ELLERBROEK PM, COENJAERTS F, HOEPELMAN IM; Interscience Conference on Antimicrobial Agents and Chemotherapy (41st : 2001 : Chicago, Ill.).
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2001 Dec 16-19; 41: abstract no. J-130.
University Medical Centre, Utrecht, The Netherlands
BACKGROUND: Cryptococcal meningitis is characterized by a low infiltration of leukocytes in the infected tissues. Previous research has shown that the capsular polysaccharide glucuronoxylomannan (GXM) inhibits leukocyte migration towards the infected tissues. In this perspective we studied the effects of GXM on neutrophil (PMN) adhesion to endothelium. METHODS: A static adhesion assay was used consisting of adhesion of fluorescence labeled PMN to TNF-stimulated monolayers of HUVEC. I. In order to assess the effect of GXM on neutrophils, adhesion of PMN pretreated with GXM (1 hr, 37 degreesC) was compared to untreated PMN. II. The effect of GXM on TNF-stimulation of endothelium was studied by incubating endothelium with GXM preceding TNF-stimulation, after which adhesion with untreated PMN was performed. RESULTS: I. Pretreatment of neutrophils with GXM (leaving the GXM present during adhesion) inhibited adhesion to endothelium in a concentration dependent way, maximal inhibition 35.6% at 100ng/ml (p<0.01) as compared to untreated PMN. Washing the PMN after incubation with GXM resulted in an even stronger inhibition (55%). The inhibition was stronger when performed with 6 hour stimulation of endothelium as compared to 24 hr stimulation. It is known that both E-selectin as well as CD11/18-ICAM binding are responsible for adhesion to 6 hr stimulated endothelium, whereas after 24 hours 80-90% of binding is dependant on CD11/18-ICAM binding. Therefore, GXM might interfere with E-selectin binding to its counter-ligands. The mechanism behind these effects will be further studied by binding assays using E-selectin and ICAM-1 transfectants. II. Pretreatment of endothelium with GXM prior to TNF stimulation led to a decrease in PMN adhesion of maximally 26.9% (p<0.01). The effect of GXM on TNF-induced upregulation of endothelial adhesionmolecules will be studied by RNA analysis in the nearby future. CONCLUSION: GXM inhibits adhesion of PMN to endothelium in vitro.
Publication Types:
Keywords:
- Antigens, CD11
- Antigens, Fungal
- Cell Adhesion Molecules
- Cell Movement
- Cryptococcosis
- Cryptococcus neoformans
- Endothelium
- Endothelium, Vascular
- In Vitro
- Intercellular Adhesion Molecule-1
- Neutrophils
- Polysaccharides
- Selectins
- glucuronoxylomannan
- immunology
Other ID:
UI: 102269189
From Meeting Abstracts