Therapeutic Efficacy of Engineered T Cells Targeting CD19 in a B-Cell Lymphoma Model.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5486-5486
Author(s):  
Robert E. Hawkins ◽  
David E. Gilham ◽  
Fiona C. Thistlethwaite ◽  
John A. Radford ◽  
Eleanor J. Cheadle

Abstract The success of monoclonal antibodies in the treatment of certain cancers demonstrates that immune based therapies can work and are particularly effective in B cell malignancies. However, tumours can still avoid antibody mediate mechanisms of attack and there is currently no estalbished method of effectively recruiting T cells to harness their potential anti-tumour effects. We are exploring gene therapy approaches to endow T cells with antibody type specificity in order to more efficiently target and lyse tumours and thereby improve the overall immune therapy of cancer T cells grafted with a CD19 specific receptor consisting of a CD19 scFv linked to human CD3zeta (CD19z) were tested for their potency against B cell lymphoma lines in vivo. T cells were engineered using retroviral vestors to possess a CD19 specific receptor which endows the T cells with specificity for B cell lymphoma. The vector incorporates a truncated hCD34 gene as a marker to facilitate assessment of transduced cells using as clinically applicable, non-immunogenic marker gene. Mice bearing B cell lymphoma were treated with a systemic infusion of targeted T cells with or without non-myeloablative chemotherapy. Human T cells targeting CD19 cured 40% of SCID/beige mice with 6 day established metastatic tumour but only in conjunction with a single dose of cyclophosphamide. Murine T cells expressing the CD19z receptor were also effective with cure of 24hr established s.c human CD19+ tumour in SCID/beige and immunocompetent mice. Pretreatment with cyclophosphamide did not affect T cell engraftment or efficacy in immuno-compromised animals but was necessary for T cell engraftment in immuno-competent animals. These results which parallel the approach successfully used with tumour infiltrating lymhocytes in melanoma patients conclusively demonstrate that the combination of engineered T cells with “pre-conditioning” chemotherapy significantly impacts upon tumour growth in vivo and this evidence supports the development of phase I clinical trials targeting B cell lymphoma.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1851-1851 ◽  
Author(s):  
Diogo Gomes da Silva ◽  
Malini Mukherjee ◽  
Madhuwanti Srinivasan ◽  
Olga Dakhova ◽  
Hao Liu ◽  
...  

