies and discuss future challenges that must be addressed with these approaches.

Immunotherapy for peritoneal ovarian carcinoma metastasis using ex vivo expanded tumor infiltrating lymphocytes

Surgery and chemotherapy have contributed to a modest overall survival in patients with epithelial ovarian carcinoma. It is therefore important to pursue novel therapy strategies for this disease that are different from conventional chemotherapy. Tumor infiltrating lymphocytes (TILs) from patients with ovarian carcinoma may represent an active immune response of the host directed against the tumor cells. These TILs can be expanded in vitro in low concentrations of recombinant interleukin-2 (rIL-2) by a few thousandfold. The resulting T-cell lines comprise CD3+CD4+TCR alpha beta + or CD3+CD8+TCR alpha beta + cells, or mixtures of both. These T-cell lines may exhibit either tumor-specific cytotoxicity against autologous tumor cells, or produce cytokines (interferon-gamma, tumor necrosis factor, and granulocyte stimulating factor) either in antigen-dependent (tumor-specific) or an antigen-independent manner. T-cell lines exhibiting primarily autologous tumor-specific cytotoxicity were developed from approximately 50% of the patients. Blocking experiments using appropriate monoclonal antibodies revealed that the CD3/TCR complex on the effector cells and the MHC class I antigens on the tumor cells were involved in the cytolytic process. We have developed a four-step method for the expansion of TILs to large numbers (1 x 10(10) to 1 x 10(11)) sufficient for clinical trials in patients with ovarian cancer. We have conducted a pilot clinical trial to examine the feasibility and clinical effects of intraperitoneal TILs and low-dose rIL-2 in patients with advanced ovarian carcinoma who were refractory to platinum-based chemotherapy. More recently, procedures have been developed for obtaining large numbers of purified CD8+ rIL-2-expanded TILs for the treatment of patients with ovarian carcinoma. The evolution of clinical trials and correlative studies necessary to develop an effective adoptive immunotherapy approach were discussed.