Hematopoietic stem cells for cancer immunotherapy

• Mobilized hematopoietic stem cells transduced with IV injected HD-Ad5/35 11 vectors home to the BM persist long term.• Our approach allows for the stable genetic modification of primitive, long-term persisting HSPCs.Current protocols for hematopoietic stem/progenitor cell (HSPC) gene therapy, involving the transplantation of ex vivo genetically modified HSPCs are complex and not without risk for the patient. We developed a new approach for in vivo HSPC transduction that does not require myeloablation and transplantation. It involves subcutaneous injections of granulocyte-colony-stimulating factor/AMD3100 to mobilize HSPCs from the bone marrow (BM) into the peripheral blood stream and the IV injection of an integrating, helper-dependent adenovirus (HD-Ad5/35 11 ) vector system. These vectors target CD46, a receptor that is uniformly expressed on HSPCs. We demonstrated in human CD46 transgenic mice and immunodeficient mice with engrafted human CD34 1 cells that HSPCs transduced in the periphery home back to the BM where they stably express the transgene. In hCD46 transgenic mice, we showed that our in vivo HSPC transduction approach allows for the stable transduction of primitive HSPCs. Twenty weeks after in vivo transduction, green fluorescent protein (GFP) marking in BM HSPCs (Lin 2 Sca1 1 Kit 2 cells) in most of the mice was in the range of 5% to 10%. The percentage of GFP-expressing primitive HSPCs capable of forming multilineage progenitor colonies (colony-forming units [CFUs]) increased from 4% of all CFUs at week 4 to 16% at week 12, indicating transduction and expansion of long-term surviving HSPCs. Our approach was well tolerated, did not result in significant transduction of nonhematopoietic tissues, and was not associated with genotoxicty. The ability to stably genetically modify HSPCs without the need of myeloablative conditioning is relevant for a broader clinical application of gene therapy. (Blood. 2016;128(18):2206-2217

show abstract

“…The simplicity and cost-effectiveness of the technology is relevant for gene therapy of inherited or infectious diseases, and cancer. 52,53 …”

Section: Discussionmentioning

confidence: 99%

In vivo transduction of primitive mobilized hematopoietic stem cells after intravenous injection of integrating adenovirus vectors

Richter

Saydaminova

Yumul

et al. 2016

Blood

145

View full text Add to dashboard Cite

show abstract

“…28 In this study, we created transgenic mice expressing a TCR recognizing a peptide derived from survivin (Sur), a tumor-associated molecule expressed in some nonneoplastic tissues, including the thymus, which has been studied as a potential target for immunotherapy of cancer. 29 The Sur-TCR was expressed downstream of a human CD2 promoter, which drives expression during early stages of thymopoiesis.…”

Section: /2mentioning

confidence: 99%

“…on June 7, 2019. by guest www.bloodjournal.org From Because extensive T-cell differentiation is associated with diminished functionality and diminished persistence following adoptive transfer, 27 there has been increasing interest in expressing receptors engineered to recognize TAAs in less differentiated T-cell progenitors, including multipotential hematopoietic progenitors. 28 In this study, we created transgenic mice expressing a TCR recognizing a peptide derived from survivin (Sur), a tumor-associated molecule expressed in some nonneoplastic tissues, including the thymus, which has been studied as a potential target for immunotherapy of cancer.29 The Sur-TCR was expressed downstream of a human CD2 promoter, which drives expression during early stages of thymopoiesis. Sur-TCRtransgenic (Sur-TCR-Tg) T cells seeded the periphery of Sur-TCR-Tg mice, but did not mediate autoimmunity or meaningful antitumor effects.…”

mentioning

confidence: 99%

Thymic expression of a T-cell receptor targeting a tumor-associated antigen coexpressed in the thymus induces T-ALL

Cui

Onozawa

Garber

et al. 2015

Blood

View full text Add to dashboard Cite

• Thymocyte signaling via a transgenic survivin-reactive TCR induced T-ALL with 100% penetrance.• Thymic expression of signaling receptors targeting TAAs coexpressed in the thymus poses a risk for leukemogenesis.T-cell receptors (TCRs) and chimeric antigen receptors recognizing tumor-associated antigens (TAAs) can now be engineered to be expressed on a wide array of immune effectors. Engineered receptors targeting TAAs have most commonly been expressed on mature T cells, however, some have postulated that receptor expression on immune progenitors could yield T cells with enhanced potency. We generated mice (survivin-TCRtransgenic [Sur-TCR-Tg]) expressing a TCR recognizing the immunodominant epitope ) of murine survivin during early stages of thymopoiesis. Spontaneous T-cell acute lymphoblastic leukemia (T-ALL) occurred in 100% of Sur-TCR-Tg mice derived from 3 separate founders. The leukemias expressed the Sur-TCR and signaled in response to the Sur 20-28 peptide. In preleukemic mice, we observed increased cycling of doublenegative thymocytes expressing the Sur-TCR and increased nuclear translocation of nuclear factor of activated T cells, consistent with TCR signaling induced by survivin expression in the murine thymus. b2M 2/2 Sur-TCR-Tg mice, which cannot effectively present survivin peptides on class I major histocompatibility complex, had significantly diminished rates of leukemia. We conclude that TCR signaling during the early stages of thymopoiesis mediates an oncogenic signal, and therefore expression of signaling receptors on developing thymocytes with specificity for TAAs expressed in the thymus could pose a risk for neoplasia, independent of insertional mutagenesis. (Blood. 2015;125(19):2958-2967) IntroductionAdoptive immunotherapy has shown increasing promise as a treatment of cancer, driven in part by advances in genetic engineering that permit efficient expression of receptors targeting tumor antigens on immune effectors. Several clinical trials have demonstrated antitumor efficacy following adoptive transfer of mature T cells engineered to express T-cell receptors (TCRs) targeting tumor-associated antigens (TAAs), including NY-ESO-1, 1 MART-1, 2,3 and MAGE-A3. 4 Similarly, impressive antitumor effects have recently been observed following transfer of mature T cells engineered using retroviruses to express chimeric antigen receptors targeting TAAs. [5][6][7] In these studies, toxicity has related to autoimmunity 3,[8][9][10] and cytokine release syndrome, [11][12][13] but oncogenesis as a result of retroviral-based gene transfer has not been observed. This stands in contrast to the clinical experience following gene therapy for interleukin 2 receptor gc 2/2 (IL2Rgc 2/2) congenital immunodeficiency where 5 of 20 patients developed T-cell acute lymphoblastic leukemia (T-ALL) following retroviral-mediated expression of IL2Rgc in hematopoietic stem cells.14-16 Leukemia in this setting was associated with insertional mutagenesis, with integration of the IL2Rgc transgene into regulatory regions of the ...

show abstract

“…In most clinical trials, engineered T cells are almost undetectable in the peripheral blood after approximately 1 month (8)(9)(10). To increase the therapeutic window, investigators have proposed to use engineered hematopoietic stem cells (HSCs) to allow for a constant source of naive engineered T cells in vivo (11). Expansion of patient peripheral blood mononuclear cells (PBMCs) can alter the tumor-homing function, reducing the efficacy of infused cells (12).…”

Section: Introductionmentioning

confidence: 99%