(447a) Migration of Artificially Activated B Cells in a Microfluidic Device-Induced CXCL-12 Gradient

Germinal centers (GCs) are intricate biological niches in which activated B cells differentiate into plasma cells and memory B cells as part of an adaptive immune response. Effective recapitulation of the germinal center dynamics in-vitro would advance the development of personalized cellular immunotherapy. While several methods have been developed to activate B cells and induce GC-like reactions, most in-vitro culture systems lack the zonality of physiological GCs. Migration between the dark and light zones (DZ and LZ) has been proven to be essential for effective somatic hypermutation and B cell survival during GC-based differentiation. In effort to assimilate this crucial element with in-vitro GC cultures, we established a gradient of a critical chemokine, CXCL12, in a biocompatible, microfluidic chamber as a synthetic GC niche. Source and sink channels maintained with constant flow developed a soluble, diffusion-based CXCL12 gradient in which artificially-activated B cells successfully migrated.