Bi-ligand surfaces with oriented and patterned protein for real-time tracking of cell migration

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 123; pp. 225 - 235
• Main Authors: Vernekar, Varadraj N, Wallace, Charles S, Wu, Mina, Chao, Joshua T, O'Connor, Shannon K, Raleigh, Aimee, Liu, Xiaji, Haugh, Jason M, Reichert, William M
• Format: Journal Article
• Language: English
• Published: Netherlands 01.11.2014
• Subjects: Animals; B-Lymphocytes - cytology; Cell adhesion; Cell Movement - physiology; Cells, Cultured; Chemokine CXCL12 - chemistry; Intercellular Adhesion Molecule-1 - chemistry; Mice; Mice, Transgenic; Migration; Platforms; Proteins; Recombinant; Surface chemistry; Tracking; Ultraviolet Rays; X-ray photoelectron spectroscopy; Chemokine; B lymphocyte; Surface immobilization; Surface gradients; Chemotaxis; Cell adhesion molecule
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2014.09.020

A bioactive platform for the quantitative observation of cell migration is presented by (1) presenting migration factors in a well-defined manner on 2-D substrates, and (2) enabling continuous cell tracking. Well-defined substrate presentation is achieved by correctly orienting immobilized proteins (chemokines and cell adhesion molecules), such that the active site is accessible to cell surface receptors. A thiol-terminated self-assembled monolayer on a silica slide was used as a base substrate for subsequent chemistry. The thiol-terminated surface was converted to an immobilized metal ion surface using a maleimido-nitrilotriacetic acid (NTA) cross-linker that bound Histidine-tagged recombinant proteins on the surface with uniform distribution and specific orientation. This platform was used to study the influence of surface-immobilized chemokine SDF-1α and cell adhesion molecule ICAM-1 on murine splenic B lymphocyte migration. While soluble SDF-1α induced trans-migration in a Boyden Chamber type chemotaxis assay, immobilized SDF-1α alone did not elicit significant surface-migration on our test-platform surface. Surface-immobilized cell adhesion protein, ICAM-1, in conjunction with activation enabled migration of this cell type on our surface. Controlled exposure to UV light was used to produce stable linear gradients of His-tagged recombinant SDF-1α co-immobilized with ICAM-1 following our surface chemistry approach. XPS and antibody staining showed defined gradients of outwardly oriented SDF-1α active sites. This test platform can be especially valuable for investigators interested in studying the influence of surface-immobilized factors on cell behavior and may also be used as a cell migration enabling platform for testing the effects of various diffusible agents.