CXCL16 participates in pathogenesis of immunological liver injury by regulating T lymphocyte infiltration in liver tissue.

AIM: To investigate the role of CXCL16 in the pathogenesis of immunological liver injury and to explore the possible mechanism of T lymphocyte infiltration regulated by CXCL16. METHODS: Immunological liver injury in murine model was induced by Bacille Calmette-Guerin and lipopolysaccharide. Expression pattern and distribution of CXCL16 were examined by real-time quantitative RT-PCR and immunohistochemical analysis. Anti-CXCL16 antibody was administrated in vivo to investigate its effect on T-cell recruitment and acute hepatic necrosis. The survival of murine model was also evaluated. RESULTS: The murine immunological liver injury model was successfully established. CXCL16 expression increased and predominantly distributed in periportal areas and vascular endothelia in injured liver tissues. Administration of anti-CXCL16 Ab protected the mice from death and acute liver damage. Approximately 70% of the mice survived for 72 h in the anti-CXCL16 Ab treatment group, whereas 80% died within 72 h in control Ab group. The number of liver-infiltrating T lymphocytes was significantly reduced from 1.01 x 10(7) to 3.52 x 10(6)/liver, compared with control Ab treatment. CONCLUSION: CXCL16 is involved in immunological liver injury by regulating T lymphocyte infiltration in liver tissue.

[The role of CXCR4 in lung cancer metastasis and its possible mechanism].

OBJECTIVE: To investigate the role of CXCR4 in the metastasis of human lung cancer and its possible mechanism. METHODS: Lung cancer cells of the lines 95C and 95D with high or low metastatic potential were transfeted with CXCR4 antisense plasmid pcDNA-ASX4, whole length eukaryotic expression plasmid pcDNA-CXCR4 (95D-ASX4 and 95C-X4 cell lines), and corresponding plasmid pcDNA3 (95C-pC and 95D-pC cell lines). 95C, 95C-pC, 95C-X4, 95D, and 95D-pC cells were injected subcutaneously into Balb/c nu/nu mice, 4 approximately 5 mice in a group. The mice were observed twice a week. Ten weeks later the mice were killed and the tumor in situ and the lungs were taken out to undergo histological examination. The effect of CXCR4 expression on the cell migration, MMP-2 activity, adhesion and GRO-a expression of lung cancer cells were detected by chemotaxis and chemoinvasion assay, zymography, adhesion assay and RT-PCR respectively. The polymerization of F-actin was measured by FACS and confocal microcopy. Western blotting was used to detect the phospharylation of ERK1/2 in 85D cells RESULTS: Metastasis was not found in the mice injected with 95C and 95C-pC cells, and was seen in 2/5 of the mice injected with 95C-X4 cells, 3/4 of the mice injected with 95D and 95D-pC cells, 2/5 of the mice injected with 95D-ASX4 cells, however, the number of metastatic nodes in the lungs of 95D-ASX4 group was significantly less than those in the 95D and 95D-pC groups (P = 0.044). SDF-1a, a CXCR4 specific ligand, induced the migratory response and F-actin polymerization in the lung cancer cells; SDF-1a promoted the MMP-2 activity, the adhesion to vascular endothelial cells and GRO-a expression; and neutralizing CXCR4 antibody inhibited these effects to some degree. Moreover, SDF-1a induced the phosphorylation of ERK1/2 in human lung cancer cells. CONCLUSION: Metastasis of human lung cancer depends on, to some degree, the interaction of CXCR4 and SDF-1 that are involved in this process by regulating the active locomotion, MMP-2 activity, adhesion ability or GRO-a expression.

Single B or T-cell epitope-based DNA vaccine using modified vector induces specific immune response against hepadnavirus.

Epitope-based DNA vaccine is an effective and powerful approach against a variety of pathogens or tumors. In present study, we reconstructed a vector that could effectively express short B and T-cell epitope of duck/hepatitis B virus, and investigated the role of the epitope-based DNA vaccination. The pUC19 was modified by inserting the compact transient framework (CTF), including HCMV IE1 promoter, enhancer, Kozak sequence, dual stop codon and 3' terminal bovine growth hormone terminal signal and so on. This modified vector was designated pEC(K) and supposed to effectively express short peptide. A well-defined single B-cell and T-cell epitope encoding gene of duck/hepatitis B virus has been synthesized as candidate epitope and cloned into pEC(K) plasmid, respectively. Transfection of the recombinant DNA into C(2)C(12) cell showed that modified plasmid could effectively express both the single B-cell and T-cell short epitope in the culture supernatant as confirmed by dot immunoblot assay (DIA). The recombinant single B and T-cell epitope-based DNA vaccine was administrated to C57BL/6 mice and could greatly induce specific humoral and CTL response. In addition, the specific antibody against B epitope could specifically bind to the DHBV particles. This report demonstrated that single epitope-based DNA vaccine using modified plasmid vector pEC(K) could induce effective specific immune responses and could be of great use for DNA vaccines.

[The role of CXCL16 in immunological liver injury induced by BCG and LPS in mice].

OBJECTIVE: To investigate the pathophysiological role of CXCL16 in immunological liver injury induced by Bacille de Calmette et Guerin (BCG) and lipopolysaccharides (LPS). METHODS: Immunological liver injury was induced by BCG and LPS in mice, and the expression of CXCL16 was detected in the liver tissues by real-time quantitative PCR and immunohistochemical examination. The relationship of the expression of CXCL16 and the extent of hepatic necrosis was investigated histopathologically and immunohistochemically. Mononuclear cells were isolated from the liver tissues and their numbers were counted; T lymphocytes populations in the liver tissue were also analyzed with FACS. RESULTS: The immunological liver injury model was successfully created. Up-regulation of CXCL16 in injured livers correlated with the extent of liver injury and the amountmononuclear cell infiltrations. CONCLUSION: These findings suggest that up-regulation of CXCL16 was closely correlated with liver injury extent during the immunological liver injury induced by BCG-LPS in mice, and intrahepatic recruitment of specific lymphocytes might be an important mechanism of liver injury.

[Construction of an eukaryotic expression plasmid for short peptides used in DNA immunization].

AIM: To construct a plasmid which efficiently express short peptides in DNA immunization. METHODS: The plasmid containing peptide-expressing cassette (PEC) was constructed and its effect in DNA immunization was investigated, using a DHBV B cell epitope as the short peptide. The peptide in vitro was detected by DOT-EIA. The BALB/c mice were immunized with the empty plasmid or the recombinant plasmid, and the specific antibodies against the epitope in the sera of the mice were determined by ELISA. RESULTS: The plasmid containing peptide-expressing cassette (PEC) was successfully constructed. Recombinant epitope-based plasmid could efficiently express the short peptide in vitro and induce immune response against it in DNA immunization. CONCLUSION: The constructed vector provides highly efficient short peptide expression in DNA immunization.