Dyalizable Leukocyte Extracts Regulate The Expression Of HBD-2 And LL37 In Human Limbal Epithelial Cells

Abstract

Purpose: : The dialyzable leukocyte extracts (DLE), is a peptidic fraction of <12KDa obtained from a dialysis of leukocytes with the capacity to transfer the cellular immune response. It has been recognized that DLE has an immunomodulatory effect on peripheral blood mononuclear cells (PBMNC). Previous reports about DLE have shown that is capable to increase the expression of HBD2 in PBMNC. HBD2 is an antimicrobian peptide, which help in control infections. The aim of this study was to determine the effect of DLE on the expression of HBD2 and LL37 in human limbal epithelial cells.

Methods: : Human Limbal Epithelial Cells (HuLEC) were obtained from sclero-corneal rings from cadaveric donors and cultured in KSFM medium. HuLEC were stimulated with different concentrations of DLE or PMA/Ionomycine at 0, 1, 3, 6 and 24h. The expression of HBD2 and LL37 were analyzed by qRT-PCR and normalized with the 18S gene. p<0.05 was considered as statistically significant.

Results: : The expression of HBD2 and LL-37 was analyzed using a 2^-ΔΔCt equation. HBD2 showed maximum expression at 3 hours after culture with 5µg of DLE (p<0.01), however with 0.5µg of DLE HBD2 expression did not change during culture. The expression of LL-37 gene was maximum at 3 hour after culture with 0.5µg of DLE (p<0.01), but not changes were showed during culture with 5µg of DLE.

Conclusions: : DLE regulate the expression of HDB2 and LL-37 genes in HuLEC. The expression of both genes was positively induced; the increased expression of these genes in the ocular microenvironment can help to control infections in general. Although the probability that a microorganism show resistance to these peptides is much lower than presented by antibiotics. However, these peptides have the ability to immunoregulate the acquired immune response, thus promotes inflammation without an eye injury.

Keywords: immunomodulation/immunoregulation • cornea: basic science