scholarly journals PD-L1 Checkpoint Blockade Augments Anti-Tumor Immune Response of GD2 or HER2-Bsab Ex Vivo Armed T-Cells (EVAT) Therapy in Osteosarcoma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1959-1959
Author(s):  
Jeong A Park ◽  
Hong fen Guo ◽  
Hong Xu ◽  
Nai-Kong V. Cheung
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Immune Checkpoint ◽  
Bispecific Antibody ◽  
Ex Vivo ◽  
Activated T Cells ◽  
The Impact ◽  
Anti Tumor Activity

Background Ex Vivo Armed T-cells (EVAT) carrying zeptomoles (10-21M) of T-cell engaging GD2-bispecific antibody (GD2-EVAT) or HER2-bispecific antibodies (HER2-EVAT) have potent anti-tumor activity against GD2(+) and/or HER2(+) solid tumors. Strategies to further optimize this approach are highly relevant. PD-1 is a key immune checkpoint receptor expressed mainly by activated T-cells and mediates immune suppression by binding to its ligands PD-L1 or PD-L2. Upregulation of PD-L1 has been found in many cancers including osteosarcoma and associated with aggressive disease and poor outcome. While the use of immune checkpoint inhibitors (ICIs) seems logical, the ideal timing when combined with T-cell engaging bispecific antibody (T-BsAb) or EVAT has yet to be defined. Here, we described the effects of anti-PD-1 or anti-PD-L1 antibodies on GD2-EVAT or HER2-EVAT therapy and explored the impact of its timing in the treatment of osteosarcoma which is GD2(+), HER2(+) and PD-L1(+). Methods GD2-BsAb and HER-BsAb were built using the IgG(L)-scFv format (Can Immunol Res, 3:266, 2015, Oncoimmunology, PMID:28405494). T-cells from healthy volunteer donors were isolated, and cultured ex vivo in the presence of CD3/CD28 beads plus 30 IU/mL of interleukin 2 (IL-2). Between day 7 and day 14, activated T-cells (ATCs) were harvested and armed for 20 minutes at room temperature with GD2-BsAb or HER2-BsAb. In vivo anti-tumor activity against GD2(+), HER2(+), and PD-L1(+) osteosarcoma cell line xenografts was tested in BALB-Rag2-/-IL-2R-γc-KO mice. Anti-human PD-1 antibody (pembrolizumab, anti-PD-1) or anti-human PD-L1 antibody (atezolizumab, anti-PD-L1) were tested for synergy with GD2-EVAT or HER2-EVAT therapy. Results The PD-1 expression increased among T-cells that circulated in the blood, that infiltrated the spleen or the tumor after EVAT therapy. While anti-PD-L1 combination therapy with GD2-EVAT or HER2-EVAT improved anti-tumor response against osteosarcoma (P=0.0123 and P=0.0004), anti-PD-1 did not (all P>0.05). The addition of anti-PD-L1 significantly increased T-cell survival in blood and T-cell infiltration of tumor when compared to GD2-EVAT or HER2-EVAT alone (all P<0.0001). Treatment of GD2-EVAT or anti-PD-L1 plus GD2-EVAT downregulated GD2 expression on tumors, but anti-PD-1 plus GD2-EVAT did not. For the next step we tested the impact of different combination schedules of ICIs on GD2-EVAT therapy. Concurrent anti-PD-1 (6 doses along with GD2-EVAT therapy) interfered with GD2-EVAT, while sequential anti-PD-1 (6 doses after GD2-EVAT) did not make a significant effect (P>0.05). On the other hand, while the concurrent use of anti-PD-L1 did not show benefit on GD2-EVAT, sequentially administered anti-PD-L1 produced a significant improvement in tumor control when compared to anti-PD-L1 or GD2-EVAT alone (P=0.002 and P=0.018). When anti-PD-L1 treatment was extended (12 doses after GD2-EVAT), the anti-tumor effect was most pronounced compared to GD2-EVAT alone (P <0.0001), which translated into improved survival (P=0.0057). These in vivo anti-tumor responses were associated with increased CD8(+) tumor infiltrating lymphocytes (TILs) of tumor. Conclusion In the arming platform, large numbers of target-specific T-cells can be generated, and this EVAT therapy is a highly effective cellular treatment with high potency in preclinical models. In addition, the advantage of ex vivo cytokine release following T-cell arming and activation could reduce or avoid life threatening cytokine storm if such activation was to proceed in vivo. Adoptive T-cell therapy induced immune response upregulates the inhibitory immune checkpoint PD-1/PD-L1 pathway, and combination treatment with anti-PD-L1 antibody, especially when combined as sequential therapy and continuously treated, significantly improved anti-tumor effect of EVAT, partly through increase in CD8(+) TILs infiltration. Disclosures Xu: MSK: Other: co-inventors in patents on GD2 bispecific antibody and HER2 bispecific antibody. Cheung:Ymabs: Patents & Royalties, Research Funding.