Abstract Although adoptive transfer of T cells with second-generation CD19-specific CARs containing CD28 or 4-1BB costimulatory endodomains shows remarkable clinical efficacy against B cell malignancies, the optimal choice of costimulatory domains in these and other CARs remains controversial. Depending on the precise CAR structure and specificity, individual endodomains may be associated with deleterious ligand-independent tonic signaling in the transduced T cell. Long et al. (Nat Med 2015) established the CD28 co-stimulatory endodomain can have a toxic tonic signaling effect, but it is unclear if tonic 4-1BB signaling may have deleterious consequences as well, and if such effects can be reversed. We therefore modeled tonic CAR signaling in T cells by transducing them with gammaretroviral vectors expressing 2nd-generation CD19.CAR constructs containing either the CD28 or 4-1BB costimulatory endodomain (in addition to the CD3-ζ chain endodomain). Compared to CAR-T cells with the CD28 endodomain alone, those with 4-1BB alone expanded 70% more slowly following transduction. Impaired expansion of 4-1BB CD19.CAR-T cells was coupled with a 4-fold increase in apoptosis and a gradual downregulation of CAR expression, and was a consequence of 4-1BB-associated tonic TRAF2-dependent signaling, leading to activation of NF-κB, upregulation of Fas and augmented Fas-dependent activation-induced T cell death (AICD). Moreover, expression of 4-1BB CAR from a gammaretroviral vector increased tonic signaling through a self-amplifying/positive feedback effect on the retroviral LTR promoter. Because of the toxicity of 4-1BB in our gammaretroviral CAR.CD19 construct (manifest by delayed expansion and increased apoptosis) we could not directly compare the in vivo fate of T cells expressing CAR.CD19 4-1BB with that of co-administered CAR.CD19 CD28 T cells in patients with lymphoma. We found, however, that the adverse effects of tonic 4-1BB costimulation could be overcome in a 3rd-generation CAR.CD19 vector, containing both CD28 and 4-1BB costimulatory molecules in tandem. We thus compared the fate of a 3rd-generation vector containing both CD28 and 4-1BB costimulatory domains with that of a 2nd-generation vector containing CD28 alone. Six patients with refractory/relapsed diffuse large B-cell lymphoma received 2 cell populations, one expressing 2nd and one expressing 3rd generation vectors. To determine whether CD28 alone was optimal (which would suggest 4-1BB is antagonistic) or whether 4-1BB had an additive or synergistic effect contributing to superior persistence and expansion of the CD28-41BB combination, patients were simultaneously infused with 1-20×106 of both 2nd and 3rd generation CAR+ T cells/m2 48-72 hours after lymphodepletion with cyclophosphamide (500 mg/m2/d) and fludarabine (30 mg/m2/d) × 3. Persistence of infused T cells was assessed in blood by CD19.CAR qPCR assays specific for each CAR. Molecular signals peaked approximately 2 weeks post infusion, remaining detectable for up to 6 months. The 3rd-generation CAR-T cells had a mean 23-fold (range 1.1 to 109-fold) higher expansion than 2nd-generation CAR-T cells and correspondingly longer persistence. Two patients had grade 2 cytokine release syndrome, with elevation of proinflammatory cytokines, including IL-6, at the time of peak expansion of T cells. Of the 5 patients evaluable for response, 2 entered complete remission (the longest ongoing for 9 months), 1 has had continued complete remission after autologous stem cell transplantation, 1 had a partial response, and 1 progressed. In conclusion, our data indicate that infusion of T cells carrying a CD19.CAR containing CD28 and 4-1BB endodomains is safe and can have efficacy at every dose level tested. Additionally, in a side-by-side comparison, the 3rdgeneration vector produced greater in vivo expansion and persistence than an otherwise identical CAR-T cell population with CD28 alone. Disclosures Rooney: Cell Medica: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Viracyte: Equity Ownership. Heslop:Celgene: Patents & Royalties, Research Funding; Chimerix: Other: Endpoint adjudication committee; Viracyte: Equity Ownership; Cell Medica: Patents & Royalties: Licensing agreement EBV-specific T cells.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 805-805 ◽  
Author(s):  
Otáhal Pavel ◽  
Dana Prukova ◽  
Vlastimil Král ◽  
Radek Jaksa ◽  
Lucie Lateckova ◽  
...  

