[Surface markers and functions of human dendritic cells exposed to mobile phone 1800 MHz electromagnetic fields].

OBJECTIVE: To investigate the effects of mobile phone 1800 MHz electromagnetic fields (EMF) on the surface markers and the functions of human dendritic cells (DC). METHODS: Human DCs were exposed to intermittent 5 min on/10 min off EMF with specific absorption rates (SAR) 4 W/kg for 0 h, 1 h, 12 h or 24 h, respectively. FACS analysis was used to detect the positive percentage of DC surface markers including HLA-DR and co-stimulatory molecules such as CD80, CD86, CD40 and CD11c. CCK-8 kit was adopted to examine the function of allo-mixed lymphocyte reaction (allo-MLR) of DC, and enzyme linked immunosorbent assay (ELISA) to identify the levels of IL-12p70 and TNF-alpha secreted by DC. RESULT: Compared with the sham radiation group, after exposure to the electromagnetic fields for 1 h, 12 h, or 24 h, HLA-DR, CD80,CD86 and CD40 were all declined except CD11c. The ability of DC allo-MLR in each exposure group was decreased significantly (P<0.05), especially in the 24 h exposure group. However, the secreted levels of IL-12p70 and TNF-alpha of DC in each exposure group remained no changed. CONCLUSION: The study showed that EMF exposure could down-regulate the surface molecules and stimulation ability of human DC.

Effects of cryptoporus polysaccharide on rat allergic rhinitis associated with inhibiting eotaxin mRNA expression.

Aqueous extract from the fruiting body of Cryptoporus volvatus has been reported to present anti-tumor, anti-allergy, anti-inflammation and immunomodulatory activities. However, the effect mechanisms of anti-allergy and anti-inflammation are poorly understood. The aim of study is to evaluate whether Cryptoporus polysaccharides (CP) extracted from fruiting body of Cryptoporus volvatus decrease the development of nasal symptoms, airway hyperresponsiveness (AHR) to methacholine (MCh) and the infiltration of eosinophils in nasal mucosa in rat model of allergic rhinitis, and investigate a possible action mechanism of CP by detecting the expression of eotaxin mRNA in nasal mucosa and lung tissues. Rats were immunized with ovalbumin and consecutive topical antigen instillation was performed. Repeated intranasal ovalbumin challenge caused rhinitis symptom, AHR to MCh, eosinophil infiltration and histological alterations into the nasal mucosa and increase of eotaxin mRNA expression in nasal mucosa and lung tissue were examined. Pretreatment with CP 3, 9 and 27 mg kg(-1) (ig) decreased the numbers of sneezing 27.4%, 38.4% and 44.3% and nasal rubbing 27.5%, 34.9% and 47.7% comparison with model group, respectively. CP caused a dose-related inhibition of MCh-induced AHR. CP 27 mg kg(-1) decreased the expression of eotaxin mRNA in the nasal mucosa by 35%. These results suggest CP can relieve the symptom, eosinophil infiltration and injury of tissue in nasal mucosa and lung tissue and AHR of allergic rhinitis in rats. Its action mechanism may be associated with the decrease of eotaxin mRNA expression.

[Therapeutic effect of cationic liposome-mediated interleukin-12 gene delivery on murine melanoma in vivo].

OBJECTIVE: To investigate the therapeutic effect of cationic liposome-mediated interleukin-12 gene delivery on established murine melanoma in vivo. METHODS: The lipofectin encapsulated pCmIL-12 plasmid was given to C57BL/6 mice on the day 3,5,7,9 after inoculation of B16 melanoma cells. The tumor size, the survival time of mice and the NK cell activity were observed. RESULTS: The pCmIL-12 plasmid coupled with cationic liposome inhibited the tumor growth and improved the survival of mice bearing established melanoma. The activity of NK cells was also enhanced after interleukin-12 gene delivery in vivo. CONCLUSION: Cationic liposome-mediated interleukin-12 gene delivery has significantly therapeutic effects on mice melanoma in vivo.

[Enhancement by FK506 of triptolide-induced inhibition of expression of COX-2 and iNOS in human rheumatoid arthritis synovial fibroblasts].

To explore the effects of FK506 on the inhibition by triptolide (TP) of cell proliferation and expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and their inducing products PGE2, NO in human rheumatoid arthritis synovial fibroblasts (RASF), and to study the mechanisms of combination of FK506 and TP in RA therapy, RASF used in the experiments were obtained from synovial tissue of patients with RA and were cultured. RASF were pretreated with FK506(10-1000 nmol/L)for 2 h, then the cells were stimulated with TNF alpha(20 microg/L) in the presence or absence of TP (10 microg/L). The RASF proliferation was determined by [(3)H]-TdR incorporation, and the productions of PGE2 and NO in culture supernatants of RASF were detected with competitive ELISA and enzyme reduction of nitrate. Expression of COX-2 and iNOS mRNA in RASF were analyzed by semi quantitative RT-PCR. Expressions of COX-2 and iNOS protein were estimated by Western blot method and cellular enzyme immunoassay in synovial fibroblasts. NF-kappa B activity in whole-cell extract of RASF was also measured by an ELISA-based method. Results showed that neither FK506 nor TP at lower concentration (10 microg/L) alone affected TNF alpha-induced COX-2, iNOS expression and production of PGE2, NO in synovial cells. Combined treatment of FK506 and a lower concentration of TP (10 microg/L) down-regulated COX-2 and iNOS mRNA and protein expression, and their inducing products PGE2 and NO of synovial fibroblasts. This effect was positively correlated with FK506 concentrations (10-1000 nmol/L). NF-kappa B activity in TNF alpha-stimulated synovial cells was suppressed more profoundly by FK506 plus TP (10 microg/L) treatment than those with TP (10 microg/L) alone. No change was observed in inhibition of proliferation of synovial cells after combined treatment of FK506 and TP. In conclusion, FK506 enhanced TP-mediated down-regulation of COX-2, iNOS and their inducing products PGE2, NO in human RASF by suppressing the activity of NF-kappa B.