scholarly journals Next Generation NKG2D-based CAR T-cells (CYAD-02): Co-expression of a Single shRNA Targeting MICA and MICB Improves Cell Persistence and Anti-Tumor Efficacy in vivo

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3931-3931
Author(s):  
Martina Fontaine ◽  
Benjamin Demoulin ◽  
Simon Bornschein ◽  
Susanna Raitano ◽  
Steve Lenger ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Next Generation ◽  
Activated T Cells ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Anti Tumor Activity ◽  
Nkg2d Receptor

Background The Natural Killer Group 2D (NKG2D) receptor is a NK cell activating receptor that binds to eight different ligands (NKG2DL) commonly over-expressed in cancer, including MICA and MICB. The product candidate CYAD-01 are chimeric antigen receptor (CAR) T-cells encoding the full length human NKG2D fused to the intracellular domain of CD3ζ. Data from preclinical models have shown that CYAD-01 cells specifically target solid and hematological tumors. Encouraging preliminary results from the Phase I clinical trial THINK, assessing CYAD-01 safety, showed initial signals of objective clinical responses in patients with r/r AML and MDS. The clinical development of CAR T-cells has been limited by several challenges including achieving sufficient numbers of cells for clinical application. We have previously shown that NKG2D ligands are transiently expressed on activated T cells and that robust cell yields are generated through the addition of a blocking antibody and a PI3K inhibitor during cell manufacture. Here, we investigated the ability of an optimized short hairpin RNA (shRNA) technology to modulate NKG2DL expression on CYAD-01 cells and to determine if there is an increase in the anti-tumor activity of NKG2D-based CAR T-cells (termed CYAD-02). Methods Molecular and cellular analyses identified MICA and MICB as the key NKG2DL expressed on activated T-cells and highly likely to participate in driving fratricide. In silico analysis and in vitro screening allowed the identification of a single shRNA targeting the conserved regions of MICA and MICB, thus downregulating both MICA and MICB expression. The selected shRNA was incorporated in the NKG2D-based CAR vector, creating the next-generation NKG2D-based CAR T-cell candidate, CYAD-02. In addition, truncated versions of the NKG2D receptor were generated to explore the mechanisms of action of NKG2D receptor activity in vivo. The in vivo persistence and anti-tumor activity of CYAD-02 cells was evaluated in an aggressive preclinical model of AML. Results Injection of CAR T-cells bearing truncated forms of the NKG2D-CAR in immunosuppressed mice resulted in similar persistence to the control T-cells. In contrast, CYAD-01 cells had reduced persistence, suggesting that the recognition of the NKG2DL by the NKG2D receptor could contribute to this effect. Analysis of cell phenotype upon CAR T-cell activation showed that MICA and MICB were transiently expressed on T-cells during manufacturing. These results collectively suggested that downregulating MICA and MICB expression in CYAD-01 cells could be a mean to increase CAR T-cell persistence in vivo. Candidate shRNA were screened for efficient targeting of both MICA and MICB at the mRNA and protein level. T-cells transduced with a single vector encoding for the NKG2D-based CAR and the selected shRNA targeting MICA and MICB (CYAD-02) demonstrated 3-fold increased expansion during in vitro culture in the absence of the blocking antibody used to increase cell yield during manufacture. When injected into immunosuppressed mice, CYAD-02 cells generated with the Optimab process showed 10-fold higher engraftment one week after injection and potent anti-tumor activity resulting in 2.6-fold increase of mouse survival in an aggressive AML model. Conclusions By using a single vector encoding the NKG2D-based CAR next to a shRNA targeting MICA and MICB and combined with improved cell culture methods, CYAD-02, the next-generation of NKG2D-based CAR T-cells, demonstrated enhanced in vivo persistence and anti-tumor activity. Following FDA acceptance of the IND application, a Phase 1 dose-escalation trial evaluating the safety and clinical activity of CYAD-02 for the treatment of r/r AML and MDS is scheduled to start in early 2020. Disclosures Fontaine: Celyad: Employment. Demoulin:Celyad: Employment. Bornschein:Celyad: Employment. Raitano:Celyad: Employment. Machado:Horizon Discovery: Employment. Moore:Avvinity Therapeutics: Employment, Other: Relationship at the time the work was performed; Horizon Discovery: Employment, Equity Ownership, Other: Relationship at the time the work was performed; Centauri Therapeutics: Consultancy, Other: Current relationship. Sotiropoulou:Celyad: Employment. Gilham:Celyad: Employment.

Naive and Ex Vivo Activated Human T Cells Generate Consistent Engraftment and Lethal Graft-Versus-Host Disease (GvHD) in NOD SCID β 2M Null Mice: A New Xenogeneic Model for GvHD.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3106-3106
Author(s):  
Bruno Nervi ◽  
Michael P. Rettig ◽  
Julie K. Ritchey ◽  
Gerhard Bauer ◽  
Jon Walker ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
Conditioning Regimen ◽  
Activation Markers ◽  
In Vivo Models ◽  
Hematopoietic Stem ◽  
Human T Cells ◽  
The Impact

Abstract GvHD remains a major cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation and donor lymphocyte infusion. The human GvHD pathophysiology includes recipient tissue destruction and proinflammatory cytokine production associated with the conditioning regimen; donor T cells become allo-activated, proliferate, and mediate tissue injury in various organs, including the liver, skin, and gut. Modern therapeutic strategies to control GvHD while maintaining the beneficial graft-versus-leukemia effects require ex vivo T cell stimulation and expansion. Multiple studies have demonstrated that these ex vivo expanded T cells exhibit decreased survival and function in vivo, including reduced alloreactivity and GvHD potential. Unfortunately no in vivo models exist to consistently examine the impact of ex vivo manipulation of human T cells (HuT) on T cell function. Naive HuT were compared to HuT activated using CD3/28 beads (XcyteTMDynabeads) with 50 U/ml IL-2 for 4 days (Act). We initially evaluated the HuT engraftment and GvHD potential of naive and Act in RAG2γ null mice (n=22) conditioned with clodronate liposomes on day −1 and 350cGy on day 0, as previously described by others. We injected 107 and 1.5x107 naive or Act HuT intravenously (iv). All mice exhibited low HuT engraftment and no lethal GvHD. NOD SCIDβ 2M null mice (β 2M) were next conditioned with 250cGy on day −1 (n=34), or 300cGy on day 0 (n=21). 107 naive vs Act HuT were injected retroorbitaly (ro). Lower HuT doses or iv injection resulted in no expansion or GvHD. Engraftment of HuT in peripheral blood of recipient mice was evaluated weekly by FACS and euthanasia was performed if mice lost &gt; 20% body weight. 60% of the mice conditioned with 250cGy that received naive HuT developed lethal GvHD, in comparison to 75% of mice that received 300cGy and nave HuT, and 100% of mice that received 300cGy and Act HuT. Table 1 250cGy 300cGy Naive (n=34) Naive (n=8) Activated (n=13) *p&lt;0.02 PB engraftment (%HuT) 20%±15 33%±21 59%±19 Lethal GvHD 60% 75% 100% All mice receiving 300cGy had well preserved CD4/CD8 ratios (1–1.5). Tissue infiltration was greatest in mice that had received 300cGy and Act HuT (spleen, liver, lung, kidney: 50–70%). Of interest, serum levels of hu IFNγ dramatically increased over time in all mice who went on to develop lethal GvHD (day 3=270 ug/ml and day 15=36,000 ug/ml) compared to mice that did not develop lethal GvHD (day 10=40 ug/ml and day 17=1,020 ug/ml)(p&lt;0.05). Interestingly, the up-regulation of the activation markers CD25 and CD30 in HuT, and IFNγ production predicted lethal GvHD in β 2M null mice. In summary, we developed a xenogeneic model of lethal GvHD where naive or ex vivo Act HuT injected ro in sublethaly irradiated β 2M not only engraft, expand in vivo, but also infiltrate and damage different mouse target organs. HuT are allo-activated against mouse antigens and damage the target tissues, sharing the major characteristics of human GvHD and causing the death of mice. This model will allow us to study the effects of specific ex vivo T cell manipulation including transduction, selection, expansion, and the depletion or addition of various T cells and other cellular subsets on the outcome of GvHD, to determine improved therapeutic interventions.

The effect of adoptive transfer of ex vivo activated T cells on the efficacy and tumor penetrance of intravenously-administered CD3-engaging bispecific antibody.

2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 30-30
Author(s):  
Patrick C. Gedeon ◽  
Carter M. Suryadevara ◽  
Bryan D. Choi ◽  
John H. Sampson
Keyword(s):  
T Cells ◽  
Cell Migration ◽  
T Cell ◽  
Adoptive Transfer ◽  
Bispecific Antibody ◽  
Ex Vivo ◽  
The Body ◽  
Whole Body ◽  
Activated T Cells ◽  
T Cell Migration

