AMG 701 Potently Induces Anti-Multiple Myeloma (MM) Functions of T Cells and IMiDs Further Enhance Its Efficacy to Prevent MM Relapse In Vivo

AMG 701 is a half-life extended BiTE® (bispecific T-cell engager) targeting the B cell maturation antigen (BCMA). Here, we confirmed AMG 701-mediated T cell-redirected lysis of MM cells, defined immunomodulatory effects of AMG 701, and investigated combination potential of AMG 701 with immunomodulatory drugs (IMiDs) in human MM. Firstly, AMG 701 induced specific and efficacious T cell-dependent cytotoxicity (TDCC) against all MM cell lines tested, regardless of sensitivity to current anti-MM agents and expression levels of BCMA. AMG 701-induced TDCC was minimally affected in the presence of myeloma-supporting cells and cytokines in the bone marrow (BM) microenvironment, including osteoclasts (OCs), BM stromal cells (BMSCs), and a proliferation-inducing ligand (100 ng/ml). Importantly, AMG 701 induced lysis of autologous patient cells from the relapse and refractory stage of MM (RRMM). AMG 701 rapidly upregulated cell surface expression of CD107a and the production of IFNγ and TNFα, more so in CD8 than CD4 T subsets. It stimulated the proliferation and activation of T cells, to a greater extent in CD8 vs CD4 T cells, leading to significantly increased ratios of CD8/CD4 T cells. Significantly, AMG 701 induced differentiation of naive T cells (CD4 and CD8) to T cells with memory phenotype. This includes central memory (CM), effector memory (EM) T cells, and stem cell like memory cells. Time-course immunophenotyping studies showed that AMG 701 transiently upregulated the expression of key immune checkpoint and costimulatory markers on both CD4 and CD8 T cells. The induced T cells purified from ex vivo co-cultures still effectively lysed MM cells with lower BCMA levels. This may suggest an increased T cell clonality. Furthermore, IMiDs (len or pom) enhanced AMG 701-mediated TDCC against MM cells at earlier time points, lower E/T ratios, lower concentrations, or in the presence of immunosuppressive OCs or BMSCs. The combination AMG 701 and IMiDs maximized MM cell lysis accompanied with a decreased EC50 value. Combined treatments induce a more pronounced immunomodulation than AMG 701 alone in the presence of OCs, as evidenced by higher percentage of CM+EM and CD8/CD4 ratio at d8. AMG 701 with IMiDs combination significantly enhance AMG 701-mediated autologous patient MM cell lysis in a synergistic manner (combination index < 1). In the human NCI-H929 xenograft model reconstituted with human T effector cells, AMG 701 effectively blocked tumor growth 5d after the first injection, regardless of doses (0.02-2 mg/kg). Tumors were completely eradicated following 3 separate injections in the host without weight loss. Next, sub-optimal doses and treatment schedules for AMG 701 and len were then used to investigate in vivo anti-MM effects by the combination vs monotherapy. Mice receiving MM cells were treated, from d15 until the end of the study, with len once daily, AMG 701 once weekly, or combination of AMG 701 and len. Two days after the first drug administration, all three treatments significantly inhibited MM tumor growth in mice (p<0.001). Most importantly, while AMG 701 or len group showed tumor progress eventually, the combination of AMG 701 with len continuously suppressed tumor growth (p<0.05 after d26; p<0.001 after d40 for combination vs either agent alone). Combination of AMG 701 and len significantly induced superior MM cell regression, compared to either monotherapy, resulting in enhanced tumor regression and prevention of disease relapse. Taken together, these results strongly support AMG 701-based clinical studies, both as monotherapy (NCT03287908) and in combination with IMiDs to enhance elimination of residual diseases and prolong long-term durable responses in MM. Disclosures Munshi: Oncopep: Consultancy; Janssen: Consultancy; Abbvie: Consultancy; Takeda: Consultancy; Adaptive: Consultancy; Amgen: Consultancy; Celgene: Consultancy. Wahl:Amgen Research GmbH: Employment. Matthes:Amgen Research GmbH: Employment. Anderson:Sanofi-Aventis: Other: Advisory Board; Bristol-Myers Squibb: Other: Scientific Founder; Oncopep: Other: Scientific Founder; Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Chapman-Arvedson:Amgen Research: Employment.

