scholarly journals Potentiate Immune Activation and Function By Targeting Inhibitor of Apoptosis Proteins (IAPs) in Relapse/Refractory DLBCL

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 30-31
Author(s):  
Juan J Gu ◽  
Cory Mavis ◽  
Pallawi Torka ◽  
Suchitra Sundaram ◽  
Francisco J. Hernandez-Ilizaliturri
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lines ◽  
Immune Activation ◽  
Cell Function ◽  
Granzyme B ◽  
Target Cells ◽  
Knock Out ◽  
T Cell Function

Background: The prognosis of relapsed/refractory diffuse large B cell lymphoma (r/r DLBCL) that had progressed after or are ineligible for high dose chemotherapy and autologous stem cell support (HDC-ASCS) is extremely poor (median overall survival of 6.3 months). Cellular based immunotherapy with Chimeric Antigen Receptor T-cell against CD19 (CART-19) has proven high effective in r/r DLBCL with an overall response rate of 52-83% and an overall survival rate of 40%. While r/r DLBCL benefits from CART-19 therapy, a significant number of progress after initial response stresses the need to improve the efficacy of this novel approach. A significant amount of work is being done in improving the manufacturing or activation of CART cells. However, there is few data on lymphoma associated factors that could influence response to CART-19 therapy. Previously we reported an imbalance and dysfunction of pro- and anti-apoptotic proteins, including Bak/Bax, Mcl-1/BCLxL/Survivin and upregulation of inhibitor of apoptosis (IAP) family proteins in rituximab+chemotherapy (R-chemo) resistant DLBCL. Targeting IAPs by small inhibitor LCL161 in lymphoma cells significantly overcame chemotherapy resistance in vitro and in vivo. LCL161 potentiated CART-19 cell cytotoxicity mediated in B-cell acute lymphoblastic leukemia and diffuse large B-cell lymphoma pre-clinical models. Here, we investigate the mechanism of action to enhance immune activation by targeting IAPs in r/r DLBCL. Methods: Primary T-cells were isolated and activated from peripheral blood apheresis samples from consenting adults (healthy human donors or patients with DLBCL) using Pan T-Cell Isolation Kit (MACS) and activated by T-cell Dynabeads human activator CD3/CD28 kit. Cells were expanded in RPMI media supplemented with IL2 for 2 weeks. At day 14, cells phenotype analysis was performed (CD3, CD4, CD8) by flow cytometry. T-cell number was calculated by trypan blue exclusion assay and proliferation was measured by presto blue assay after exposure to LCL161 or control for 48hrs. After exposure, CD4 and CD8 ratios were determined by cellular surface staining. T-cell function assay was determined by intracellular staining with perforin and granzyme B. Regulatory T-cells were determined as CD25+ and FOXP3+ staining cells. T-cell cytolytic activity was accessed by 51Cr release assay using 51Cr labeled rituximab-chemotherapy sensitive (Raji and RL cells) or resistant (Raji 4RH and RL 4RH) cell lines as target cells (effector/target ratio 10/1). To confirm the role of IAP proteins in the effects of LCL161 in T-cell activation, we conducted cytotoxicity assays using XIAP knock out lymphoma cell lines as target cells. Stable XIAP knock out cell lines were generated by CRISPR-Cas9 gene editing system. Lentiviral Cas9 nuclease particles were transduced into Raji and Raji 4RH cells followed by lentiviral XIAP sgRNA transduction. Lentiviral sgRNA non-targeting control was also used as negative control. Result: In vitro exposure of T-cells to LCL161 did not affect cell viability. On the other hand, it led to an increase in CD8+ T-cells and in the CD8:CD4 ratio. In addition, the percentage of regulatory T cells (CD25+ and FOXP3+) was reduced following LCL161 exposure. Using the T-cell function assay, we found that perforin and granzyme B inside T-cell was significantly increased post LCL161 exposure. The presence of LCL161 significantly improved the T-cell killing activity towards rituximab-chemotherapy sensitive and more importantly resistant cell lines. XIAP knock out in target cells resulted in abrogation of the enhance cytotoxicity exhibited by T-cells exposed to LCL161. Conclusion: Our data suggest that besides its previously documented direct anti-tumor activity, LCL161 has dual functions modulating immune cells function. LCL161 improve T-cell function by increasing the number of CD8+ T-cells and intracellular levels of granzyme B and perforin leading to an increase in T-cell cytotoxicity. In addition, LCL161 decreases the number of T-reg cells further enhancing immune activation. Taking together, targeting IAPs would be an attractive approach that potentiate current CART-19 immunotherapy in the clinical setting. Disclosures Hernandez-Ilizaliturri: Astra Zeneca: Consultancy; Karyopharm: Consultancy; Celgene: Consultancy; Takeda: Consultancy; Seattle Genetics: Consultancy; Epyzome: Consultancy; Pharmacyclics: Consultancy; Amgen: Consultancy; Gilead: Consultancy.

