Genetically targeted T cells eradicate established breast cancer in syngeneic mice

Breast cancer immunotherapy using scFv antibody-based approaches, a systematic review

Breast cancer is considered as the most common malignancy in women and the second leading cause of death related to cancer. Recombinant DNA technologies accelerated the development of antibody-based cancer therapy, which is effective in a broad range of cancers. The objective of the present study was to perform a systematic review on breast cancer immunotherapy using single-chain fragment variable (scFv) antibody formats. Searches were performed up to March 2023 using PubMed, Scopus, and Web of Science (ISI) databases. Three reviewers independently assessed study eligibility, data extraction, and evaluated the methodological quality of included primary studies. Different immunotherapy approaches have been identified and the most common approaches were scFv-conjugates, followed by simple scFvs and chimeric antigen receptor (CAR) therapy, respectively. Among breast cancer antigens, HER superfamily, CD family, and EpCAM were applied as the most important breast cancer immunotherapy targets. The present study shed more lights on scFv-based breast cancer immunotherapy approaches.

Making Potent CAR T Cells Using Genetic Engineering and Synergistic Agents

Immunotherapies are emerging as powerful weapons for the treatment of malignancies. Chimeric antigen receptor (CAR)-engineered T cells have shown dramatic clinical results in patients with hematological malignancies. However, it is still challenging for CAR T cell therapy to be successful in several types of blood cancer and most solid tumors. Many attempts have been made to enhance the efficacy of CAR T cell therapy by modifying the CAR construct using combination agents, such as compounds, antibodies, or radiation. At present, technology to improve CAR T cell therapy is rapidly developing. In this review, we particularly emphasize the most recent studies utilizing genetic engineering and synergistic agents to improve CAR T cell therapy.

Chimeric antigen receptor T-cell therapy for breast cancer

One of the main reasons that researchers pay enormous attention to immunotherapy is that, despite significant advances in conventional therapy approaches, breast cancer remains the leading cause of death from malignant tumors among women. Genetically modifying T cells with chimeric antigen receptors (CAR) is one of the novel methods that has exhibited encouraging activity with relative safety, further urging investigators to develop several CAR T cells to target overexpressed antigens in breast tumors. This article is aimed not only to present such CAR T cells and discuss their remarkable results but also indicates their shortcomings with the hope of achieving possible strategies for improving therapeutic response.

Clinical application of adoptive T cell therapy in solid tumors

As an emerging therapeutic approach, adoptive T cell therapy shown promise in advanced solid malignancies. The results obtained in patients with metastatic melanoma and kidney cancer are encouraging because of the visible clinical benefits and limited adverse effects. Recently, the genetically-modified T cells expressing specific T cell receptors or chimeric antigen receptors are just now entering the clinical arena and show great potential for high avidity to tumor-associated antigens and long-lasting anti-tumor responses. However, continued investigations are necessary to improve the cell product quality so as to decrease adverse effects and clinical costs, and make adoptive T cell therapy a tool of choice for solid malignancies.

Immunotherapy of malignant disease using chimeric antigen receptor engrafted T cells

Chimeric antigen receptor- (CAR-) based immunotherapy has been under development for almost 25 years, over which period it has progressed from a new but cumbersome technology to an emerging therapeutic modality for malignant disease. The approach involves the genetic engineering of fusion receptors (CARs) that couple the HLA-independent binding of cell surface target molecules to the delivery of a tailored activating signal to host immune cells. Engineered CARs are delivered most commonly to peripheral blood T cells using a range of vector systems, most commonly integrating viral vectors. Preclinical refinement of this approach has proceeded over several years to the point that clinical testing is now being undertaken at several centres, using increasingly sophisticated and therapeutically successful genetic payloads. This paper considers several aspects of the pre-clinical and clinical development of CAR-based immunotherapy and how this technology is acquiring an increasing niche in the treatment of both solid and haematological malignancies.