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Lenalidomide Promotes The Expansion Of CD8 T Cells With An Effector Memory Phenotype In a Murine Xenograft Model Of Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood.v122.21.119.119 ◽

2013 ◽

Vol 122 (21) ◽

pp. 119-119

Author(s):

Rita Simone ◽

Sonia Marsilio ◽

Piers E.M. Patten ◽

Gerardo Ferrer ◽

Shih-Shih Chen ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cells ◽

T Lymphocytes ◽

B Cell ◽

Xenograft Model ◽

Lymphocytic Leukemia ◽

Effector Memory ◽

Cell Engraftment

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.

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The Role of Pretransplant Conditioning On Graft-Versus-Leukemia Effects: Migration Matters.

Blood ◽

10.1182/blood.v114.22.3563.3563 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3563-3563

Author(s):

Ji-Young Lim ◽

Mi-Sun Choi ◽

Eun Young Choi ◽

Hyewon Youn ◽

Chang-Ki Min

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Growth ◽

Cd4 T Cells ◽

Tumor Tissue ◽

Cell Trafficking ◽

Tnf Α ◽

Ifn Γ ◽

Conditioning Intensity

Abstract Abstract 3563 Poster Board III-500 The therapeutic potential of allogeneic hematopoietic stem cell transplantation (HSCT) relies on the graft-versus-leukemia (GVL) effect to eradicate residual tumor cells by immunologic mechanisms. However, the relationship of conditioning intensity to GVL effect has not been clearly established independent of immunosuppression or the tolerance induced by mixed donor-host chimerism. Using a murine allogeneic HSCT model, we have compared two total body irradiation (TBI) doses (1,300 vs. 900 cGy), both of which provided complete donor engraftment and elimination of host lympho-hematopoetic cells. We used C57BL/6 (H-2b) → B6D2F1 (H-2b/d) model of GVHD, which differ at major and minor histocompatibility loci, to address the role of conditioning intensity on the GVL effect. Lethally irradiated (either 900 or 1300 cGy) recipient mice were transplanted with either C57BL/6 (allogeneic) or B6D2F1 (syngeneic) bone marrow (5 × 106) and spleen T cells (1 × 106) on day 0 and then P815 (H-2d) mastocytoma cells (1 × 106) injected subcutaneously on day 1 to generate a GVL model. As expected, GVHD morbidity after the higher TBI dose was aggravated compared to the lower TBI dose (P<.05). Among the syngeneic recipients, the injection of P815 cells into the recipient skin led to progressive tumor growth and death of about 100% 21 days after transplant regardless of the TBI dose. In contrast, tumor growth was remarkably suppressed and tumor death was not observed in the allogeneic recipients. Surprisingly, tumors in the allogeneic recipients receiving 1300 cGy TBI exhibited markedly delayed growth in vivo compared to those with 900 cGy (tumor volume on day 42, 428 vs. 8735mm3, P<.01), which was associated with an increase in the in vivo cytotoxicity using comparing the clearance of infused allogeneic B cells labeled with CFSE reflecting the enhanced alloimmune reactivity. To ask whether the diminished GVL effect after the lower TBI dose was due to reduced production of inflammatory cytokines, we measured the levels of TNF-α or IFN-γ in recipient sera on days 6, 28 and 42 after transplantation and did not find any significant difference according to the intensity of radiation dose (P>.05). In parallel, the in vitro P815-specific TNF-α or IFN-γ responses of splenocytes were comparable between the two doses. The percentages of donor T cells to undergo proliferation or apoptosis in response to alloantigens in vivo between the two TBI doses also were comparable (P>.05). Collectively, these data indicate that the impaired ability of alloreacive T cells to inhibit tumor growth after the lower TBI dose was not attributed to an intrinsic defect in T-cell expansion and activation. We next analyzed the spleen for the number of donor CD4+ and CD8+ T cells and observed no difference between the two TBI doses. In contrast to spleen, the number of CD8+ but not CD4+ T cells from the recipients that had received 1300 cGy was significantly increased in the skin (P<05). The effector function of donor CD8+ and CD4+ cells in both spleen and tumor tissue was examined by intracellular staining for IFN-γ. In the spleen, the percentages of CD8+ and CD4+ T cells expressing IFN-γ were not different between the two TBI doses. (5.9% vs 4.8%, P>.05, and 7.6% vs. 6.5%, P>.05 respectively) By contrast, 45.5% and 50.3% of CD8+ and CD4+ T cells, respectively, isolated from the tumor tissue of recipients receiving the higher TBI dose were IFN-γ; secreting cells, whereas only 25.5% and 16.3% of those cells from the tumor tissue of recipients treated with the lower dose showed this phenotype (P<.01 and <.05, respectively). After the higher TBI dose, secondary lymphoid organ homing receptors including CD62L and CCR7 were down-regulated on donor CD8+ T cells while CD44 expression was up-regulated compared to the lower TBI dose, which may facilitate migration to the tumor sites. In summary, the higher TBI dose (1300 vs. 900 cGy) resulted in significantly enhanced GVL effect, and the alterations in effector T cell trafficking into tumor tissue are the most likely mechanism. Moreover, T-cell activation and function were largely comparable between these conditioning regimens. This provides the rationale for targeting T cell trafficking by inflammation, possibly in combination with integrin or chemokine receptor agonists as a new therapeutic approach in leukemia relapse after allogeneic HSCT. Disclosures: No relevant conflicts of interest to declare.

