Biological correlates to support a clinical role for tagraxofusp, a novel targeted therapy directed to CD123, in combination with pomalidomide and dexamethasone, to target plasmacytoid dendritic cells in poor-risk patients with multiple myeloma.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e20537-e20537
Author(s):  
Dharminder Chauhan ◽  
Arghya Ray ◽  
Yan Song ◽  
Arturo Olguin ◽  
Janice Chen ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Dendritic Cells ◽  
Targeted Therapy ◽  
Cell Growth ◽  
Phase 1 ◽  
Plasmacytoid Dendritic Cells ◽  
Study Cohort ◽  
Serum Samples ◽  
Clinical Role

e20537 Background: We have previously described the pivotal pathogenetic role of plasmacytoid dendritic cells (pDCs; CD123/IL-3Ra+) in multiple myeloma (MM) (Chauhan et al Cancer Cell, 2009,16:309). In preclinical MM models, we demonstrated that tagraxofusp, a novel targeted therapy directed to CD123, triggers anti-MM activity by reducing the viability of MM-promoting pDCs. These observations led to an ongoing phase 1/2 clinical trial of tagraxofusp in MM patients (NCT02661022). The treatment regimen demonstrated safety and efficacy, with 5 of 9 heavily pretreated patients achieving durable partial response (PR). Here, we report the initial results of our translational exploratory studies using bone marrow (BM), peripheral blood (PB), and serum from the study cohort. Methods: pDCs and MM tumor cells were purified from BM/PB samples and quantified using FACS, as described ( Ray et al Leukemia, 2018,32:843). A high-throughput seroproteomics platform SOMAscan was utilized to analyze 1,310 protein analytes in serum samples from MM patients (N = 9). SOMAscan data were subjected to meta-analysis to generate heatmaps, followed by hierarchical cluster analysis. SOMAscan results were validated with ELISA using supernatants from MM patient pDCs cultured with or without tagraxofusp. Results: Analysis of BM/PB samples from MM patients receiving tagraxofusp therapy showed a marked reduction in the frequency of viable pDCs [average 2% at screen vs 0.75% post-tagraxofusp; N = 6; p = 0.036]. pDCs isolated from tagraxofusp-treated patients showed decreased ability to trigger MM cell growth. Seroproteomics analysis of MM patient serum before and after tagraxofusp therapy showed alterations in the levels of 100 proteins [Median Fold Change in expression: 0.39 to 4.5; n = 6; 3 each; p < 0.05]. Importantly, we found that tagraxofusp treatment reduced pDC-related soluble proteins, in particular, IFN-a and IL-3Rα. Additionally, our earlier study showed that pDC-MM interactions triggered secretion of MM cell growth including IL-3, which serves a dual role of promoting pDC survival and MM cell growth. Importantly, tagraxofusp decreased serum IL-3, suggesting that tagraxofusp attenuates survival mechanisms for tumor-promoting pDCs. Conclusions: Our current correlative studies validate target specificity of tagraxofusp and support further evaluation for this novel therapeutic to improve the clinical outcome of patients with MM.

Plasmacytoid Dendritic Cells Induce Growth and Survival of Multiple Myeloma Cells: Therapeutic Application.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3507-3507
Author(s):  
Dharminder Chauhan ◽  
Mohan Brahmandam ◽  
Ajita Singh ◽  
Giada Bianchi ◽  
Klaus Podar ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Dendritic Cells ◽  
Cell Growth ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Plasmacytoid Dendritic Cells ◽  
Thymidine Uptake ◽  
Growth And Survival ◽  
Significant Growth ◽  
Growth Of Tumor

