Autologous CD33-CAR-T cells for treatment of relapsed/refractory acute myelogenous leukemia

Abstract Tumor-associated immune suppression can lead to defective T cell-mediated antitumor immunity. Here, we identified a unique phenotype of exhausted T cells in mice with advanced acute myelogenous leukemia (AML). This phenotype is characterized by the coexpression of Tim-3 and PD-1 on CD8+ T cells in the liver, the major first site of AML metastases. PD-1 and Tim-3 coexpression increased during AML progression. PD-1+Tim-3+ CD8+ T cells were deficient in their ability to produce IFN-γ, TNF-α, and IL-2 in response to PD-1 ligand (PDL1) and Tim-3 ligand (galectin-9) expressing AML cells. PD-1 knockout (KO), which were partially resistant to AML challenge, up-regulated Tim-3 during AML progression and such Tim-3+PD-1- KO CD8+ T cells had reduced cytokine production. Galectin-9 KO mice were more resistant to AML, which was associated with reduced T-regulatory cell accumulation and a modest induction of PD-1 and Tim-3 expression on CD8+ T cells. Whereas blocking the PD-1/PDL1 or Tim-3/galectin-9 pathway alone was insufficient to rescue mice from AML lethality, an additive effect was seen in reducing—albeit not eliminating—both tumor burden and lethality when both pathways were blocked. Therefore, combined PD-1/PDL1 and Tim-3/galectin-9 blockade may be beneficial in preventing CD8+ T-cell exhaustion in patients with hematologic malignancies such as advanced AML.

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Targeting Leukemias by CD123 Specific Chimeric Antigen Receptor

Blood ◽

10.1182/blood.v118.21.1908.1908 ◽

2011 ◽

Vol 118 (21) ◽

pp. 1908-1908

Author(s):

Radhika Thokala ◽

Harjeet Singh ◽

Simon Olivares ◽

Richard Champlin ◽

Laurence J N Cooper

Keyword(s):

T Cells ◽

Chimeric Antigen Receptor ◽

Lymphoblastic Leukemia ◽

Antigen Receptor ◽

Leukemic Cell ◽

Sleeping Beauty ◽

Myelogenous Leukemia ◽

Hematopoietic Stem ◽

Car T Cells ◽

Car T

Abstract Abstract 1908 Chimeric antigen receptors (CARs) are employed to genetically modify T cells to redirect their specificity to target antigens on tumor cells. Typically a second generation CAR is derived by fusing an extracellular domain derived from the scFv of monoclonal antibody (CAR) specific to targeted antigen with CD3 zeta, and CD28 endodomains. CD123 (IL3RA) is expressed on 45% to 95%of acute myelogenous leukemia (AML) and B-cell lineage acute lymphoblastic leukemia (B-ALL). Expression of CD123 is high in the leukemic stem cell (LSC) population, but not in normal hematopoietic stem cells. Thus, CD123 appears to be potential target for immunotherapy in leukemias through chimeric antigen receptor (CAR). We hypothesized that the generation of CD123 specific CAR can redirect the specificity of T cells to CD123 and this was tested by cloning the scFv of CD123 mAb in our CAR construct. The sleeping beauty system was used to express the CAR and DNA plasmids were electroporated into peripheral blood mononuclear cells and cells were numerically expanded on artificial antigen presenting cells genetically modified to express co stimulatory molecules CD86, 4-1BBL, membrane-bound IL-15, and CD123 antigen in presence of IL-21 and 1L–2. CAR+ T numerically expanded to clinically relevant numbers and showed antigen specific cytotoxicity in leukemic celllines. CAR+ T cells expressed both effector and memory markers showing the potential for in vivo persistence after T cell infusion. The bonemarrow homing receptor CXCR4 was expressed by CAR T cells shows the potential to target LSC that reside in BM niches. The preliminary data suggests that mirroring an approach we are using to manufacture clinical grade CD19 specific CAR+ T cells.Figure 1:(A) CAR expression on day 35. (B) Cytotoxicity of CD123CAR in leukemic cell lines.Figure 1:. (A) CAR expression on day 35. (B) Cytotoxicity of CD123CAR in leukemic cell lines.CD3CD3 Disclosures: No relevant conflicts of interest to declare.

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Early lymphocyte recovery after intensive timed sequential chemotherapy for acute myelogenous leukemia: peripheral oligoclonal expansion of regulatory T cells

Blood ◽

10.1182/blood-2010-04-277939 ◽

2011 ◽

Vol 117 (2) ◽

pp. 608-617 ◽

Cited By ~ 33

Author(s):

Christopher G. Kanakry ◽

Allan D. Hess ◽

Christopher D. Gocke ◽

Christopher Thoburn ◽

Ferdynand Kos ◽

...