30 Background: Activated T cells are known to traffic throughout the body including past the blood-brain barrier where they perform routine immune surveillance. Whether activated T cells can be used to enhance the efficacy and delivery of intravenously-administered, immunotherapeutic antibodies has yet to be explored. Methods: To examine efficacy, T cell migration and antibody delivery in vivo, the invasive murine glioma, CT-2A-EGFRvIII, was implanted orthotopically in human CD3 transgenic mice. Cohorts of mice were given vehicle or 1x107 non-specifically activated, syngeneic T cells intravenously. Beginning the subsequent day, groups were treated with daily intravenous infusions of human-CD3-binding, tumor-lysis-inducing bispecific antibody (hEGFRvIII-CD3 bi-scFv) or control bispecific antibody. To block T cell extravasation, cohorts received natalizumab or isotype control via intraperitoneal injection every other day beginning on the day of adoptive cell transfer. T cell migration was assessed using whole body bioluminescence imaging of activated T cells transduced to express firefly luciferase. Bispecific antibody biodistribution was assessed using PET-CT imaging of iodine-124 labeled antibody. Results: Following intravenous administration, ex vivo activated T cells tracked to invasive, syngeneic, orthotopic glioma, reaching maximal levels on average four days following adoptive transfer. Administration of ex vivo activated T cells enhanced bispecific antibody efficacy causing a statistically significant increase in survival (p = 0.007) with 80% long-term survivors. Treatment with the T cell extravasation blocking molecule natalizumab abrogated the increase in efficacy to levels observed in cohorts that did not receive adoptive transfer of activated T cells (p = 0.922). Pre-administration with ex vivo activated T cells produced a statistically significant increase in tumor penetrance of radiolabeled bispecific antibody (p = 0.023). Conclusions: Adoptive transfer of non-specifically activated T cells enhances the efficacy and tumor penetrance of intravenously-administered CD3-binding bispecific antibody.

scholarly journals The Injury Response to DNA Damage Promotes Anti-Tumor Immunity

2020 ◽  
Author(s):  
Ganapathy Sriram ◽  
Lauren Milling ◽  
Jung-Kuei Chen ◽  
Wuhbet Abraham ◽  
Erika D. Handly ◽  
...  
Keyword(s):  
Dna Damage ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Immune Checkpoint ◽  
Ex Vivo ◽  
Injured Cell ◽  
Ifn Γ

ABSTRACTInhibition of immune checkpoints has shown promising results in the treatment of certain tumor types. However, the majority of cancers do not respond to immune checkpoint inhibition (ICI) treatment, indicating the need to identify additional modalities that enhance the response to immune checkpoint blockade. In this study, we identified a tumor-tailored approach using ex-vivo DNA damaging chemotherapy-treated tumor cells as a live injured cell adjuvant. Using an optimized ex vivo system for dendritic cell-mediated T-cell IFN-γ induction in response to DNA-damaged tumor cells, we identified specific dose-dependent treatments with etoposide and mitoxantrone that markedly enhance IFN-γ production by T-cells. Unexpectedly, the immune-enhancing effects of DNA damage failed to correlate with known markers of immunogenic cell death or with the extent of apoptosis or necroptosis. Furthermore, dead tumor cells alone were not sufficient to promote DC cross-presentation and induce IFN-γ in T-cells. Instead, the enhanced immunogenicity resided in the fraction of injured cells that remained alive, and required signaling through the RIPK1, NF-kB and p38MAPK pathways. Direct in vivo translation of these findings was accomplished by intra-tumoral injection of ex vivo etoposide-treated tumor cells as an injured cell adjuvant, in combination with systemic anti-PD1/CTLA4 antibodies. This resulted in increased intra-tumoral CD103+ dendritic cells and circulating tumor antigen-specific CD8+ T-cells, leading to enhanced anti-tumor immune responses and improved survival. The effect was abrogated in BATF3-deficient mice indicating that BATF3+ DCs are required for appropriate T-cell stimulation by live but injured DNA-damaged tumor cells. Notably, injection of the free DNA-damaging drug directly into the tumor failed to elicit such an enhanced anti-tumor response as a consequence of simultaneous damage to dendritic cells and T-cells. Finally, the DNA damage induced injured cell adjuvant and systemic ICI combination, but not ICI alone, induced complete tumor regression in a subset of mice who were then able to reject tumor re-challenge, indicating induction of a long-lasting anti-tumor immunological memory by the injured cell adjuvant treatment in vivo.

Quantitative Assessment of the Impact of Ex Vivo Manipulation on the In Vivo Functionality of Human T Cells in RAG2−/− γc−/− mice.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 450-450
Author(s):  
Rozemarijn S. van Rijn ◽  
Elles R. Simonetti ◽  
Gert Storm ◽  
Mark Bonyhadi ◽  
Anton Hagenbeek ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
T Cell Subsets ◽  
Critical Parameters ◽  
In Vivo Evaluation ◽  
Human T Cells ◽  
The Impact

