Bevilacqua Claudia, Montagnac Guillaume, Benmerah Alexandre, Candalh Céline, Brousse Nicole, Cerf-Bensussan Nadine, Perdue Mary H, Heyman Martine
INSERM EMI0212, Faculté Necker, Paris, France.
Int Arch Allergy Immunol. 2004 Oct;135(2):108-16. doi: 10.1159/000080653. Epub 2004 Sep 2.
CD23 (FcepsilonRII) is expressed by intestinal epithelial cells (IEC) following allergic stimulation and increases the uptake of IgE/allergen complexes. The aim of this study was to further analyze the role of CD23 in the intraepithelial processing of food allergens during transepithelial transport.
Balb-C mice were sensitized intraperitoneally with horseradish peroxidase (HRP) or beta-lactoglobulin (beta-LG) in the presence of pertussis toxin. In control and sensitized mice, 3H-HRP, intact HRP, or 14C-beta-LG fluxes were measured across jejunal segments mounted in Ussing chambers, in the presence or absence of mucosal anti-CD23 antibodies. HPLC analysis of serosal buffer was performed to detect HRP- or beta-LG-derived radiolabelled metabolites generated during transepithelial transport.
In HRP-sensitized mice, 3H-HRP fluxes and intact HRP fluxes (3,836 +/- 476 and 290 +/- 86 ng/h x cm2, respectively) were significantly increased compared to control mice (1,677 +/- 297 ng/h x cm2, p < 0.01, and 106 +/- 23 ng/h x cm2, p < 0.02, respectively). HPLC analysis indicated the presence of intact HRP in the serosal compartment already 10 min after addition of HRP to the mucosal compartment, a result not observed in the control mice. In the presence of anti-CD23 antibodies, intact HRP fluxes were significantly decreased (131 +/- 27 ng/h x cm2) compared to control values in sensitized mice (290 +/- 86 ng/h x cm2, p < 0.02), suggesting that CD23 is involved is this 'protected' transport pathway. A similar protection during intestinal transport was observed for beta-LG in beta-LG sensitized mice.
These results confirm that CD23 is involved in the rapid transepithelial transport of intact allergens in sensitized animals, and indicate that CD23 opens a 'protected' transport pathway in IECs.
肠道上皮细胞（IEC）在过敏刺激后可表达CD23（FcepsilonRII），并增加IgE/过敏原复合物的摄取。本研究旨在进一步分析CD23在经上皮转运过程中对食物过敏原上皮内加工的作用。
在百日咳毒素存在的情况下，用辣根过氧化物酶（HRP）或β-乳球蛋白（β-LG）对Balb-C小鼠进行腹腔致敏。在对照小鼠和致敏小鼠中，在有或没有黏膜抗CD23抗体的情况下，测量安装在尤斯灌流小室中的空肠段的3H-HRP、完整HRP或14C-β-LG通量。对浆膜缓冲液进行HPLC分析，以检测经上皮转运过程中产生的HRP或β-LG衍生的放射性标记代谢物。
与对照小鼠相比，HRP致敏小鼠的3H-HRP通量和完整HRP通量（分别为3,836±476和290±86 ng/h·cm2）显著增加（对照小鼠分别为1,677±297 ng/h·cm2，p<0.01；106±23 ng/h·cm2，p<0.02）。HPLC分析表明，在向黏膜腔室添加HRP后仅10分钟，浆膜腔室中就已存在完整的HRP，对照小鼠未观察到这一结果。在抗CD23抗体存在的情况下，与致敏小鼠的对照值相比，完整HRP通量显著降低（131±27 ng/h·cm2）（290±86 ng/h·cm2，p<0.02），表明CD23参与了这种“受保护”的转运途径。在β-LG致敏小鼠的肠道转运过程中也观察到了类似的β-LG保护作用。
这些结果证实CD23参与了致敏动物中完整过敏原的快速经上皮转运，并表明CD23在IEC中开启了一条“受保护”的转运途径。