Abstract Tumor immunotherapy based on the use of Chimeric Receptor Modified T cells (CAR T cells) is a promising approach for the treatment of a refractory hematological cancer. However, a robust response mediated by CAR T cells is observed only in a minority of patients and the expansion and persistence of CAR T cells in vivo is mostly unpredictable. In order to enhance the effectiveness of CAR-based immunotherapy we tested the immunoadjuvant properities of lenalidomide in combination with CAR19 T cells in a mouse model of B cell lymphoma. CAR19 construct which was used is composed of anti-CD19scFv joined with signaling domain of 4-1BB and TCR zeta and was delivered into T cell via lentiviral transduction. Lenalidomide is an immunomodulatory drug used for the treatment of multiple myeloma and selected B-cell malignancies, e.g. mantle cell lymphoma (MCL) or activated B-cell subtype of diffuse large B-cell lymphoma (ABC-DLBCL). However, the precise mechanism of action is not very well understood and it is believed that is mediated by a modulation of activity of E3 ubiquitin ligase cereblon which leads to increased ubiquitinylation of Ikaros and Aiolos transcription factors resulting in changes of expression of various receptors on the surface of tumor cells. To test our hypothesis, immunodeficient NSG mice (NOD-SCID-gamma chain null mice) were s.c. transplanted with various human B cells lymphoma cells (MCL or ABC-DLBCL) followed by i.v treatment with CAR19 T cells with or without daily i.p. lenalidomide. First, when we measured the growth of tumors following treatment with CAR19 T cells plus lenalidomide we found that this combination more effectively suppressed growth of s.c. B-NHL tumors than treatment with only CAR19 T cells or only lenalidomide (Figure 1, 1x10e7 Nemo tumor cell s.c., followed with 2 doses of 1x10(7) CAR19 T cells + Lenalidomide daily, tumor weight was measured 14 days after treatment). Additionally, in this experiment lenalidomide significantly enhanced infiltration of residual tumors by CD8+CAR19 T cells (not shown). Next, we tested the response of CAR19 T cells in vitro to B-NHL cells in the presence or, absence of lenalidomide to determine the costimulatory effect of lenalidomide on signaling via CAR, our data show that lenalidomide significantly enhanced functional response of CAR19 T cells following recognition of B cells in vitro which is demonstrated by enhanced production of IFN-gamma and by increased expression of CD69 by CAR19 T cells, interestingly, this effect was seen only if CAR19 T cells but not B-NHL cells were pre-treated with lenalidomide or, when we activated CAR19 T cell with antibody to CAR but not with antibody to CD3. Thus, our data indicate that lenalidomide might work through direct effects on T cells and specifically enhance signaling via CAR. The biochemical events underlying this costimulatory effect of lenalidomide on signaling by CAR are currently being investigated. In summary, our data support the use of lenalidomide for augmentation CAR-based immunotherapy in clinical settings. Figure 1 Figure 1. Disclosures Klener: Cellgene: Research Funding.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Gary Kwok Cheong Lee ◽  
Dorothee Bienzle ◽  
Stefan Matthias Keller ◽  
Mei-Hua Hwang ◽  
Nikos Darzentas ◽  
...  

Abstract Background Lymphocytic neoplasms with frequent reactive lymphocytes are uncommonly reported in dogs, and can pose a diagnostic challenge. Different diagnostic modalities such as cytology, flow cytometry, histopathology, immunohistochemistry, and clonality testing, are sometimes required for a diagnosis. This report illustrates the value of using a multi-modal diagnostic approach to decipher a complex lymphocytic tumor, and introduces immune repertoire sequencing as a diagnostic adjunct. Case presentation A 10-month-old Great Dane was referred for marked ascites. Cytologic analysis of abdominal fluid and hepatic aspirates revealed a mixed lymphocyte population including numerous large lymphocytes, yielding a diagnosis of lymphoma. Flow cytometrically, abdominal fluid lymphocytes were highly positive for CD4, CD5, CD18, CD45, and MHC II, consistent with T cell lymphoma. Due to a rapidly deteriorating clinical condition, the dog was euthanized. Post mortem histologic evaluation showed effacement of the liver by aggregates of B cells surrounded by T cells, suggestive of hepatic T cell-rich large B cell lymphoma. Immune repertoire sequencing confirmed the presence of clonal B cells in the liver but not the abdominal fluid, whereas reactive T cells with shared, polyclonal immune repertoires were found in both locations. Conclusions T cell-rich large B cell lymphoma is a rare neoplasm in dogs that may be challenging to diagnose and classify due to mixed lymphocyte populations. In this case, the results of histopathology, immunohistochemistry and immune repertoire sequencing were most consistent with a hepatic B cell neoplasm and reactive T cells exfoliating into the abdominal fluid. Immune repertoire sequencing was helpful in delineating neoplastic from reactive lymphocytes and characterizing repertoire overlap in both compartments. The potential pitfalls of equating atypical cytomorphology and monotypic marker expression in neoplasia are highlighted.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2199-2199
Author(s):  
Matt L Cooper ◽  
Karl W. Staser ◽  
Julie Ritchey ◽  
Jessica Niswonger ◽  
Byung Ha Lee ◽  
...  

Abstract Background: Chimeric antigen receptor T cell (CART) therapy is revolutionizing modern cancer therapy, with two anti-CD19 CARTs FDA-approved for relapsed/refractory B cell lymphoma/leukemia and many other CARTs for solid and liquid tumors currently undergoing clinical trials. Our group recently demonstrated multiplexed CRISPR/Cas9 gene-editing of anti-CD7 CARTs to produce CD7 and T cell receptor alpha constant (TRAC)-deleted "off-the-shelf" universal (U)CART7s that effectively kill CD7+ T cell lymphoma in vivo without causing GVHD or fratricide (Cooper et al, Leukemia, 2018). However, in current clinical practice, suboptimal CART persistence and tumor killing permit tumor cell escape and, ultimately, disease relapse. Reasoning that a pro-lymphoid growth factor could promote CART efficacy, we supplemented UCART infusion with subcutaneous injections of the long-acting form of recombinant human interleukin-7 fused with hybrid Fc (rhIL-7-hyFc, NT-I7) in vivo using a CD19+ lymphoma xenograft model. Methods: To create anti-CD19 universal CARTs (UCART19), we activated human T cells on CD3/CD28 beads, electroporated the T cells with Cas9 mRNA and a TRAC-targeted gRNA, and virally transduced an anti-CD19 scFv 3rd generation CAR containing a peptidase 2A-cleaved human CD34 construct for both purification and tracking in vivo. Residual TRAC+ cells were depleted using magnetic selection. For xenograft tumor modeling in vivo, we injected NOD-scid IL2Rgammanull (NSG) mice with 5x105 RamosCBR-GFP cells four days prior to UCART19 (2x106 cells). Mice were treated with NT-I7 (10mg/kg SC) on days +1, +15 and +29 post UCART19 infusion. Results:RamosCBR-GFP mice receiving NT-I7 without UCART19 (NT-I7 only group) survived marginally longer (24 day med survival) than mice receiving RamosCBR-GFP cells alone (No tx group) (21 day medium survival, p=0.018, NT-I7 only vs. No Tx). While RamosCBR-GFP mice treated with UCART19 alone (UCART19 group) survived 33 days, 100% of RamosCBR-GFP mice treated with UCART19 and NT-I7 (UCART19+NT-I7 group) were alive at 80 days (Fig 1a), with no mouse showing signs of xenogeneic GVHD (p<0.0001, UCART19+NT-I7 vs. UCART19). At three weeks post UCART19 infusion, bioluminescent imaging (BLI) revealed minimal tumor signal in UCART19+NT-I7 treated mice (108 vs. 1010 photon flux/s, p<0.05, UCART19+NT-I7 vs. UCART19) and near-undetectable photon flux/s at four weeks (107 vs 1011 photon flux/s, p<0.0001, UCART19+NT-I7 vs. UCART19). Quantitative 17-parameter flow cytometric analyses of the blood, bone marrow, and spleens revealed an up to ~8000-fold increase in UCART19 cells in NT-I7-treated mice four weeks post UCART19 infusion (Fig 1a). These UCART19 cells demonstrated a predominantly effector and effector memory phenotype. Discussion: CARTs engineered to express interleukin-7 and CCL19 showed increased migration to and killing of solid tumors (Adachi et al, Nature Biotechnology, 2018). However, genetically engineered potentiation strategies lack "off-switches" and may preclude additional genetic enhancements required for universal "off-the-shelf" CART development. Here, we demonstrate that a pharmacological grade long-acting interleukin-7 agonist can potentiate adoptive cellular therapies. Specifically, NT-I7 can dramatically enhance gene modified T cell proliferation, persistence and tumor killing in vivo, resulting in enhanced survival, providing a tunable clinic-ready adjuvant for reversing suboptimal CART activity in vivo. Disclosures Cooper: WUGEN: Consultancy, Equity Ownership. Lee:NeoImmuneTech: Employment. Park:NeoImmuneTech: Employment.


