Ocular surface expression and in vitro activity of antimicrobial peptides.
Huang. Ling C LC; Jean. Daniele D; Proske. Rita J RJ; Reins. Rose Y RY; McDermott. Alison M AM
Key Findings
- The eye’s surface cells produce several antimicrobial peptides, including hBD‑1,‑2,‑3, LL‑37, MIP‑3α, and Tβ4.
- hBD‑3 was the strongest at killing Pseudomonas, Staphylococcus aureus, and Staphylococcus epidermidis, even in the presence of salt.
- Salt and natural tears greatly reduced the antibacterial activity of hBD‑1, hBD‑2, and Tβ4, but not hBD‑3.
Practical Outcomes
- For most DIY health enthusiasts, this research offers little actionable guidance on using LL‑37. The only potentially useful insight is that hBD‑3 shows promise for eye‑infection protection, but it’s not a ready‑to‑use supplement or treatment for general longevity or performance goals.
Summary
The study looked at natural antimicrobial proteins on the eye’s surface, finding that one called hBD‑3 can kill common eye bacteria even in salty conditions, while others lose effectiveness when mixed with salt or tears. LL‑37, the peptide you asked about, wasn’t shown to have clear benefits in this eye‑specific test.
Abstract
Human ocular surface epithelia express four antimicrobial peptides (APs): beta -defensin (hBD) 1-3 and LL-37. Here the expression of additional APs (hBD 4-6, HE2beta 1; histatin-1, -3; liver expressed antimicrobial peptide-1, -2; macrophage inflammatory protein (MIP)-3alpha, and thymosin (T)beta -4) was sought and activity against common ocular pathogens studied. AP expression was determined in human corneal and conjunctival epithelial cells (HCEC, HCjEC) by RT-PCR and in corneal sections by immunostaining. Antimicrobial assays were performed to assess peptide (hBD 1-3, LL-37, MIP-3alpha, and Tbeta 4) activity against Pseudomonas aeruginosa (PA), Staphylococcus aureus (SA), and Staphylococcus epidermidis (SE) in the presence of NaCl or tears. HCEC and HCjEC expressed MIP-3alpha and Tbeta 4. hBD 1-3, MIP-3alpha, and Tbeta 4 showed activity against PA. hBD-3 had potent activity against SA and SE, whereas hBD-2, MIP-3alpha and Tbeta 4 had moderate activity and hBD-1 had none. NaCl markedly attenuated, and tears almost completely inhibited the activity of hBD 1-2 and Tbeta 4, but not that of hBD-3. The ocular surface epithelia additionally express MIP-3alpha and Tbeta 4 which have moderate antimicrobial activity. The current data support a role for hBD-3 as an antimicrobial peptide in vivo, but call in to question the effectiveness of some other APs. However, further study is required to conclusively elucidate the physiological role of each AP.
Study Information
pubmed
2007
2007-01-01T00:00:00.000Z
10.1080/02713680701446653
101
88