Abstract T cells retrovirally modified to express therapeutic genes encoding cytokines, exogenous TCRs or suicide molecules represent a novel class of immune therapeutics of great potency. However, recent clinical trials using retrovirally-modified T cells have indicated that T cells exhibit a diminished reactivity upon ex vivo manipulation. In addition, virus-specific memory T cells seem to be lost during gene transfer. In a BNML rat model we have shown that the culture procedure is one of the critical parameters. To preserve T cell reactivity, reliable models are required which permit readout of human T cell activity. We recently developed a huPBMC-RAG2−/−γc−/− mouse model for xenogeneic graft-versus-host disease (xGVHD), in which iv injection of 15 x 106 human T cells into RAG2−/−γc−/− mice consistently leads to high level engraftment and lethal xGVHD within 3 weeks in 80% of mice (van Rijn et al, Blood 2003). We have now used this model to analyze in vivo functionality of human T cells following different ex vivo culture procedures. For this, we cultured human T cells for 7 days with either of the two currently available clinically applicable stimulation conditions: 1) via CD3 and 2) via CD3/CD28. In addition, we included CD3/CD28/4-1BB stimulation to explore the effect of extensive costimulation. Mice were injected with escalating doses T cells. HuCD45+ cells in peripheral blood were measured by FACS. Lethal xGVHD occurred at only 6 times (90.106) the dose of fresh cells for CD3-stimulated T cells and 3 times for CD3/28- or CD3/28/4-1BB-stimulated cells. About 20% of surviving mice developed chronic xGVHD, independent of culture method. While lethal xGVHD was always associated with very high levels of engraftment (up to 95%) engraftment levels in chronic mice ranged from 1–75%. To compare the impact of the different culture conditions on in vivo T cell function, we analyzed engraftment potential. The fraction of huCD45+ cells was plotted against the time and the areas under the curves were compared. Based on a total of 68 mice, statistical analysis showed a 2-fold improvement of engraftment potential for C28-costimulated human T cells compared to CD3-stimulated cells (P&lt;0.0001). Additional ligation of 4-1BB did not increase engraftment potential. In addition, different T cell subsets (naïve, memory, effector) were monitored based on the combined expression of CD45RA, CD27 and CCR7. For all primary T cells and variably cultured T cells, a strikingly similar pattern was observed in vivo. After 3 weeks mainly effector and memory effector T cells (both CD4+ and CD8+) could be detected, suggesting a (xeno-)antigen-driven survival and expansion. This was a very consistent observation independent of donor, culture condition, engraftment level or severity of disease. In conclusion, in vitro costimulation preserves in vivo functionality of human T cells and should therefore be included in future clinical protocols for ex vivo manipulation of T cells. These data show the feasibility to use the huPBMC-RAG2−/−γc−/− model for in vivo evaluation of in vitro effects on human T cells. This model is the most sensitive to date for in vivo evaluation of human T cells and will be a promising new tool for the study of human T cells in, for instance, autoimmune disease, cancer and infectious diseases like AIDS.

Targeted ‘Off-the-Shelf’ Tumor Immunotherapy Using Allogeneic T-Cell Precursors.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 579-579
Author(s):  
Johannes L. Zakrzewski ◽  
David Suh ◽  
Odette M. Smith ◽  
Christopher King ◽  
Gabrielle L. Goldberg ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Genetic Engineering ◽  
Adoptive Transfer ◽  
Ex Vivo ◽  
Precursor Cells ◽  
Host Cells ◽  
Anti Tumor Activity ◽  
Selection Of

Abstract T cell deficiencies can occur in many settings, including aging, autoimmune and genetic disorders, hematological malignancies, infectious diseases, and exposure to cytotoxic/cytostatics agents. Notch-based culture systems can be utilized for ex vivo generation of large numbers of T lineage committed lymphoid precursor cells, and we recently reported that the adoptive transfer of T cell precursors significantly enhances T cell reconstitution and function after allogeneic T cell depleted HSCT. The aim of this study was to evaluate if allogeneic T cell precursors are safe and effective when used for adoptive transfer across MHC barriers in the absence of allogeneic HSCs to overcome radiation injury, enhance T cell function and improve anti-tumor activity in immunosuppressed recipients. We found that positive selection of adoptively transferred allogeneic (C57BL/6) precursor cells ± syngeneic (BALB/c) HSCs in irradiated hosts (BALB/c) is dependent on MHC molecules on non-hematopoietic host cells, resulting in the in vivo development of host-MHC restricted allogeneic T cells. We demonstrate that negative selection of these cells is mediated by donor-derived antigen presenting cells (APCs), resulting in host-tolerance. Adoptively transferred allogeneic T cell precursors significantly improved survival of BALB/c mice after irradiation (675 cGy) and enhanced anti-tumor activity against liquid (A20 lymphoma) and solid (renal cell carcinoma) tumors in syngeneic HSCT recipients. Furthermore, we demonstrate the feasibility of genetic engineering of antigen-specific T cell precursors, by transducing them to express a chimeric antigen receptor (CAR) targeting human CD19. Transduction efficiencies were routinely in the range of 50%–70%. Adoptive transfer of CAR-expressing T cell precursors resulted in the in vivo generation of high numbers of appropriately selected CAR-expressing T cells with significantly enhanced anti-tumor activity (compared with CAR-negative T cell precursors) against a CAR-sensitive tumor, but without any undesirable auto/alloreactivity. We conclude that adoptively transferred allogeneic T cell precursors develop into host-MHC restricted and host-tolerant T cells characterized by selection of a functional TCR repertoire even in a fully mismatched thymic epithelial MHC environment. This strategy overcomes important limitations of conventional adoptive T cell therapies: rejection, alloreactivity and impaired antigen recognition due to restriction to MHC disparate from the one expressed on APCs. The use of allogeneic instead of autologous cells eliminates the risk of contamination with residual malignant patient cells and allows the generation and storage of virtually unlimited quantities of precursor cells for ‘off-the-shelf’ immunotherapy. This procedure has not only substantial logistic advantages, but it facilitates ex vivo manipulation, in particular genetic engineering, to generate antigen-specific or otherwise enhanced designer cells. Adoptive transfer of MHC mismatched and genetically enhanced T cell precursors therefore represents a promising novel strategy for targeted ‘off-the-shelf’ immunotherapy in immunosuppressed patients.

