OBJECTIVEIn contrast to CD(4)(+) helper T-lymphocytes (T(H)), little is known about the transcriptional regulation of CD(8)(+) cytotoxic T-lymphocytes (Tc) and its role in the pathogenesis of asthma is unclear. This study was conducted to investigate the effect of T-bet and GATA-3 mRNA expression on profiles of type 1 and type 2 cytotoxic T lymphocytes in asthmatic children.

METHODTotally 38 asthmatic children, including acute attack group composed of 20 cases (age 3 - 13 years, mean 6.2 +/- 2.9), remission group with 18 cases (age 3 - 12 years, mean 6.1 +/- 2.5) and 20 healthy control children (age 3 - 12, 6.9 +/- 2.7) were recruited in this study from Sep. 2005 to Mar. 2006. The mRNA expression of T-bet and GATA-3 in the peripheral blood mononuclear cells were detected by using semi-quantitative PCR and Tc1, Tc2 cell numbers by flow cytometry analysis system.

RESULTT-bet mRNA in asthmatic children was lower than that in control group and lower in attack stage than in remission stage (0.14 +/- 0.04, 0.21 +/- 0.03, 0.28 +/- 0.03, P < 0.05). In contrast, GATA-3 mRNA was higher in asthmatic children than in control group and higher in attack stage than in remission stage (0.49 +/- 0.09, 0.44 +/- 0.08, 0.37 +/- 0.04, P < 0.05). It was shown that Tc1 percentage was lower in asthmatic children than those of control group and lower in attack stage than those of remission stage (6.6 +/- 2.4, 14.2 +/- 4.3, 31.2 +/- 3.8, P < 0.05). Tc2 percentage in asthmatic children was higher than that of control group and higher in attack stage than that of remission stage (10.0 +/- 4.2, 5.4 +/- 2.2, 3.5 +/- 1.1, P < 0.05). Spearman correlation analysis revealed that T-bet mRNA was positively correlated with Tc1 percentage (r = 0.704) and negatively correlated with Tc2 percentage (r = -0.629). GATA3 mRNA was negatively correlated with Tc1 percentage (r = -0.612) and positively correlated with Tc2 percentage (r = 0.673). The T-bet/GATA-3 mRNA ratio was positively correlated with Tc1 percentage (r = 0.731) and Tc1/Tc2 (r = 0.773), while negatively correlated with Tc2 percentage (r = -0.642).

CONCLUSIONThe imbalance of T-bet/GATA-3 mRNA expression is closely correlated with skewed Tc2 dominance in asthmatic children.

Adolescent ; Asthma ; genetics ; immunology ; metabolism ; Case-Control Studies ; Child ; Child, Preschool ; Female ; GATA3 Transcription Factor ; genetics ; metabolism ; Humans ; Male ; RNA, Messenger ; genetics ; metabolism ; T-Box Domain Proteins ; genetics ; metabolism ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo detect the expression of lung aquaporin 5 (AQP5) in mice with acute allergic asthma and the effect of dexamethasone (DEX) treatment on AQP5 expression, and investigate the role of AOP5 in asthma pathogenesis.

METHODSMouse models of acute allergic asthma were randomly divided into acute asthma group, normal control group and DEX treatment group. The total number of white blood cells, the subpopulations, and the levels of IL-5 and IFN-gamma were detected in the bronchoalveolar larvage fluid (BALF). The lung tissue AQP5 mRNA expression was detected by RT-PCR, and AQP5 distribution by immunohistochemical method.

RESULTSIn asthma group, the total white blood cells, eosinophils and IL-5 levels were all significantly higher (P<0.01) and IFN-gamma levels lower than those of the control group (P<0.01). After DEX treatment, the levels underwent a significant reverse change (P<0.05, P<0.01, P<0.01, and P<0.01, respectively). AQP5 mRNA expression in the asthma group was significantly higher than that in the control group (P<0.01), and was significantly lowered with DEX treatment (P<0.01). Extensive inflammatory changes, mucus hypersecrection, several edema and inflammatory cell infitration around the blood vessels were observed in the lung tissue of the mice in the asthma group. The morphological changes of the treatment group were significantly ameliorated. AQP5 protein was detected in the type I alveolar epithelial cells, the airway columnar epithelial cells and the apical membranes of the submucosal gland acinar cells in the control group. Stronger AQP5 protein expression was found in the asthma group.

CONCLUSIONAQP5 is over-expressed in mice with acute asthma which is possibly associated with mucus hypersecrection. DEX can inhibit AQP5 expression and ameliorate allergic airway inflammation, edema and mucus hypersecrection.

Animals ; Anti-Inflammatory Agents ; pharmacology ; Aquaporin 5 ; biosynthesis ; genetics ; Asthma ; genetics ; metabolism ; prevention & control ; Dexamethasone ; pharmacology ; Female ; Immunohistochemistry ; Lung ; drug effects ; metabolism ; pathology ; Mice ; Mice, Inbred C57BL ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction