Role of CD37SMIP a Novel Engineered Small Modular Immunopharmaceutical in the Treatment of CLL.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 801-801 ◽  
Author(s):  
Rosa Lapalombella ◽  
Xiaobin B. Zhao ◽  
Peter R. Baum ◽  
Jeffrey A. Ledbetter ◽  
Natarajan Muthusamy ◽  
...  

Abstract CD37 is a lineage-specific B-cell antigen highly expressed on both normal and transformed B-cells. The significant B-cell selective CD37 expression makes it a valuable target for therapy against B cell malignancies including chronic lymphocytic leukemia (CLL), hairy cell leukemia (HCL), and non-Hodgkins lymphoma (B-NHL). A novel CD37-specific small modular immunopharmaceutical (CD37SMIP) was engineered to contain a single chain variable region (scFv) linked to a human IgG1 hinge, CH2 and CH3 domains. CD37SMIP induces potent apoptosis in the presence of a crosslinker and antibody dependent cellular cytotoxicity (ADCC) against primary CLL cells. Significant in vivo therapeutic efficacy was demonstrated in a SCID mouse xenograft leukemia/lymphoma model that is dependent upon NK cell function. The induced cytotoxicity in primary CLL cells was independent of activation of caspase cascade, and consistent with this, the pan-caspase inhibitor z-VAD-fmk failed to rescue CD37 SMIP drug induced cytotoxicity. In an attempt to define the CD37 mediated early signaling events and their role in cytotoxicity, we investigated protein tyrosine phosphorylation as a potential early activation event responsible for CD37 SMIP drug mediated cytotoxicity. Primary B CLL cells were stimulated with increasing concentration of CD37 SMIP with or without crosslinker. Western blot analysis of cellular lysates with anti-phosphotyrosine antibody revealed several tyrosine phosphorylated proteins including a predominant ∼65KDa protein in response to the cross-linking of CD37 SMIP within 10 minutes. Further, pre-treatment with the tyrosine kinase inhibitor herbimycin prevented tyrosine phosphorylation of the predominant 65KDa protein and inhibited CD37 SMIP induced apoptosis in a dose dependent manner. Attempts to identify the tyrosine phosphorylated proteins, using MALDI-TOF mass spectrometry, and to define the potential role of these target proteins in the apoptotic pathway are ongoing. To further examine the molecular mechanism whereby CD37 SMIP triggers cell death, we investigated the involvement of mitochondrial pathways including changes in mitochondrial potential (Δψm) and generation of reactive oxygen species. Treatment with CD37 SMIP induces a time dependent mitochondrial membrane depolarization and increased production of ROS. Further, primary B CLL cells cultured with CD37SMIP induced cleavage and mitochondrial translocation of Bax and upregulation of Bim in a time dependent manner indicating a potential role for Bim and Bax pro apoptotic proteins in CD37 induced apoptosis. These findings provide strong justification for CD37 as a therapeutic target aimed at modulation of pro apoptotic proteins and introduce small modular immunopharmaceuticals as a novel class of targeted therapies for B-cell malignancies. (SMIP trademark is owned by Trubion Pharmaceuticals).

2021 ◽  
Vol 12 ◽  
Author(s):  
Jinming Liu ◽  
Haiman Xu ◽  
Li Zhang ◽  
Shuai Wang ◽  
Danyi Lu ◽  
...  

