Ocular surface expression and in vitro activity of antimicrobial peptides.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Huang
Ling C
LC
College of Optometry, University of Houston, Houston, Texas 77204-2020, USA.
Jean
Daniele
D
Proske
Rita J
RJ
Reins
Rose Y
RY
McDermott
Alison M
AM
D000328:Adult; D018929:Cell Culture Techniques; D054418:Chemokine CCL20; D019742:Chemokines, CC / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D015169:Colony Count, Microbial; D003228:Conjunctiva / Q000187:drug effects / Q000378:metabolism*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D019573:Epithelium, Corneal / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D015870:Gene Expression / Q000502:physiology*; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D019402:Macrophage Inflammatory Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012965:Sodium Chloride / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects; D013212:Staphylococcus epidermidis / Q000187:drug effects; D013666:Tears / Q000502:physiology; D013947:Thymosin / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D023083:beta-Defensins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D000099201:Thymosin beta(4)
D054418:Chemokine CCL20; D019742:Chemokines, CC; D053583:Interleukin-1beta; D019402:Macrophage Inflammatory Proteins; D012333:RNA, Messenger; D012965:Sodium Chloride; D013947:Thymosin; D014409:Tumor Necrosis Factor-alpha; D023083:beta-Defensins; D000099201:Thymosin beta(4); C108355:CCL20 protein, human