Fourth-generation chimeric antigen receptor T cells targeting folate receptor alpha antigen expressed on breast cancer cells for adoptive T cell therapy.

Abstract

PURPOSE:

Treatment of breast cancer (BC) by standard methods is effective in the early stage, but ineffective in the advanced stage of disease. To develop an adoptive T cell therapy for advanced and severe BC, we generated fourth-generation chimeric antigen receptor (CAR) T cells targeting folate receptor alpha antigen (FRα) expressed on BC cells, and preclinically evaluated their anti-BC activities.

METHODS:

The fourth-generation FRα-CAR T cells containing extracellular FRα-specific single-chain variable fragment (scFv) and three intracellular costimulatory domains (CD28, 4-1BB, and CD27) linked to CD3ζ were generated using a lentiviral system, and then were evaluated for their anti-BC activities in two-dimensional and three-dimensional (spheroid) cultures.

RESULTS:

When our fourth-generation FRα-CAR T cells were cocultured with FRα-expressing MDA-MB-231 BC cell line at an effector to target ratio of 20:1, these CAR T cells specifically lysed 88.7 ± 10.6% of the target cells. Interestingly, the cytotoxic lysis of FRα-CAR T cells was more pronounced in target cells with higher surface FRα expression. This specific cytotoxicity of the CAR T cells was not observed when cocultured with FRα-negative MCF10A normal breast-like cell line at the same ratio (34.3 ± 4.7%). When they were cocultured with MDA-MD-231 spheroid, the FRα-CAR T cells exhibited antitumor activity marked with spheroid size reduction and breakage.

CONCLUSION:

This proof-of-concept study thus shows the feasibility of using these fourth-generation FRα-CAR T cells for adoptive T cell therapy in BC.

• Authors: Piriya Luangwattananun, Mutita Junking, Jatuporn Sujjitjoon, Yupanun Wutti-In, Naravat Poungvarin, Chanitra Thuwajit, Pa-Thai Yenchitsomanus
• Journal: Breast cancer research and treatment (Breast Cancer Res Treat) Vol. 186 Issue 1 Pg. 25-36 (Feb 2021) ISSN: 1573-7217 [Electronic] Netherlands
• PMID: 33389403 (Publication Type: Journal Article)

Chemical References

• Folate Receptor 1
• Receptors, Antigen, T-Cell
• Receptors, Chimeric Antigen

Topics

• Breast Neoplasms (genetics, therapy)
• Cell Line, Tumor
• Cell- and Tissue-Based Therapy
• Female
• Folate Receptor 1 (genetics)
• Humans
• Immunotherapy, Adoptive
• Receptors, Antigen, T-Cell (genetics)
• Receptors, Chimeric Antigen (genetics, metabolism)
• T-Lymphocytes (metabolism)
• Xenograft Model Antitumor Assays