Role of mast cells in allergic inflammation in the skin

在干细胞因子和白介素6的共同作用下，从脐血细胞中培养出肥大细胞。免疫细胞化学染色显示，所有细胞均含有类胰蛋白酶。抗-IgE有效地刺激肥大细胞以剂量依赖和时间依赖的方式释放组胺。钙离子载体A23187也以剂量依赖和时间依赖的方式诱导组胺释放。化合物48/80和P物质不能诱导细胞释放组胺。作为研究的下一步，研究了紫外光照射对P物质诱导的大鼠腹膜肥大细胞组胺释放的影响。紫外线B(UVB)照射抑制组胺释放呈剂量依赖关系，8-甲氧补骨脂素+长波紫外线(UVA)照射抑制组胺释放呈剂量依赖关系。含有类胰蛋白酶和乳糜酶的肥大细胞是色素性荨麻疹患者皮损中唯一可见的类型。1例惰性全身性肥大细胞增多症患者的非皮损皮肤以含类胰蛋白酶和糜乳酶的肥大细胞为主，而皮损皮肤以含类胰蛋白酶的肥大细胞为主(但不含糜乳酶)。系统性肥大细胞增多症患者不仅皮肤，而且淋巴、骨髓、支气管、鼻粘膜、胃粘膜均可见含有类胰蛋白酶(但不含糜酶)的肥大细胞。肥大细胞增多症患者血中组胺、类胰蛋白酶、白三烯C4和尿甲基组胺、白三烯E4水平均升高。

Mast cells were raised from umbilical cord blood cells in the presence of stem cell factor and interleukin 6. Immunocytochemical staining for mast cell proteases revealed that all cells contained tryptase. Anti-IgE effectively stimulated the mast cells to release histamine in a dose-dependent, time-dependent manner. Calcium ionophore A23187 also induced histamine release in a dose-dependent, time-dependent manner. Compund 48/80 and substance P failed to induce histamine release from the cells. As a next step of the study, the effects of ultraviolet light irradiation on substance P-induced histamine release from rat peritoneal mast cells were investigated. Ultraviolet light B (UVB) irradiation inhibited the histamine release in a dose-dependent manner, and 8-methoxypsoralen plus long-wave ultraviolet light (UVA) irradiation inhibited in a dose-dependent manner of UVA.UVB irradiation and 8-methoxypsoralen plus UVA irradiation inhibited the histamine release through the suppression of intracellular calcium concentrations.Mast cell subtype of patients with mastocytosis was investigated. Mast cells containing tryptase and chymase were the only type seen in the skin lesions of a patient with urticaria pigmentosa. Mast cells containing tryptase and chymase were predominant in the nonlesional skin of a patient with indolent systemic mastocytosis, however mast cells containingtryptase (but not chymase) were predominant in the lesional skin of the patient. Biopsy specimens from not only the skin but also the lymphnode, bone marrow, bronchus, nasal mucosa, gastric mucosa showed infiltrations of mast cells containing tryptase (but not chymase) in a patient with systemic mastocytosis. Blood levels of histamine, tryptase, leukotriene C4 and urine levels of methylhistamine, leukotriene E4 were elevated in the patients with mastocytosis.