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The Effect of miR-520b on Macrophage Polarization and T Cell Immunity by Targeting PTEN in Breast Cancer

Journal of Oncology ◽

10.1155/2021/5170496 ◽

2021 ◽

Vol 2021 ◽

pp. 1-19

Author(s):

Qin Zhu ◽

Jiaqi Yuan ◽

Yuqiong He ◽

Yu Hu

Keyword(s):

Breast Cancer ◽

T Cells ◽

T Cell ◽

Tumor Growth ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

Differentially Expressed ◽

Luciferase Reporter ◽

Mcf 7

Background. Breast cancer is the most common cancer in women. miR-520b had binding sites with PTEN through the bioinformatics prediction. But few studies have been conducted on miR-520b and PTEN in breast cancer. We aimed to explore the effect of miR-520b and PTEN on breast cancer and the mechanisms involved. Methods. Clinical samples of breast cancer were collected. Bioinformatics analysis was performed to screen the differentially expressed miRNAs. CD4 T cells and CD8 T cells were cocultured with MCF-7 cells in the Transwell system. Moreover, MCF-7 cells and M0 macrophage cocultured cell lines were constructed. qRT-PCR, IF, western blot, flow cytometry, and ELISA were performed to detect related factors expression. Starbase and dual-luciferase reporter assay verified the binding of miR-520b to PTEN. The tumor formation model was established to study miR-520b and PTEN effects in vivo. Results. The differentially expressed miR-520b was screened via miRNAs sequencing and cell verification. miR-520b expression was high, PTEN was low in tumor tissues, T cells and NK cells were inhibited, and macrophages were transformed into M2 type, promoting immune escape. In addition, miR-520b bound to PTEN. Then, splenic CD4 T cells and CD8 T cells were successfully sorted. During CD4 T cell differentiation to Th1 and Treg, Th1 was inhibited, and Treg was activated. We found the polarization of macrophages was related to breast cancer. The proportion of CD206 cells increased and CD68 cells decreased in the miR-520b mimics group compared with the mimic NC group. Compared with the inhibitor NC group, the proportion of CD206 cells decreased, and CD68 cells increased in the miR-520b inhibitor group. In vivo experiments showed that miR-520b inhibitor inhibited tumor growth and promoted PTEN expression. The proportion of CD3, CD4, CD8, NK1.1, CD4+IFNγ, and CD68 cells increased, while FOXP3 and CD206 cells decreased in the miR-520b inhibitor group compared with the inhibitor NC group. However, the proportion of CD3, CD4, CD8, NK1.1, CD4+IFNγ, and CD68 cells decreased, while FOXP3 and CD206 cells increased after the addition of siPTEN. Conclusions. miR-520b inhibited PTEN and aggravated breast tumors. miR-520b inhibitor enhanced CD4 and CD8 cell populations in the tumor immune microenvironment and inhibited tumor growth.

