B7-H1, a recently described member of the B7 family of costimulatory molecules, is thought to be involved in tumor immune escape by inducing T-cell apoptosis. In order to investigate the relationship between B7-H1 and immune escape of bladder cancer, B7-H1 expression in 50 cases of bladder cancer was detected by using immunohistochemical method. Survival curves were constructed using the Kaplan-Meier method and independent prognostic factors were evaluated using the Cox regression model. Our results showed that the positive rate of B7-H1 immunostaining in normal bladder tissue and bladder cancer was 0 and 72% respectively. The expression of B7-H1 was strongly associated with the pathological grade, clinical stage and recurrence (P<0.05). The survival rate was significantly lower in patients with B7-H1 positive group than in those with B7-H1 negative group and multi-variable analysis revealed that B7-H1 could be regarded as an independent factor in evaluating the prognosis of bladder cancer. It is concluded that the expression of B7-H1 is strongly associated with neoplastic progression and prognosis of bladder cancer. The manipulation of B7-H1 may become a beneficial target for immunotherapy in human bladder cancer.
Antigens, CD/genetics ; Antigens, CD/*metabolism ; Antigens, CD80/genetics ; Antigens, CD80/*metabolism ; Prognosis ; Tumor Escape/*genetics ; Urinary Bladder Neoplasms/*immunology ; Urinary Bladder Neoplasms/metabolism

CD80 is mainly expressed on Ag-presenting cells (APCs) as a costimulatory molecule but is also detected on T cells. However, the origin and physiological role of CD80 on CD8⁺ T cells remain unclear. In the present study, we demonstrated that effector and memory CD8⁺ T cells, but not naïve CD8⁺ T cells, displayed CD80 molecules on their surfaces after acute lymphocytic choriomeningitis virus infection. Using adoptive transfer of CD80-knockout (KO) CD8⁺ T cells into a wild type or CD80-KO recipient, we demonstrated that the effector CD8⁺ T cells displayed CD80 by both intrinsic expression and extrinsic acquisition, while memory CD8⁺ T cells displayed CD80 only by extrinsic acquisition. Interestingly, the extrinsic acquisition of CD80 by CD8⁺ T cells was observed only in the lymphoid organs but not in the periphery, indicating the trogocytosis of CD80 molecules via interaction between CD8⁺ T cells and APCs. We compared the recall immune responses by memory CD8⁺ T cells that either extrinsically acquired CD80 or were deficient in CD80, and found that CD80, presented by memory CD8⁺ T cells, played a role in limiting their expansion and IL-2 production upon exposure to secondary challenge. Our study presents the in vivo dynamics of the extrinsic acquisition of CD80 by Ag-specific CD8⁺ T cells and its role in the regulation of recall immune responses in memory CD8+ T cells.
Adoptive Transfer ; Antigens, CD80 ; Interleukin-2 ; Lymphocytic choriomeningitis virus ; Memory ; T-Lymphocytes

BACKGROUND/AIMS: Immunogene therapy is extensively studied for a therapeutic modality of various cancers. This study was conducted to investigate the efficacy of immunogene therapy using the T-cell costimulatory molecule and human B7-1 (CD80, hB7-1) in an in vivo human hepatocellular carcinoma (HCC) model. METHODS: The stable HCC cell line expressing hB7-1 gene was established using retroviral vector (Huh-7/hB7-1). Of fourteen BALB/c nude mice, 7 were subcutaneously injected with 2 X 10(6) Huh-7/hB7-1 cells, while the other 7 were injected with 2 X 10(6) Huh-7/mock cells as a control group. After the injection, the mice were observed weekly for three months for subcutaneous tumor formation. Assay for natural killer (NK) cell cytotoxicity and serum IFN-gamma was performed at 1 and 2 weeks after inoculation. RESULTS: In BALB/c nude mice inoculated with Huh-7/hB7-1 cells, no tumor growth was observed. BALB/c nude mice inoculated with Huh-7/hB7-1 cells showed significantly increased NK cell activities of splenocytes compared with those with Huh-7/mock cells. Serum IFN-gamma was not measurable at 1 week, but significantly increased at 2 weeks after inoculation to the level of 470 pg/ml in BALB/c nude mice with Huh-7/mock cells and 521 pg/ml in BALB/c nude mice with Huh-7/hB7-1. CONCLUSIONS: Our results demonstrate the in vivo anti-tumor immunity and NK cell activation by transfer of hB7-1 gene into human HCC in xenogeneic BALB/c nude mice model. This approach may provide a tool for the development of immunogene therapies against human malignant tumors.
Animals ; Antigens, CD80/*genetics ; Cytotoxicity, Immunologic ; Gene Transfer Techniques ; Humans ; Interferon-gamma/metabolism ; Killer Cells, Natural/*immunology ; Liver Neoplasms, Experimental/genetics/*immunology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation

Several myeloid leukemia-derived cells have been reported to possess the ability to differentiate into dendritic cells (DC). MUTZ-3, a myeloid leukemia cell line, responds to GM-CSF, IL-4 and TNF-alpha, and acquires a phenotype similar to immature monocyte-derived DC (MoDC). In the present study, MUTZ-3-derived DC (MuDC) showed high level expression of HLA class II molecules, CD80 and CD86, and were able to function as potent antigen presenting cells as previously reported. Interestingly, MuDC maturation was induced by CD40-mediated stimulation, but not by LPS stimulation. We analyzed CCR1, CCR7 and Toll-like receptor (TLR) expressions in MuDC, and measured IL-10 and IL-12 production after maturation stimuli. Although MuDC expressed the mRNA for TLR4, a major component of the LPS receptor system, they did not show an enhanced level of CCR7 or cytokine production after LPS stimulation. In contrast, they responded to CD40 stimulation, which resulted in increased levels of CD83, CD86 and CCR7. Moreover, while LPSstimulated MoDC could potently stimulate NK cells in a DC-NK cell co-culture, LPS-stimulated MuDC failed to stimulate primary NK cells. Taken together, our findings suggest that, although MuDC express TLR4, unlike TNF-alpha and IL-1beta, LPS does not stimulate MuDC to acquire mature phenotypes, and they may have impaired activity to initiate innate immune response.
Antigens, CD40/metabolism/pharmacology ; Antigens, CD80/metabolism ; Antigens, CD86/metabolism ; Blotting, Western ; CD40 Ligand/metabolism/pharmacology ; Cell Differentiation ; Cell Line, Tumor ; Coculture Techniques ; Dendritic Cells/*drug effects/metabolism ; Enzyme-Linked Immunosorbent Assay ; Fluorescein-5-isothiocyanate ; Fluorescent Antibody Technique, Indirect ; Fluorescent Dyes ; Humans ; Interleukin-10/analysis/biosynthesis ; Interleukin-12/analysis/biosynthesis ; Killer Cells, Natural/metabolism ; Leukemia, Myeloid/*pathology ; Lipopolysaccharides/*pharmacology ; Mitogen-Activated Protein Kinase 3/metabolism ; RNA, Messenger/metabolism ; Research Support, Non-U.S. Gov't ; Reverse Transcriptase Polymerase Chain Reaction ; Toll-Like Receptor 4/metabolism ; Tumor Necrosis Factor-alpha/pharmacology ; p38 Mitogen-Activated Protein Kinases/metabolism