Preparation of antibodies against TXR1 and construction of a new DNA tumor vaccine

Abstract

Background: Taxol-resistance gene 1 (TXR1) is closely correlated with the paclitaxel resistance in the cancer chemotherapy. However, due to the lack of monoclonal antibodies (mAbs) with strong specificity and high sensitivity, little information is found about TXR1 target-related tumor therapy.

Methods: We developed an TXR1 recombinant DNA vaccine by inserting TXR1 DNA sequence into lysosome-associated membrane protein 1 (LAMP1). Adaptive immune responses were assessed by indirect enzyme-linked immunosorbent assay (ELISA), Enzyme-linked immunospot test (ELISpot), and cytotoxic T-lymphocyte (CTL) cytotoxicity.

Results: The pGEX4T-1-TXR1 reconstructed prokaryotic expression plasmid was constructed for producing high-purity TXR1 protein. Subsequently, a total of four mAbs for TXR1 and two PcAbs were successfully constructed and identified. We further found that TXR1 was highly expressed in breast cancer tissue than normal controls. Therefore, we constructed four tumor vectors, pVAX1-LAMP/TXR1, pVAX1-LAMP, pVAX1/TXR1 and pVAX1, for immunization. After three times of immunization, ELISpot data showed that single peptide 6,9,11 could stimulate T cells secreting IFN-γ in pVAX1-LAMP/TXR1 group. Moreover, the number of specific T cells and immune response effects significantly increased comparing to the pVAX1-LAMP control group. In addition, cytotoxicity showed that when the effect to target ratio was 40:l the killing effect of pVAX1-LAMP/TXR1 group was significantly higher than the pVAX1-TXR1 group.

Conclusion: Our results provides new evidence for the TXR1 related tumor immunology and aids the early prevention of cancer.

Keywords: DNA vaccine; Immune response; Lysosome-associated membrane protein (LAMP); Monoclonal antibodies (mAbs); Taxol-resistance gene 1 (TXR1).