2018 ◽  
Vol 2 (19) ◽  
pp. 2568-2580 ◽  
Author(s):  
Suparna Dutt ◽  
Michelle B. Atallah ◽  
Yoshitaka Minamida ◽  
Alexander Filatenkov ◽  
Kent P. Jensen ◽  
...  

Abstract Conventional local tumor irradiation (LTI), delivered in small daily doses over several weeks, is used clinically as a palliative, rather than curative, treatment for chemotherapy-resistant diffuse large B-cell lymphoma (DLBCL) for patients who are ineligible for hematopoietic cell transplantation. Our goal was to test the hypothesis that accelerated, but not conventional, LTI would be more curative by inducing T cell–mediated durable remissions. We irradiated subcutaneous A20 and BL3750 lymphoma tumors in mice with a clinically relevant total radiation dose of 30 Gy LTI, delivered in 10 doses of 3 Gy over 4 days (accelerated irradiation) or as 10 doses of 3 Gy over 12 days (conventional irradiation). Compared with conventional LTI, accelerated LTI resulted in more complete and durable tumor remissions. The majority of these mice were resistant to rechallenge with lymphoma cells, demonstrating the induction of memory antitumor immunity. The increased efficacy of accelerated LTI correlated with higher levels of tumor cell necrosis vs apoptosis and expression of “immunogenic cell death” markers, including calreticulin, heat shock protein 70 (Hsp70), and Hsp90. Accelerated LTI–induced remissions were not seen in immunodeficient Rag-2−/− mice, CD8+ T-cell–depleted mice, or Batf-3−/− mice lacking CD8α+ and CD103+ dendritic cells. Accelerated, but not conventional, LTI in immunocompetent hosts induced marked increases in tumor-infiltrating CD4+ and CD8+ T cells and MHCII+CD103+CD11c+ dendritic cells and corresponding reductions in exhausted PD-1+Eomes+CD8+ T cells and CD4+CD25+FOXP3+ regulatory T cells. These findings raise the possibility that accelerated LTI can provide effective immune control of human DLBCL.


Blood ◽  
1995 ◽  
Vol 86 (4) ◽  
pp. 1487-1492 ◽  
Author(s):  
B Hertenstein ◽  
B Wagner ◽  
D Bunjes ◽  
C Duncker ◽  
A Raghavachar ◽  
...  

CD52 is a phosphatidylinositolglycan (PIG)-anchored glycoprotein (PIG- AP) expressed on normal T and B lymphocytes, monocytes, and the majority of B-cell non-Hodgkin lymphomas. We observed the emergence of CD52- T cells in 3 patients after intravenous treatment with the humanized anti-CD52 monoclonal antibody Campath-1H for refractory B- cell lymphoma and could identify the underlaying mechanism. In addition to the absence of CD52, the PIG-AP CD48 and CD59 were not detectable on the CD52- T cells in 2 patients. PIG-AP-deficient T-cell clones from both patients were established. Analysis of the mRNA of the PIG-A gene showed an abnormal size in the T-cell clones from 1 of these patients, suggesting that a mutation in the PIG-A gene was the cause of the expression defect of PIG-AP. An escape from an immune attack directed against PIG-AP+ hematopoiesis has been hypothesized as the cause of the occurrence of PIG-AP-deficient cells in paroxysmal nocturnal hemoglobinuria (PNH) and aplastic anemia. Our results support the hypothesis that an attack against the PIG-AP CD52 might lead to the expansion of a PIG-anchor-deficient cell population with the phenotypic and molecular characteristics of PNH cells.


2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S107-S107
Author(s):  
E Ozluk ◽  
E Wei

Abstract Introduction/Objective Growth patterns of nodular lymphocyte predominant Hogdkin lymphoma (NLPHL) has been further described by Fan et all. Pattern E is T cell/histiocyte rich large B-cell lymphoma-like and is quite rare. The treatment usually may follow large B cell lymphoma protocol instead of Hodgkin lymphoma regimen. Methods Here we report a patient with NLPHL pattern E. Patient was a 25 years-old African American man who initially presented with generalized lymphadenopathy. Results Biopsy of the axillary lymph node revealed effaced lymph node architecture by a malignant neoplasm in a diffuse and vaguely nodular pattern. In the background of a diffuse infiltrate, there were small to medium sized lymphocytes, numerous atypical large cells with irregular, basophilic nucleoli, and variable cytoplasm. The large cells focally sheeted out. Many histiocytes were also seen in the background. The large atypical cells were positive for CD20, BOB-1, OCT2, BCL-2 (focally), BCL-6, PAX5, and MUM-1, and IgD, whereas negative for BCL-1, CD10, CD15, CD30. CD2, CD3, CD4, CD5, CD7, CD8 highlighted numerous T cells with mild cytological atypia, forming rosettes around the large atypical cells. T cells were negative for ALK-1, CD1a, TdT with increased Ki-67 proliferation index around 35%. Although the surrounding T cells appear atypical in morphology, flow cytometric analysis showed predominantly reactive T-cells with no loss of T-cell associated antigens. PCR analysis showed a producible peak in a single IgH reaction. However, the fragment size of the peak observed did not meet the criteria. T-cell gene rearrangement by TCR gamma and TCR beta PCR was negative for monoclonal T-cells. BCL-1, BCL-2, and BCL-6 FISH panel were negative for gene rearrangements. Based on these findings the diagnosis was made at stage IV. Patient started treatment with R-CHOP therapy with subsequent relapse. Patient has been placed on RICE chemotherapy with partial response. Conclusion NLPHL Pattern E type should be differentiated from classical Hodgkin lymphoma, diffuse large B-cell lymphoma and peripheral T cell lymphoma because the treatment greatly differs from those with higher stage and tendency for recurrence. It is the pathologist role to lead the clinician and render a correct histopathologic diagnosis.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 724-724
Author(s):  
Fuliang Chu ◽  
Myriam Foglietta ◽  
Hong Qin ◽  
Rakesh Sharma ◽  
Qing Yi ◽  
...  

Abstract Abstract 724 Background: Programmed death (PD)–1 is an inhibitory receptor that impairs the function of activated T-cells and natural killer (NK) cells when engaged by its ligands PD-L1 or PD-L2. We have previously demonstrated that PD-1 is markedly up-regulated in intratumoral and peripheral blood CD4+ and CD8+ T cells in patients with follicular lymphoma (FL), a finding associated with impaired T-cell function, suggesting that PD-1 blockade may improve FL immune control. CT-011, a humanized anti PD-1 monoclonal antibody, was previously studied in a phase I clinical trial in patients with advanced hematological malignancies. CT-011 was well tolerated and induced sustained elevations of CD4+ T cells in the peripheral blood. More importantly, apparent clinical benefit was observed in six patients, including one patient with FL who had large tumor masses that achieved a durable complete remission lasting >14 months. Here, we studied the in vitro and in vivo effects of CT-011 on T-cell and/or NK-cell immune responses against human B-cell lymphoma and the hypothesis that CT-011 may improve tumor control when combined with rituximab, a chimeric anti-CD20 monoclonal antibody for the treatment of human FL. Materials and Methods: To determine the effects of CT-011 on antitumor T cells, intratumoral T cells were isolated from primary FL tumor samples, and cultured with or without autologous tumor cells in the presence or absence of CT-011 or isotype control antibody (50 μg/ml each) for 5 days, and tested for proliferation by 3H thymidine incorporation assay. To determine the effects of CT-011 on NK cells, peripheral blood mononuclear cells (PBMCs) derived from normal donors or patients with FL were cultured in the presence or absence of CT-011 (50 μg/ml) with or without IL-2 for 96 hours and analyzed for expression of various activating receptors including CD16, CD32, CD64, Fas ligand, NKG2D, NKp30, NKp44, and NKp46. The in vivo effects of CT-011 were tested in two B-cell lymphoma xenograft models. Ramos and RL lymphoma tumor cells were injected subcutaneously into nude and SCID mice, respectively, and CT-011 (10 μg/mouse) was injected weekly with or without rituximab starting approximately 7–10 days after tumor inoculation. Results: We observed that CT-011 significantly increased the proliferation of intratumoral T cells in response to autologous tumor cells compared with isotype control antibody. Treatment with CT-011 enhanced the expression of Fas ligand, CD32, CD64, and NKp30 on human NK cells in the presence of IL-2 as compared with PBMCs treated with IL-2 alone or media control. In the RL lymphoma xenograft model in SCID mice, treatment with CT-011 significantly delayed tumor growth (P≤0.05) and improved survival (P≤0.01) compared with control mice injected with saline. In a Ramos lymphoma xenograft model in nude mice, treatment with CT-011 and rituximab eradicated established tumors in a significant proportion of mice (P≤0.05) and markedly improved survival compared with rituximab alone or saline. Conclusions: Taken together, these studies suggest that blockade of PD-1 with CT-011 enhances the function of anti-tumor T-cells and augments the expression of activating receptors on NK cells. Treatment with CT-011 led to improved tumor control against human B-cell lymphoma in xenograft models and the combined use of CT-011 and rituximab was more effective that rituximab alone. These results provide the rationale to test the combination of CT-011 with rituximab in patients with B-cell lymphoma, given that the combination is likely to be complementary and may even be synergistic, leading to enhanced clinical efficacy without increasing toxicity. The development of such approaches that activate both the innate (NK-cells) and adaptive (T-cells) immune systems is likely to minimize the emergence of immune escape variants and improve clinical outcome in patients with lymphoma. A clinical trial evaluating CT-011 in combination with rituximab is planned in patients with relapsed FL. Disclosures: Rodionov: Cure Tech Ltd.: Employment. Rotem-Yehudar:Cure Tech Ltd.: Employment.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 119-119
Author(s):  
Rita Simone ◽  
Sonia Marsilio ◽  
Piers E.M. Patten ◽  
Gerardo Ferrer ◽  
Shih-Shih Chen ◽  
...  

