The present study aimed to investigate the efficacy of a myeloid dendritic cell (mDCs) and plasmacytoid (p)DC
combined vaccine loaded with heat-treated
cancer cell lysates against
lung cancer cells. The mDCs and pDCs were selected using magnetic bead sorting.
Antigen loading was performed by adding heat-treated Lewis
lung cancer cell lysates to mDC, pDC or mDC+pDC (1:1). Surface expression of CD80, CD86, CD40 and major histocompatibility complex (
MHC)-II molecules were determined using flow cytometry, and the secretion of
cytokines IL-12,
IL-6 and TNF-α were assessed using ELISA assays. The effect of the mDC and pDC
vaccine on cytotoxic T lymphocytes (CTLs) against
tumor cells was investigated.
Tumor-bearing nude mice were intravenously injected with the mDC and pDC
combined vaccine.
Tumor tissues were collected for
hematoxylin and
eosin and TUNEL staining. Loading with
tumor cell lysate significantly upregulated the surface expression of costimulatory
molecules MHC-II on DCs and enhanced secretions of
IL-6,
IL-12 and TNF-α by DCs. In addition, the
tumor cell lysate-loaded mDC and pDC
combined vaccine significantly promoted lymphocyte proliferation and enhanced CTL-mediated cytotoxicity against Lewis
lung cancer cells compared with mDC or pDC treatment alone. Furthermore,
intravenous injection of the mDC and pDC
combined vaccine into
tumor-bearing nude mice significantly inhibited subcutaneous
tumor growth and induced
necrosis and apoptosis within the
tumor tissue. Overall, the pDC and mDC combination
vaccine loaded with heat-treated Lewis
lung cancer cell lysate had a synergistic effect on the induction of T lymphocyte proliferation and antitumor efficacy, which may be associated with the upregulation of co-stimulatory molecules and
cytokine secretions.