Pneumococcal Conjugate Vaccine Modulates Macrophage-mediated Innate Immunity in Pneumonia Caused by Streptococcus pneumoniae Following Influenza

Publication date: Available online 17 January 2020Source: Microbes and InfectionAuthor(s): Kazuyuki Mimura, Soichiro Kimura, Chiaki Kajiwara, Sho Nakakubo, Matthew A. Schaller, Yoshikazu Ishii, Theodore J. Standiford, Steven L. Kunkel, Kazuhiro TatedaAbstractPneumococcal conjugate vaccination (PCV) may prevent influenza-related pneumonia, including Streptococcus pneumoniae pneumonia. To investigate PCV efficacy against secondary pneumococcal pneumonia following influenza, PCV was administered intramuscularly 2 and 5 weeks before S. pneumoniae serotype-3 colonization of murine nasopharynges followed by intranasal challenge with a sublethal dose of influenza A virus. Bacterial and viral loads, including innate immune responses were compared across conditions. PCV vaccination improved the survival of mice with secondary pneumococcal pneumonia and significantly reduced the pulmonary bacterial burden. Increased monocyte/macrophage influx into the lungs, alleviated loss of alveolar macrophages and decreased neutrophil influx into the lungs occurred in PCV-treated mice irrespective of pneumococcal colonization. Higher monocyte chemoattractant protein 1 levels and lower levels of CXCL1, interferon-γ, interleukin-17A, and IL-10, were detected in PCV-treated mice. Additionally, PCV treatment activated the macrophage intracellular killing of S. pneumoniae. Collectively, PCV potentially modulates the host’s innate immunity and specific antibodies induction. Macrophage-related innate i...
Source: Microbes and Infection - Category: Infectious Diseases Source Type: research