595 Inhibition of integrin αvβ8 in combination with low dose radiation induces antitumor effect in advanced immune checkpoint blockade refractory tumor model by Natalia Reszka-Blanco, Megan Krumpoch, Michaela Mentzer, Vinod Yadav Yadav, Brianna Bannister, Dan Cui, Elizabeth Konopka, Dooyoung Lee, Fu-Yang Lin, Terence Moy, Eugene Nebelitsky, Qi Qiao, Inese Smutske, Charlotte Root, Patrick Allison, Sarah Krueger, Dawn Troast, Blaise Lippa, Bruce Rogers, Adrian Ray