Effects of the very late adhesion molecule 4 antagonist WAY103 on human peripheral blood eosinophil vascular cell adhesion molecule 1-dependent functions.
BACKGROUND
Eosinophil infiltration to the lung in allergic inflammation can be initiated by the tethering of circulating cells through very late adhesion molecule 4 (VLA-4; alpha4beta1, CD49d/CD29) to vascular cell adhesion molecule 1 (VCAM-1) expressed on pulmonary vascular endothelium. Small-molecule VLA-4 antagonists have been proposed as a therapeutic mechanism to prevent eosinophil infiltration in asthma; however, they might affect other eosinophil functions.


OBJECTIVE
The small-molecule VLA-4 antagonist (2S)-3-(4-Dimethylcarbamoyloxyphenyl)-2-{[(4R)-5,5-dimethyl-3-(1-methyl-1H-pyrazole-4 sulfonyl)thiazolidine-4-carbonyl]amino}propionic acid (WAY103) was assessed for its effects on eosinophil VLA-4-dependent functions, including adhesion, migration, respiratory burst, and degranulation.


METHODS
Human peripheral blood eosinophils were preincubated with WAY103, anti-alpha4, and/or anti-beta2 integrin mAbs and then assessed for adhesion to recombinant VCAM-1, intercellular adhesion molecule 1, and endothelial cell monolayers. Transmigration was measured by using human pulmonary microvascular endothelial cell monolayers and Transwell filters. Superoxide anion generation was determined by means of cytochrome C reduction and degranulation by means of eosinophil-derived neurotoxin release.


RESULTS
WAY103 inhibition of eosinophil adhesion to recombinant VCAM-1 was dose dependent (63% inhibition with 100 nM WAY103, P < .04) and comparable with inhibition caused by anti-alpha4 mAb (60.1% inhibition). Although pretreatment with WAY103 also decreased eosinophil adhesion to TNF-alpha plus IL-4-activated human pulmonary microvascular endothelial cell monolayers, it did not prevent eosinophil transendothelial migration in response to RANTES. Finally, WAY103 inhibited VCAM-1-stimulated superoxide generation but enhanced cytokine-activated eosinophil-derived neurotoxin degranulation.


CONCLUSIONS
Although small-molecule VLA-4 antagonists, such as WAY103, might reduce eosinophil adhesion, this approach might not be sufficient to eliminate this cell from in vivo allergic airway inflammatory participation and could even promote specific cell activation.
Sedgwick
Julie B
JB
Allergy and Immunology Unit, Department of Medicine, University of Wisconsin, Madison, WI, USA. jxs@medicine.wisc.edu
Jansen
Kristyn J
KJ
Kennedy
Jeffrey D
JD
Kita
Hirohito
H
Busse
William W
WW
D000293:Adolescent; D000328:Adult; D002448:Cell Adhesion; D015550:Cell Degranulation; D002465:Cell Movement; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology; D047208:Eosinophil-Derived Neurotoxin / Q000378:metabolism; D004804:Eosinophils / Q000187:drug effects* / Q000276:immunology / Q000502:physiology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D039041:Integrin alpha4beta1 / Q000037:antagonists & inhibitors* / Q000502:physiology; D018799:Intercellular Adhesion Molecule-1 / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011720:Pyrazoles / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism; D013844:Thiazoles / Q000494:pharmacology*; D053778:Thiazolidines; D019010:Vascular Cell Adhesion Molecule-1 / Q000502:physiology*
D039041:Integrin alpha4beta1; D011720:Pyrazoles; D013844:Thiazoles; D053778:Thiazolidines; D019010:Vascular Cell Adhesion Molecule-1; C505330:WAY103; D013481:Superoxides; D018799:Intercellular Adhesion Molecule-1; D047208:Eosinophil-Derived Neurotoxin; C479221:RNASE2 protein, human