Keyword(s):

T Cells ◽

T Lymphocytes ◽

Regulatory T Cells ◽

Acute Myelogenous Leukemia ◽

Myelogenous Leukemia ◽

Newly Diagnosed ◽

Sequential Chemotherapy ◽

Regulatory T Lymphocytes ◽

Acute Myelogenous ◽

Oligoclonal Expansion

AbstractFew published studies characterize early lymphocyte recovery after intensive chemotherapy for acute myelogenous leukemia (AML). To test the hypothesis that lymphocyte recovery mirrors ontogeny, we characterized early lymphocyte recovery in 20 consecutive patients undergoing induction timed sequential chemotherapy for newly diagnosed AML. Recovering T lymphocytes were predominantly CD4+ and included a greatly expanded population of CD3+CD4+CD25+Foxp3+ T cells. Recovering CD3+CD4+CD25+Foxp3+ T cells were phenotypically activated regulatory T cells and showed suppressive activity on cytokine production in a mixed lymphocyte reaction. Despite an initial burst of thymopoiesis, most recovering regulatory T cells were peripherally derived. Furthermore, regulatory T cells showed marked oligoclonal skewing, suggesting that their peripheral expansion was antigen-driven. Overall, lymphocyte recovery after chemotherapy differs from ontogeny, specifically identifying a peripherally expanded oligoclonal population of activated regulatory T lymphocytes. These differences suggest a stereotyped immunologic recovery shared by patients with newly diagnosed AML after induction timed sequential chemotherapy. Further insight into this oligoclonal regulatory T-cell population will be fundamental toward developing effective immunomodulatory techniques to improve survival for patients with AML.

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CD8+ T Cells Activated During the Course of Murine Acute Myelogenous Leukemia Elicit Therapeutic Responses to Late B7 Vaccines After Cytoreductive Treatment

Blood ◽

10.1182/blood.v89.8.2915 ◽

1997 ◽

Vol 89 (8) ◽

pp. 2915-2924 ◽

Cited By ~ 20

Author(s):

Kyriaki Dunussi-Joannopoulos ◽

Werner Krenger ◽

Howard J. Weinstein ◽

James L.M. Ferrara ◽

James M. Croop

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Growth ◽

Cd8 T Cells ◽

Acute Myelogenous Leukemia ◽

Tumor Rejection ◽

Myelogenous Leukemia ◽

Vaccine Administration ◽

Acute Myelogenous

Abstract We have previously shown in a murine acute myelogenous leukemia (AML) model that leukemic mice can be cured with a B7 vaccine if immunized early in the disease and that CD8+ T cells are necessary for tumor rejection. However, when B7 vaccine is administered 2 weeks after leukemia inoculation, the effect is only prolonged survival, ending in death virtually of all the mice. To distinguish between tumor kinetics and tumor-induced immunosuppression as potential mechanisms eliminating the therapeutic potential of late B7 vaccines, we performed in vitro T-cell studies during leukemia progression and in vivo studies on the clinical outcome of late B7 vaccines in combination with prior cytoreductive chemotherapy. Our results show that CD8+ T cells from leukemic mice 1 and 2 weeks after leukemia inoculation proliferate more vigorously in response to in vitro activation than cells from normal mice and produce Th1-type cytokines interleukin-2 and interferon-γ. Cytotoxic T lymphocyte (CTL) assays demonstrate that cells from week-2 vaccinated mice (which succumb to their leukemia), surprisingly develop a stronger CTL activity than cells from week-1 vaccinated mice (which reject their leukemia). Finally, the combination of late chemotherapy and late B7 vaccine administration can cure only 20% of leukemic mice, whereas early chemotherapy and the same late B7 vaccine administration cure 100% of leukemic mice. These results demonstrate that in murine AML tumor growth does not induce T-cell anergy or a Th2 cytokine profile and suggest that tumor growth is most likely to be the limiting factor in the curative potential of late B7 vaccines.

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Increased Frequency and Suppression by Regulatory T Cells in Patients with Acute Myelogenous Leukemia

Clinical Cancer Research ◽

10.1158/1078-0432.ccr-08-3010 ◽

2009 ◽

Vol 15 (10) ◽

pp. 3325-3332 ◽

Cited By ~ 159

Author(s):

Miroslaw J. Szczepanski ◽

Marta Szajnik ◽

Malgorzata Czystowska ◽

Magis Mandapathil ◽

Laura Strauss ◽

...

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Acute Myelogenous Leukemia ◽

Myelogenous Leukemia ◽

Acute Myelogenous

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Regulatory T cells in acute myelogenous leukemia: is it time for immunomodulation?

Blood ◽

10.1182/blood-2011-07-365817 ◽

2011 ◽

Vol 118 (19) ◽

pp. 5084-5095 ◽

Cited By ~ 94

Author(s):

Celalettin Ustun ◽

Jeffrey S. Miller ◽

David H. Munn ◽

Daniel J. Weisdorf ◽

Bruce R. Blazar

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Acute Myelogenous Leukemia ◽

Myelogenous Leukemia ◽

Leukemic Cells ◽

Immune Effector ◽

Effector Cells ◽

Allogeneic Hct ◽

Acute Myelogenous

AbstractThe microenviroment of acute myelogenous leukemia (AML) is suppressive for immune effector cells. Regulatory T cells (Tregs) have been recognized as a contributor factor and may be recruited and exploited by leukemic cells to evade immunesurveillance. Studies have shown that the frequencies of marrow and blood Tregs are greater in patients with AML than in control patients. Although increased Tregs have been associated with a decreased risk of GVHD after allogeneic HCT and hence may impede the graft-versus-tumor effect, recent findings indicate that that this may not be the case. Because there is a need to improve outcomes of standard treatment (chemotherapy with or without allogeneic HCT) in AML, targeting Tregs present an outstanding opportunity in AML because discoveries may apply throughout its treatment. Here, we review data on the roles of Tregs in mediating immune system-AML interactions. We focused on in vitro, animal, and observational human studies of Tregs in AML biology, development, prognosis, and therapy in different settings (eg, vaccination and HCT). Manipulation of Tregs or other types of immunomodulation may become a part of AML treatment in the future.

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