The Induction of Inhibitory Pathways in Dendritic Cells May Hamper the Efficient Activation of Anti-Leukemia T Cells within Chemotherapy-Induced Immunogenic Cell Death

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1019-1019
Author(s):  
Darina Ocadlikova ◽  
Mariangela Lecciso ◽  
Elisa Orioli ◽  
Elena De Marchi ◽  
Sabina Sangaletti ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Ex Vivo ◽  
Atp Release ◽  
Inhibitory Pathways ◽  
Ifn Γ

Abstract BACKGROUND: Overall survival of adult acute myeloid leukemia (AML) is still poor due to the lack of novel and effective therapies. In different malignancies including AML, some chemotherapy agents, such as daunorubicin (DNR) but not cytarabine (Ara-C), activate the immune response via the cross-priming of anti-tumor T cells by dendritic cells (DCs). Such process, known as immunogenic cell death (ICD), is characterized by intracellular and pericellular modifications of tumor cells, such as the cell surface translocation of calreticulin (CRT) and heat shock proteins 70/90 (HSPs 70/90), the extracellular release of ATP and pro-inflammatory factor HMGB1. Alongside with ICD, chemotherapy is known to induce inflammatory modifications within the tumor microenvironment, which may also elicit immunosuppressive pathways. In particular, DCs may be driven to acquire tolerogenic features, which may ultimately affect anti-tumor T-cell responses. In this study, we characterize ICD in AML to evaluate the involvement of some DC-related inhibitory pathways, such as the expression of indoleamine-2,3-dioxygenase 1 (IDO1) and the activation of PD-L1/PD-1 axis. METHODS: AML patients were analyzed at diagnosis.Before and after DNR-based chemotherapy, patient-derived T cells were extensively characterized by FACS and analyzed for their capacity to produce IFN-γ in response to autologous blasts. The AML cell line HL-60 and primary AML cells were then exposed, in vitro, to different drugs, including DNR and, as control drug, Ara-C. Dying cells were tested for the surface expression of CRT and HSPs 70/90, the release of HMGB1 and ATP. Functionally, immature DCs generated from healthy donors were pulsed with DNR-treated AML cells. Then, loaded DCs were tested for the expression of maturation-associated markers and of inhibitory pathways, such as IDO1 and PD-L1 and used to stimulate autologous CD3+ T cells. After co-culture, autologous healthy donor T cells were analyzed for IFN-g production, PD-1 expression and Tregs induction. A mouse model was set up to investigate in vivo the mechanism(s) underlying ICD in AML. The murine myelomonocytic leukemia cell line WEHI was transfected with luciferase PmeLUC probe, inoculated subcutaneously into BALB/c mice and used to measure in vivo ATP release after chemotherapy. Tumor-infiltrating T cells and DCs were characterized and correlated with ATP release. RESULTS: DNR treatment induced ICD-related modifications in both AML cell lines and primary blasts, including CRT, HSP70 and HSP90 exposure on cell surface, HMGB1 release from nucleus to cytoplasm and supernatant increase of ATP. Ex vivo, T-cell monitoring of DNR-treated AML patients displayed an increase in leukemia-specific IFN-g-producing CD4+ and CD8+ T cells in 20/28 evaluated patients. However, FACS analysis of CD8+ effector T cells emerging after chemotherapy showed a significant up-regulation of exhaustion marker such as LAG3 and PD-1, which paralleled with their reduced ability to produce active effector molecules, such as perforin and granzyme. Moreover, an increase of circulating Tregs was observed after DNR-based chemotherapy. In vitro, loading of chemotherapy-treated AML cells into DCs resulted not only in the induction of a maturation phenotype, but also in over-expression of inhibitory pathways, such as IDO1 and PD-L1. The silencing of IDO1 increased the capacity of DCs loaded with DNR-treated AML cells to induce leukemia-specific IFN-γ production by CD4+ and CD8+ T cells. In vivo, DNR therapy of mice inoculated with established murine AML cell line resulted in increased ATP release. Similarly to ex vivo and in vitro results, tumor-infiltrating DCs showed an increase in maturation status. Moreover, CD4+ and CD8+ T cells had increased IFN-γ production, but showed an exhausted phenotype. CONCLUSIONS: Our data confirm that chemotherapy-induced ICD may be active in AML and results in increased leukemia-specific T-cell immune response. However, a deep, ex vivo, in vitro and in vivo characterization of chemotherapy-induced T cells demonstrated an exhausted phenotype, which may be the result of the inhibitory pathways induction in DCs, such as IDO and PD-L1. The present data suggest that combination of chemotherapy with inhibitors of IDO1 and PD-L1 may represent an interesting approach to potentiate the immunogenic effect of chemotherapy, thus resulting in increased anti-leukemia immune response. Disclosures Cavo: Janssen-Cilag, Celgene, Amgen, BMS: Honoraria.

