Relation between viremia level and liver disease in patients with chronic HCV infection

Preparation of human single chain Fv antibody against hepatitis C virus E2 protein and its identification in immunohistochemistry

AIM: To screen human single chain Fv antibody (scFv) against hepatitis C virus E2 antigen and identify its application in immunohistochemistry.

METHODS: The phage antibody library was panned by HCV E2 antigen, which was coated in microtiter plate. After five rounds of biopanning, 56 phage clones were identified specific to HCV E2 antigen. The selected scFv clones were digested by Sfi I/Not I and DNA was sequenced. Then it was subcloned into the vector pCANTAB5E for expression as E-tagged soluble scFv. The liver tissue sections from normal person and patients with chronic hepatitis B and chronic hepatitis C were immunostained with HCV E2 scFv antibody.

RESULTS: The data of scFv-E2 DNA digestion and DNA sequencing showed that the scFv gene is composed of 750 bp. ELISA and immunohistochemistry demonstrated that the human single chain Fv antibody against hepatitis C E2 antigen has a specific binding character with hepatitis virus E2 antigen and paraffin-embedded tissue, but did not react with liver tissues from healthy persons or patients with chronic hepatitis B.

CONCLUSION: We have successfully screened and identified HCV E2 scFv and the scFv could be used in the immunostaining of liver tissue sections from patients with chronic hepatitis C.

mIL-2R, T cell subsets and hepatitis C

AIM: To study the levels of membrane interleukin-2 receptor (mIL-2R) and T cell subsets in peripheral blood mononuclear cells (PBMC) from patients with hepatitis C and their role in the pathogenesis of hepatitis C.

METHODS: The levels of mIL-2R and T cells subsets in PBMC were detected by biotin- streptatividin (BSA) technique before and after stimulation with PHA in 203 patients with hepatitis C with HCV-RNA (+), anti-HCV (+), anti-HCV (-).

RESULTS: The total expressive levels of mIL-2R before and after stimulation with PHA (0.03 ± 0.01, 0.03 ± 0.02, 0.04 ± 0.02, 0.36 ± 0.03), and T cell subsets in PBMC (0.62 ± 0.06, 0.37 ± 0.05, 0.35 ± 0.07) were all lower in patients with hepatitis C than those in normal controls (0.66 ± 0.07, 0.41 ± 0.06, 0.31 ± 0.05, P < 0.01). Among the patients, the levels of mIL-2R were lower in silence than those in situation of PHA inducting (P < 0.01). However, the levels of mIL-2R were similar in acute hepatitis C to that in chronic hepatitis C (P > 0.05). The levels of CD₃⁺, CD₄⁺, CD₄⁺/CD₈⁺ were lower and CD₈⁺ was higher in patients with acute and chronic hepatitis C with anti-HCV (+) than those in normal controls (0.62 ± 0.06, 0.37 ± 0.05, 0.35 ± 0.07, 1.18 ± 0.30, 0.61 ± 0.07, 0.37 ± 0.05, 1.39 ± 0.33, 0.31 ± 0.05, P < 0.05 - P < 0.01).

CONCLUSION: The cellular immunity is obviously changed in patients with hepatitis C. The levels of mIL-2R and activation of T cells are closely associated with chronicity of hepatitis C.

Construction of HCV-core gene vector and its expression in cholangiocarcinoma

AIM: To establish an experimental model for exploring the role of hepatitis C virus (HCV) in the development of cholangiocarcinoma.

METHODS: Recombinant plasmid of HCV-core gene was constructed with molecular cloning technique and transfected into QBC939 cells with lipofection. After it was selected with G418, resistant colonies were obtained. The colonies were analysed by immunocytochemistry and Western blotting.The morphology was observed under transmission electron microscope(TEM) and microscope.

RESULTS: The recombinant plasmid was proved to carry the target gene by PCR and restriction enzymed mapping. Moreover, it could express HCV-C protein efficiently in QBC939 cells. The HCV-like particles were found in the cytoplasm by electron microscope, which were spherical with a diameter of 50 nm-80 nm possessing outer membrane.The transfected cells had lower differentiation and higher malignant degree under microscope.

CONCLUSION: Because HCV-core gene could express steadily in cholangiocarcinoma cells,the transfected tumor cells(QBC939-HCVC) could be used to study the effect of HCV in the development of cholangiocarcinoma.