title: Effect of maternal immune status on responsiveness of bacillus calmette-gurin vaccination in mouse neonates.
abstract: OBJECTIVE
  Bacillus Calmette-Guérin (BCG) vaccination has proven to be efficient in immunologically naïve infants; however, it has not been investigated that maternal natural exposure to Mycobacterium and/or BCG vaccine could influence the characteristics of immune responses to BCG in newborns. In this study, we analyzed whether the maternal immune status to M tuberculosis (M tb) can affect neonatal immunity to BCG using a mouse model.
  
  
  METHODS
  Neonates were obtained from mice that were previously exposed to live BCG, to live M avium, or to heat-killed M tb H37Rv, and from naïve control mothers. One week after birth, the neonates were divided into two subgroups: one group immunized with live BCG via the subcutaneous route and the other group of neonates sham-treated. Interferon-gamma (IFNγ) secretion in response to in vitro stimulation with heat-killed BCG or purified protein derivative (PPD) was examined. Protection against M tb infection was evaluated by challenging mice nasally with live M tb H37Rv followed by counting colonies from spleen and lung homogenates.
  
  
  RESULTS
  BCG-immunized neonates showed increased IFNγ secretion in response to heat-killed BCG or PPD. All mice in BCG-immunized neonates subgroups showed reduced bacterial burden (colony forming unit) in the lungs when compared with control naive neonate mice. However, no statistically significant difference was observed when comparing BCG-immunized mice born from mothers previously exposed to M avium or immunized with either heat-killed H37Rv or live BCG and mice born from naïve mothers.
  
  
  CONCLUSIONS
  The maternal immune status to M tb does not appear to impact on the immunogenicity of BCG vaccine in their progeny in our experimental conditions.
authors.affiliation: Laboratory Science Division, International Vaccine Institute, Seoul, Korea.
authors.forename: Jong Su
authors.initials: JS
authors.lastname: Choi
authors.forename: Ryang Yeo
authors.initials: RY
authors.lastname: Kim
authors.forename: Semi
authors.initials: S
authors.lastname: Rho
authors.forename: Fanny
authors.initials: F
authors.lastname: Ewann
authors.forename: Nathalie
authors.initials: N
authors.lastname: Mielcarek
authors.forename: Man Ki
authors.initials: MK
authors.lastname: Song
authors.forename: Cecil
authors.initials: C
authors.lastname: Czerkinsky
authors.forename: Jae-Ouk
authors.initials: JO
authors.lastname: Kim
keywords: BCG; Mycobacterium tuberculosis; maternal effect; neonates; tuberculosis