Abstract The bone marrow (BM) microenvironment confers growth, survival, and drug resistance in multiple myeloma (MM) cells. Here we have characterized the role of plasmacytoid dendritic cells (pDCs) in the MM BM milieu. Immunochemistry (IHC) analysis of tissue microarrays on MM patient BM biopsies with Abs specific against pDCs (CD123) and MM cells (CD138) shows pDCs in proximity of MM cells. Quantification of pDCs obtained by direct isolation from MM patient BM aspirates or peripheral blood (PB) showed increased numbers of pDCs in MM-BM compared to PB. Freshly isolated pDCs from normal healthy donors stimulate significant growth of MM cells: 4.1 ± 0.8 fold increase {3H}-thymidine uptake in MM cells co-cultured with pDCs versus control MM cells alone, (P < 0.005). Irradiated pDCs retain their ability to trigger proliferation of MM cells; furthermore, pDC-depleted PBMCs did not trigger significant growth of MM cells, confirming a specific MM cell growth-promoting activity of pDCs. Co-culture of patient MM cells with pDCs triggered a significant growth of tumor cells, but not normal BM-derived plasma cells. Importantly, both allogeneic and autologous MM-derived pDCs induced tumor cell growth. To determine whether pDCs enhance MM cell growth in vivo, mice were implanted subcutaneously with pDCs alone, MM cells alone or pDCs + MM cells, and tumor growth was monitored over 3 weeks. A robust growth of tumor in mice receiving pDC + MM occurred within 12 days, whereas mice injected with MM cell alone showed a similar tumor growth only at day 21. We further examined the ability of pDCs to prolong ex-vivo survival of patient MM cells. Co-culture of pDCs with patient MM cells significantly increased the survival of patient tumor cells (59%, n=5 P<0.05), and IHC analysis of pDCs-MM cells co-cultures at 4 weeks confirmed that MM cells are clonal. We next examined the effect of anti-MM agents bortezomib and dexamethasone on the viability of pDCs and pDC-induced MM cell growth. Treatment of pDCs with bortezomib (20 nM) or dexamethasone (500 nM) does not significantly decrease viability of these cells (P = 0.25), higher concentrations of bortezomib (50 and 100 nM) decrease the viability of pDCs by less than 10%. Importantly, proliferation assays confirmed that pDCs triggered MM cell growth even in the presence of bortezomib, albeit to a lesser extent than without bortezomib(P<0.05). Microarray analysis showed that the pDCs-MM cells interaction triggered significant changes in transcriptional activity of genes related to growth, survival, anti-apoptosis, and migration in MM cells. Cytokine bead array analysis of supernatants from pDCs-MM cells co-cultures showed a marked increase in the secretion of MM cell growth, survival and chemotactic factors, such as IL-10, IL-6, IL-8, TNF-α, IL-1Rα, IL-1α, IL-13, IL-15, CD40L, MCP-1, MIP-1β, IP10 and VEGF. Overall, our data therefore show that pDCs predominantly localize in the MM BM and functionally interact with MM cells via cell-cell contact and subsequent cytokine secretion, allowing for MM cell growth and survival even in the presence of conventional and novel drugs. These studies will provide the basis for novel therapeutic approaches targeting pDC-MM interaction to improve patient outcome in MM.

scholarly journals Eminent role of ICOS costimulation for T cells interacting with plasmacytoid dendritic cells

Immunology ◽  
2006 ◽  
Vol 118 (3) ◽  
pp. 353-360 ◽  
Author(s):  
Marko Janke ◽  
Esther J. Witsch ◽  
Hans W. Mages ◽  
Andreas Hutloff ◽  
Richard A. Kroczek
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Plasmacytoid Dendritic Cells

scholarly journals Dual Role of the Tyrosine Kinase Syk in Regulation of Toll-Like Receptor Signaling in Plasmacytoid Dendritic Cells

PLoS ONE ◽  
2016 ◽  
Vol 11 (6) ◽  
pp. e0156063 ◽  
Author(s):  
Besma Aouar ◽  
Denisa Kovarova ◽  
Sebastien Letard ◽  
Albert Font-Haro ◽  
Jonathan Florentin ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Tyrosine Kinase ◽  
Plasmacytoid Dendritic Cells ◽  
Dual Role ◽  
Receptor Signaling ◽  
Toll Like Receptor

scholarly journals Blockade of Ubiquitin Receptor Rpn13 in Plasmacytoid Dendritic Cells Enhances Anti-Myeloma Immunity

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3098-3098
Author(s):  
Arghya Ray ◽  
Yan Song ◽  
Ting DU ◽  
Dharminder Chauhan ◽  
Kenneth C. Anderson
Keyword(s):  
Dendritic Cells ◽  
Cell Growth ◽  
Nk Cells ◽  
Tumor Cells ◽  
Immune Suppression ◽  
Nk Cell ◽  
Plasmacytoid Dendritic Cells ◽  
Cytolytic Activity ◽  
Immune Checkpoints ◽  
Autologous Tumor