Hydroxyurea Is Most Suitable for Cytoreduction of AML Prior to CD33/CD3 Bispecific BiTE® Antibody (AMG 330) Therapy: Uncompromised T-Cell Proliferation Ex-Vivo and CD33 Upregulation on AML Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 986-986 ◽  
Author(s):  
Christina Krupka ◽  
Franziska Brauneck ◽  
Felix S Lichtenegger ◽  
Peter Kufer ◽  
Roman Kischel ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Cell Function ◽  
Expression Level ◽  
T Cell Proliferation ◽  
Hl60 Cells ◽  
T Cell Function ◽  
Equity Ownership

Abstract Bispecific T-cell engager (BiTE®) antibodies represent a promising tool for anti-leukemic immunotherapy. The CD19/CD3-bispecific antibody blinatumomab was shown to be active in refractory and relapse patients with B-precursor acute lymphoblastic leukemia (Topp et al, ASCO 2014). Transient, blinatumomab-mediated cytokine release syndrome has been linked to target cell numbers as this phenomenon is predominantly observed within the first treatment cycle. In our previous work, we demonstrated that the bispecific CD33/CD3 BiTE® antibody AMG 330 is able to induce activation and proliferation of residual autologous T-cells and effectively mediates lysis of primary acute myeloid leukemia (AML) cells (Krupka et al, Blood 2014; 123(3):356-65). We hypothesize that in AML patients with high initial leukocyte counts (WBC > 30.000/μl) a cytoreductive phase prior to AMG 330 therapy might be beneficial to reduce the incidence and severity of cytokine mediated toxicity. Ideally, the cytoreductive drug does not impair T-cell function or reduce target antigen expression level. In the current study, we evaluated the effect of cytarabine (20 µM), decitabine (5 µM), azacitidine (1 µM and 5 µM) and hydroxyurea (10 µM and 100 µM) on T-cell proliferation and function in close analogy to potential treatment algorithms for AML. Healthy donor (HD) T-cells were pre-incubated with the cytoreductive drugs for 72 hours. T-cells were CFSE-labeled and co-cultured with either HL60 or MV4-11 cells (effector cell:target (E:T) ratio 1:1) in the presence or absence of AMG 330 (5 ng/ml). After 3 days of co-culture, lysis of HL60 cells and T-cell proliferation was assessed by flow cytometry. Pretreatment of T-cells with cytarabine completely abrogated T-cell function (lysis of HL60 cells: untreated (UT): 96.9% vs 20 µM: 4.2%) and significantly impaired T-cell proliferation (UT: 31.2% vs 20 µM: 4.6%). These findings correlated to data using primary AML samples collected 3 and 6 days after discontinuation of cytarabine treatment. After a 3-day chemotherapy-free interval, we observed no relevant T-cell proliferation and lysis of AML cells upon the addition of AMG 330 to the ex-vivo long-term culture system (lysis of AML cells on day 12: 30%; fold change T-cell expansion 0.9). After a 6-day treatment-free interval, high T-cell proliferation