Shoji Jun, Sakimoto Tohru, Muromoto Keiko, Inada Noriko, Sawa Mitsuru, Ra Chisei
Department of Ophthalmology, Nihon University School of Medicine, Tokyo, Japan.
Jpn J Ophthalmol. 2005 May-Jun;49(3):205-10. doi: 10.1007/s10384-004-0187-3.
To evaluate the efficacy of topical dexamethasone and topical FK506 treatment on allergic inflammation in conjunctiva, we performed a comparative study using a mouse experimental allergic conjunctivitis model.
The experimental allergic conjunctivitis model was developed by ovalbumin (OVA) instillation after OVA sensitization by intraperitoneal application of a mixed solution of OVA and aluminum hydroxide. The Balb/c mice of the experimental allergic conjunctivitis model were divided into three groups, depending on whether or not they received topical treatment and which type of treatment they received. The allergy group comprised six mice without topical treatment; the dexamethasone (Dx) group comprised six mice receiving topical 0.1% dexamethasone ointment treatment; and the FK506 (FK) group comprised six mice receiving topical 0.1% FK506 ointment treatment. The negative control group comprised six mice with neither sensitization nor topical treatment. For the histological examination, frozen sections of the eyelids, eyeballs, and lacrimal glands were stained with acid Giemsa stain or, in the immunohistochemical method, with alkaline phosphatase-antialkaline phosphatase (APAAP), for CD4. Densities of eosinophils and CD4-positive lymphocytes in the conjunctival tissue were counted. Productive C epsilon gene expression in the conjunctival tissue, including the lacrimal gland, was also evaluated by reverse transcriptase polymerase chain reaction (RT-PCR).
In the histological study, the cell density of eosinophils infiltrating into subconjunctival tissues was 66.3 +/- 34.7 cells/mm(2) (mean +/- SD) for the allergy group, 2.5 +/- 4.2 cells/mm(2) for the Dx group, 4.2 +/- 8.6 cells/mm(2) for the FK group, and 3.7 +/- 7.6 cells/mm(2) for the negative control group. The cell density of CD4-positive cells infiltrating into subconjuctival tissues was 145.9 +/- 66.4 cells/mm(2) for the allergy group, 10.0 +/- 12.9 cells/mm(2) for the Dx group, 10.1 +/- 15.5 cells/mm(2) for the FK group, and 21.7 +/- 17.8 cells/mm(2) for the negative control group. The allergy group showed significant differences in the density of eosinophils and CD4-positive cells compared with those of the Dx (P < 0.0001) and FK (P < 0.0001) groups. In the RT-PCR study, the expression of productive C epsilon gene was positive in the Dx group, but negative in the allergy group, the FK group, and the negative control group.
Topical Dx and FK506 treatments were both efficacious in suppressing eosinophil and lymphocyte infiltration into subconjunctival tissue in the mouse experimental allergic conjunctivitis model. However, the influence of their IgE productive mechanisms seemed to differ, causing different efficacy of productive C epsilon gene expression in the conjunctival tissue.
为评估局部应用地塞米松和局部应用FK506治疗对结膜过敏性炎症的疗效，我们使用小鼠实验性过敏性结膜炎模型进行了一项对比研究。
通过腹腔注射卵清蛋白（OVA）与氢氧化铝混合溶液致敏后，再滴入OVA建立实验性过敏性结膜炎模型。根据是否接受局部治疗以及接受何种治疗，将实验性过敏性结膜炎模型的Balb/c小鼠分为三组。过敏组包括6只未接受局部治疗的小鼠；地塞米松（Dx）组包括6只接受局部0.1%地塞米松软膏治疗的小鼠；FK506（FK）组包括6只接受局部0.1% FK506软膏治疗的小鼠。阴性对照组包括6只既未致敏也未接受局部治疗的小鼠。对于组织学检查，眼睑、眼球和泪腺的冰冻切片用酸性吉姆萨染色，或在免疫组织化学方法中用碱性磷酸酶 - 抗碱性磷酸酶（APAAP）染色以检测CD4。对结膜组织中的嗜酸性粒细胞和CD4阳性淋巴细胞密度进行计数。还通过逆转录聚合酶链反应（RT-PCR）评估包括泪腺在内的结膜组织中分泌性Cε基因的表达。
在组织学研究中，过敏组结膜下组织中浸润的嗜酸性粒细胞细胞密度为66.3±34.7个细胞/mm²（平均值±标准差），Dx组为2.5±4.2个细胞/mm²，FK组为4.2±8.6个细胞/mm²，阴性对照组为3.7±7.6个细胞/mm²。结膜下组织中浸润的CD4阳性细胞密度，过敏组为145.9±66.4个细胞/mm²，Dx组为10.0±12.9个细胞/mm²，FK组为10.1±15.5个细胞/mm²，阴性对照组为21.7±17.8个细胞/mm²。与Dx组（P<0.0001）和FK组（P<0.0001）相比，过敏组在嗜酸性粒细胞和CD4阳性细胞密度方面存在显著差异。在RT-PCR研究中，分泌性Cε基因的表达在Dx组为阳性，但在过敏组、FK组和阴性对照组中为阴性。
在小鼠实验性过敏性结膜炎模型中，局部应用Dx和FK506治疗在抑制嗜酸性粒细胞和淋巴细胞浸润到结膜下组织方面均有效。然而，它们对IgE分泌机制似乎有不同影响，导致结膜组织中分泌性Cε基因表达的疗效不同。
