Immune response against prostate cancer cells induced by recombinant adenovirus encoding truncated prostate specific membrane antigen gene and 4-1BBL gene modified dendritic cells in vitro

Abstract

Objective To study the cytotoxic T lymphocyte response induced by dendritic cells (DCs) transduced with recombinant adenovirus vector bearing truncated human prostate specific membrane antigen (tPSMA) gene and mouse 4-1BB ligand (m4-1BBL) gene against prostate cancer cells in vitro.Methods tPSMA cDNAs and m4-1BBL cDNAs were cloned into pDC316 vector,which was then transfected into HEK 293 cells with adenovirus backbone vector pBHGlox_E1,3Cre to obtain adenovirus expression vector Ad-tPSMA-IRES-m4-1BBL.tPSMA and m4-1BBL proteins were detected by using Western blotting.DCs generated from C57BL/6 mice were transduced with Ad-tPSMA-IRES-m4-1BBL,and the phenotype of DCs was analysed by flow cytometry; Proliferation of T cells stimulated by Ad-tPSMA-IRES-m4-1BBL-transduced DCs in allogeneic mixed lymphocyte reactions and cytotoxic cytotoxic T lymphocyte (CTL) activity induced by Ad-tPSMA-IRES-m4-1BBL-transduced DCs were detected by cell counting kit-8 (CCK-8) assay.Results Recombinant adenovirus Ad-tPSMA-IRES-m4-1BBL was constructed,and tPSMA gene and m4-1BBL gene were expressed correctly.pDC316-tPSMA-IRES-m4-1BBL-transduced DCs upregulated the expression of major histocompatibility complex (MHC) Ⅱ [(87.1 ± 4.7) ％],CD80 [(1.6 ± 5.4) ％] and CD86 [(80.1 ± 2.8) ％].Proliferation rate of T cells stimulated by pDC316-tPSMA-IRES-m4-1BBL-transduced DCs (A450 =0.61 ± 0.02) was significantly higher than that in DCs control group (0.38 ±0.13) and Ad-eGFP-transfected DCs group (0.42 ±0.18) (P ＜0.05).pDC316-tPSMA-IRES-m4-1BBL-transduced DCs induced obvious CTL specific cytotoxicity [(53.5 ± 0.1)％] against tPSMA-expressing prostate cancer cells in vitro.Conclusion DCs vaccines modified by recombinant adenovirus pDC316-tPSMA-IRES-m4-1BBL can induce effective CTL specific cytotoxicity against tPSMA-expressing prostate cancer cells. Key words: Prostate cancer; Dendritic cells; Recombinant adenovirus