AIMTo investigate the antitumor immunity by a dendritic cell (DC) vaccine encoding secondary lymphoid chemokine gene and tumor lysate on murine prostate cancer.

METHODSDC from bone marrow of C57BL/6 were transfected with a plasmid vector expressing secondary lymphoid chemokine (SLC) cDNA by Lipofectamine 2,000 liposome and tumor lysate. Total RNA extracted from SLC+lysate-DC was used to verify the expression of SLC by reverse transcriptase-polymerase chain reaction (RT-PCR). The immunotherapeutic effect of DC vaccine on murine prostate cancer was assessed.

RESULTSWe found that in the prostate tumor model of C57BL/6 mice, the administration of SLC+lysate-DC inhibited tumor growth most significantly when compared with SLC-DC, lysate-DC, DC or phosphate buffer solution (PBS) counterparts (P < 0.01). Immunohistochemical fluorescent staining analysis showed the infiltration of more CD4(+), CD8(+) T cell and CD11c(+) DC within established tumor treated by SLC+lysate-DC vaccine than other DC vaccines (P < 0.01).

CONCLUSIONDC vaccine encoding secondary lymphoid chemokine and tumor lysate can elicit significant antitumor immunity by infiltration of CD4(+), CD8(+) T cell and DC, which might provide a potential immunotherapy method for prostate cancer.

Animals ; Antibodies, Neoplasm ; biosynthesis ; Antigens, Neoplasm ; immunology ; CD11 Antigens ; immunology ; Cancer Vaccines ; immunology ; therapeutic use ; Cell Line ; Chemokines ; biosynthesis ; Dendritic Cells ; immunology ; metabolism ; Epitopes ; immunology ; Fluorescent Antibody Technique ; Killer Cells, Natural ; immunology ; Lymphocytes ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Plasmids ; genetics ; Prostatic Neoplasms ; immunology ; pathology ; prevention & control ; Reverse Transcriptase Polymerase Chain Reaction ; T-Lymphocytes ; immunology

CD137, which is expressed on activated T cells, plays a critical role in inflammatory responses. However, the exact role that CD137 plays in monocytes is not fully known. Here we studied the expression and function of CD137 in human monocytic THP-1 cells, which we found constitutively expresses CD137 at the mRNA and protein level. Cross-linking of CD137 increased the secretion of IL-8 and TNF-alpha, promoted the expression of CD54 and CD11b, and increased adhesion to extracellular matrix (ECM) proteins. In particular CD137-induced adhesion of THP-1 cells was inhibited by an inhibitor of mitogen-activated protein kinase kinase (MEK), but not by a p38 kinase inhibitor. Taken together, these results show that the adhesion and cytokine production of THP-1 cells induced by CD137 occur via activation of MEK, which results in the activation of ERK-1/2 signaling pathways. Therefore, this study suggests that CD137 induces an activating and migrating signal during inflammatory processes.
Antigens, CD/biosynthesis/*immunology ; Antigens, CD11/biosynthesis ; *Cell Adhesion ; Cell Adhesion Molecules/biosynthesis ; Cell Line ; Cytokines/*biosynthesis ; Enzyme Activation ; Extracellular Matrix Proteins/metabolism ; Flow Cytometry ; Humans ; Immunity, Natural ; Intercellular Adhesion Molecule-1/biosynthesis ; Interleukin-8/biosynthesis ; Mitogen-Activated Protein Kinase 1/metabolism ; Mitogen-Activated Protein Kinase 3/metabolism ; Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors/metabolism ; Monocytes/metabolism/*physiology ; Phosphorylation ; Protein Binding ; Receptors, Nerve Growth Factor/biosynthesis/*immunology ; Receptors, Tumor Necrosis Factor/biosynthesis/*immunology ; Research Support, Non-U.S. Gov't ; Signal Transduction ; Tumor Necrosis Factor-alpha/biosynthesis ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors