Superantigens impair innate immune response inducing monocytes/macrophages death and inefficient activation which would be mediated by interaction with MCH-II and gp130

NOLI TRUANT S; DE MARZI MAURICIO C.; SARRATEA, MARÍA B.; ANTONOGLOU, MARÍA B. ; MEO AP; IANNANTUONO LOPEZ LV; FERNÁNDEZ LYNCH, JULIETA; TODONE, MARCOS; MALCHIODI, EMILIO L. ; FERNÁNDEZ, MARISA M.

Frontiers in Immunology

Frontiers Res Found

Lugar: Basel; Año: 2020

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 non-classical SAgs of the staphylococcal egc operon, namely, SEG, SEI, SEO, and SEM 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 egc SAgs depleted the pool of innate immune effector cells and induced an inefficient activation of monocytic?macrophagic cells, driving the immune response to an impairedproinflammatory profile, which could be mediated directly or indirectly by interactionswith MHC class II. In addition, performing surface plasmon resonance assays, wedemonstrated that non-classical SAgs bind the gp130 molecule, which is also presentin the monocytic cell surface, among other cells.