Abstract Lenalidomide (Revlimid®), a thalidomide analogue, is an orally administered second generation immunomodulator with anti-angiogenic and anti-neoplastic properties. Initial studies treating patients with chronic lymphocytic leukemia (CLL) suggest that lenalidomide can have considerable efficacy and that its mode of action is mainly indirect, affecting non-malignant cells in the microenvironment, in particular T lymphocytes. Because a recently described xenograft model for CLL has highlighted the importance of CLL-derived, autologous T cells in promoting leukemic B-cell engraftment and growth in vivo, we have studied the influence of lenalidomide on the expansion of CLL B- and T-lymphocytes in this model. After an initial 12 day culture of FACS-isolated CLL-derived T cells with or without anti-CD3/CD28 beads plus IL-2 (30 IU/ml), T lymphocytes were transferred into alymphoid NSG mice via the retro-orbital plexus (day 0). On day 7, CLL cells were delivered retro-orbitally. These recipient animals are referred to as “T + PBMC mice”. Mice that did not receive T cells on day 0 but were given CLL PBMCs at day 7, with or without lenalidomide, served as controls (“PBMC only mice”). Recipient mice received lenalidomide (10mg/kg/day) or vehicle control daily by gavage starting at day 0. All mice were sacrificed at day 28 (28 days after T-cell and 21 days after B-cell transfer), and blood, spleen, and bone marrow were collected. On this material, four analyses were performed: [1] level of human CD45+ cell engraftment; [2] numbers and types of CLL-derived T cells; [3] numbers of CLL B cells; and [4] levels of cytokines reflective of Th1 and Th2 immune responses. There was a clear enhancement in human hematopoietic (CD45+) cell engraftment in those mice exposed to lenalidomide. This was most marked for the PBMC only mice (vehicle: 10.64%; lenalidomide: 38.53%), although it was also evident for T + PBMC mice (vehicle: 55.96%; lenalidomide: 69.65%). T-cell phenotyping was carried out, before and after cell culture and also at sacrifice. Prior to culture, CLL samples contained on average ∼96% CD5+CD19+ cells and ∼3% CD5+CD19- cells; for the latter, ∼67% were CD4+ and ∼33% CD8+. After 12-day culture, these percentages remained largely unchanged. However, the numbers and types of T cells recovered from the spleens at sacrifice were quite different after in vivo exposure to lenalidomide. For the PBMC only, the percentages of CD4+ and CD8+ cells in the spleens differed somewhat based on lenalidomide exposure (CD4: Vehicle 86% vs. Lenalidomide 61%; CD8: Vehicle 10% vs. Lenalidomide 28%). However, this change was dramatic for the T + PBMC mice (CD4: Vehicle 64.1% vs. Lenalidomide 28.9%; CD8: Vehicle 34% vs. Lenalidomide 62%). Furthermore, when the CD8+ cells from these animals were subsetted based on antigen-experience and function, it appeared that lenalidomide exposure had led to the outgrowth of a greater number of effector memory (CD45RO+ CD62L-) than central memory (CD45RO+ CD62L+) T-cells. For CLL-derived B cells, the numbers differed, based not only on lenalidomide exposure but also on prior in vitro activation. Specifically, in PBMC only mice, the addition of lenalidomide led to increased numbers of CLL B cells in the spleen (Vehicle: 7.81% vs. Lenalidomide: 14%). Conversely, in the T + PBMC mice, the numbers of B cells decreased (Vehicle: 2.36% vs. Lenalidomide: 0.34%). An analysis of Th1 and Th2-related cytokines in the plasmas of the mice at sacrifice revealed a fall in IL-4, IL-5, and IL-10 and a marked increase in IFNg, consistent with a Th2 to Th1 transition. The above data suggest that administration of lenalidomide permits greater engraftment of human hematopoietic cells in alymphoid mice. Although this enhancement involves all members of the hematopoietic lineage, T cells, in particular CD8+ effector memory T cells, emerge in excess over time. This CD8 expansion is associated with diminished levels of CLL B cells suggesting that the decrease is due to T-cell mediated cytolysis. In contrast, in the absence of prior T-cell activation, CLL T cells appear to support better CLL B-cell growth. These findings suggest that lenalidomide alters B-cell expansion in vivo depending on the activation and differentiation state of the autologous T-cell compartment. They also implicate the generation of cytolytic T cells as one mechanism whereby lenalidomide leads to clinical improvement in CLL. Disclosures: Allen: Celgene Corporation: Honoraria.


