Inhibitory Effect On Asthma By The Dendritic Cell Subset Of Schistosoma Japonicum-infected Mice

Objective To study the inhibition of allergic asthma by adoptive transfer of dendritic cell (DC) subsets from Schistosoma japonicum-infected mice. Methods DC subsets from S.japonicum-infected mice and naive mice were respectively isolated and purified using CD8a and CDllc microbeads. Thirty BALB/c mice were divided into six groups randomly. Group A was control.5×105CD8α-CD11c+DCs of S. japonicum-infected mice were injected into the tail vein of each mouse in Group B1, while5×105CD8α+CD11c+DCs were injected into the tail vein of each mouse in Group B2. Meantime, the same quantity of CD8α-CD11c+and CD8a+CD11c+DCs of naive mice were respectively injected into each mouse in Group C1and C2in the same way. Group D was asthma group. One hour after adoptive transfer, mice in Group B1, B2, C1, C2and D were sensitized and challenged with ovalbumin(OVA) to induce asthma. Mice were sacrificed after four weeks, Sera were collected for measurement of OVA-specific IgE, Bronchoalveolar lavage fluids (BALF) were collected for Eosinophils cell counting, the left lungs were removed for histopathological analysis and immunohistochemistry staining, and the right lung homogenate were prepared for Eosinophil Peroxidase(EPO) detecting. Results Compared with mice in Group B2, C1, C2and D, the level of OVA-specific IgE of mice in Group B1diminished markedly(P<0.05). The number of eosinophils (104) in BALF for the mice in Group A, B1, B2,C1, C2and D were3.20±1.79,13.50±4.04,28.50±3.99,28.67±4.93,25.00±3.61,40.00±3.39respectively. The number of eosinophils in Group B1decreased significantly (P<0.05), and pulmonary inflammation of mice in Group B1diminished markedly. According to Underwood’s standard, average total scores of Group A, B1, B2,C1, C2and D were0,7.67±2.34,11.17±1.47,10.86±1.35,12.00±1.73and11.75±2.22respectively(P<0.05). Moreover, the immunohistochemistry staining indicated that the average optical density (AOD) of CCL-2-positive regions in mouse lung tissue were0.0327±0.0154,0.3967±0.0250,0.5274±0.0281,0.5458±0.0267,0.5375±0.0309and0.563±0.0282for the six groups. The difference in optical density between groups was statically significant (P<0.05). The level of EPO in mouse lung tissue were1.0073±0.2496,1.5277±0.4430, 3.3077±0.5944,3.3406±0.5011,3.3017±0.3345,3.4032±0.6884, the Group B1was different from the other asthma groups as well(P<0.05). Conclusion The CD8α-CD11c+DC subset, from mice infected with Schistosoma japonicum, can inhibit pulmonary inflammation in the OVA-induced asthma.