title: Heterologous Vaccination and Checkpoint Blockade Synergize To Induce Antileukemia Immunity.
abstract: Checkpoint blockade-based immunotherapies are effective in cancers with high numbers of nonsynonymous mutations. In contrast, current paradigms suggest that such approaches will be ineffective in cancers with few nonsynonymous mutations. To examine this issue, we made use of a murine model of BCR-ABL(+) B-lineage acute lymphoblastic leukemia. Using a principal component analysis, we found that robust MHC class II expression, coupled with appropriate costimulation, correlated with lower leukemic burden. We next assessed whether checkpoint blockade or therapeutic vaccination could improve survival in mice with pre-established leukemia. Consistent with the low mutation load in our leukemia model, we found that checkpoint blockade alone had only modest effects on survival. In contrast, robust heterologous vaccination with a peptide derived from the BCR-ABL fusion (BAp), a key driver mutation, generated a small population of mice that survived long-term. Checkpoint blockade strongly synergized with heterologous vaccination to enhance overall survival in mice with leukemia. Enhanced survival did not correlate with numbers of BAp:I-A(b)-specific T cells, but rather with increased expression of IL-10, IL-17, and granzyme B and decreased expression of programmed death 1 on these cells. Our findings demonstrate that vaccination to key driver mutations cooperates with checkpoint blockade and allows for immune control of cancers with low nonsynonymous mutation loads.
authors.affiliation: Center for Immunology, University of Minnesota, Minneapolis, MN 55455; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455;
authors.forename: Luke S
authors.identifier: 0000-0003-4781-7707
authors.initials: LS
authors.lastname: Manlove
authors.affiliation: Center for Immunology, University of Minnesota, Minneapolis, MN 55455; Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN 55455;
authors.forename: Jason M
authors.identifier: 0000-0003-4641-6872
authors.initials: JM
authors.lastname: Schenkel
authors.affiliation: Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802;
authors.forename: Kezia R
authors.identifier: 0000-0002-7200-5236
authors.initials: KR
authors.lastname: Manlove
authors.affiliation: Center for Immunology, University of Minnesota, Minneapolis, MN 55455; Department of Microbiology, Institute of Immunology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104;
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Pauken
authors.affiliation: Medical Sciences, Amgen, Inc., Thousand Oaks, CA 91320; and.
authors.forename: Richard T
authors.initials: RT
authors.lastname: Williams
authors.affiliation: Center for Immunology, University of Minnesota, Minneapolis, MN 55455; Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN 55455;
authors.forename: Vaiva
authors.initials: V
authors.lastname: Vezys
authors.affiliation: Center for Immunology, University of Minnesota, Minneapolis, MN 55455; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455; Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455 farra005@umn.edu.
authors.forename: Michael A
authors.identifier: 0000-0002-5569-0366
authors.initials: MA
authors.lastname: Farrar
mesh_terms: D000818:Animals; D059447:Cell Cycle Checkpoints / Q000502:physiology*; D004195:Disease Models, Animal; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology* / Q000473:pathology*; D014611:Vaccination