Fahy G T, Hooper D C, Easty D L
Department of Ophthalmology, University of Bristol.
Br J Ophthalmol. 1993 Jul;77(7):440-4. doi: 10.1136/bjo.77.7.440.
Ia antigen (class II antigen) is a histocompatibility antigen that foreign peptides associate with, before antigen presentation to T cells and subsequent triggering of the CD4 T cells. Although corneal epithelium is normally Ia negative it may become Ia positive under abnormal circumstances but the functional significance of this is uncertain. In this study the expression of Ia antigen on corneal epithelium of mice during in vivo primary and secondary herpes simplex keratitis and the in vitro accessory function of corneal epithelium in the presentation of herpes simplex virus (HSV) antigen to in vivo HSV primed T cells were evaluated. Whole mount preparations of corneal epithelium were found to express Ia antigen on days 3, 5, and 7 following corneal inoculation with live HSV. The intensity of the Ia expression was greater in non-immune mice on day 7 after corneal inoculation compared with immune mice. A cellular suspension of corneal epithelium induced HSV primed T cells to proliferate in the presence of HSV antigen. Induction of Ia antigen on corneal epithelium during herpes simplex keratitis may functionally expand the population of antigen presenting cells in the cornea and contribute to T cell activation.
Ia抗原（II类抗原）是一种组织相容性抗原，在外源肽呈递给T细胞并随后触发CD4 T细胞之前，外源肽与之结合。尽管角膜上皮通常为Ia阴性，但在异常情况下可能会变为Ia阳性，但其功能意义尚不确定。在本研究中，评估了单纯疱疹性角膜炎原发和继发过程中小鼠角膜上皮Ia抗原的表达，以及角膜上皮在将单纯疱疹病毒（HSV）抗原呈递给体内经HSV致敏的T细胞过程中的体外辅助功能。发现角膜接种活HSV后第3、5和7天，角膜上皮的整装标本表达Ia抗原。角膜接种后第7天，非免疫小鼠的Ia表达强度高于免疫小鼠。角膜上皮细胞悬液在HSV抗原存在的情况下诱导经HSV致敏的T细胞增殖。单纯疱疹性角膜炎期间角膜上皮Ia抗原的诱导可能在功能上扩大角膜中抗原呈递细胞的群体，并有助于T细胞活化。
