title: Quantitative analysis of B-lymphocyte migration directed by CXCL13.
abstract: B-lymphocyte migration, directed by chemokine gradients, is essential for homing to sites of antigen presentation. B cells move rapidly, exhibiting amoeboid morphology like other leukocytes, yet quantitative studies addressing B-cell migration are currently lacking relative to neutrophils, macrophages, and T cells. Here, we used total internal reflection fluorescence (TIRF) microscopy to characterize the changes in shape (morphodynamics) of primary, murine B cells as they migrated on surfaces with adsorbed chemokine, CXCL13, and the adhesive ligand, ICAM-1. B cells exhibited frequent, spontaneous dilation and shrinking events at the sides of the leading membrane edge, a phenomenon that was predictive of turning versus directional persistence. To characterize directed B-cell migration, a microfluidic device was implemented to generate gradients of adsorbed CXCL13 gradients. Haptotaxis assays revealed a modest yet consistently positive bias of the cell's persistent random walk behavior towards CXCL13 gradients. Quantification of tactic fidelity showed that bias is optimized by steeper gradients without excessive midpoint density of adsorbed chemokine. Under these conditions, B-cell migration is more persistent when the direction of migration is better aligned with the gradient.
authors.affiliation: Department of Chemical and Biomolecular Engineering, North Carolina State University, Campus Box 7905, 911 Partners Way, Raleigh, NC 27695-7905, USA. jason_haugh@ncsu.edu.
authors.forename: Xiaji
authors.initials: X
authors.lastname: Liu
authors.forename: Sreeja B
authors.initials: SB
authors.lastname: Asokan
authors.forename: James E
authors.initials: JE
authors.lastname: Bear
authors.forename: Jason M
authors.initials: JM
authors.lastname: Haugh
mesh_terms: D000327:Adsorption; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002465:Cell Movement; D054382:Chemokine CXCL13 / Q000378:metabolism*; D019295:Computational Biology; D003198:Computer Simulation; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D044085:Microfluidics; D008856:Microscopy, Fluorescence; D010641:Phenotype
chemical_list: D054382:Chemokine CXCL13; C486386:Cxcl13 protein, mouse; C090509:Icam1 protein, mouse; D018799:Intercellular Adhesion Molecule-1