IL-23 gene therapy for mouse bladder tumour cell lines
Tomomi Kuramoto, Department of Urology, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-0012, Japan. e-mail: email@example.com
- • To evaluate the antitumour effects of IL-23 gene transfer into mouse bladder carcinoma (MBT2) cells.
- • To investigate the mechanisms underlying the subsequent constitutive secrection of IL-23 by the MBT2 cells
MATERIALS AND METHODS
- • An expression vector containing IL-23 gene was introduced into MBT2 cells by liposome-mediated gene transfer, and secretion of IL-23 was confirmed by ELISA.
- • The in vivo antitumour effect of IL-23-secreting MBT2 cells (MBT2/IL-23) was examined by injecting the cells into syngeneic C3H mice.
- • A tumour vaccination study using mitomycin C (MMC)-treated IL-23-secreting MBT2 cells was carried out, and the usefulness of in vivo CD25 depletion for an additional vaccine effect was also investigated.
- • The mechanisms underlying the antitumour effects were investigated by antibody depletion of CD8 or CD4 T cells, or natural killer cells, and cells infiltrating the tumour sites in vivo were assessed using immunohistochemistry.
- • Stable transformants transduced with MBT2/IL-23 secreted IL-23 into the culture supernatant.
- • Genetically engineered IL-23-secreting MBT2 cells were rejected in syngeneic mice.
- • MBT2/IL-23-vaccinated mice inhibited the tumour growth of parental MBT2 cells injected at a distant site and this vaccine effect was enhanced by combination with in vivo CD25 depletion by an antibody.
- • The main effector cells for the direct antitumour effect of MBT2/IL-23 were CD8 T cells, which was shown by in vivo depletion and immunohistochemical study.
- • IL-23-secreting MBT2 cells were rejected in syngeneic mice by the activation of CD8 T cells.
- • MMC-treated MBT2/IL-23 can have a tumour vaccine effect for parental MBT2 cells, and this effect was enhanced by combination with in vivo CD25 depletion.