title: Bacterial extract (OM-85) with human-equivalent doses does not inhibit the development of asthma in a murine model.
abstract: BACKGROUND
  OM-85 is an immunostimulant bacterial lysate, which has been proven effective in reducing the number of lower airways infections. We investigated the efficacy of the bacterial lysate OM-85 in the primary prevention of a murine model of asthma.
  
  
  METHODS
  In the first phase of our study the animals received doses of 0.5μg, 5μg and 50μg of OM-85 through gavage for five days (days -10 to -6 of the protocol), 10 days prior to starting the sensitisation with ovalbumin (OVA), in order to evaluate the results of dose-response protocols. A single dose (5μg) was then chosen in order to verify in detail the effect of OM-85 on the pulmonary allergic response. Total/differential cells count and cytokine levels (IL-4, IL-5, IL-13 and IFN-γ) from bronchoalveolar lavage fluid (BALF), OVA-specific IgE levels from serum, lung function and lung histopathological analysis were evaluated.
  
  
  RESULTS
  OM-85 did not reduce pulmonary eosinophilic response, regardless of the dose used. In the phase protocol using 5μg/animal of OM-85, no difference was shown among the groups studied, including total cell and eosinophil counts in BALF, serum OVA-specific IgE, lung histopathologic findings and lung resistance. However, OM-85 decreased IL-5 and IL-13 levels in BALF.
  
  
  CONCLUSIONS
  OM-85, administered in early life in mice in human-equivalent doses, does not inhibit the development of allergic pulmonary response in mice.
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Rodrigues
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: L P
authors.initials: LP
authors.lastname: Gualdi
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: R G
authors.initials: RG
authors.lastname: de Souza
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: M H M
authors.initials: MH
authors.lastname: Vargas
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: N K
authors.initials: NK
authors.lastname: Nuñez
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: aline.cunha@pucrs.br.
authors.forename: A A
authors.initials: AA
authors.lastname: da Cunha
authors.affiliation: Laboratory of Respiratory Physiology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: M H
authors.initials: MH
authors.lastname: Jones
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: L A
authors.initials: LA
authors.lastname: Pinto
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: R T
authors.initials: RT
authors.lastname: Stein
authors.affiliation: Laboratory of Pediatric Respirology, Infant Center, Institute of Biomedical Research, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: P M
authors.initials: PM
authors.lastname: Pitrez
mesh_terms: D000818:Animals; D001249:Asthma / Q000276:immunology / Q000517:prevention & control*; D002457:Cell Extracts / Q000008:administration & dosage*; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004804:Eosinophils / Q000187:drug effects* / Q000276:immunology; D005260:Female; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D000095983:Bacterial Lysates
chemical_list: D002457:Cell Extracts; D016207:Cytokines; D007073:Immunoglobulin E; C030259:Broncho-Vaxom; D000095983:Bacterial Lysates
keywords: Asthma; Inflammation; Mice; OM-85