[T-bet gene modified dendritic cells abrogate and reverse the airway inflammation in allergic asthma: experiment with mice].

OBJECTIVE: To explore the feasibility of the therapeutic strategy to use T-bet gene modified dendritic cells (DCs) to reverse the course of asthma. METHODS: (1) Mature DCs were derived from mononuclear cells obtained from femur of BALB/c mouse and divided into 3 groups, T-bet group transfected with recombinant adenovirus Ad-T-bet containing T-bet gene, LacZ group transfected with recombinant adenovirus Ad-LacZ containing LacZ gene, and control group. Seven days later ELISA was used to detect the interferon (IFN)-gamma level in the culture fluid. (2) Airway inflammation abrogating trial. Twenty-four BALB/c mice were sensitized with intraperitoneal injection of ovalbumin (OVA) (on day 1 and 15) to establish asthma models, and then randomly divided into 3 equal groups: T-bet group injected intravenously with T-bet-modified DCs on day 27, LacZ group injected with LacZ-modified DCs, and model control group without intravenous injection. Two days later the model mice began to undergo challenge by inhalation of OVA twice (on day 29 - 31). Eight mice were used as control group treated with PBS. On day 37 all mice were killed, ELISA was used to detect the blood interleukin (IL)-4 and IFN-gamma levels, and microscopy was conducted to observe the airway inflammation. (3) Airway inflammation reversing trial. Another 24 model mice were divided into 3 equal groups as well: re-challenged T-bet group injected intravenously with T-bet-modified DCs on day 27 and 42, re-challenged LacZ group injected intravenously with LacZ-modified DCs on day 27 and 42, and model control group. Since the day 45 OVA inhalation was given once a day for successive 3 days. On day 49 these mice were all killed to undergo the tests as mentioned above. RESULTS: The IFN-gamma level in the culture fluid of the T-bet gene modified DCs was (15.24 +/- 4.75) ng/ml, significantly higher than that of the LacZ gene modified DCs and control DCs [(3.08 +/- 0.61) and (2.35 +/- 0.41) ng/ml respectively, both P < 0.01]. The IFN-gamma in mice blood plasma of T-bet groups in abrogating and reversing trial were (130.2 +/- 10.5) and (145.7 +/- 16.7) pg/ml respectively, both significantly higher than those of the abrogating and reversing trial normal control groups [(25.0 +/- 6.5) and (24.6 +/- 5.9) pg/ml respectively], asthmatic model control groups [(20.7 +/- 4.5) and (16.5 +/- 7.0) pg/ml respectively] and LacZ groups [(17.6 +/- 7.0) and (24.2 +/- 9.0) pg/ml respectively] (all P < 0.01). However, the IL-4 levels in mice blood plasma of T-bet groups were both significantly lower than those of asthmatic model control groups and LacZ groups (all P < 0.01). The airway inflammation of T-bet groups were remarkable milder than those of the model control groups and LacZ groups. CONCLUSION: The asthma management strategy based on T-bet gene modified DCs is feasible with the plausible mechanism that the T-bet gene modified DCs regulate the T cells differentiation and polarization on the antigen presenting level.

[A strategy for targeting gene therapy against cancer mediated by epidermal growth factor receptor].

OBJECTIVE: To establish a protocol for the targeting gene therapy against cancer with rich epidermal growth factor receptor (EGFR). METHODS: A recombinant pcDNA3.1-PE III mut was constructed and combined with a non-viral vector, a fusion protein histone H1, epidermal growth factor C-loop previously expressed by us, to be a protein-DNA complex in vitro. Using the complex to treat BT-325 and Hela cancer cells with EGFR and JK cells without EGFR. The killing rates of the cells was calculated after 48 h of incubation at 37 degrees C. RESULTS: To BT-325 and Hela cells, the killing rates were 46.03% and 48.12% respectively. To JK cells, the complex had no killing function. CONCLUSION: The protocol for targeting gene therapy against cancer with EGFR has been established successfully.

[Construction of a non-viral vector H1s-EGFc and a preliminary study on its function].

OBJECTIVE: To construct a non-viral vector for targeting cancer gene therapy. METHODS: The coding sequence of H1s-EGFc was inserted into the expression vectors of Pichia pastoris, and the fusion protein was expressed in secretary way. H1s-EGFc was purified by anion exchange chromatography and size exclusion chromatography. H1s-EGFc fusion protein and "killing gene" expression recombinant pKG plasmid DNA were dissolved in serum-free RPMI-1640 culture to produce H1s-EGFc/pKG complex. HeLa cells, an epidermal growth factor receptor (EGFR) highly expressing cell line, and Jurkat cells, an EGFR non-expressing cell line, were cultured and transfected with H1s-EGFc/pKG complex of different concentrations. Trypan blue staining was used to calculate the number of live cells and the killing rate of H1s-EGFc/pKG. RESULTS: H1s-EGFc fusion protein was constructed and expressed with a purity of over 90%. When the concentrations of H1s-EGFc/pKG complex were 3 microg/ml, 6 microg/ml, and 9 microg/ml respectively the killing rates were 30.6%, 36.2%, and 58.1% respectively. CONCLUSION: The fusion protein H1s-EGFc binds functional gene efficiently and targets it into specific cells. It can be used as non-viral vector in target cancer gene therapy.

[Expression and purification of gene transfer vehicle mediated by epidermal growth factor receptor].

OBJECTIVE: To create a gene transfer vehicle for targeting gene therapy of cancer with epidermal growth factor receptor overexpressing. METHODS: Encoding sequences of the first domain of histone gene (H1) and EGF C-loop (EGFc) were obtained by PCR amplification. These two DNA fragments were ligated by EcoR I site, and cloned and sequenced. E. coli expression vector of the fusion gene was then constructed. The fusion protein H1EGFc was purified by specific band isolation from SDS-PAGE. RESULTS: The molecular weight of purified protein was consistent with the designed request. Its purity reached 94.02%. CONCLUSION: A fusion protein H1EGFc was expressed and purified.

[Comparative analysis of diuretic activities of human ANP gene injected intramuscularly and intravenously in adriamycin-induced nephrotic rats].

In order to explore the feasibility of gene therapy strategy based on the human atrial natriuretic peptide (hANP) gene delivery for the treatment of nephropathy and compare the diuretic activities of the hANP gene injected intramuscularly(i.m.) and intravenously(i.v.), the naked retroviral vector DNA harboring the hANP cDNA under the control of retroviral 5' long terminal repeat at a dose of 5 mg/kg body weight was injected i.m. or i.v. into the nephrotic model rats induced with adriamycin(ADR) injected i.v. at a dose of 7.5 mg/kg body weight. A single injection of the hANP gene resulted in a marked elevation in plasma level of hANP 5 days after gene delivery and a significant increase in the ratio of urine volume to body weight and the diuretic effect continued for more than 15 days. In addition, there was a significant rise in the body weight of treatment groups as compared with that of negative control group and no difference in the concentrations of electrolytes in urine between groups. There was no significant differences in total effects resulted from the two routes of gene delivery and the way of gene delivery through the skeletal muscle is simpler and easier. These results suggest that somatic gene delivery of the hANP gene could enhance the renal functions in nephrotic rats significantly and would be a potential strategy for the treatment of renal disorders.