and cytotoxicity against primary AML cells were observed (lysis of AML cells on day 12: 61%; fold change T-cell expansion: 3.1). In contrast to cytarabine, decitabine treatment only marginally impaired T-cell function. Similarly, pre-incubation with azacitidine did not convey a negative effect on T-cell function (lysis of HL60 cells: UT: 100% vs 1 µM: 94.9% vs 5µM: 86.8%; proliferation: UT: 90.9% vs 1 µM: 80% vs 5 µM: 66.8%). Pretreatment with hydroxyurea had the least impact on T-cell performance. It did not impair T-cell function (lysis of HL60 cells: UT: 100% vs 10 µM: 100% vs 100 µM: 100%) and proliferation compared to untreated controls (UT: 92.9% vs 100 µM 90.8% vs 10 µM 92.9%). As we have previously shown that the level of CD33 expression correlates to kinetics of AMG 330-mediated lysis (Krupka et.al, EHA 2014), we analyzed the effect of the cytoreductive agents on CD33 expression level in AML cell lines and primary AML cells. Five AML cell lines (HL60, MV4-11, PL21, OCI-AML3, KG1a) and a primary AML patient sample were cultured in the presence or absence of decitabine (5 µM and 50 µM), azacitidine (1 µM and 5 µM) or hydroxyurea (10 µM and 100 µM) for 72 hours. The change of CD33 expression level was evaluated by flow cytometry (median fluorescence intensity, MFI). No significant changes in CD33 expression level were observed after culture of AML cell lines and primary AML cells with decitabine or azacitidine. In contrast, hydroxyurea upregulated surface expression of CD33 on 2/5 cell lines (HL60 and PL21) in a dose dependent manner (HL 60 MFI Ratio: UT 134.9 vs 10 µM 171.3 vs 100 µM 210; PL21 MFI Ratio: UT 166.9 vs 10 µM 177.9 vs 100 µM 191.8). In summary, we could show that pretreatment with hydroxyurea did not impair T-cell function and proliferation. In addition, we observed an upregulation of CD33 expression on AML cell lines. As the BiTE® technology relies on T-cell function and target antigen expression level, sequential and combinatorial immuno-chemotherapeutic approaches need to address both issues. Our data support the use of hydroxyurea in AML patients that require cytoreduction prior to AMG 330 treatment. Disclosures Krupka: AMGEN Inc.: Research Funding. Kufer:AMGEN Research (Munich): Employment; AMGEN Inc.: Equity Ownership. Kischel:AMGEN Research (Munich): Employment; AMGEN Inc.: Equity Ownership. Zugmaier:AMGEN Inc.: Equity Ownership; AMGEN Research (Munich): Employment. Sinclair:AMGEN Inc.: Employment, Equity Ownership. Newhall:AMGEN Inc.: Employment, Equity Ownership. Frankel:AMGEN Inc.: Employment, Equity Ownership. Baeuerle:AMGEN Research (Munich): Employment; AMGEN Inc.: Equity Ownership. Riethmüller:AMGEN Inc.: Equity Ownership. Subklewe:AMGEN Inc.: Research Funding.

Immunopharmacodynamic response to blinatumomab in patients with relapsed/refractory B-precursor acute lymphoblastic leukemia (ALL).

