title: Enhancement of the function of neutrophil type-1 and type-3 complement receptors by human leukocyte inhibitory factor (LIF).
abstract: The lymphokine leukocyte inhibitory factor (LIF) has previously been documented to enhance several neutrophil (PMN) functions, including stimulated chemotaxis and superoxide generation, phagocytosis and adherence of opsonized targets, and antibody-dependent cellular cytotoxicity. The present studies were designed to investigate the effects of LIF on PMN function mediated by the complement components C3b and C3bi. LIF induced a dose-dependent increase in superoxide production generated by opsonized zymosan (up to 97.1 +/- 31.4% at 16 U LIF/ml; P less than 0.01). While neither control nor LIF-treated PMN were capable of inducing phagocytosis of either C3b- or C3bi-opsonized sheep erythrocytes (E) directly, exposure to LIF caused a significant (P less than 0.05) increase in their adherence to E (137.4 and 59.4%, respectively). Specificity for complement receptor function was confirmed by the ability of anti-CR1 antibody to block adherence of LIF-treated PMN to EAC3b (77.0% inhibition) and anti-CR3 antibody to block adherence to EAC3bi (70.2% inhibition). Increased C3b and C3bi function may have been due, at least in part, to increased expression of their respective surface membrane receptors. Thus, using indirect immunofluorescence, LIF induced a 38.2% increase in fluorescence of the anti-CR1 antibody and a 96.1% increase in anti-CR3 binding. These studies describe an additional mechanism through which LIF may have an important pro-inflammatory role in vivo.
authors.affiliation: Allergy Division, New England Medical Center, Boston, Massachusetts 02111.
authors.forename: L
authors.initials: L
authors.lastname: Borish
authors.forename: C
authors.initials: C
authors.lastname: Audera
authors.forename: R
authors.initials: R
authors.lastname: Rosenbaum
authors.forename: R E
authors.initials: RE
authors.lastname: Rocklin
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D002448:Cell Adhesion; D005434:Flow Cytometry; D006801:Humans; D008222:Lymphokines / Q000494:pharmacology*; D009504:Neutrophils / Q000502:physiology*; D010587:Phagocytosis; D011951:Receptors, Complement / Q000502:physiology*; D017463:Receptors, Complement 3b; D012397:Rosette Formation; D013481:Superoxides / Q000096:biosynthesis
chemical_list: D000911:Antibodies, Monoclonal; D008222:Lymphokines; D011951:Receptors, Complement; D017463:Receptors, Complement 3b; C010598:leukocyte inhibitory factor; D013481:Superoxides