Effect Of CD28/CTLA-4on Treating Bronchial Asthma

Objectives: The expression of T lymphocytes auxiliary receptor CD4、CD8andsynergy exciting molecular receptors CD28、CTLA-4on bronchial asthma is analyzed.According to the analysis, we aim to discuss the effect of synergy exciting molecularreceptors CD28、CTLA-4on bronchial asthma respectively.Methods:40cases of bronchial asthma patients, i.e.20male,20female are selectedas the experimental group. The average age is35±12. Simultaneously,40healthy ones(20male and20female) are chosen as comparative group. The average age is30±8. Boththe group of cases are selected according to the diagnosis standard of bronchial asthmathat is described on the instruction of prevention and cure on bronchial asthma made byAsthma group in Chinese Medical Association in2008. The criteria are as follows: morethan16years old; symptoms like wheezing, shortness of breath, chest tightness, or coughSigns; more eosinophils are observed in sputum smear under a microscope; pulmonaryfunction tests: the result of bronchodilation test is positive. That is FEV1is improvedover15%and the absolute value of the increase is larger than200ml after the use ofbronchodilator; no history of smoking; without using glucocorticoid orimmunomodulator within one month prior to testing.2milliliter blood sample arepumped from each case on the status of fasting plasma and then CD4+、CD8+、CD4+/CD8+、CD4+CD28+、CD4+CD28-、CD8+CD28+、CD8+CD28-、CD4+CTLA-4+、CD8+CTLA-4+,etc. from the blood sample are analyzed by flow cytometry. On the dataanalysis, SPSS10.0is used and the data is expressed in the form of χ±δ. Also, the data isstatistically analyzed by using the non-parameter Mann-Whitney U test.Results: Observed from the comparative results, CD4+、CD8+、CD4+CD28+andCD8+CD28+in the group of asthma are found to be statistically higher than those in thegroup of healthy at the99%or95%confidence level. In addition, CD4+CD28-andCD8+CD28-in the group of asthma is statistically lower than those in the group of healthy (p＜0.05)；Furthermore, there is no significant difference ((p＞0.05) betweenbetween the group of asthma and the group of healthy on CD4+/CD8+、CD4+CTLA-4+、CD8+CTLA-4+、CD4+CTLA-4-and CD8+CTLA-4-.Conclusion: The main immunological abnormality of bronchial asthma is due to thedisorders in the ratio of the number and the function of the subsets of T lymphocytes. Tobe specific compared to control group, the number of CD4+and CD8+T lymphocytesin the patients with asthma is higher. The percentage of CD28+T lymphocytes (whichhas a positive regulatory role) for all lymphocytes is increased compared to the controlgroup. However, the proportion of CTLA-4+T lymphocytes in lymphocytes expressesno difference for the asthma group and control group. As the co-stimulatory moleculereceptors CD28and B7molecules are combined, the generation of the cytokines IL-2and the anti-apoptotic proteins (Bcl-x) are promoted and so the participation of CD4+Tcells on the inflammation induced by exogenous antigen peptide-MHC composite isenhanced. Such reaction results in a higher percentage of CD4+CD28+T cells and alower percentage of CD4+CD28-T cells in in asthmatic group. The number of CD8+CD28+T-lymphocytes cells is increased compared to the control group. However, thenumber of co-stimulatory molecule receptor CD28(which is lack of positive regulationeffect) and CD8+CD28-T lymphocytes (to provide stimulating signal together with thecorresponding object) is reduced compared to the control group. There is no significantdifferent between the asthma group and the control group on CD4+CTLA-4、CD4+CTLA-4-、CD8+CTLA-4+and CD8+CTLA-4-. The reasons are concluded: Tlymphocytes in patients with asthma are active, co-stimulatory molecule receptorCTLA-4with negative regulator fail to upward and asthma patients themselves cannotgenerate enough inhibitory signals.