The Role of B Cells in Carriage and Clearance of Mycoplasma pneumoniae From the Respiratory Tract of Mice

J Infect Dis. 2018 Jan 4;217(2):298-309. doi: 10.1093/infdis/jix559.


Background: Carriage of Mycoplasma pneumoniae (Mp) in the nasopharynx is considered a prerequisite for pulmonary infection. It is interesting to note that Mp carriage is also detected after infection. Although B cells are known to be involved in pulmonary Mp clearance, their role in Mp carriage is unknown.

Methods: In this study, we show in a mouse model that Mp persists in the nose after pulmonary infection, similar to humans.

Results: Infection of mice enhanced Mp-specific immunoglobulin (Ig) M and IgG levels in serum and bronchoalveolar lavage fluid. However, nasal washes only contained elevated Mp-specific IgA. These differences in Ig compartmentalization correlated with differences in Mp-specific B cell responses between nose- and lung-draining lymphoid tissues. Moreover, transferred Mp-specific serum Igs had no effect on nasal carriage in B cell-deficient μMT mice, whereas this enabled μMT mice to clear pulmonary Mp infection.

Conclusions: We report the first evidence that humoral immunity is limited in clearing Mp from the upper respiratory tract.

Keywords: B cells; Mycoplasma pneumoniae; carriage; mouse model; pneumonia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Bacterial / blood
  • B-Lymphocytes / immunology*
  • Carrier State / immunology*
  • Immunoglobulin A / analysis
  • Immunoglobulin G / blood
  • Mice, Inbred C57BL
  • Mycoplasma pneumoniae / immunology*
  • Nasal Mucosa / immunology
  • Nasopharynx / immunology*
  • Nasopharynx / microbiology*
  • Pneumonia, Mycoplasma / immunology*


  • Antibodies, Bacterial
  • Immunoglobulin A
  • Immunoglobulin G