Expression of CRAMP via PGN-TLR-2 and of alpha-defensin-3 via CpG-ODN-TLR-9 in corneal fibroblasts.

Abstract

To search for the induction of the expression of antimicrobial peptides in corneal fibroblasts treated with bacterial components. RT-PCR was performed to search for mRNAs expression of antimicrobial peptides and toll-like receptors (TLRs) in murine primary cultures of corneal fibroblast (PCCF) treated with lipopolysaccharide (LPS) from Escherichia coli, peptidoglycan from Staphylococcus aureus, and cytosine-phosphorous-guanine oligonucleotide (CpG-ODN). Cellular activation was blocked with anti-TRL antibodies. LPS did not induce expression of antimicrobial peptide in corneal fibroblasts. Cathelin related antimicrobial peptide (CRAMP) and alpha-defensin 3 were overexpressed in a time and dose dependent manner in corneal fibroblasts treated with peptidoglycan and with CpG-ODN, respectively. CRAMP expression was blocked when PCCF were treated with anti-TLR-2 antibodies. alpha-Defensin 3 was not expressed in NIH murine corneal fibroblasts (which do not express the TLR-9 molecule) treated with CpG-ODN. Results suggest that corneal fibroblasts, which are the second cellular barrier of the cornea, can play an important part in the innate immunity of the eye via TLR stimulation.