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 7020-7020 ◽  
Author(s):  
Andrea Schub ◽  
Virginie Nägele ◽  
Gerhard Zugmaier ◽  
Christian Brandl ◽  
Youssef Hijazi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Lymphoblastic Leukemia ◽  
Granzyme B ◽  
Significant Proportion ◽  
Target Cells ◽  
Cell Counts

7020 Background: Blinatumomab is an anti-CD19/anti-CD3 bispecific T cell engager (BiTE) that induces target cell-dependent, polyclonal T cell activation and proliferation, resulting in redirected lysis of CD19+ target cells. Methods: In a phase 2 study, adult patients (N=36) with relapsed/refractory B-precursor ALL received continuous blinatumomab IV infusion for 28 days in ≤5 treatment/consolidation cycles. Whole blood and serum samples were collected throughout treatment and analyzed for lymphocyte subpopulations, cytokines, granzyme B, and blinatumomab serum concentrations. Results: Lymphocytes in all patients responded in a similar fashion. After infusion start, peripheral B cell counts dropped to ≤1 B cell/μL in <1 week and remained undetectable throughout treatment. Peripheral T cells showed a redistribution characterized by swift disappearance within the first 2-6 hrs and subsequent recovery to baseline within several days. Otherwise, T cell counts remained at least stable in most patients. In some patients even an expansion of the T cell compartments was observed, most likely due to specific proliferation of activated T cells but could not be defined as prerequisite for treatment efficacy. During the first infusion days, a significant proportion of T cells newly expressed the activation marker CD69, and the T cell effector molecule granzyme B was detectable in serum. Additionally, a transient cytokine release dominated by IL-10, IL-6 and IFN-γ was observed in most patients shortly after first infusion start, which was alleviated or absent in subsequent cycles. Blinatumomab serum steady state concentrations (mean±SD) were 198±61 pg/mL and 694±236 pg/mL at doses of 5 and 15 μg/m²/d, respectively, which is comparable to those from previous studies. Conclusions: Immunopharmacodynamic response to blinatumomab was characterized by B cell depletion, T cell activation and redistribution, and release of granzyme B and cytokines, suggesting T cell engagement according to the expected BiTE mode of action. The tested pharmacodynamic markers did not allow for predictive differentiation between patients achieving a hematologic response and those who did not. Clinical trial information: NCT01209286.

scholarly journals Treatment-Free Intervals Mitigate T-Cell Exhaustion Induced By Continuous CD19xCD3-BiTE® Construct Stimulation in Vitro

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 44-45
Author(s):  
Nora Zieger ◽  
Alyssa Nicholls ◽  
Jan Wulf ◽  
Gerulf Hänel ◽  
Maryam Kazerani Pasikhani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Research Funding ◽  
Cell Function ◽  
Granzyme B ◽  
T Cell Exhaustion ◽  
Specific Lysis ◽  
Cell Exhaustion ◽  
T Cell Function

