Fig 1: Jurkat cell chemotaxis towards CXCL12 on membrane-bound vs. immobilized ICAM-1 in the diffusion microdevice. Representative images of Jurkat cells and migration trajectories in 1 h with and without CXCL12 gradient, on (A) mb-ICAM-1 and (B) im-ICAM-1, respectively. The migration trajectories of Jurkat T cells in 1 h on (C) mb-ICAM-1 and (D) im-ICAM-1 without and with CXCL12 gradient. (E) Schematic of the definitions of cell migration parameters. Quantification of (F) total movements, (G) directionality, (H) migration persistency as assessed by Runs% and (I) forward migration index, as assessed by averaged movement toward chemoattractant gradient over accumulated distance. n = 66–71 single cell trajectory per condition. Not specified: p > 0.05; *: p < 0.05; ***: p < 0.001; ****: p < 0.0001 by ANOVA with Tukey’s test.
Fig 2: Lipid bilayer formation and confirmation of lateral mobility of the membrane-bound ICAM-1. (A) Schematic of filling the center channel with Laplace pressure. R and r are the radii of the larger and smaller droplets, respectively. The difference in pressure generated by the surface tension of each droplet drives liquid movement in the microchannel. (B) Dye loading test showing the filling direction. (C) Evaluating lateral mobility of membrane-bound (mb-) and immobilized (im-) ICAM-1 with fluorescent recovery after photobleaching (FRAP). (D,E) Line scan of mb-ICAM-1 and im-ICAM-1 fluorescence profiles right after vs. 20 min after photobleaching.
Fig 3: Mechanical Rigidity of ICAM1 Nano-Topographies Controls T Cell On-Ridge Spreading and In-Groove Invasiveness Plasticity Balance(A) 3D super-resolution reconstruction of the ICAM1-functionalized PAA nano-topographic surface (G’=16 kPa).(B) Test super-resolution imaging (3D reconstruction) of human CD4+ T cells spreading and migrating along the ICAM1-coated nano-topographic surfaces on soft (16 kPa) and rigid (50 kPa) PAA surfaces.(C) Schematic of the T cell morphometric analysis and metrics: T cell height, projected area of spreading of entire cell interface (Sentire cell IF) and projected area of in-groove invasive T cell interface (Sinvasive IF).(D and E) Mechanoregulation of T cell height, spreading area and invasiveness as indicated by T cell spreading assay on soft (G’=16 kPa) and rigid (G’=50 kPa) ICAM1 nano-textures. T cell spreading enhances on the rigid ICAM1, accompanied with T cell flattening, i.e. decrease of the T cell height. Results indicate a mechanically controlled dynamic balance between on-ridge T cell spreading and in-groove invasiveness, as shown on the schematic panel (E). I.e. T cell in-groove invasiveness structurally competes with on-ridge spreading, indicating that on-ridge spreading is mechanically enhanced and out-balances in-groove invasiveness on the rigid (G’=50 kPa) ICAM1 nano-topography. Alternatively, soft (G’=16 kPa) ICAM-1 nano-textures are unable to promote the mechanically sensitive on-ridge T cell spreading, shifting the balance towards steric in-groove T cell invasiveness.Data on the plots on (D) are as follows: boxes - means, Q1 and Q3; whiskers - max and min, X - medians; p values - one way ANOVA test. Experimental data collected in triplicates, total n>50.
Supplier Page from Sino Biological, Inc. for Human ICAM-1 / CD54 Protein (His & Fc Tag)