Potential targets for pancreatic cancer immunotherapeutics

Pancreatic adenocarcinoma is the fourth leading cause of cancer death with an overall 5-year survival of less than 5%. As there is ample evidence that pancreatic adenocarcinomas elicit antitumor immune responses, identification of pancreatic cancer-associated antigens has spurred the development of vaccination-based strategies for treatment. While promising results have been observed in animal tumor models, most clinical studies have found only limited success. As most trials were performed in patients with advanced pancreatic cancer, the contribution of immune suppressor mechanisms should be taken into account. In this article, we detail recent work in tumor antigen vaccination and the recently identified mechanisms of immune suppression in pancreatic cancer. We offer our perspective on how to increase the clinical efficacy of vaccines for pancreatic cancer.

Inhibition of p38 MAPK activity in B-NHL Raji cells by treatment with engineered CD20-specific T cells

Adoptive immunotherapy with T cells expressing CD20-specific chimeric T-cell receptors is a promising approach to lymphoma therapy. However, modification of the cellular signaling pathways in target tumor cells by treatment with engineered CD20-specific T cells has yet to be fully elucidated. In this study, the non-Hodgkin's lymphoma Raji cell line was co-cultured with T cells that were genetically modified with anti-CD20scFvFc/CD28/CD3ζ or anti-CD20scFvFc gene. The cytolytic activity of engineered CD20-specific T cells and IL-10 secretion was quantitated by Cytotoxicity and ELISA assays, respectively. The engineered CD20-specific T cells and Raji cells were sorted using flow cytomety for the Western blot analysis. Treatment of Raji cells with T cells genetically modified with anti-CD20scFvFc/CD28/CD3ζ chimera (compared to anti-CD20scFvFc) yielded a higher cytotoxicity against Raji cells in vitro. Additionally, we found that engineered CD20-specific T cells caused a decrease in IL-10 secretion and inhibition of phosphor-STAT3 and Bcl-2 expression in Raji cells, possibly through the down-regulation of p38 MAPK and NF-κB activity. These results indicate that the treatment of Raji cells with engineered CD20-specific T cells inhibited the cellular p38 MAPK signaling pathways, which enhanced its antitumor activities against CD20-positive tumor cells.

Anti-GD3 chimeric sFv-CD28/T-cell receptor zeta designer T cells for treatment of metastatic melanoma and other neuroectodermal tumors

PURPOSE

The aims of this study are to compare antitumor activities of two generations of GD3-specific chimeric antigen receptors (CAR) in human primary T lymphocytes in vitro and to evaluate the antitumor efficacy of using a combination of systemic infusion of interleukin-2 (IL2) and designer T cells to eradicate subcutaneous established GD3+ melanoma in nude mice.

EXPERIMENTAL DESIGN

Antitumor activities were compared for two generations of designer T cells, the progenitor first-generation with immunoglobulin T-cell receptor (TCR) with Signal 1 and the second-generation designer T cells with Signal 1+2. Osmotic IL2 pumps were used to deliver the maximum tolerated dose of IL2 to enhance the antitumor effects of designer T cells on subcutaneous established melanoma in nude mice.

RESULTS

Melanoma is associated with high expression of ganglioside GD3, which has been targeted with modest effect in antibody therapies. We previously showed that an anti-GD3 CAR (sFv-TCRzeta) will recruit T cells to target this non-T-dependent antigen, with potent killing of melanoma cells. Here, we report the addition of a CD28 costimulation domain to create a second-generation CAR, called Tandem for two signals. We show that this Tandem sFv-CD28/TCRzeta receptor on T cells confers advantages of improved cytokine secretion, cytotoxicity, proliferation, and clonal expansion on tumor contact versus the same CAR without costimulation. In an adoptive transfer model using established melanoma tumors, designer T cells with CD28 showed a 50% rate of complete remissions but only where IL2 was supplemented.

CONCLUSIONS

As a reagent for clinical development, the second-generation product is shown to have superior properties to warrant its preference for clinical designer T-cell immunotherapy for melanoma and other tumors. Systemic IL2 was required for optimal activity in an established tumor model.