The bispecific T-cell engager (BiTE®) blinatumomab is approved for treatment of relapsed/refractory B-cell precursor acute lymphoblastic leukemia and applied as continuous infusion over 28 days. The overall response rate to blinatumomab reported in clinical trials was 43 % and correlated to T-cell expansion (Zugmaier et al. 2015). In chronic viral infections, continuous antigen stimulation induces T-cell exhaustion, defined by phenotypic changes and functional impairment (Wherry 2011). Thus, we hypothesized that continuous BiTE® construct stimulation leads to T-cell exhaustion and that a treatment-free interval (TFI) reverses progressive T-cell dysfunction. To simulate continuous application of a BiTE® construct in vitro, T-cell long-term co-cultures were set up. Healthy donor T cells were stimulated in the presence of CD19+ OCI-Ly1 cells for 28 days with AMG 562, a half-life extended CD19 and CD3 specific BiTE® construct. T cells were harvested from the co-culture every 3-4 days between day 7 and 28 and assessed for markers of T-cell exhaustion: (1) AMG 562-mediated cytotoxicity of T cells was evaluated as specific lysis of CD19+ Ba/F3 target cells after 3 days, (2) T-cell expansion during the cytotoxicity assay was calculated as fold change (FC) of CD2+ counts, (3) Cytokine secretion of AMG 562-stimulated T cells was evaluated in co-culture supernatants by cytometric bead array (CBA) or after PMA/Ionomycine stimulation via intracellular cytokine staining (ICCS), (4) T-cell metabolic fitness was determined by Mito- and Glycolytic Stress Test using a Seahorse Analyzer, and (5) expression of the exhaustion-related transcription factor TOX was assessed by multiparameter flow cytometry. In order to assess the effect of a TFI on T-cell function, we cultured T cells and CD19+ OCI-Ly1 cells in the absence of AMG 562 from day 7-14 and 21-28 and compared their activity to T cells stimulated continuously with AMG 562. On day 7 of continuous (CONT) AMG 562 stimulation, we observed high cytotoxic and proliferative potential (% specific lysis=93±0.2, FC=2.9±0.2) as well as high IFN-g and TNF-a secretion analyzed by ICCS (% CD8+IFN-g+TNF-a+=23±6.7). However, cytotoxicity and proliferation decreased gradually until day 28 (% specific lysis=28±8.9; FC=0.6±0.1). CBA analysis confirmed decreasing secretion of IFN-g (day 3: 61113±12482, day 24: 3085±1351 pg/ml) and TNF-a (day 3: 1160±567, day 24: 43±7.6 pg/ml) as well as decreased IL-2 and granzyme B levels in culture supernatants. We furthermore observed highest mitochondrial fitness and basal glycolysis in T cells on day 7 of stimulation (basal OCR=2.2±0.6, maximal OCR=3.7±1.0, SRC=1.5±1.1 pmol/min/1000 cells, basal ECAR=2.0±0.4 mpH/min/1000 cells) which decreased until day 28 (basal OCR=0.4±0.2, maximal OCR=1.5±0.5, SRC=1.0±0.2 pmol/min/1000 cells, basal ECAR=0.5±0.2 mpH/min/1000 cells). In concordance, TOX increased during continuous stimulation (MFI ratio CD8+ day 7=6±0.8 to 12±0.8 on day 28). Strikingly, implementation of a TFI of 7 days led to superior cytotoxicity in T cells compared to continuously stimulated T cells (% specific lysis on day 14 CONT=34±4.2, TFI=99±2.2) and granzyme B production (CD8+; MFI ratio on day 14 CONT=124±11, TFI=303±34). Furthermore, increased proliferation during the cytotoxicity assay was observed in previously rested T cells (FC CONT=0.2±0.0, TFI=1.6±0.6). Although T cell function also decreased over time in TFI T cells, they maintained a strikingly higher cytotoxic potential (CONT=6±4.4, TFI=52±9.9) as well as higher granzyme B production (CONT=25±2, TFI=170±11) on day 28 compared to continuously stimulated T cells. In addition, TFI T cells showed increased IFN-g and TNF-a secretion after PMA/Ionomycine stimulation on day 28 (% CD8+IFN-g+TNF-a+ CONT=21±3.8, TFI=38±11.6). Our in vitro results demonstrate that continuous AMG 562 exposure negatively impacts T-cell function. Comprehensive analysis of T-cell activity in an array of functional assays suggests that continuous BiTE® construct exposure leads to T-cell exhaustion which can be mitigated through TFI. Currently, T cells from patients receiving blinatumomab are being analyzed to confirm the clinical relevance of our findings. Furthermore, RNA-Seq of continuously vs. intermittently AMG 562-exposed T cells will help us to understand underlying transcriptional mechanisms of BiTE® construct induced T-cell exhaustion. Disclosures Zieger: AMGEN Research Munich: Research Funding. Buecklein:Pfizer: Consultancy; Novartis: Research Funding; Celgene: Research Funding; Amgen: Consultancy; Gilead: Consultancy, Research Funding. Brauchle:AMGEN Inc.: Research Funding. Marcinek:AMGEN Research Munich: Research Funding. Kischel:AMGEN: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties. Subklewe:Gilead Sciences: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Morphosys: Research Funding; Seattle Genetics: Research Funding; AMGEN: Consultancy, Honoraria, Research Funding; Janssen: Consultancy; Roche AG: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Celgene: Consultancy, Honoraria.

