Effect Of Mycobacterium Tuberculosis Culture Filtrate Protein On The Expression Of Ifn-γ And Il-5 In Respiratory Tract Of Allergic Rhinitis Model In Rats.

BackgroundAllergic diseases occur commonly in upper and lower respiratory tract, especially for allergic rhinitis(AR) and bronchial asthma(BA) which show the clinical manifestations respectively. As its incidence has been increasing annually ,AR and BA affect human life quality seriously. Studies have shown that AR and BA often coexist. It is now well established that AR and BA frequently occur together, with approximately 38% of allergic rhinitic patients having concomitant BA and upwards of 80% of asthmatic patients having chronic nasal symptoms.Now the concept of"one way,one disease"has been accepted widely. The concepts of"United airway disease","Chronic allergic inflammantory airway syndrome"depict the consistency and relevance vividly. The World Health Organization initiative Allergic Rhinitis and its Impact on Asthma (ARIA) in 2001,which pointed out the effects of concomitant asthma specifically except discussed AR.At present, the treatment of allergic airway inflammation mainly include: avoid contacting with allergens, drug therapy,immune therapy and so on.It is difficult to avoid contacting with allergens and the drug therapy only improve the symptoms. Immune therapy modulate the onset of the disease ,which is the only treatment for the cause recommended by WHO. Mycobacterium culture filtrate protein is a mixture which is exist in the mycobacterium culture supernatant.It can stimulate T cells into secretion of IFN-γefficient and mainly used for the diagnosis of tuberculosis now.In this research, allergic rhinitis model was established by ovalbumin (OVA). Then to observe the airway inflammation and the expresssion of IFN-γand IL-5. CFP was administrated by instranasal instillation. Then to observe the effect of CFP on the airway inflammation and the expresssion of IFN-γand IL-5. And provide the experimental basis for CFP as an immunomodulator in the treatment of allergic airway inflammation.Part one Research on the airway inflammation of allergic rhinitis model in rats.Objective:To investigate the relationship between upper and lower respiratory tract by researching on the inflammation of allergic rhinitis model.Methods:Male SD rats (SPF grade) were randomly divided into two groups: normal control group, model group, 10 in each group.Allergic rhinitis model was established by ovalbumin(OVA). Nasal mucosa and lung tissue were stained with hematoxylin- eosin(HE) to study the pathological changes.Immunohistochemistry was used to examine the ex- pression of interleukin-5(IL-5) and IFN-gamma (IFN-γ).The level of IL-5 and IFN-γin bronchial alveolus lavage fluid (BALF) were measured by Enzyme-linked imm- unosorbent assay (ELISA).Results:1.Infiltration of inflammatory cells in nasal mucosa and lung tissue of allergic rhinitis (AR) model in rat was evident.2.The expression of IL-5 in nasal mucosa and lung tissue of AR group was significant higher compared with that in control group.Meawhile, the average value of absorbance A was positively correlated with the number of eosinophils in nasal mucosa and lung tissue. The expression of IFN-γin nasal mucosa and lung tissue of AR group was significant lo- wer compared with that in control group.3.The level of IL-5 in BALF of AR group was significant higher than control group while the level of IFN-γwas significant low er than control group.Conclusions:The dominant expression of Th2 cytokines lead to the imbalance state of the Th1 and Th2 cytokines exist in upper and lower airway of allergic rhinitis model in rat.The inflammation is similar and related between upper and lower airway.Part two Effect of Mycobacterium tuberculosis culture filtrate protein on the expression of IFN-γand IL-5 in respiratory tract of allergic rhinitis model in rats.Objective:To investigate the effect of Mycobacterium tuberculosis culture filtrate protein on the airway inflammation and the expression of IFN-γand IL-5 in respiratory tract of allergic rhinitis model in rats.Methods:Male SD rats (SPF grade) were randomly divided into five groups: normal control group, model group, CFP-treated group, budesonide treatment group, CFP control group, 10 in each group.Allergic rhinitis model was established by ovalbumin (OVA).CFP was administrated by instranasal instillation.Typical symptoms of allergic rhinitis ,such as nasal blockage, sneezing,nasal scratching were evaluated. Nasal muc- osa and lung tissue were stained with hematoxylin-eosin(HE) to study the pathologi- cal changes. Immunohistochemistry was used to examine the expression of interleuk- in-5(IL-5) and IFN-gamma (IFN-γ). The level of IL-5 and IFN-γin bronchial alveolus lavage fluid (BALF) were measured by Enzyme-linked immunosorbent assay (ELISA). Results:1. Allergic rhinitis model was established successfully.2. CFP can improve the symptoms and the inflammation of the sensitized rats in nasal mucosa and lung tissue.At the same time,it can increase the level of Th1 cytokine IFN-γand decrease the level of Th2 cytokine IL-5.Conclusion:As an immunemodulator,CFP can increase the expression of IFN-γand reduce the expression of IL-5 effectively in respiratory tract of allergic rhinitis model in rats,which shows it may have the effect of correcting the imbalance of Th1 and Th2,suggesting its potential application in the treatment of allergic airway inflammation.