Graft-versus-leukemia (GVL) against mouse blast-crisis chronic myelogenous leukemia (BC-CML) and chronic-phase chronic myelogenous leukemia (CP-CML) …

C Matte-Martone, S Venkatesan, HS Tan… - The Journal of …, 2011 - journals.aai.org
C Matte-Martone, S Venkatesan, HS Tan, I Athanasiadis, J Chang, J Pavisic, WD Shlomchik
The Journal of Immunology, 2011journals.aai.org
Abstract Graft-versus-leukemia (GVL) against chronic-phase chronic myelogenous leukemia
(CP-CML) is potent, but it is less efficacious against acute leukemias and blast-crisis chronic
myelogenous leukemia (BC-CML). The mechanisms underlying GVL resistance are
unknown. Previously, we found that alloreactive T cell targeting of GVL-sensitive bcr-abl–
induced mouse CP-CML (mCP-CML) required TCR–MHC interactions and that multiple and
redundant killing mechanisms were in play. To better understand why BC-CML is resistant to …
Abstract
Graft-versus-leukemia (GVL) against chronic-phase chronic myelogenous leukemia (CP-CML) is potent, but it is less efficacious against acute leukemias and blast-crisis chronic myelogenous leukemia (BC-CML). The mechanisms underlying GVL resistance are unknown. Previously, we found that alloreactive T cell targeting of GVL-sensitive bcr-abl–induced mouse CP-CML (mCP-CML) required TCR–MHC interactions and that multiple and redundant killing mechanisms were in play. To better understand why BC-CML is resistant to GVL, we performed a comprehensive analysis of GVL against mouse BC-CML (mBC-CML) induced by the retroviral transfer of the bcr-abl and NUP98/HOXA9 fusion cDNAs. Like human BC-CML, mBC-CML was GVL resistant, and this was not due to accelerated kinetics or a greater leukemia burden. To study T cell recognition and killing mechanisms, we generated a panel of gene-deficient leukemias by transducing bone marrow from gene-deficient mice. T cell target recognition absolutely required that mBC-CML cells express MHC molecules. GVL against both mCP-CML and mBC-CML required leukemia expression of ICAM-1. We hypothesized that mBC-CML would be resistant to some of the killing mechanisms sufficient to eliminate mCP-CML, but we found instead that the same mechanisms were effective against both types of leukemia, because GVL was similar against wild-type or mBC-CML genetically lacking Fas, TRAIL-R, Fas/TRAIL-R, or TNFR1/R2 or when donor T cells were perforin−/−. However, mCP-CML, but not mBC-CML, relied on expression of programmed death-1 ligands 1 and 2 (PD-L1/L2) to resist T cell killing, because only GVL against mCP-CML was augmented when leukemias lacked PD-L1/L2. Thus, mBC-CML cells have cell-intrinsic mechanisms, distinct from mCP-CML cells, which protect them from T cell killing.
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