scholarly journals Attenuation of CD8+ T-Cell Function by CD4+CD25+ Regulatory T Cells in B-Cell Non-Hodgkin's Lymphoma

2006 ◽  
Vol 66 (20) ◽  
pp. 10145-10152 ◽  
Author(s):  
Zhi-Zhang Yang ◽  
Anne J. Novak ◽  
Steven C. Ziesmer ◽  
Thomas E. Witzig ◽  
Stephen M. Ansell
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
B Cell ◽  
Hodgkin’S Lymphoma ◽  
Cell Function ◽  
Cd8 T Cell ◽  
Hodgkin's Lymphoma ◽  
T Cell Function ◽  
Non Hodgkin's Lymphoma

scholarly journals Blocking effect of lyt-2 antibodies on T cell functions.

1980 ◽  
Vol 152 (3) ◽  
pp. 674-687 ◽  
Author(s):  
N Hollander ◽  
E Pillemer ◽  
I L Weissman
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mixed Lymphocyte Reaction ◽  
Cell Function ◽  
Mixed Lymphocyte Culture ◽  
Lymphocyte Culture ◽  
Target Cells ◽  
Cell Functions ◽  
T Cell Function ◽  
Helper Function

Monoclonal anti-Lyt-2 antibodies blocked effector function of cytotoxic thymus-derived (T) cells in the absence of added complement. Cytolysis of both allogeneic cells and syngeneic lymphoma or sarcoma target cells was inhibited at the level of the effector lymphocytes. Anti-Lyt-1 and anti-Thy-1 antibodies did not block killer cells. Proliferation of T cells in mixed lymphocyte culture was also inhibited by anti-Lyt-2, but not affected by anti-Lyt-1 or anti-Thy-1 antibodies. Although Lyt-1+ lymphocytes were required in the mixed lymphocyte reaction as helper cells for proliferation of Lyt-2+ lymphocytes, their helper function was not affected by the presence of Lyt-1 antibodies. Thus, although anti-Lyt-1, anti-Lyt-2 and anti-Thy-1 were of the same gamma 2A immunoglobulin class, had high titers, and interacted with T cells to the same extent, only anti-Lyt-2 blocked T cell functions. Polyclonal activation of T lymphocytes by concanavalin A, in contrast to activation by alloantigens, was not inhibited by Lyt-2 antibodies, suggesting that Lyt-2 antibodies interfere with T cell function at the level of the T cell antigen-receptor. The role which Lyt-2 molecules may play in T cell function is discussed.

scholarly journals Preservation of CD20-Specific Chimeric Antigen Receptor T Cell Function in the Presence of Residual Rituximab

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4428-4428
Author(s):  
Gregory A. Rufener ◽  
Philip Olsen ◽  
Sang Yun Lee ◽  
Michael C Jensen ◽  
Ajay K. Gopal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Binding Sites ◽  
Research Funding ◽  
Cell Function ◽  
Target Cells ◽  
T Cell Function ◽  
Car T ◽  
Anti Cd20

