Spantide I decreases type I cytokines, enhances IL-10, and reduces corneal perforation in susceptible mice after Pseudomonas aeruginosa infection.

Abstract

PURPOSE:

To determine the effects of blocking substance P (SP) interactions with its major receptor (NK1-R) using the antagonist spantide I in susceptible mice infected with Pseudomonas aeruginosa.

METHODS:

Immunohistochemistry and enzyme immunosorbent assay (EIA) tested levels of SP in the cornea of B6 and BALB/c mice. B6 mice were treated with spantide, and after infection, slit lamp examination; clinical score; bacterial counts; and myeloperoxidase (MPO), RT-PCR, ELISA, and polymorphonuclear (PMN) cell chemotaxis assays were performed.

RESULTS:

SP corneal levels were significantly elevated constitutively and after infection in the B6 more than in BALB/c mice. Spantide treatment of B6 mice significantly decreased the number of perforated corneas, bacterial counts, and PMNs. mRNA levels for type I cytokines (e.g., IFN-gamma) as well as MIP-2, IL-6, TNF-alpha, and IL-1beta (mRNA and protein) also were significantly reduced after spantide treatment. The type II cytokine IL-10 (mRNA and protein) was elevated, whereas TGF-beta mRNA levels were unchanged after spantide treatment. PMN chemotaxis was induced by SP and other neuropeptides in vitro, but was not affected by spantide I. mRNA for neurokinin-1-receptor-1 (NK-1R) was detected in the normal and infected corneas and on macrophages (Mphis), but not on PMNs (unstimulated or stimulated with endotoxin [LPS]). Spantide treatment of Mphis reduced IL-1beta after LPS+SP treatment but not after either alone.

CONCLUSIONS:

The SP antagonist Spantide provides a novel approach to reduce type 1 and enhance the type 2 cytokine IL-10 in the infected cornea of B6 mice, leading to a significant reduction in corneal perforation and improved disease outcome.

• Authors: Linda D Hazlett, Sharon A McClellan, Ronald P Barrett, Jianhua Liu, Yunfan Zhang, Shahrzad Lighvani
• Journal: Investigative ophthalmology & visual science (Invest Ophthalmol Vis Sci) Vol. 48 Issue 2 Pg. 797-807 (Feb 2007) ISSN: 0146-0404 [Print] United States
• PMID: 17251480 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Cytokines
• Interleukin-10
• Substance P
• spantide
• Peroxidase

Topics

• Animals
• Chemotaxis, Leukocyte
• Cornea (metabolism, microbiology, pathology)
• Corneal Ulcer (drug therapy, metabolism, pathology)
• Cytokines (metabolism)
• Disease Models, Animal
• Enzyme-Linked Immunosorbent Assay
• Eye Infections, Bacterial (drug therapy, metabolism, pathology)
• Female
• Immunoenzyme Techniques
• Interleukin-10 (metabolism)
• Macrophages (physiology)
• Mice
• Mice, Inbred BALB C
• Mice, Inbred C57BL
• Neutrophils (physiology)
• Peroxidase (metabolism)
• Pseudomonas Infections (drug therapy, metabolism, pathology)
• Pseudomonas aeruginosa
• Reverse Transcriptase Polymerase Chain Reaction
• Rupture, Spontaneous (drug therapy)
• Substance P (analogs & derivatives, antagonists & inhibitors, metabolism, therapeutic use)