title: Balance between early life tolerance and sensitization in allergy: dependence on the timing and intensity of prenatal and postnatal allergen exposure of the mother.
abstract: Allergens can be maternally transferred to the fetus or neonate, though it is uncertain how this initial allergen exposure may impact the development of allergy responses. To evaluate the roles of timing and level of maternal allergen exposure in the early life sensitization of progeny, female BALB/c mice were given ovalbumin (OVA) orally during pregnancy, lactation or weekly at each stage to investigate the immunoglobulin E (IgE) antibody production and cellular responsiveness of their offspring. Exposure to OVA during pregnancy was also evaluated in OVA-specific T-cell receptor (TCR) transgenic (DO11.10) mice. The effect of prenatal antigen exposure on offspring sensitization was dependent on antigen intake, with low-dose OVA inducing tolerance followed by neonatal immunization that was sustained even when pups were immunized when 3 weeks old. These offspring received high levels of transforming growth factor-beta via breastfeeding. High-dose exposure during the first week of pregnancy or perinatal period induced transient inhibition of IgE production following neonatal immunization; although for later immunization IgE production was enhanced in these offspring. Postnatal maternal antigen exposure provided OVA transference via breastfeeding, which consequently induced increased offspring susceptibility to IgE antibody production according to week post-birth. The effect of low-dose maternal exposure during pregnancy was further evaluated using OVA transgenic TCR dams as a model. These progeny presented pronounced entry of CD4(+) T cells into the S phase of the cell cycle with a skewed T helper type 2 response early in life, revealing the occurrence of allergen priming in utero. The balance between tolerance and sensitization depended on the amount and timing of maternal allergen intake during pregnancy.
authors.affiliation: Laboratory of Dermatology and Immunodeficiencies, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Ana Elisa
authors.initials: AE
authors.lastname: Fusaro
authors.forename: Cyro Alves
authors.initials: CA
authors.lastname: de Brito
authors.forename: Eliana Futata
authors.initials: EF
authors.lastname: Taniguchi
authors.forename: Bruno Pacola
authors.initials: BP
authors.lastname: Muniz
authors.forename: Jefferson Russo
authors.initials: JR
authors.lastname: Victor
authors.forename: Noemia Mie
authors.initials: NM
authors.lastname: Orii
authors.forename: Alberto José da Silva
authors.initials: AJ
authors.lastname: Duarte
authors.forename: Maria Notomi
authors.initials: MN
authors.lastname: Sato
mesh_terms: D000284:Administration, Oral; D000485:Allergens / Q000276:immunology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology*; D005260:Female; D006967:Hypersensitivity / Q000276:immunology*; D007108:Immune Tolerance; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D018811:Maternal Exposure; D008431:Maternal-Fetal Exchange / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D010047:Ovalbumin / Q000276:immunology; D011247:Pregnancy; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D000485:Allergens; D016207:Cytokines; D011948:Receptors, Antigen, T-Cell; D016212:Transforming Growth Factor beta; D007073:Immunoglobulin E; D010047:Ovalbumin