Abstract
Purpose :
An increasing number of pro-inflammatory cytokines, angiogenic and fibrogenic growth factors and their receptors have been related to pterygium (Pt). T helper cells CD4+ (Th) are an important constituent on Pt tissues, however The effect of Th cytokines on Pt pathogenesis has been poorly studied. To date, only interleukin 4 (IL-4) from Th cells has been linked to pterygium recurrence. Therefore, this study was undertaken to evaluate the expression of Th cytokines and Th transcription factors in primary Pt.
Methods :
Pterygia heads were collected from 28 eyes of 28 Mexican patients undergoing primary pterygium excision with conjunctival autografting. Conjunctival biopsies from 8 patients undergoing cataract surgery were used as control group. Gene expression of the Th citokines; interferon gamma (IFN-γ), IL-13, IL-17, IL-10, as well as the gene expression of the Th transcription factors; T-bet, GATA3, Foxp3 and RORγt were analyzed by real time RT-PCR using TaqMan assays. The 2-ΔΔCT method was used for data analysis.
Results :
The expression of T-bet, GATA3, RORγt, IFN-γ, IL-13 and IL-10 were downregulated in Pt. Interestingly, the lowest transcript expression for IL-13 and GATA3 were reached at maximum corneal invasion. The expressions of IL-17 and Foxp3 were increased up to 6 fold changes in Pt tissues (P< 0.0001), and occurred for the latter gene in a Pt size and Pt extension dependent manner.
Conclusions :
The increased expression of IL-17 and Foxp3 in Pt specimens suggest the presence of IL-17+Foxp3+ T cells, a subset of Th population which suppress T cell proliferation and promotes tumor progression. Therefore, IL17+Foxp3+ T cells could be a therapeutic target to prevent pterygium growth.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.