Introduction Although proteasome inhibitor (PI) based combination therapies achieve remarkable responses multiple myeloma (MM), emergence of PI resistance is common. The mechanism(s) of PI-resistance include tumor-intrinsic factors such as mutations of the 20S proteasomal subunits, and/or tumor-extrinsic cellular components in the BM microenvironment. Interactions of BM accessory cells, immune effector cells, and tumor cells confer both drug-resistance and immune suppression in MM. For example, we showed that interactions of MM plasmacytoid dendritic cells (pDCs) with MM cells and with T/NK cells both confer immune suppression via immune checkpoints, as well as trigger MM cell growth by inducing secretion of MM cell growth factors. We recently reported that targeting proteasome-associated ubiquitin receptor Rpn13 triggers cytotoxicity and overcomes tumor-intrinsic PI-resistance in MM (Song et al, Leukemia 2016;30:1877). Here we utilized our co-culture models of patient pDCs, T cells, NK cells, and autologous MM cells to characterize the immune sequelae of Rpn13 inhibition. Methods Analysis of pDCs activation Purified patient-pDCs (n =7) were treated with Rpn13 inhibitor RA190 (0.05 µM) for 24h, followed by multicolor staining using fluorophore-conjugated Abs against pDC activation/maturation markers CD80, CD83, and CD86. Transient transfections Purified MM patient pDCs were transfected with Rpn13-siRNA using TransIT-X2 transfection Kit,and analyzed for alterations in maturation markers. CTL/NK activity assays Purified MM-BM CD8+ T- or NK-cells (n = 8) were co-cultured with autologous BM-pDCs (pDC:T/NK; 1:10 ratio) for 3 days, in the presence or absence of Rpn13 inhibitor RA190 (100 nM). After washing, cells were cultured for 24h with autologous MM cells pre-stained with CellTracker/CellTrace Violet (10 T/NK:1 MM), followed by 7-AAD staining and quantification of CTL-or NK cell-mediated MM cell lysis by FACS. Results 1) RA190 triggers significant upregulation of maturation markers CD80, CD83, and CD86 on MM-pDCs (fold change vs untreated: CD80: 1.2; p = 0.007; CD83: 2.15; p = 0.006; CD86: 1.4; p = 0.003). In contrast, bortezomib-treated pDCs showed no significant upregulation of these markers. 2) Similar to pharmacological inhibition of Rpn13 with RA190, Rpn13-siRNA increased CD80 (1.76-fold), CD83 (3.12-fold), and CD86 (2.28-fold) expression on MM pDCs (p<0.01). Of note, both RA190 and bortezomib block protein degradation via proteasome, but only RA190 activates pDCs. 3) RA190 treatment increases pDC-induced MM-specific CD8+ CTL activity, as well as NK cell-mediated cytolytic activity against autologous tumor cells, evidenced by decreased viable patient MM cells. 4) Treatment of MM-pDCs with RA190 increases expression of calnexin, a molecular chaperone protein of endoplasmic reticulum which regulates immune co-stimulatory molecules, immune-regulatory signaling, and restores the ability of pDCs to induce proliferation of MM-specific CTLs or NK cells. These findings were also confirmed using pDC cell line CAL-1. Conclusions Our prior findings showed that inhibition of UbR Rpn13 overcomes intrinsic PI-resistance in MM cells. Here we show that targeting Rpn13 also triggers anti-MM immune responses. Rpn13 blockade therefore represents a novel therapeutic approach to overcome both PI-resistance and immune suppression in MM. Disclosures Chauhan: C4 Therapeutics.: Equity Ownership; Stemline Therapeutics: Consultancy. Anderson:Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Other: Scientific Founder; Oncopep: Other: Scientific Founder; Amgen: Consultancy, Speakers Bureau; Sanofi-Aventis: Other: Advisory Board.

scholarly journals Correlation Between Immune Lymphoid Cells and Plasmacytoid Dendritic Cells in Human Colon Cancer

2020 ◽  
Author(s):  
Jing Wu ◽  
Hang Cheng ◽  
Tete Li ◽  
Helei Wang ◽  
Guoxia Zang ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Dendritic Cells ◽  
Rna Sequencing ◽  
Immune Cells ◽  
Human Colon ◽  
Tumour Microenvironment ◽  
Plasmacytoid Dendritic Cells ◽  
Lymphoid Cells ◽  
Human Colon Cancer

Abstract Background: Innate lymphoid cells (ILCs), so far studied mostly in mouse models, are important tissue-resident innate immune cells that play important roles in the colorectal cancer microenvironment and maintain the mucosal tissue homeostasis. Plasmacytoid dendritic cells (pDCs) present complexity in various tumour types and are correlated with poor prognosis. pDCs can promote HIV-1–induced group 3 ILC (ILC3) depletion through the CD95 pathway. However, the role of ILC3s in human colon cancer and their correlation with other immune cells, especially pDCs, remain unclear. Methods: We characterised ILCs and pDCs in the tumour microenvironment of 58 colon cancer patients by flow cytometry and selected three patients for RNA sequencing. Results: ILC3s were negatively correlated, and pDCs were positively correlated, with cancer pathological grade. There was a negative correlation between the numbers of ILC3s and pDCs in tumour tissues. RNA sequencing confirmed the correlations between ILC3s and pDCs and highlighted the potential function of many ILC- and pDC-associated differentially expressed genes in the regulation of tumour immunity. pDCs can induce apoptosis of ILC3s through the CD95 pathway in the tumour microenvironment. Conclusions: One of the interactions between ILC3s and pDCs is via the CD95 pathway, which may help explain the role of ILC3s in colon cancer.

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