Extracellular vesicles from methicillin resistant Staphylococcus aureus stimulate proinflammatory cytokine production and trigger IgE-mediated hypersensitivity

Autor: Krisana Asano, Shouhei Hirose, Kouji Narita, Phawinee Subsomwong, Noriaki Kawai, Rojana Sukchawalit, Akio Nakane
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Emerging Microbes and Infections, Vol 10, Iss 1, Pp 2000-2009 (2021)
Druh dokumentu: article
ISSN: 22221751
2222-1751
DOI: 10.1080/22221751.2021.1991239
Popis: Extracellular vesicles (EVs) released from bacteria are enclosed particles carrying biological active molecules. They have been shown to play a role in bacterial communications and delivery of virulence factors to the host cells. Staphylococcus aureus is an opportunistic pathogen causing a variety of infections ranging from impetigo to septicaemia. The EVs released from S. aureus have a high potential to be used for vaccine development against S. aureus infections. However, it is important to clearly understand the impact of SaEVs on the host’s immune response. Our study demonstrated that purified EVs from a clinical isolated methicillin-resistant S. aureus (SaEVs) significantly stimulated proinflammatory cytokine production in mouse immune cells and induced host cell death. An impairment of cytokine production in the Toll-like receptor (TLR)-silenced macrophages suggested that SaEVs stimulate proinflammatory response via TLRs 2, 4 and 9. In mouse infection model, the results demonstrated that SaEV immunization did not provide protective effect. In contrast, all SaEV-immunized mice died within Day 1 after methicillin-resistant S. aureus (MRSA) infection. After MRSA infection for 3 h, the production of IL-6, TNF-α and IL-17 in the spleen of SaEV-immunized mice was significantly higher than that of control mice. On Day 5 after the second immunization, total IgE in the serum was significantly enhanced, and a high titre of Th2-related cytokines was remarkably induced after ex vivo stimulation of the spleen cells with SaEVs. These results suggested that MRSA-derived EVs act as an immunostimulant that induces inflammatory response and IgE-mediated hypersensitivity after MRSA infection.
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