VLA-4 integrin can mediate CD11/CD18-independent transendothelial migration of human monocytes

• Published in: The Journal of clinical investigation 1993-12, Vol.92 (6), p.2768-2777
• Main Authors: CHULUYAN, H. E, ISSEKUTZ, A. C
• Format: Article
• Language: English
• Subjects: Antibodies, Monoclonal - pharmacology; Antigens, CD - genetics; Antigens, CD - physiology; Biological and medical sciences; CD11 Antigens; CD18 Antigens; Cell Line; Cell Movement - drug effects; Cell Movement - physiology; Cells, Cultured; Child; Complement C5a - pharmacology; Endothelium, Vascular - physiology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Immunobiology; Interleukin-1 - pharmacology; Male; Monocytes - drug effects; Monocytes - immunology; Monocytes - physiology; Monocytes, macrophages; Myeloid cells: ontogeny, maturation, markers, receptors; Receptors, Very Late Antigen - immunology; Receptors, Very Late Antigen - physiology; Recombinant Proteins - pharmacology; Reference Values; Tumor Necrosis Factor-alpha - pharmacology; Umbilical Veins
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/JCI116895

The migration of human monocytes across unactivated and activated human umbilical vein endothelium (HUVE) in response to chemotactic factors was studied, and the adhesion molecules involved were characterized. Migration of blood monocytes or U937 cell line-derived monocytes across unactivated HUVE induced by C5a, was partially inhibited (by 75%) by mAbs (R15.7 or 60.3) to CD18 of the CD11/CD18 complex on the monocyte. However, when the HUVE was pretreated for 5 h with IL-1 alpha (0.1 ng/ml), TNF-alpha (100 U/ml), or LPS (1 ng/ml), migration induced by C5a was no longer inhibited; i.e., migration became CD18 independent. The monocyte CD18-independent migration was completely blocked by mAbs against alpha 4 or beta 1 integrin chains of VLA-4. This migration was also partially inhibited by mAbs against vascular cell adhesion molecule-1 (VCAM-1), a major counter-receptor on HUVE for VLA-4, but not by mAbs to E-selectin or intercellular adhesion molecule-1. The significant CD18-independent migration across "unactivated" HUVE was also inhibited by mAbs against alpha 4 or beta 1 chains of VLA-4, although mAbs against VCAM-1 did not inhibit under these conditions. Finally, considerable VLA-4-dependent transendothelial migration to C5a was also observed with monocytes from a patient with CD18 deficiency (leukocyte adhesion deficiency). These results suggest that (a) there is a major CD18-independent component in monocyte chemotactic factor-dependent migration across activated and unactivated endothelium; (b) that VLA-4 integrin on the monocyte has a major role in this migration; and (c) that VCAM-1 on activated endothelium functions as a counter-receptor in this process, but other ligands for VLA-4, especially on unactivated endothelium, may also be involved.