SDF- 1 -stimulated tethering, rolling, and arrest of nave CD4 + T - PowerPoint PPT Presentation

The state diagram of SDF- 1α -stimulated tethering, rolling, and arrest of naïve CD4 + T lymphocytes Nicholas R. Anderson, Dooyoung Lee, and Daniel A. Hammer UPenn CBE GSS

T cells at the forefront of cancer treatments 3 Liddy, et al ., Nat Med , 2012 .

Leukocyte adhesion cascade Capture Activation Spreading Transmigration Crawling Rolling Arrest 4 Adapted from Ley, Nat Rev Immunol , 2007 .

Simulated state diagram 100 k f 0,integrin = 10 s -1 Firm adhesion Selectin density (molecules/µm 2 ) k f 0,integrin = 1000 s -1 10 Rolling adhesion 1 0.1 10 1 5 ICAM-1 density (molecules/µm 2 ) Adapted from Bhatia, et al , Biophys J , 2003 .

Experimental System Capture Rolling Arrest Free flowing Protein A/G E-selectin ligands CXCR4 LFA-1 SDF-1 α Pluronic F127 E-selectin ICAM-1 6

Cellular motion Tethering 8

Cellular motion Tethering Rolling 9

Cellular motion Tethering Rolling Arrest 10

ICAM-1 only surfaces have high levels of tethering 11

E-selectin enhances rolling 12

Both E-selectin and ICAM-1 are required for efficient arrest 13

Rolling velocity is constant across many surfaces 18

ICAM-1 is required for stopping 19

Connection to upstream migration? 20

Conclusions • System allows for study of entire leukocyte adhesion cascade • E-selectin and ICAM-1 can act synergistically to promote arrest • Small numbers of E-selectin or ICAM-1 can rapidly change prominent adhesion types • Naïve CD4 + T cells maintain constant rolling velocity across many surface types • Time to stop can vary significantly depending on surface composition 21

Acknowledgements Hammer Lab Alex Buffone, Jr., PhD Eric Wang Woo Sik Jang, PhD Sarah Kim Ben Schuster, PhD Ellen Reed Katie Pulsipher, PhD Adam Suppes Chen Gao 22