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AFM11, a CD19/CD3 bispecific tandab, to facilitate T-cell-mediated killing of CD19+ cells.

Journal of Clinical Oncology ◽

10.1200/jco.2013.31.15_suppl.3068 ◽

2013 ◽

Vol 31 (15_suppl) ◽

pp. 3068-3068

Author(s):

Eugene Zhukovsky ◽

Uwe Reusch ◽

Carmen Burkhardt ◽

Stefan Knackmuss ◽

Ivica Fucek ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

T Cell Activation ◽

Xenograft Model ◽

Cell Lysis ◽

Full Length ◽

Primary Tumors

3068 Background: CD19, due to broader expression on B cell subtypes, is an attractive alternative to CD20 as a target for treatment of B cell malignancies. T cells are potent tumor-killing effectors that cannot be recruited by full length antibodies, however TandAb technology harnesses their cytotoxic nature for oncology indications. The CD3 RECRUIT TandAb AFM11 enables T cells to potently and specifically kill CD19+ tumors and possesses advantageous PK properties enabling intravenous dosing. Methods: We constructed AFM11, a human bispecific tetravalent antibody with two binding sites for both CD3 and CD19. In vitro efficacy and safety were evaluated on CD19+ cell lines and primary tumors. In vivo efficacy was evaluated in a murine NOD/scid xenograft model reconstituted with human PBMC. Results: In vitro assays demonstrate higher potency and efficacy of target cell lysis by AFM11 relative to a bispecific tandem scFv. CD8+ T cells dominate early cytotoxicity (4 hrs) while after 24 hrs both CD4+ and CD8+ T cells equally contribute to tumor lysis with EC50 of 0.5 – 5 pM; cytotoxicity is independent of cell CD19 density. AFM11 exhibits similar cytotoxicity at Effector:Target ratios from 5:1 to 1:5 and facilitates T cell serial killing of its targets. AFM11 activates T cells only in the presence of CD19+ cells. In PBMC cultures AFM11 induces CD69 and CD25 expression, T cell proliferation, and production of IFN-γ, TNF-α, IL-2, IL-6, and IL-10. Depletion of CD19+ cells from PBMC abrogates these effects, and indicates strict CD19+ target-dependent T cell activation. Thus, AFM11 should not elicit the devastating cytokine release observed when full length antibodies bind CD3. Cell lysis by AFM11 is restricted to CD19+ targets asCD19- bystanders are not lysed in co-culture assays. Up to one week co-incubation with AFM11 does not inhibit T cell cytotoxicity and thus it does not induce anergy. In vivo AFM11 exhibits a dose-dependent growth inhibition of Raji tumors; a single dose of AFM11 exhibits similar efficacy as 5 daily injections. Conclusions: AFM11 is a highly efficacious novel drug candidate for the treatment of CD19+ malignancies with an advantageous safety profile and anticipated dosing regimen.

