Microfluidic squeezing for intracellular antigen loading in polyclonal B-cells as cellular vaccines

B-cells are promising candidate autologous antigen-presenting cells (APCs) to prime antigen-specific T-cells both in vitro and in vivo. However to date, a significant barrier to utilizing B-cells as APCs is their low capacity for non-specific antigen uptake compared to “professional” APCs such as de...

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Bibliographic Details
Main Authors: Lee Szeto, Gregory, Alejandro, Brian, Park, Clara, Frew, Kirubel, Brefo, Mavis S., Mao, Shirley, Heimann, Megan, Van Egeren, Debra S., Sharei, Armon Reza, Worku, Hermoon A., Langer, Robert S, Irvine, Darrell J, Jensen, Klavs F, Szeto, Gregory
Other Authors: Massachusetts Institute of Technology. Department of Biological Engineering
Format: Article
Language:en_US
Published: Nature Publishing Group 2015
Online Access:http://hdl.handle.net/1721.1/97090
https://orcid.org/0000-0003-1833-9822
https://orcid.org/0000-0001-7604-1333
https://orcid.org/0000-0001-7192-580X
https://orcid.org/0000-0003-4255-0492
Description
Summary:B-cells are promising candidate autologous antigen-presenting cells (APCs) to prime antigen-specific T-cells both in vitro and in vivo. However to date, a significant barrier to utilizing B-cells as APCs is their low capacity for non-specific antigen uptake compared to “professional” APCs such as dendritic cells. Here we utilize a microfluidic device that employs many parallel channels to pass single cells through narrow constrictions in high throughput. This microscale “cell squeezing” process creates transient pores in the plasma membrane, enabling intracellular delivery of whole proteins from the surrounding medium into B-cells via mechano-poration. We demonstrate that both resting and activated B-cells process and present antigens delivered via mechano-poration exclusively to antigen-specific CD8[superscript +]T-cells, and not CD4[superscript +]T-cells. Squeezed B-cells primed and expanded large numbers of effector CD8[superscript +]T-cells in vitro that produced effector cytokines critical to cytolytic function, including granzyme B and interferon-γ. Finally, antigen-loaded B-cells were also able to prime antigen-specific CD8[superscript +]T-cells in vivo when adoptively transferred into mice. Altogether, these data demonstrate crucial proof-of-concept for mechano-poration as an enabling technology for B-cell antigen loading, priming of antigen-specific CD8[superscript +]T-cells, and decoupling of antigen uptake from B-cell activation.