[The effect of a mouse IL-12 plasmid on airway inflammation and cytokine production in a mouse asthmatic model].

OBJECTIVE: To investigate the effect of a mouse IL-12 gene expressive plasmid (mIL-12 plasmid) on the airway inflammation and the cytokine production in asthmatic mice and to study the possible mechanisms. METHODS: A mouse model of asthma was established by sensitization with ovalbumin (OVA). Forty-one BALB/c mice were divided into six groups including an asthmatic model group (group A, eight mice, sensitized with OVA plus challenging with OVA by aerosol), a model control group (group B, six mice, sensitized with OVA plus aerosolizing with normal saline), a mIL-12 plasmid prevention group (group C, eight mice, receiving intramuscularly mIL-12 plasmid 100 micro g on day 1, day 3, and day 5), a mIL-12 plasmid treatment group (group D, eight mice, receiving intramuscularly mIL-12 plasmid 100 micro g on day 14, day 16, and day 18), an empty plasmid prevention group (group E, five mice, receiving intramuscularly empty plasmid 100 micro g on day 1, day 3, and day 5), and an empty plasmid treatment group (group F, six mice, receiving intramuscularly empty plasmid 100 micro g on day 14, day 16 and day 18). The number of EOS and the concentration of IL-4, IL-5 and IFN-gamma in the mouse bronchoalveolar lavage fluids (BALF) were detected. RESULTS: The number of EOS and the concentration of IL-4, IL-5 and IFN-gamma from group B were (0.01 +/- 0.03) x 10(8)/L, (24 +/- 4) pg/ml, (33 +/- 6) pg/ml, (725 +/- 59) pg/ml,respectively; those from group C were (0.06 +/- 0.04) x 10(8)/L, (43 +/- 13) pg/ml, (63 +/- 10) pg/ml, (626 +/- 60) pg/ml, respectively, and those from group D were (0.11 +/- 0.12) x 10(8)/L, (38 +/- 14) pg/ml, (66 +/- 14) pg/ml, (661 +/- 40) pg/ml, respectively; the difference was significant as compared with those from group A [(2.97 +/- 1.20) x 10(8)/L, (122 +/- 45) pg/ml, (126 +/- 34) pg/ml, and (435 +/- 49) pg/ml] (P < 0.001). The number of EOS and the concentration of IL-4, IL-5 and IFN-gamma from group C and group D also showed significant difference in comparison with those from group E [(1.96 +/- 0.93) x 10(8)/L, (110 +/- 24) pg/ml, (112 +/- 11) pg/ml and (464 +/- 51) pg/ml], and group F [(2.11 +/- 0.90) x 10(8)/L, (88 +/- 17) pg/ml, (107 +/- 6) pg/ml and (481 +/- 64) pg/ml] (P < 0.01). CONCLUSION: The mIL-12 plasmid can significantly inhibit airway inflammation. Its regulatory effect on the balancing of Th1/Th2 cytokines may be a possible mechanism.

[Expression of eotaxin mRNA and TNF-alpha mRNA in lung tissues of sensitized mice and modulation by anti-inflammatory drugs].

OBJECTIVE: To establish determination methods of eotaxin mRNA and TNF-alpha mRNA expression in the lung tissue of mice. METHODS: Eotaxin mRNA and TNF-alpha mRNA expressions were determined by semi-quantitative RT-PCR. The functional implications of eotaxin mRNA and TNF-alpha mRNA expression were examined by detecting the numbers of total leucocytes and eosinophils in bronchoalveolar lavage fluid(BALF). RESULT: Eotaxin mRNA and TNF-alpha mRNA expression in lung tissue total numbers of leucocyte and numbers of eosinophil in BALF increased in sensitized mice compared with those in normal mice. Dexamethasone significantly but did not inhibit eotaxin mRNA and TNF-alpha mRNA expressions, and eosinophil infiltration in the lungs of the sensitized mice. A compound preparation of traditional Chinese medicine inhibited eotaxin mRNA and eosinophil infiltration, influenced TNF-alpha mRNA expression. CONCLUSION: Increased eotaxin mRNA expression in lung tissue is associated with eosinophil infiltration in BALF, which indicates that the methods of semi-quantitative RT-PCR may be useful to the study of the mechanism of antiasthmatic medicine.

[Construction of bi-cistronic co-expression plasmid of mIL-12 and the expression in vitro or in vivo]

OBJECTIVE: To construct a bi-cistronic co-expression plasmid for mouse interleukin-12 and to observe its expression in vitro or in vivo.METHODS: The full-length cDNA encoding p35 and p40 was cloned into eukaryotic cells expression vector pcDNA 3.1 respectively. Subsequently,the p35 expression unit was inserted into pcDNA 3.1/p40 to produce the bi-cistronic co-expression plasmid in which the p35 and p40 genes were controlled by their own CMV.The plasmid was expressed in vitro and in vivo. RESULTS: The mIL-12 in the supernatant was detected by ELISA after the pCmIL-12 was transfected into COS-7 cells. The activity of NK cells could be augmented by the supernatant in vitro and also by by intradermal delivery of pCmIL-12 in vivo. CONCLUSION: The plasmid constructed by us can express biologically active mIL-12 in vitro and in vivo.