title: Maternal immunization with ovalbumin prevents neonatal allergy development and up-regulates inhibitory receptor Fc gamma RIIB expression on B cells.
abstract: BACKGROUND
  Preconception allergen immunization prevents neonatal allergen sensitization in mice by a complex interaction between regulatory cells/factors and antibodies. The present study assessed the influence of maternal immunization with ovalbumin (OVA) on the immune response of 3 day-old and 3 week-old offspring immunized or non-immunized with OVA and evaluated the effect of IgG treatment during fetal development or neonatal period.
  
  
  RESULTS
  Maternal immunization with OVA showed increased levels of Fc gamma RIIb expression in splenic B cells of neonates, which were maintained for up to 3 weeks and not affected by additional postnatal OVA immunization. Maternal immunization also exerted a down-modulatory effect on both IL-4 and IFN-gamma-secreting T cells and IL-4 and IL-12- secreting B cells. Furthermore, immunized neonates from immunized mothers showed a marked inhibition of antigen-specific IgE Ab production and lowered Th2/Th1 cytokine levels, whereas displaying enhanced Fc gamma RIIb expression on B cells. These offspring also showed reduced antigen-specific proliferative response and lowered B cell responsiveness. Moreover, in vitro evaluation revealed an impairment of B cell activation upon engagement of B cell antigen receptor by IgG from OVA-immunized mice. Finally, in vivo IgG transference during pregnancy or breastfeeding revealed that maternal Ab transference was able to increase regulatory cytokines, such as IL-10, in the prenatal stage; yet only the postnatal treatment prevented neonatal sensitization. None of the IgG treatments induced immunological changes in the offspring, as it was observed for those from OVA-immunized mothers.
  
  
  CONCLUSIONS
  Maternal immunization upregulates the inhibitory Fc gamma RIIb expression on offspring B cells, avoiding skewed Th2 response and development of allergy. These findings contribute to the advancement of prophylactic strategies to prevent allergic diseases in early life.
authors.affiliation: Laboratory of Dermatology and Immunodeficiencies, School of Medicine, University of São Paulo, LIM 56, São Paulo, Brazil.
authors.forename: Jefferson R
authors.initials: JR
authors.lastname: Victor
authors.forename: Bruno P
authors.initials: BP
authors.lastname: Muniz
authors.forename: Ana E
authors.initials: AE
authors.lastname: Fusaro
authors.forename: Cyro A
authors.initials: CA
authors.lastname: de Brito
authors.forename: Eliana F
authors.initials: EF
authors.lastname: Taniguchi
authors.forename: Alberto J S
authors.initials: AJ
authors.lastname: Duarte
authors.forename: Maria N
authors.initials: MN
authors.lastname: Sato
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D000831:Animals, Newborn; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D019013:CD40 Antigens / Q000235:genetics / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D005260:Female; D047109:Fetal Development / Q000187:drug effects / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology* / Q000517:prevention & control; D007112:Immunity, Maternally-Acquired; D007114:Immunization; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000235:genetics; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000209:etiology* / Q000517:prevention & control; D008213:Lymphocyte Activation / Q000187:drug effects; D018811:Maternal Exposure / Q000009:adverse effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000517:prevention & control; D017455:Receptors, IgE / Q000235:genetics / Q000378:metabolism; D017452:Receptors, IgG / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D015854:Up-Regulation
chemical_list: D000485:Allergens; D019013:CD40 Antigens; D016207:Cytokines; C499172:Fcgr2b protein, mouse; D017455:Receptors, IgE; D017452:Receptors, IgG; D007073:Immunoglobulin E; D010047:Ovalbumin