Active Immunization with Extracellular Vesicles Derived from Staphylococcus aureus Effectively Protects against Staphylococcal Lung Infections, Mainly via Th1 Cell-Mediated Immunity

PLoS One. 2015 Sep 2;10(9):e0136021. doi: 10.1371/journal.pone.0136021. eCollection 2015.

Abstract

Staphylococcus aureus is an important pathogenic bacterium that causes various infectious diseases. Extracellular vesicles (EVs) released from S. aureus contain bacterial proteins, nucleic acids, and lipids. These EVs can induce immune responses leading to similar symptoms as during staphylococcal infection condition and have the potential as vaccination agent. Here, we show that active immunization (vaccination) with S. aureus-derived EVs induce adaptive immunity of antibody and T cell responses. In addition, these EVs have the vaccine adjuvant ability to induce protective immunity such as the up-regulation of co-stimulatory molecules and the expression of T cell polarizing cytokines in antigen-presenting cells. Moreover, vaccination with S. aureus EVs conferred protection against lethality induced by airway challenge with lethal dose of S. aureus and also pneumonia induced by the administration of sub-lethal dose of S. aureus. These protective effects were also found in mice that were adoptively transferred with splenic T cells isolated from S. aureus EV-immunized mice, but not in serum transferred mice. Furthermore, this protective effect of S. aureus EVs was significantly reduced by the absence of interferon-gamma, but not by the absence of interleukin-17. Together, the study herein suggests that S. aureus EVs are a novel vaccine candidate against S. aureus infections, mainly via Th1 cellular response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptive Immunity
  • Animals
  • Antibody Formation
  • Humans
  • Immunity, Cellular
  • Immunity, Innate
  • Interleukin-17 / immunology
  • Lung / immunology
  • Lung / microbiology*
  • Male
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Pneumonia / immunology
  • Pneumonia / microbiology
  • Pneumonia / prevention & control*
  • Staphylococcal Infections / immunology
  • Staphylococcal Infections / prevention & control*
  • Staphylococcal Vaccines / immunology
  • Staphylococcal Vaccines / therapeutic use*
  • Staphylococcus aureus / cytology
  • Staphylococcus aureus / immunology*
  • Th1 Cells / immunology*
  • Toll-Like Receptors / immunology
  • Vaccination

Substances

  • Interleukin-17
  • Staphylococcal Vaccines
  • Toll-Like Receptors

Grants and funding

This research was supported by Korea Drug Development Fund (KDDF) funded by MSIP, MOTIE, and MOHW (Grant No. KDDF-201212-05) and a grant of the Korea Health Technology R & D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI14C2694).