Abstract BACKGROUND: The CD20 antigen is an attractive immunotherapy target for B cell non-Hodgkin lymphomas, and adoptive transfer of T cells genetically modified to express a chimeric antigen receptor (CAR) targeting CD20 is a promising strategy. A theoretical limitation of this approach is that residual serum rituximab from prior chemoimmunotherapy regimens might block CAR binding to CD20 and prevent T cell mediated anti-lymphoma responses. However, previous data from our group and others have suggested that CD20 CAR+ T cell function is only partially blocked by anti-CD20 antibody (Ab), and T cell function in the setting of anti-CD3 x anti-CD20 bispecific Ab is not blocked by rituximab levels of up to 100 μg/ml. We have further tested the impact of various concentrations of rituximab on CD20-CAR T cell activity in vitro and in vivo. METHODS: CD3+ T cells (proliferation and cytokine assays) or CD8+ selected T cells (cytotoxicity assays) were isolated from healthy donors, activated with anti-CD3/CD28 beads, and transduced with epHIV7 lentiviral vectors encoding 2nd or 3rd generation anti-CD20 CAR constructs (Leu16-28-ζ, Leu16-28-BB-ζ, or fully human 1-5-3-NQ-28-BB-ζ). Functional assays, performed using target cells pre-incubated for 30 min. with varying concentrations of rituximab, included a CFSE assay to assess CAR T cell proliferation, Luminex assays for cytokine secretion, and a 5-hour standard 51 chromium release assay for cytotoxicity. Target cells included K562 cells transduced to express CD80 with or without CD20 (denoted "K80" and "K80-20"), Raji, Daudi, Granta, Rec-1, and FL-18 lymphoma cells. K80-20 cell lines expressing low, medium, and high CD20 were established by limiting dilution cloning. For in vivo experiments, NOD/SCID/γ-/- (NSG) mice were inoculated i.v. with rituximab-resistant Raji-ffLuc lymphoma cells. After 5 days, rituximab was administered i.p. at 25 μg/ml or 200 μg/ml, and then at 24 hours after rituximab administration CAR+ central memory T cells expressing the 1-5-3-NQ-28-BB-ζ vector were injected i.v. Tumor growth was measured with bioluminescence imaging twice weekly and mice were followed for survival. RESULTS: The availability of CD20 binding sites on Ramos lymphoma cells pre-incubated with various concentrations of rituximab was assessed with flow cytometry, and as expected, we found a dose-dependent blockade of CD20, with complete blockade at 50 μg/ml rituximab at 4°C. However, when anti-CD20-PE was incubated at 37°C, low-level CD20 binding could occur even at 200 μg/ml of rituximab. Despite the low number of available CD20 binding sites after rituximab, proliferation of CFSE-labeled CAR+ T cells was largely unimpaired in rituximab concentrations up to 200 μg/ml. In contrast, cytokine secretion was impaired in a dose-dependent manner, although even at 100 μg/ml of rituximab, interferon-γ, interleukin-2, and tumor necrosis factor a were still produced at 34-51%, 70-92%, and 79-108% of baseline levels, respectively. Cytotoxicity also decreased with increasing rituximab concentration but >75% of baseline cytolytic activity was retained at 100 μg/ml. We hypothesized that the level of CD20 expression on target cell lines might impact sensitivity to rituximab blockade. Using K80-20 cells with low, medium, or high CD20 expression we found that cytokine secretion and cytotoxicity (but not proliferation) were highly impaired upon stimulation with CD20low target cells, whereas T cell function remained completely intact when CD20high cells were used as targets. In vivo, mice bearing rituximab-refractory Raji-ffLuc tumors experienced only slight delay of tumor growth when treated with either low or high doses of rituximab, and mice treated with T cells alone had significant clearance of tumor. In mice that received low or high-dose rituximab prior to T cell infusions, tumor rejection and survival prolongation were equivalent to or better than that observed with mice receiving T cells alone (see figure). CONCLUSION: We have shown that the in vitro and in vivo activity of CD20-targeted CAR T cells is minimally impacted after rituximab, despite a low number of available CD20 binding sites. These data suggest that residual serum rituximab levels will not present a significant impediment to CD20-targeted CAR therapy in patients who have received rituximab-containing chemotherapy regimens. Figure 1. Figure 1. Disclosures Jensen: Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding. Gopal:Merck: Research Funding; BioMarin: Research Funding; Seattle Genetics: Consultancy, Honoraria; Gilead: Consultancy, Research Funding; Spectrum: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Piramal: Research Funding; Millenium: Honoraria, Research Funding; BMS: Research Funding; Janssen: Consultancy; Emergent/Abbott: Research Funding; Sanofi-Aventis: Honoraria. Riddell:Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Cell Medica: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy. Till:Pfizer: Research Funding; Roche/Genentech: Research Funding.

