title: Leukocytosis and resistance to septic shock in intercellular adhesion molecule 1-deficient mice.
abstract: Intercellular adhesion molecule 1 (ICAM-1) is one of three immunoglobulin superfamily members that bind to the integrins lymphocyte function associated 1 (LFA-1) and Mac-1 on leukocytes. We have generated mice that are genetically and functionally deficient in ICAM-1. These mice have elevated numbers of circulating neutrophils and lymphocytes, as well as diminished allogeneic T cell responses and delayed type hypersensitivity. Mutant mice are resistant to lethal effects of high doses of endotoxin (lipopolysaccharide [LPS]), and this correlates with a significant decrease in neutrophil infiltration in the liver. Production of inflammatory cytokines such as tumor necrosis factor alpha or interleukin 1 is normal in ICAM-1-deficient mice, and thus protection appears to be related to a diminution in critical leukocyte-endothelial interactions. After sensitization with D-galactosamine (D-Gal), ICAM-1-deficient mice are resistant to the lethal effect of low doses of exotoxin (Staphylococcus aureus enterotoxin B [SEB]), which has been shown to mediate its toxic effects via the activation of specific T cells. In this model, ICAM-1-mediated protection against SEB lethality correlates with a decrease in the systemic release of inflammatory cytokines, as well as with prevention of extensive hepatocyte necrosis and hemorrhage. ICAM-1-deficient mice sensitized with D-Gal, however, are not protected from lethality when challenged with low doses of endotoxin (LPS). These studies show that the different contribution of ICAM-1 in the activation of either T cells or macrophages is decisive for the fatal outcome of the shock in these two models. This work suggests that anti-ICAM-1 therapy may be beneficial in both gram-positive and -negative septic shock, either by reducing T cell activation or by diminishing neutrophil infiltration.
authors.affiliation: Center for Blood Research, Harvard Medical School, Boston, Massachusetts.
authors.forename: H
authors.initials: H
authors.lastname: Xu
authors.forename: J A
authors.initials: JA
authors.lastname: Gonzalo
authors.forename: Y
authors.initials: Y
authors.lastname: St Pierre
authors.forename: I R
authors.initials: IR
authors.lastname: Williams
authors.forename: T S
authors.initials: TS
authors.lastname: Kupper
authors.forename: R S
authors.initials: RS
authors.lastname: Cotran
authors.forename: T A
authors.initials: TA
authors.lastname: Springer
authors.forename: J C
authors.initials: JC
authors.lastname: Gutierrez-Ramos
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000502:physiology*; D004768:Enterotoxins / Q000633:toxicity; D005260:Female; D018799:Intercellular Adhesion Molecule-1; D007375:Interleukin-1 / Q000096:biosynthesis; D007964:Leukocytosis / Q000517:prevention & control*; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D012772:Shock, Septic / Q000209:etiology / Q000517:prevention & control*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D015815:Cell Adhesion Molecules; D004768:Enterotoxins; D007375:Interleukin-1; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; C031818:enterotoxin B, staphylococcal