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Hirsutella Sinensis Fungus Regulates CD8+ T Cell Exhaustion Through Involvement of T-Bet/Eomes in the Tumor Microenvironment

Frontiers in Pharmacology ◽

10.3389/fphar.2020.612620 ◽

2021 ◽

Vol 11 ◽

Author(s):

Lu Jin ◽

Lushuai Jin ◽

Renjie Wu ◽

Xia Liu ◽

Xinhai Zhu ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Microenvironment ◽

Tumor Growth ◽

Lung Metastasis ◽

Cell Function ◽

T Cell Subsets ◽

Effector Memory

Background: Targeting exhausted T (Tex) cells is a promising strategy for anti-tumour treatment. Previously, we demonstrated that Hirsutella sinensis fungus (HSF) could significantly increase T cell infiltration and the effector T cell ratio in the tumor microenvironment, activating systemic immune responses. However, we do not know how HSF regulates Tex cells in the tumor microenvironment. Here, we explored the mechanism underlying HSF inhibition of Tex cells and tumor growth and metastasis in breast cancer.Methods: We examined the effects of HSF on various tumor mouse models using in vivo imaging technology. Lung metastasis was detected by H&E staining and the T cell subsets in the tumor microenvironment were assayed with flow cytometry. The in vitro proliferation, function and apoptosis of CD8+ T cells were measured, as well as the T-bet and PD-1 mRNA expressions.Results: HSF inhibited tumor growth and lung metastasis in the mice, and had significantly higher CD44LowCD62LHi and CD44HiCD62LLowpopulations in the tumour-infiltrating CD8+ T cells. However, HSF significantly reduced levels of inhibitory receptors, such as PD-1, TIGIT, CTLA-4, and regulatory T cells. In vitro, HSF inhibited the CD8+ T cell apoptosis rate, and promoted CD8+ T cell proliferation and secretion of interferon (IFN)-γ and granzyme B. Furthermore, HSF treatment both in vivo and in vitro significantly increased Eomes expression, while decreasing T-bet expression.Conclusion: HSF exerted anti-tumour effects mainly through the immune system, by promoting effector/memory T cells and reducing Tex cell production in the tumor microenvironment. The specific mechanisms involved inhibiting T-bet and promoting Eomes to decrease the expression of immune inhibitor receptors and enhance the T cell function, respectively.

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627 The DLL3-targeted half-life extended bispecific T cell engager (HLE BiTE®) immune-oncology therapy AMG 757 has potent antitumor activity in neuroendocrine cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0627 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A663-A663

Author(s):

