title: TNF and CD28 Signaling Play Unique but Complementary Roles in the Systemic Recruitment of Innate Immune Cells after Staphylococcus aureus Enterotoxin A Inhalation.
abstract: Staphylococcus aureus enterotoxins cause debilitating systemic inflammatory responses, but how they spread systemically and trigger inflammatory cascade is unclear. In this study, we showed in mice that after inhalation, Staphylococcus aureus enterotoxin A rapidly entered the bloodstream and induced T cells to orchestrate systemic recruitment of inflammatory monocytes and neutrophils. To study the mechanism used by specific T cells that mediate this process, a systems approach revealed inducible and noninducible pathways as potential targets. It was found that TNF caused neutrophil entry into the peripheral blood, whereas CD28 signaling, but not TNF, was needed for chemotaxis of inflammatory monocytes into blood and lymphoid tissue. However, both pathways triggered local recruitment of neutrophils into lymph nodes. Thus, our findings revealed a dual mechanism of monocyte and neutrophil recruitment by T cells relying on overlapping and nonoverlapping roles for the noninducible costimulatory receptor CD28 and the inflammatory cytokine TNF. During sepsis, there might be clinical value in inhibiting CD28 signaling to decrease T cell-mediated inflammation and recruitment of innate cells while retaining bioactive TNF to foster neutrophil circulation.
authors.affiliation: Department of Immunology, School of Medicine, UConn Health, Farmington, CT 06030.
authors.forename: Julia
authors.identifier: 0000-0003-0836-4725
authors.initials: J
authors.lastname: Svedova
authors.affiliation: Department of Immunology, School of Medicine, UConn Health, Farmington, CT 06030.
authors.forename: Naomi
authors.initials: N
authors.lastname: Tsurutani
authors.affiliation: Department of Immunology, School of Medicine, UConn Health, Farmington, CT 06030.
authors.forename: Wenhai
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Immunology, School of Medicine, UConn Health, Farmington, CT 06030.
authors.forename: Kamal M
authors.identifier: 0000-0002-9328-3817
authors.initials: KM
authors.lastname: Khanna
authors.affiliation: Department of Immunology, School of Medicine, UConn Health, Farmington, CT 06030 vella@uchc.edu.
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Vella
mesh_terms: D000818:Animals; D018106:CD28 Antigens / Q000276:immunology*; D004768:Enterotoxins / Q000008:administration & dosage* / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology*; D001239:Inhalation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009000:Monocytes / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D048069:Tumor Necrosis Factors / Q000276:immunology*
chemical_list: D018106:CD28 Antigens; D004768:Enterotoxins; D048069:Tumor Necrosis Factors; C026066:enterotoxin A, Staphylococcal