Mucosal vaccination promotes clearance of Streptococcus agalactiae vaginal colonization

Vaccine. 2017 Mar 1;35(9):1273-1280. doi: 10.1016/j.vaccine.2017.01.029. Epub 2017 Feb 2.

Abstract

Group B Streptococcus (GBS) is a leading cause of morbidity and mortality in infants, and colonization of the maternal genital tract is the primary risk factor for newborn infection. Despite the importance of mucosal colonization in GBS pathogenesis, relevant host and bacterial factors are incompletely understood. We investigated the role of humoral immunity in clearance of vaginal colonization in vivo. B-cell-deficient mice or those lacking neonatal Fc-receptor, a mediator of IgG transport to the vaginal mucosa, exhibit prolonged GBS vaginal colonization compared to wild type animals. Intranasal but not intramuscular immunization induced systemic and mucosal immune responses and decreased GBS colonization duration without altering initial colonization density. Vaccine-induced clearance of GBS was serotype-specific, suggesting a role for anti-capsule antibodies in protection. Our results support a role for humoral immunity in GBS eradication from the female genital tract and suggest that mucosal vaccination may prime colonization clearance.

Keywords: Colonization; Group B Streptococcus; Vaccine.

MeSH terms

  • Animals
  • Antibodies, Bacterial / immunology
  • Asymptomatic Infections
  • Female
  • Histocompatibility Antigens Class I
  • Immunity, Humoral
  • Immunity, Mucosal*
  • Mice
  • Mice, Knockout
  • Receptors, Fc / deficiency
  • Streptococcal Infections / immunology
  • Streptococcal Infections / prevention & control*
  • Streptococcus agalactiae / growth & development
  • Streptococcus agalactiae / immunology
  • Streptococcus agalactiae / physiology*
  • Vaccination / methods*
  • Vagina / immunology*
  • Vagina / microbiology

Substances

  • Antibodies, Bacterial
  • Histocompatibility Antigens Class I
  • Receptors, Fc
  • Fc receptor, neonatal