Keegan Cooke ◽

Juan Estrada ◽

Jinghui Zhan ◽

Jonathan Werner ◽

Fei Lee ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Growth ◽

Mouse Models ◽

T Cell Activation ◽

Phase 1 ◽

Phase 1 Study ◽

Human T Cells

BackgroundNeuroendocrine tumors (NET), including small cell lung cancer (SCLC), have poor prognosis and limited therapeutic options. AMG 757 is an HLE BiTE® immune therapy designed to redirect T cell cytotoxicity to NET cells by binding to Delta-like ligand 3 (DLL3) expressed on the tumor cell surface and CD3 on T cells.MethodsWe evaluated activity of AMG 757 in NET cells in vitro and in mouse models of neuroendocrine cancer in vivo. In vitro, co-cultures of NET cells and human T cells were treated with AMG 757 in a concentration range and T cell activation, cytokine production, and tumor cell killing were assessed. In vivo, AMG 757 antitumor efficacy was evaluated in xenograft NET and in orthotopic models designed to mimic primary and metastatic SCLC lesions. NSG mice bearing established NET were administered human T cells and then treated once weekly with AMG 757 or control HLE BiTE molecule; tumor growth inhibition was assessed. Pharmacodynamic effects of AMG 757 in tumors were also evaluated in SCLC models following a single administration of human T cells and AMG 757 or control HLE BiTE molecule.ResultsAMG 757 induced T cell activation, cytokine production, and potent T cell redirected killing of DLL3-expressing SCLC, neuroendocrine prostate cancer, and other DLL3-expressing NET cell lines in vitro. AMG 757-mediated redirected lysis was specific for DLL3-expressing cells. In patient-derived xenograft and orthotopic models of SCLC, single-dose AMG 757 effectively engaged human T cells administered systemically, leading to a significant increase in the number of human CD4+ and CD8+ T cells in primary and metastatic tumor lesions. Weekly administration of AMG 757 induced significant tumor growth inhibition of SCLC (figure 1) and other NET, including complete regression of established tumors and clearance of metastatic lesions. These findings warranted evaluation of AMG 757 (NCT03319940); the phase 1 study includes dose exploration (monotherapy and in combination with pembrolizumab) and dose expansion (monotherapy) in patients with SCLC (figure 2). A study of AMG 757 in patients with neuroendocrine prostate cancer is under development based on emerging data from the ongoing phase 1 study.Abstract 627 Figure 1AMG 757 Significantly reduced tumor growth in orthotopic SCLC mouse modelsAbstract 627 Figure 2AMG 757 Phase 1 study designConclusionsAMG 757 engages and activates T cells to kill DLL3-expressing SCLC and other NET cells in vitro and induces significant antitumor activity against established xenograft tumors in mouse models. These preclinical data support evaluation of AMG 757 in clinical studies of patients with NET.Ethics ApprovalAll in vivo work was conducted under IACUC-approved protocol #2009-00046.

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IMMU-31. QUANTITATIVE EVALUATION OF ROUTES OF ADMINISTRATION OF IMMUNOTHERAPEUTIC T CELLS TO ORTHOTOPIC GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa215.461 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii111-ii111

Author(s):

Lan Hoang-Minh ◽

Angelie Rivera-Rodriguez ◽

Fernanda Pohl-Guimarães ◽

Seth Currlin ◽

Christina Von Roemeling ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Growth ◽

Ex Vivo ◽

Adoptive T Cell Therapy ◽

Whole Body ◽

T Cell Therapy ◽

Clinical Responses

Abstract SIGNIFICANCE Adoptive T cell therapy (ACT) has emerged as the most effective treatment against advanced malignant melanoma, eliciting remarkable objective clinical responses in up to 75% of patients with refractory metastatic disease, including within the central nervous system. Immunologic surrogate endpoints correlating with treatment outcome have been identified in these patients, with clinical responses being dependent on the migration of transferred T cells to sites of tumor growth. OBJECTIVE We investigated the biodistribution of intravenously or intraventricularly administered T cells in a murine model of glioblastoma at whole body, organ, and cellular levels. METHODS gp100-specific T cells were isolated from the spleens of pmel DsRed transgenic C57BL/6 mice and injected intravenously or intraventricularly, after in vitro expansion and activation, in murine KR158B-Luc-gp100 glioma-bearing mice. To determine transferred T cell spatial distribution, the brain, lymph nodes, heart, lungs, spleen, liver, and kidneys of mice were processed for 3D imaging using light-sheet and multiphoton imaging. ACT T cell quantification in various organs was performed ex vivo using flow cytometry, 2D optical imaging (IVIS), and magnetic particle imaging (MPI) after ferucarbotran nanoparticle transfection of T cells. T cell biodistribution was also assessed in vivo using MPI. RESULTS Following T cell intravenous injection, the spleen, liver, and lungs accounted for more than 90% of transferred T cells; the proportion of DsRed T cells in the brains was found to be very low, hovering below 1%. In contrast, most ACT T cells persisted in the tumor-bearing brains following intraventricular injections. ACT T cells mostly concentrated at the periphery of tumor masses and in proximity to blood vessels. CONCLUSIONS The success of ACT immunotherapy for brain tumors requires optimization of delivery route, dosing regimen, and enhancement of tumor-specific lymphocyte trafficking and effector functions to achieve maximal penetration and persistence at sites of invasive tumor growth.

