Out Theo A, Wang Shan-Ze, Rudolph Karin, Bice David E
Academic Medical Centre B1-236 and CLB Sanquin Blood Supply Foundation, Clinical Immunology Laboratory, PO Box 22700, 1100 DE Amsterdam, the Netherlands.
Immunology. 2002 Apr;105(4):499-508. doi: 10.1046/j.1365-2567.2002.01383.x.
Dogs with immunoglobulin E (IgE) allergy for ragweed that are sensitized by intrapulmonary exposure to ragweed can be used to study the pulmonary immune response that is important in allergic asthma. Using this model, we tested the hypothesis that T lymphocytes are activated locally in the airways shortly after allergen exposure of the lungs. The airways of six allergic dogs and three non-allergic dogs were exposed to ragweed by segmental allergen challenge (SAC). T-cell subsets and T-cell activation in blood and bronchoalveolar lavage (BAL) fluid were measured by flow cytometry before SAC and at 4, 24 and 72 hr thereafter. SAC caused a statistically significant increase in the percentage of major histocompatibility complex (MHC) class II-positive CD4 and CD8 T cells in BAL fluid and a significant increase in the mean fluorescent activity of MHC class II from 4 hr after SAC onward. This activation was significantly different from that found in cells from lung lobes challenged with saline, or from lung lobes in non-allergic dogs challenged with ragweed. The percentage of CD45RA(bright) CD8 cells increased significantly in allergic dogs after both ragweed and saline challenges. This was significantly higher than in non-allergic dogs. We conclude that T-cell activation in the airways of dogs can be measured after in vivo activation of the cells by measuring MHC class II and CD45RA expression in BAL fluid T cells. Furthermore, in allergic dogs, T cells are activated locally in the lungs within 4 hr after exposure to ragweed allergen. These results suggest a role for T lymphocytes in the development of late-phase allergic reactions in the airways.
对豚草产生免疫球蛋白E（IgE）过敏且经肺内接触豚草致敏的犬可用于研究在过敏性哮喘中起重要作用的肺部免疫反应。利用该模型，我们检验了以下假设：在肺部接触过敏原后不久，T淋巴细胞在气道内被局部激活。通过分段过敏原激发（SAC），使6只过敏性犬和3只非过敏性犬的气道接触豚草。在SAC前以及此后4小时、24小时和72小时，通过流式细胞术测量血液和支气管肺泡灌洗（BAL）液中的T细胞亚群和T细胞活化情况。SAC导致BAL液中主要组织相容性复合体（MHC）II类阳性CD4和CD8 T细胞的百分比出现统计学显著增加，并且从SAC后4小时起，MHC II类的平均荧光活性显著增加。这种活化与用盐水激发的肺叶细胞或用豚草激发的非过敏性犬肺叶细胞中的活化情况显著不同。在豚草和盐水激发后，过敏性犬中CD45RA（明亮）CD8细胞的百分比均显著增加。这显著高于非过敏性犬。我们得出结论，通过测量BAL液T细胞中MHC II类和CD45RA的表达，可以在体内激活细胞后测量犬气道中的T细胞活化情况。此外，在过敏性犬中，接触豚草过敏原后4小时内，T细胞在肺内被局部激活。这些结果表明T淋巴细胞在气道迟发性过敏反应的发生中起作用。
