title: Levocetirizine inhibits migration of immune cells to lymph nodes and induces treg cells in a murine type I allergic conjunctivitis model.
abstract: BACKGROUND #ENTITYSTARTX00026;
  
  
  OBJECTIVE
  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.
  
  
  METHODS
  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)A(4) 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.
  
  
  RESULTS
  OVA exposure induced AC in the animal model indicated by increased expression of LXA(4), TNF-α and TGF-β. Levocetirizine treatment (0.01-0.02% v/w) reduced LXA(4) 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 #ENTITYSTARTX00026;
  
  
  CONCLUSIONS
  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.
authors.affiliation: Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados- IPN. Av. IPN 2508, San Pedro Zacatenco, México D.F. 07360, México;
authors.forename: Sihomara
authors.initials: S
authors.lastname: García-Zepeda
authors.forename: Elizabet
authors.initials: E
authors.lastname: Estrada-Muñiz
authors.forename: Guillermo
authors.initials: G
authors.lastname: Elizondo
authors.forename: Luis I
authors.initials: LI
authors.lastname: Terrazas
authors.forename: Miriam
authors.initials: M
authors.lastname: Rodríguez-Sosa
authors.forename: Juan D
authors.initials: JD
authors.lastname: Quintana-Hau
authors.forename: Rubén
authors.initials: R
authors.lastname: Tornero-Montaño
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Baiza-Durán
authors.forename: Libia
authors.initials: L
authors.lastname: Vega
keywords:  Levocetirizine; allergic conjunctivitis; antigen-presenting cells.; cytokines