scholarly journals Oligomeric Procyanidins Interfere with Glycolysis of Activated T Cells. A Novel Mechanism for Inhibition of T Cell Function

Molecules ◽  
2015 ◽  
Vol 20 (10) ◽  
pp. 19014-19026 ◽  
Author(s):  
Masao Goto ◽  
Manabu Wakagi ◽  
Toshihiko Shoji ◽  
Yuko Takano-Ishikawa
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Activated T Cells ◽  
T Cell Function

scholarly journals Epiligrin, a component of epithelial basement membranes, is an adhesive ligand for alpha 3 beta 1 positive T lymphocytes.

1993 ◽  
Vol 121 (5) ◽  
pp. 1141-1152 ◽  
Author(s):  
E A Wayner ◽  
S G Gil ◽  
G F Murphy ◽  
M S Wilke ◽  
W G Carter
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Basement Membrane ◽  
B Cell ◽  
Cell Lines ◽  
B Cell Lymphoma ◽  
Lymphokine Activated Killer Cells ◽  
Cutaneous Inflammation ◽  
Epidermal Basement Membrane

The cutaneous T cell lymphomas (CTCL), typified by mycosis fungoides, and several chronic T cell mediated dermatoses are characterized by the migration of T lymphocytes into the epidermis (epidermotropism). Alternatively, other types of cutaneous inflammation (malignant cutaneous B cell lymphoma, CBCL, or lymphocytoma cutis, non-malignant T or B cell type) do not show evidence of epidermotropism. This suggests that certain T lymphocyte subpopulations are able to interact with and penetrate the epidermal basement membrane. We show here that T lymphocytes derived from patients with CTCL (HUT 78 or HUT 102 cells), adhere to the detergent-insoluble extracellular matrix prepared from cultured basal keratinocytes (HFK ECM). HUT cell adhesion to HFK ECM was inhibitable with monoclonal antibodies (mAbs) directed to the alpha 3 (P1B5) or beta 1 (P4C10) integrin receptors, and could be up-regulated by an activating anti-beta 1 mAb (P4G11). An inhibitory mAb, P3H9-2, raised against keratinocytes identified epiligrin as the ligand for alpha 3 beta 1 positive T cells in HFK ECM. Interestingly, two lymphocyte populations could be clearly distinguished relative to expression of alpha 3 beta 1 by flow cytometry analysis. Lymphokine activated killer cells, alloreactive cytotoxic T cells and T cells derived from patients with CTCL expressed high levels of alpha 3 beta 1 (alpha 3 beta 1high). Non-adherent peripheral blood mononuclear cells, acute T or B lymphocytic leukemias, or non-cutaneous T or B lymphocyte cell lines expressed low levels of alpha 3 beta 1 (alpha 3 beta 1low). Resting PBL or alpha 3 beta 1low T or B cell lines did not adhere to HFK ECM or purified epiligrin. However, adhesion to epiligrin could be up-regulated by mAbs which activate the beta 1 subunit indicating that alpha 3 beta 1 activity is a function of expression and affinity. In skin derived from patients with graft-vs.-host (GVH) disease, experimentally induced delayed hypersensitivity reactions, and CTCL, the infiltrating T cells could be stained with mAbs to alpha 3 or beta 1 and were localized in close proximity to the epiligrin-containing basement membrane. Infiltrating lymphocytes in malignant cutaneous B disease (CBCL) did not express alpha 3 beta 1 by immunohistochemical techniques and did not associate with the epidermal basement membrane. The present findings clearly define a function for alpha 3 beta 1 in T cells and strongly suggest that alpha 3 beta 1 interaction with epiligrin may be involved in the pathogenesis of cutaneous inflammation.

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