Activation of Human NK Cells by Bordetella pertussis Requires Inflammasome Activation in Macrophages

• Published in: Frontiers in immunology Vol. 10; p. 2030
• Main Authors: Kroes, Michiel M, Mariman, Rob, Hijdra, Daniëlle, Hamstra, Hendrik-Jan, van Boxtel, Karlijn J W M, van Putten, Jos P M, de Wit, Jelle, Pinelli, Elena
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 27.08.2019
• Subjects: crosstalk; Immunology; inflammasome; innate immunity; interferon-gamma; interleukin-18; NLRP3; crosstalk; innate immunity; interleukin-18; inflammasome; NLRP3; Bordetella pertussis; human; interferon-gamma
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2019.02030

Pertussis is a highly contagious respiratory infection caused by the bacterium . Humans are the only known natural reservoir of . In mice, macrophages and NK cells have a key role in confining to the respiratory tract. However, the mechanisms underlying this process, particularly during human infections, remain unclear. Here we characterized the activation of human macrophages and NK cells in response to and unraveled the role of inflammasomes in this process. NLRP3 inflammasome activation by in human macrophage-like THP-1 cells and primary monocyte-derived macrophages (mo-MΦ) was shown by the visualization of ASC-speck formation, pyroptosis, and the secretion of caspase-mediated IL-1β and IL-18. In contrast to macrophages, stimulation of human CD56 CD3 NK cells by alone did not result in activation of these cells. However, co-culture of -stimulated mo-MΦ and autologous NK cells resulted in high amounts of IFNγ secretion and an increased frequency of IL-2Rα and HLA-DR NK cells, indicating NK cell activation. This activation was significantly reduced upon inhibition of inflammasome activity or blocking of IL-18 in the mo-MΦ/NK cell co-culture. Furthermore, we observed increased secretion of proinflammatory cytokines in the -stimulated mo-MΦ/NK co-culture compared to the mo-MΦ single culture. Our results demonstrate that induces inflammasome activation in human macrophages and that the IL-18 produced by these cells is required for the activation of human NK cells, which in turn enhances the pro-inflammatory response to this pathogen. Our data provides a better understanding of the underlying mechanisms involved in the induction of innate immune responses against . These findings contribute to the knowledge required for the development of improved intervention strategies to control this highly contagious disease.