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Upregulation of PD-1 expression on circulating CD8+ but not CD4+ T cells is associated with tuberculosis infection in health care workers

BMC Immunology ◽

10.1186/s12865-021-00433-9 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Cui-lin Shi ◽

Jian-ping Zhang ◽

Ping Xu ◽

Jin Li ◽

Jie Shen ◽

...

Keyword(s):

Health Care ◽

T Cells ◽

T Cell ◽

Health Care Workers ◽

Cd4 T Cells ◽

Receptor Expression ◽

Effector Memory ◽

Care Workers ◽

Latent Tb ◽

Latent Tb Infection

Abstract Background Health care workers (HCWs) are at risk for occupationally acquired Mycobacterium tuberculosis infection and tuberculosis (TB) disease due to repeated exposure to workplace tubercle bacilli. To determine whether continual mycobacterial stimulation correlates with increased expression of inhibitory T cell receptors, here we compared PD-1 receptor expression on surfaces of circulating T cells between naïve (uninfected) HCWs and HCWs with latent TB infection (LTBI). Result Data collected from 133 medical workers who met study selection criteria were included in the final analysis. QuantiFERON-TB Gold In-Tube (QFT-GIT) testing yielded positive results for 32 HCWs, for an overall LTBI rate of 24.1%. Multivariate analysis identified HCW length of service > 15 years as an independent risk factor for a positive QFT-GIT result. In addition, comparisons of blood T cell subgroup profiles between QFT- and QFT+ groups indicated QFT+ subjects possessed greater proportions of mature (TM), transitional memory (TTM) and effector memory (TEM) CD4+ T cell subgroups and lower proportions of naïve T cells (TN). Moreover, the QFT+ group percentage of CD8+ T cells with detectable surface PD-1 was significantly higher than the corresponding percentage for the QFT- group. Meanwhile, no statistical intergroup difference was observed in percentages of CD4+ T cells with detectible surface PD-1. Conclusions Our data demonstrated that upregulated PD-1 expression on circulating CD8+, but not CD4+ T cells, was associated with latent TB infection of HCWs. As compared to other hospitals, occupational TB infection risk in our hospital was substantially mitigated by implementation of multitiered infection control measures.

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Cd40-Independent Pathways of T Cell Help for Priming of Cd8+ Cytotoxic T Lymphocytes

Journal of Experimental Medicine ◽

10.1084/jem.191.3.541 ◽

2000 ◽

Vol 191 (3) ◽

pp. 541-550 ◽

Cited By ~ 144

Author(s):

Zhengbin Lu ◽

Lingxian Yuan ◽

Xianzheng Zhou ◽

Eduardo Sotomayor ◽

Hyam I. Levitsky ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd4 T Cells ◽

Cytotoxic T Lymphocyte ◽

Cell Communication ◽

Cd8 T Cell ◽

Cd4 Help ◽

T Cell Help

In many cases, induction of CD8+ CTL responses requires CD4+ T cell help. Recently, it has been shown that a dominant pathway of CD4+ help is via antigen-presenting cell (APC) activation through engagement of CD40 by CD40 ligand on CD4+ T cells. To further study this three cell interaction, we established an in vitro system using dendritic cells (DCs) as APCs and influenza hemagglutinin (HA) class I and II peptide–specific T cell antigen receptor transgenic T cells as cytotoxic T lymphocyte precursors and CD4+ T helper cells, respectively. We found that CD4+ T cells can provide potent help for DCs to activate CD8+ T cells when antigen is provided in the form of either cell lysate, recombinant protein, or synthetic peptides. Surprisingly, this help is completely independent of CD40. Moreover, CD40-independent CD4+ help can be documented in vivo. Finally, we show that CD40-independent T cell help is delivered through both sensitization of DCs and direct CD4+–CD8+ T cell communication via lymphokines. Therefore, we conclude that CD4+ help comprises at least three components: CD40-dependent DC sensitization, CD40-independent DC sensitization, and direct lymphokine-dependent CD4+–CD8+ T cell communication.

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