Association of TCR-signaling pathway with the development of lacrimal gland benign lymphoepithelial lesions.

Aim: To identify the association of the T cell receptor (TCR) signaling with the development of benign lymphoepithelial lesions (BLEL) of the lacrimal gland.

Methods: We collected affected lacrimal gland tissues from 9 patients who underwent dacryoadenectomy in the Capital Medical University Beijing Tongren Hospital Eye Center between August 2010 and March 2013 and were confirmed to have lacrimal gland BLEL by histopathological analysis. Tumor tissues from 9 patients with orbital cavernous hemangioma were also collected and used as control. Whole genome gene expression microarray was used to compare gene expression profiles of affected lacrimal gland tissues from patients with lacrimal gland BLEL to those from of orbital cavernous hemangiomas. Differential expression of TCR pathway genes between these tissues was confirmed by polymerase chain reaction (PCR) and immunohistochemistry.

Results: Microarray analysis showed that in lacrimal glands with BLEL, 32 signaling pathways were enriched in the upregulated genes, while 25 signaling pathways were enriched in the downregulated genes. In-depth analysis of the microarray data showed that the expression of 27 genes of the TCR signaling pathway increased significantly. To verify the differential expression of three of these genes, CD3, CD4, and interleukin (IL)-10, reverse transcription-PCR (RT-PCR) and immunohistochemistry assays were performed. RT-PCR analysis showed that CD3 and CD4 were expressed in the lacrimal glands with BLEL, but IL-10 was not expressed. Immunohistochemistry confirmed that CD3 and CD4 proteins were also present, but IL-10 protein was not. CD3, CD4, or IL-10 expression was not found in the orbital cavernous hemangiomas with either RT-PCR or immunohistochemistry.

Conclusion: TCR signaling pathway might be involved in the pathogenesis of lacrimal gland BLEL.