egc Superantigens impair monocytes/macrophages inducing cell death and inefficient activation

SOFIA NOLI TRUANT; MAURICIO DE MARZI; MARÍA B. SARRATEA; MARÍA B. ANTONOGLOU; ANA P. MEO; LAURA V. IANNANTUONO LÓPEZ; MARÍA J. FERNÁNDEZ; MARCOS TODONE; EMILIO L. MALCHIODI; MARISA M FERNÁNDEZ

Frontiers in Immunology

Frontiers Media

Año: 2019

1664-3224

Bacterial superantigens (SAgs) are enterotoxins that bind to MHC-II and TCR molecules, activating as much as 20% of the T cell population and promoting a cytokine storm which enhances susceptibility to endotoxic shock, causing immunosuppression and hindering the immune response against bacterial infection. Since monocytes/macrophages are one of the first cells SAgs find in infected host and considering the effect these cells have on directing the immune response, here, we investigated the effect of four SAgs of the staphylococcal egc operon, namely, SEG, SEI, SEO and SEM (some of the most prevalent SAg genes worldwide), on monocytic-macrophagic cells, in the absence of T cells. We also analyzed the molecular targets on APCs which could mediate SAg effects. We found that SAgs depleted the pool of innate immune effector cells and induced an inefficient activation of monocytic-macrophagic cells, driving the immune response to an impaired proinflammatory profile, which could be mediated directly or indirectly by interactions with MHC class II and gp130 molecules among others superantigens targets present on the monocytic cells surface.