A Cleavage-potentiated Fragment of Tear Lacritin Is Bactericidal

McKown, Robert L.; Frazier, Erin V. Coleman; Zadrozny, Kaneil K.; Deleault, Andrea M.; Raab, Ronald W.; Ryan, Denise S.; Sia, Rose K.; Lee, Jae K.; Laurie, Gordon W.

doi:10.1074/jbc.m114.570143

Cited by 29 publications

(47 citation statements)

References 64 publications

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“…Many other tear proteins, including a-and b-defensins, and cathelicidin have antimicrobial activities against commensals and pathogens; however, only few (eg, lipocalin-derived peptide) are insensitive to the ionic strength of normal tear fluid. [27][28][29] Similarly, other TSP-derived peptides were previously reported to carry an antimicrobial activity against Escherichia -/ -(n = 7) and C57BL/6/(n = 7) mice. To determine the antibody titers, serial dilutions of serum derived from the TSP-1 -/ -and wild-type (WT) mice were exposed to bind to the CNS sp.…”

Section: Discussionmentioning

confidence: 99%

TSP-1 Deficiency Alters Ocular Microbiota: Implications for Sjögren's Syndrome Pathogenesis

Terzulli

Contreras-Ruiz

Kugadas

et al. 2015

Journal of Ocular Pharmacology and Therapeutics

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Purpose: The potential role of commensals as triggering factors that promote inflammation in dry eye disease has not been explored. The objective of this study was to evaluate whether ocular microbiota changes with the onset of dry eye disease in thrombospondin-1-deficient (TSP-1 -/ -) mice, a strain that develops Sjögren's syndrome-like disease. Methods: Conjunctival swabs were collected from TSP-1 -/ -and C57BL/6 mice and analyzed for bacterial presence. Opsonophagocytosis of the bacterial conjunctival isolates derived from the aged TSP-1 -/ -mice by neutrophils derived from either TSP-1 -/ -or C57BL/6 bone marrow was evaluated. The bactericidal activities of TSP-1-derived peptide were examined. Results: We found that in TSP-1 -/ -mice, the conjunctival colonization with Staphylococcus aureus and coagulase negative staphylococci sp (CNS) species was significantly increased with aging and preceded that of the wild-type C57BL/6 control mice. This correlated with increased neutrophil infiltration into the conjunctiva of the TSP-1 -/ -mice, suggesting that TSP-1 plays a significant role in regulating immunity to commensals. Accordingly, the TSP-1 -/ -PMNs opsonophagocytozed the ocular commensals less efficiently than the TSP-1-sufficient neutrophils. Furthermore, a TSP-1-derived peptide, 4N1K, exhibited significant antimicrobial activity when compared to a control peptide against commensal sp. Conclusion: These studies illustrate that alterations in the commensal frequency occur in the early stages of development of Sjögren's-like pathology and suggest that interventions that limit commensal outgrowth such as the use of TSP-1-derived peptides could be used for treatment during the early stages of the disease to reduce the commensal burden and ensuing inflammation.

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Section: Discussionmentioning

confidence: 99%

TSP-1 Deficiency Alters Ocular Microbiota: Implications for Sjögren's Syndrome Pathogenesis

Terzulli

Contreras-Ruiz

Kugadas

et al. 2015

Journal of Ocular Pharmacology and Therapeutics

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“…In silico analysis by the Protease Specificity Prediction Server suggested Lacrt’s serine protease sensitivity liberates the C-terminal amphipathic α-helix intact for downstream co-receptor binding to syndecan-1 (Table 2) [65]. Recent reports suggest that this proteolysis releases an α-helical carboxy terminal peptide from Lacrt that displays bactericidal activity, which may represent an innate defensive immunity on the ocular surface [66]. The cleavage may be regulated by serine proteases, as specific protease inhibitors (chymostatin, leupeptin) or boiling were reported to inhibit proteolysis.…”

Section: Discussionmentioning

confidence: 99%

“…The carboxy-terminal amphipathic α-helix of Lacrt has been reported to associate with co-receptor syndecan-1, which thus regulates functional specificity [20] and maintains corneal epithelium homeostasis [19]. New data suggested that the same region undergoes proteolytic processing and demonstrates crucial bactericidal activity in tears [66]. Similar to our recent reports in SV40-transduced human corneal epithelial cells (HCE-Ts)[39], Lacrt triggers a cascade of mitogenic events involving Gαi or Gαo–PKCα-PLC–Ca 2+ –calcineurin–NFATC1 and Gαi or Gαo–PKCα-PLC–phospholipase D (PLD)–mTOR pathways [18].…”

Section: Discussionmentioning

confidence: 99%

A thermo-responsive protein treatment for dry eyes

Wang

Jashnani

Aluri

et al. 2015

Journal of Controlled Release

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Millions of Americans suffer from dry eye disease, and there are few effective therapies capable of treating these patients. A decade ago, an abundant protein component of human tears was discovered and named lacritin(Lacrt). Lacrt has prosecretory activity in the lacrimal gland and mitogenic activity at the corneal epithelium. Similar to other proteins placed on the ocular surface, the durability of its effect is limited by rapid tear turnover. Motivated by the rationale that a thermo-responsive coacervate containing Lacrt would have better retention upon administration, we have constructed and tested the activity of a thermo-responsive Lacrt fused to an Elastin-like polypeptide (ELP). Inspired from the human tropoelastin protein, ELP protein polymers reversibly phase separate into viscous coacervates above a tunable transition temperature. This fusion construct exhibited the prosecretory function of native Lacrt as illustrated by its ability to stimulate β-hexosaminidase secretion from primary rabbit lacrimal gland acinar cells. It also increased tear secretion from non-obese diabetic (NOD) mice, a model of autoimmune dacryoadenitis, when administered via intra-lacrimal injection. Lacrt ELP fusion proteins undergo temperature-mediated assembly to form a depot inside the lacrimal gland. We propose that these Lacrt ELP fusion proteins represent a potential therapy for dry eye disease and the strategy of ELP-mediated phase separation may have applicability to other diseases of the ocular surface.

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“…A recent report has shown that the main antimicrobial activity of lacritin relied on N-65, a form of lacritin (lacking 65 amino acids from its N-terminus) with a potent antimicrobial activity (49). Its core antimicrobial activity maps to the last 15 amino acids (N-15), the sequence AQKLLKKFSLLKPWA.…”

Section: Accepted Manuscriptmentioning

confidence: 98%