Effect of anti-tuberculosis therapy on liver function of pulmonary tuberculosis patients infected with hepatitis B virus

AIM: To observe the effect of anti-tuberculosis therapy on liver function of pulmonary tuberculosis patients with hepatitis B virus (HBV) infection, and to compare the differences of liver function by two treatments of antituberculosis.METHODS: Forty-seven TB patients with HBV infection and 170 TB patients without HBV infection were divided into HPBE(S) and HLAMKO treatment groups. Liver function tests before and after the treatments were performed once in 2 wk or monthly, and their clinical manifestations were recorded.RESULTS: The rate of hepatotoxicity occurred in 26 (59%)TB patients with HBV during anti-TB treatment, higher than that in 40 (24%) TB patients without HBV. Hepatotoxicity occurred in 66 out of 217 patients, and the incidence of liver dysfunction was 46.1% in HPBE(S) group, significantly higher than that in HLAMKO group (12.7%) (P＜0.01).CONCLUSION: TB patients with HBV should choose HLAMKO treatment because of fewer hepatotoxicity.

Solubility of disulfide-bonded proteins in the cytoplasm of Escherichia co/i and its “oxidizing” mutant

AIM: To study the influence of redox environment of Escherichia coli ( E. coli) cytoplasm on disulfide bond formation of recombinant proteins.METHODS: Bovine fibroblast growth factor (BbFGF) was selected as a model of simple proteins with a single disulfide bond and free cysteines. Anti-HBsAg single-chain Fv (HBscFv), an artificial multidomain protein, was selected as the model molecule of complex protein with 2 disulfide bonds. A BbFGF-producing plasmid, pJN-BbFGF,and a HBscFv producing-plasmid, pQE-HBscFv, were constructed and transformed into E. coli strains BL21(DE3)and M15[pREP4]respectively. At the same time, both plasmids were transformedinto a reductase-deficient host strain, E. coli Origami(DE3). The 4 recombinant E. coli strains were cultured and the target proteins were purified. Solubility and bioactivity of recombinant BbFGF and HBscFv produced in different host strains were analyzed and compared respectively.RESULTS: All recombinant E. colistrains could efficiently produce target proteins. The level of BbFGF in BL21(DE3)was 15-23% of the total protein, and was 5-10% in Origami (DE3). In addition, 65% of the BbFGF produced in BL21(DE3) formed into inclusion body in the cytoplasm,and all the target proteins became soluble in Origami (DE3). The bioactivity of BbFGF purified from Origami(DE3)was higher than its counterpart from BL21(DE3). The ED50of BbFGF from Origami(DE3) and BL21(DE3) was 1.6 μg/L and 2.2 μg/L, respectively. Both HBscFv formed into inclusion body in the cytoplasm of M15[pQE-HBscFv] or Origami[pQE-HBscFv]. But the supernatant of Origami[pQE-HBscFv] lysate displayed weak bioactivity and its counterpart from M15[pQE-HBscFv] did not display any bioactivity. The soluble HBscFv in Origami[pQE-HBscFv]was purified to be 1-2 mg/L and its affinity constant was determined to be 2.62×107 mol/L. The yield of native HBscFv refolded from indusion body in M15[pQE-H Fv] was30-35 mg/L and the affinity constant was 1.98×107 mol/L.There was no significant difference between the bioactivity of HBscFvs refolded from the inclusion bodies produced in different host strains.CONCLUSION: Modification of the redox environment of E. coli cytoplasm can significantly improve the folding of recombinant disulfide-bonded proteins produced in it.