RESEARCH ARTICLE
Levocetirizine Inhibits Migration of Immune Cells to Lymph Nodes and Induces Treg Cells in a Murine Type I Allergic Conjunctivitis Model
Sihomara García-Zepeda1, Elizabet Estrada-Muñiz1, Guillermo Elizondo2, Luis I Terrazas3, Miriam Rodríguez-Sosa3, Juan D Quintana-Hau4, Rubén Tornero-Montaño4, Leopoldo Baiza-Durán4, Libia Vega*, 1
Article Information
Identifiers and Pagination:
Year: 2012Volume: 6
First Page: 129
Last Page: 136
Publisher ID: TOOPHTJ-6-129
DOI: 10.2174/1874364101206010129
Article History:
Received Date: 25/9/2012Revision Received Date: 22/11/2012
Acceptance Date: 25/11/2012
Electronic publication date: 14/12/2012
Collection year: 2012

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Abstract
Background & Purpose:
Levocetirizine is a histamine H(1) receptor antagonist. Here, we utilised DO11.10TCR transgenic mice to establish an antigen-specific T cell-dependent allergic conjunctivitis (AC) model to determine the effect of the topical application of an ophthalmic formulation of Levoceritizine as a treatment for AC.
Experimental Approach:
DO11.10 mice (n=6/each) were exposed to ovalbumin (OVA, 50 µg) and treated with a Levocetirizine ophthalmic formulation (0.001–0.02% v/w) or placebo (vehicle) for 24–72 h. Serum, aqueous/vitreous humour and conjunctiva were obtained. Immunoglobulin (Ig)-E, interleukin (IL)-10 and lipoxin (LX)A4 were determined by ELISA. Levels of tumour necrosis factor (TNF)-α, transforming growth factor (TGF)-β, interferon (IFN)-γ and 18rS expression were measured by RT-PCR. Proportions of total and activated antigen-presenting cells (APC), recruited T lymphocytes (CD4+), activated T lymphocytes (CD25+) and T regulatory cells (Treg) were measured by flow cytometry.
Key Results:
OVA exposure induced AC in the animal model indicated by increased expression of LXA4, TNF-α and TGF-β. Levocetirizine treatment (0.01–0.02% v/w) reduced LXA4 in the eye humours. This treatment approach increased systemic IL-10 secretion and reduced TNF-α and TGF-β expression in conjunctiva without changing IFN-γ expression. Levocetirizine reduced APC levels in draining lymph nodes but increased the proportion of total lymphocytes recruited and their differentiation to Treg cells.
Conclusions & Implications:
Levocetirizine effectively reduces the activation and migration of APC to local draining lymph nodes and induces differentiation of Treg cells as one possible mechanism of its anti-inflammatory action.