Blood ◽  
2008 ◽  
Vol 111 (12) ◽  
pp. 5637-5645 ◽  
Author(s):  
Gourapura J. Renukaradhya ◽  
Masood A. Khan ◽  
Marcus Vieira ◽  
Wenjun Du ◽  
Jacquelyn Gervay-Hague ◽  
...  

Abstract Natural killer T (NKT) cells are a T-cell subpopulation known to possess immunoregulatory functions and recognize CD1d molecules. The majority of NKT cells express an invariant T-cell receptor (TCR) α chain rearrangement (Vα14Jα18 in mice; Vα24Jα18 in humans) and are called type I NKT cells; all other NKT cells are type II. In the current study, we have analyzed the roles for these NKT-cell subsets in the host's innate antitumor response against a murine B-cell lymphoma model in vivo. In tumor-bearing mice, we found that type I NKT cells conferred protection in a CD1d-dependent manner, whereas type II NKT cells exhibited inhibitory activity. Pro- and anti-inflammatory cytokines secreted by splenocytes from tumor-bearing mice correlated with tumor progression. Myeloid cells (CD11b+Gr1+) were present in large numbers at the tumor site and in the spleen of tumor-bearing type I NKT–deficient mice, suggesting that antitumor immunosurveillance was inhibited by CD11b+Gr1+ cells. Overall, these data suggest that there are distinct roles for NKT-cell subsets in response to a B-cell lymphoma in vivo, pointing to potential novel targets to be exploited in immunotherapeutic approaches against blood cancers.


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