Sullivan D A, Allansmith M R
Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
Immunology. 1988 Mar;63(3):403-10.
The objective of the present study was to examine the influence of aging on the ocular secretory immune system of the eye. Levels of IgA and free secretory component (FSC) were measured in lacrimal glands and/or tears of 0.6, 1.3, 3, 8 and 17-month-old male and female rats. In addition, the FSC output of lacrimal tissue cultured in vitro was evaluated. During the period from 0.6 to 1.3 months of age, the content of tear IgA increased nine- and 13-fold in females and males, respectively. This rise was paralleled by changes in the concentration of tear FSC. Prior to the onset of puberty, FSC could be detected in only 7% of tear samples, whereas after pubertal maturation, tear FSC levels had attained adult concentrations. This tear FSC profile was similar to the age-related pattern of FSC output by lacrimal tissue incubated in vitro. Following puberty, tear IgA content continued to increase in both sexes until adulthood (3 months of age) and then plateaued in females from 8 to 17 months of age. In contrast, tear IgA in males appeared to stabilize from 3 to 8 months and then rose significantly to the highest levels at 17 months of age. This increase in males was also reflected in their lacrimal tissue: IgA content underwent a six-fold elevation from 3 to 17 months. Of interest is that the differential kinetics involved in tear IgA and FSC expression resulted in an age-associated decline in the FSC/IgA ratio from post-puberty to senescence. A striking finding in these studies was the persistence of a sexual dimorphism in the secretory immune system of the eye. After pubertal development, IgA and FSC levels were significantly higher in tears of males, compared to those of females, at all ages tested up to 17 months. These gender- and age-related variations in tear IgA and FSC amounts could not be accounted for by changes in either the volume of, or total protein content in, tears.
本研究的目的是探讨衰老对眼部分泌性免疫系统的影响。在0.6、1.3、3、8和17月龄的雄性和雌性大鼠的泪腺和/或泪液中测量了IgA和游离分泌成分（FSC）的水平。此外，还评估了体外培养的泪腺组织的FSC产量。在0.6至1.3月龄期间，雌性和雄性大鼠泪液中IgA的含量分别增加了9倍和13倍。这种增加与泪液中FSC浓度的变化平行。在青春期开始之前，仅7%的泪液样本中可检测到FSC，而青春期成熟后，泪液中FSC水平已达到成年浓度。这种泪液FSC模式与体外培养的泪腺组织中FSC产量的年龄相关模式相似。青春期后，两性泪液中IgA含量持续增加直至成年（3月龄），然后在8至17月龄的雌性大鼠中趋于稳定。相比之下，雄性大鼠泪液中IgA在3至8月龄时似乎稳定，然后在17月龄时显著上升至最高水平。雄性大鼠泪腺组织中IgA含量也有类似变化：从3月龄到17月龄增加了6倍。有趣的是，泪液中IgA和FSC表达的不同动力学导致从青春期后到衰老阶段FSC/IgA比值随年龄下降。这些研究中的一个显著发现是眼部分泌性免疫系统中性别二态性的持续存在。青春期发育后，在测试的所有年龄段（直至17月龄），雄性大鼠泪液中IgA和FSC水平均显著高于雌性大鼠。泪液中IgA和FSC含量的这些性别和年龄相关变化不能用泪液体积或总蛋白含量的变化来解释。