Vaccination Strategies for Patients with B-CLL.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2106-2106
Author(s):  
Fatma V Okur ◽  
Eric Yvon ◽  
Gianpietro Dotti ◽  
George Carrum ◽  
Helen E. Heslop ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Ex Vivo ◽  
Lymphocytic Leukemia ◽  
Th2 Cells ◽  
Ifn Γ ◽  
Adenoviral Vaccine

Abstract B-chronic lymphocytic leukemia (B-CLL) cells express tumor associated antigens that may generate a T cell mediated immune response, but present these antigens poorly. Moreover, patients with B-CLL often have poor immune function due to the disease or its treatment. We have shown that expression of transgenic CD40L increases the immunogenecity of human B-CLL cells ex vivo and in vivo, and that this effect can be potentiated by co-expression of transgenic IL2. Previous studies described outcomes when adenoviral vectors were used to obtain gene transfer, but because of the complexities and expense of manufacture of viral vectors, and their lingering safety concerns, we determined whether it was possible to use electroporation (with the MaxCyte device) as a physical means of transferring CD40L and IL2 plasmids to produce vaccines with similar biological properties in vitro and in vivo. Table 1 compares the phenotype of the vaccines using each vector. Table 1. Comparision of immunogenic characteristics and viability of the adenoviral and plasmid vaccines Type of Vaccine CD40L (%) CD80 (%) CD86 (%) IL-2 (pg/ml/10e6 cells) Viability (%) IL2 CD40L All the values are given as mean ± SE. * P&lt; 0.01, Paired Student’s t test. Adenoviral Pre 0.2 ± 0.01 2.6 ± 2.4 7.5 ± 3.9 Post 66.1 ± 5.5* 50.2 ± 7.8* 69.5 ±11* 253.5 ± 82.6 93.6 94.2 Plasmid Pre 1.3 ± 0.85 11.5 ± 6.2 19.7 ± 6.8 Post 55.5 ± 5.1* 19.2 ± 9.3 26.4 ± 9.7 4806.6 ±1398.9 84.4 88.4 Vaccines made by both approaches met the release criteria for CD40L and IL2 expression (CD40L ≥20% and IL-2 ≥ 150 pg/ml/1x10e6 cells ), but expression of IL2 was higher in the plasmid vaccines, expression of CD40L was equivalent in each and expression of the additional co-stimulatory molecules CD80 and CD86 (induced after CD40 activation by transgenic CD40L) was higher in the adenoviral vaccines. Fourteen patients were given adenoviral-vaccines and nine the plasmid transduced cells. Each of these patients received up to 18 s.c. injections of IL-2 secreting and CD40L expressing tumor cells. Both types of vaccine were well tolerated. Table 2 shows the results of culturing patient T cells with autologous B-CLL tumor cells. Table 2. Comparision of anti-B-CLL T cell responses induced by adenoviral and plasmid vaccines Type of Vaccine Pre-vaccine After 3rd vaccine After 6th vaccine All the values were are given as mean ± SE. *P&lt;0.05, Wilcoxon Signed Ranks test Adenoviral 307.3 ± 293.9 375 ± 306.8 656.8 ± 373.8 IFN-γ spots/10e6 T cells&#x2028; IL-5 spots/10e6 T cells 0 12.8 ± 7.9 5.8 ± 2.3 Plasmid 31.1 ± 14.8 38 ± 17.8 32.9 ± 19.5 IFN-γ spots/10e6 T cells&#x2028; IL-5 spots/10e6 T cells 4 ± 2.7 14 ± 10.2 203.9 ± 156.3* After 3 and 6 injections, both the adenoviral and plasmid vaccines had induced a rise in spot forming cells (SFC) for IL5, a cytokine associated with Th2 cells, but the rise was greatest in the recipients of the electroporated plasmid vaccine. By contrast, only the adenoviral vaccine induced a rise in SFC that produced IFN-γ, a cytokine associated with Th1 cells. Studies using MHC class I and II blocking antibodies showed that the IL5 and IFN-γ responses to both types of vaccine were mediated by HLA restricted T lymphocytes. The 1-year progression-free survival rates (PFS) for adenoviral vaccine group and plasmid vector group were 43% and 22% respectively. Figure 1 shows 1-year PFS rates for each group. Hence electroporation provides a more rapid and simpler means of preparing IL2/CD40L expressing B-CLL vaccines, but the cells express higher levels of IL2 and lower levels of “secondary” co-stimulator molecules than adenoviral vaccines, and produce an anti-tumor immune response of different polarity. Currently, we are evaluating electroporation of mRNA encoded CD40L which appears to augment upregulation of additional costimulatory molecules. Figure Figure

