Alpha(4)beta(7)/alpha(4)beta(1) dual integrin antagonists block alpha(4)beta(7)-dependent adhesion under shear flow.
The alpha(4) integrin, alpha(4)beta(7), plays an important role in recruiting circulating lymphocytes to the gastrointestinal tract, where its ligand mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is preferentially expressed on high endothelial venules (HEVs). Dual antagonists of alpha(4)beta(1) and alpha(4)beta(7), N-(2,6-dichlorobenzoyl)-(L)-4-(2',6'-bis-methoxyphenyl)phenylalanine (TR14035) and N-(N-[(3,5-dichlorobenzene)sulfonyl]-2-(R)-methylpropyl)-(D)-phenylalanine (compound 1), were tested for their ability to block the binding of alpha(4)beta(7)-expressing cells to soluble ligand in suspension and under in vitro and in vivo shear flow. Compound 1 and TR14035 blocked the binding of human alpha(4)beta(7) to an (125)I-MAdCAM-Ig fusion protein with IC(50) values of 2.93 and 0.75 nM, respectively. Both compounds inhibited binding of soluble ligands to alpha(4)beta(1) or alpha(4)beta(7) on cells of human or rodent origin with similar potency. Under shear flow in vitro, TR14035 and compound 1 blocked binding of human alpha(4)beta(7)-expressing RPMI-8866 cells or murine mesenteric lymph node lymphocytes to MAdCAM-Ig with IC(50) values of 0.1 and 1 microM, respectively. Intravital microscopy was used to quantitate alpha(4)-dependent adhesion of fluorescent murine lymphocytes in Peyer's patch HEVs. When cells were prestimulated with 2 mM Mn(2+) to activate alpha(4)beta(7) binding to ligand, anti-alpha(4) monoclonal antibody (mAb) [10 mg/kg (mpk) i.v.] blocked adhesion by 95%, and anti-beta(1) mAb did not block adhesion, demonstrating that this interaction was dependent on alpha(4)beta(7). TR14035 blocked adhesion to HEVs [ED(50) of 0.01-0.1 mpk i.v.], and compound 1 blocked adhesion by 47% at 10 mpk i.v. Thus, alpha(4)beta(7)/alpha(4)beta(1) antagonists blocked alpha(4)beta(7)-dependent adhesion of lymphocytes to HEVs under both in vitro and in vivo shear flow.
Egger
Linda A
LA
Pharmacology Division, Merck, PO Box 2000, RY8ON-A26, Rahway, NJ 07065, USA. linda_egger@merck.com
Kidambi
Usha
U
Cao
Jin
J
Van Riper
Gail
G
McCauley
Ermengilda
E
Mumford
Richard A
RA
Amo
Suzanne
S
Lingham
Russell
R
Lanza
Thomas
T
Lin
Linus S
LS
De Laszlo
Stephen E
SE
Young
David N
DN
Kopka
Ihor E
IE
Tong
Sharon
S
Pikounis
Bill
B
Benson
Evelyn
E
Warwood
Sarah
S
Bargatze
Robert F
RF
Hagmann
William K
WK
Schmidt
John A
JA
Detmers
Patricia A
PA
D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000276:immunology; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules; D003520:Cyclophosphamide / Q000276:immunology; D004317:Doxorubicin / Q000276:immunology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D005047:Etoposide / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000302:isolation & purification / Q000494:pharmacology; D007136:Immunoglobulins; D039041:Integrin alpha4beta1; D016023:Integrins / Q000037:antagonists & inhibitors*; D008024:Ligands; D008214:Lymphocytes / Q000187:drug effects; D008727:Methotrexate / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009088:Mucoproteins / Q000037:antagonists & inhibitors; D010581:Peyer's Patches / Q000166:cytology / Q000187:drug effects; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000494:pharmacology*; D016201:Receptors, Lymphocyte Homing / Q000037:antagonists & inhibitors*; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D012212:Rheology
D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D007074:Immunoglobulin G; D007136:Immunoglobulins; D039041:Integrin alpha4beta1; D016023:Integrins; D008024:Ligands; C504265:MADCAM1 protein, human; C489082:Madcam1 protein, mouse; D009088:Mucoproteins; C459380:N-(2,6-dichlorobenzoyl)-4-(2',6'-bismethoxyphenyl)phenylalanine; C459381:N-(N-((3,5-dichlorobenzene)sulfonyl)-2-methylpropyl)phenylalanine; D016201:Receptors, Lymphocyte Homing; D011993:Recombinant Fusion Proteins; C071777:integrin alpha4beta7; D010649:Phenylalanine; D005047:Etoposide; D004317:Doxorubicin; D003520:Cyclophosphamide; D008727:Methotrexate