Abrogating Cbl-b in effector CD8+ T cells improves the efficacy of adoptive therapy of leukemia in mice
Ingunn M. Stromnes, … , Hua Gu, Philip D. Greenberg
Ingunn M. Stromnes, … , Hua Gu, Philip D. Greenberg
Published September 20, 2010
Citation Information: J Clin Invest. 2010;120(10):3722-3734. https://doi.org/10.1172/JCI41991.
View: Text | PDF
Research Article Hematology

Abrogating Cbl-b in effector CD8+ T cells improves the efficacy of adoptive therapy of leukemia in mice

Abstract

The clinical use of adoptive immunotherapy with tumor-reactive T cells to treat established cancers is limited in part by the poor in vivo survival and function of the transferred T cells. Although administration of exogenous cytokines such as IL-2 can promote T cell survival, such strategies have many nonspecific activities and are often associated with toxicity. We show here that abrogating expression of Casitas B-lineage lymphoma b (Cbl-b), a negative regulator of lymphocyte activation, in tumor-reactive CD8+ T cells expanded ex vivo increased the efficacy of adoptive immunotherapy of disseminated leukemia in mice. Mechanistically, Cbl-b abrogation bypassed the requirement for exogenous IL-2 administration for tumor eradication in vivo. In addition, CD8+ T cells lacking Cbl-b demonstrated a lower threshold for activation, better survival following target recognition and stimulation, and enhanced proliferative responses as a result of both IL-2–dependent and –independent pathways. Importantly, siRNA knockdown of Cbl-b in human CD8+CD28– effector T cell clones similarly restored IL-2 production and proliferation following target recognition independent of exogenous IL-2, enhanced IFN-γ production, and increased target avidity. Thus, abrogating Cbl-b expression in effector T cells may improve the efficacy of adoptive therapy of some human malignancies.

Authors

Ingunn M. Stromnes, Joseph N. Blattman, Xiaoxia Tan, Sara Jeevanjee, Hua Gu, Philip D. Greenberg

×

Figure 5

Abrogating Cbl-b expression in tumor-reactive TCRgag cells during adoptive immunotherapy of disseminated leukemia.

Options: View larger image (or click on image) Download as PowerPoint
Abrogating Cbl-b expression in tumor-reactive TCRgag cells during adopti...
(A) Thy1.1 B6 mice were injected with 5 × 106 live FBL. Five days later, mice received Cytoxan (180 mg/kg), followed by injection of 1 × 105 Thy1.2+TCRgagCblb+/+ or Cblb–/– effectors that had previously undergone 3 cycles of in vitro restimulation with antigen and r-h-IL-2 (25 U/ml). Some recipients also received IL-2 (104 U/mouse for 10 days). Transfer of TCRgagCblb–/– cells significantly improved survival in the absence of IL-2 administration compared with TCRgag cells (P < 0.0001, log-rank Mantel-Cox test). Data were pooled from 3 independent experiments (n = 10–16 mice/group). Cy, cyclophosphamide. (B) Representative FACS plots of donor Thy1.2+ CD8+ T cells in the blood 10 days after T cell transfer during therapy. The percentage of donor cells in the blood (top) and the percentage of donor Thy1.2 cells of the CD8 cells (bottom) is indicated. (C) The percentage of donor T cells in the spleen was determined by FACS. TCRgagCblb–/– cells (white symbols) expanded significantly better than wild-type TCRgag cells (black symbols) in either the presence (squares) or absence (circles) of IL-2 injections at day 10 (P < 0.05 and P < 0.005, respectively, t test).