scholarly journals Ex vivo modelling of PD-1/PD-L1 immune checkpoint blockade under acute, chronic, and exhaustion-like conditions of T-cell stimulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Roberts ◽  
Lindsay Bentley ◽  
Tina Tang ◽  
Fay Stewart ◽  
Chiara Pallini ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Immune Checkpoint ◽  
Inflammatory Cytokine ◽  
Cell Activation ◽  
Ex Vivo ◽  
In Vitro Assays ◽  
The Impact

AbstractBlockade of PD-1/PD-L1 interactions is proving an exciting, durable therapeutic modality in a range of cancers whereby T cells are released from checkpoint inhibition to revive their inherent anti-tumour activity. Here we have studied various ways to model ex vivo T cell function in order to compare the impact of the clinically utilised anti-PD-1 antibody, pembrolizumab (Keytruda) on the activation of human T cells: focussing on the release of pro-inflammatory IFNγ and anti-inflammatory IL-10 to assess functionality. Firstly, we investigated the actions of pembrolizumab in an acute model of T-cell activation with either immature or mature allogeneic dendritic cells (DCs); pembrolizumab enhanced IFNγ and IL-10 release from purified CD4+ T-cells in the majority of donors with a bias towards pro-inflammatory cytokine release. Next, we modelled the impact of pembrolizumab in settings of more chronic T-cell activation. In a 7-day antigen-specific response to EBV peptides, the presence of pembrolizumab resulted in a relatively modest increase in both IFNγ and IL-10 release. Where pembrolizumab was assessed against long-term stimulated CD4+ cells that had up-regulated the exhaustion markers TIM-3 and PD-1, there was a highly effective enhancement of the otherwise exhausted response to allogeneic DCs with respect to IFNγ production. By contrast, the restoration of IL-10 production was considerably more limited. Finally, to assess a direct clinical relevance we investigated the consequence of PD-1/PD-L1 blockade in the disease setting of dissociated cells from lung and colon carcinomas responding to allogeneic DCs: here, pembrolizumab once more enhanced IFNγ production from the majority of tumour preparations whereas, again, the increase in IL-10 release was modest at best. In conclusion, we have shown that the contribution of PD-1—revealed by using a canonical blocking antibody to interrupt its interaction with PD-L1—to the production of an exemplar pro- and anti-inflammatory cytokine, respectively, depends in magnitude and ratio on the particular stimulation setting and activation status of the target T cell. We have identified a number of in vitro assays with response profiles that mimic features of dissociated cell populations from primary tumours thereby indicating these represent disease-relevant functional assays for the screening of immune checkpoint inhibitors in current and future development. Such in vitro assays may also support patient stratification of those likely to respond to immuno-oncology therapies in the wider population.

scholarly journals The T cell-B cell interaction via OX40-OX40L is necessary for the T cell-dependent humoral immune response.

1996 ◽  
Vol 183 (3) ◽  
pp. 979-989 ◽  
Author(s):  
E Stüber ◽  
W Strober
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Germinal Centers ◽  
Antibody Treatment ◽  
Activated T Cells ◽  
Activated B Cells

Recent in vitro studies have established that activated B cells express OX40 ligand (L), a member of the tumor necrosis factor/nerve growth factor family of cytokines, and become stimulated to proliferate and secrete immunoglobulin (Ig) after cross-linking of OX40L by its counterreceptor OX40, which is expressed on activated T cells. In the present study we investigated the in vivo role of this receptor-ligand pair for the interaction of T and B cells in the course of the T-dependent B cell response against 2,4,6 trinitro-phenyl-keyhole limpet hemocyanin. First, we showed that OX40 is maximally expressed by T cells in the periarteriolar lymphoid sheath (PALS) 3 d after primary immunization. These OX40+ cells are located in close proximity to antigen-specific, activated B cells. Second, we demonstrated that blocking of OX40-OX40L interaction with polyclonal anti-OX40 antibody or with antibodies against certain peptide sequences within its extracellular domain resulted in a profound decrease of the anti-hapten IgG response, whereas the antihapten IgM response was grossly unchanged. Third, we showed that this antibody treatment leads to an inhibition of the development of PALS-associated B cell foci, whereas the formation of germinal centers remained intact. Finally, our data suggest that, whereas B cell memory development was not impaired by anti-OX40 administration, OX40-OX40L interaction seems to be crucial in the secondary immune response. We conclude from these data that the OX40-OX40L interaction in vivo is necessary for the differentiation of activated B cells into highly Ig-producing cells, but is not involved in other pathways of antigen-driven B cell differentiation such as memory cell development in the germinal centers.

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