Identifying drugs with dosing time-dependent effects (chronoeffects) and understanding the underlying mechanisms would help to improve drug treatment outcome. Here, we aimed to determine chronoeffects of the herbal medicines Puerariae radix (PR) and Coptidis rhizoma (CR), and investigate a potential role of REV-ERBα as a drug target in generating chronoeffects. The pharmacological effect of PR on hyperhomocysteinemia in mice was evaluated by measuring total homocysteine, triglyceride levels and lipid accumulation. PR dosed at ZT10 generated a stronger effect on hyperhomocysteinemia than drug dosed at ZT2. Furthermore, PR increased the expression levels of REV-ERBα target genes Bhmt, Cbs and Cth (encoding three key enzymes responsible for homocysteine catabolism), thereby alleviating hyperhomocysteinemia in mice. Moreover, CR attenuated chronic colitis in mice in a dosing time-dependent manner based on measurements of disease activity index, colon length, malondialdehyde/myeloperoxidase activities and IL-1β/IL-6 levels. ZT10 dosing generated a stronger anti-colitis effect as compared to ZT2 dosing. This was accompanied by lower production of colonic inflammatory cytokines (i.e., Nlrp3, IL-1β, IL-6, Tnf-α and Ccl2, REV-ERBα target genes) in colitis mice dosed at ZT10. The diurnal patterns of PR and CR effects were respectively consistent with those of puerarin (a main active constituent of PR, a REV-ERBα antagonist) and berberine (a main active constituent of CR, a REV-ERBα agonist). In addition, loss of Rev-erbα in mice abolished the dosing time-dependency in PR and CR effects. In conclusion, the therapeutic effects of PR and CR depend on dosing time in mice, which are probably attributed to diurnal expression of REV-ERBα as the drug target. Our findings have implications for improving therapeutic outcomes of herbal medicines with a chronotherapeutic approach.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 753-753 ◽  
Author(s):  
Rosa Lapalombella ◽  
Xiaobin B. Zhao ◽  
Laura Grosmaire ◽  
Jeffrey A. Ledbetter ◽  
Natarajan Muthusamy ◽  
...  

Abstract CD37 is a heavily glycosylated 40–52 kDa tetraspan transmembrane family (TSTF) protein that is highly expressed on normal B cells and transformed B-cell malignancies. Peripheral blood mononuclear cells from CLL patients revealed surface expression of CD37 on CD19+ B cells but not CD3+ T cells, CD16+ or CD56+ NK, or CD64+ monocytes. The significant B-cell selective CD37 expression makes it a valuable target for therapy against B cell malignancies including B-CLL, hairy cell leukemia (HCL), and B cell non-Hodgkin’s lymphoma (B-NHL). A small modular immuno pharmaceutical targeted against CD37 (CD37-SMIP™drug) was engineered to contain a single chain variable region (scFv) linked to a human IgG1 hinge, CH2 and CH3 domains. The CD37-SMIP mediated direct cytotoxicity in dose and time dependent manner with maximal effect seen at 5μg/mL. The CD37-SMIP™drug mediated cytotoxicity is dependent on secondary cross linking with goat anti- human IgG (Fc specific) and is directly correlated with the levels of surface expression of CD37. The induced cytotoxicity in primary CLL cells is independent of activation of caspase cascade, and consistent with this, the pan–caspase inhibitor z-VAD-fmk failed to rescue CD37-SMIP™drug induced cytotoxicity. In an attempt to define the CD37 mediated early signaling events and their role in cytotoxicity, we investigated protein tyrosine phosphorylation as a potential early activation event responsible for CD37-SMIP™drug mediated cytotoxicity. CD19+ B cells from CLL patients were stimulated with 1, 5 or 25μg/ml of CD37-SMIP™drug in the presence or absence of goat anti- human IgG (Fc specific). Protein lysates prepared at 1, 3 and 10 minutes post stimulation, revealed time and dose dependent tyrosine phosphorylation of several unknown proteins including a predominant ~65kDa protein, as detected by Westernblot analysis using anti-phosphotyrosine antibody. Further, pre-treatment of CD19+ primary CLL cells with the tyrosine kinase inhibitor, herbimycin, prevented the CD37-SMIP™drug induced tyrosine phosphorylation of several of these proteins including the predominant ~65kDa protein. Interestingly, consistent with a potential role for tyrosine phosphorylation events in CD37-SMIP™drug induced cell death, increasing concentrations of herbimycin inhibited CD37-SMIP™drug induced cytotoxicity of CD19+ primary CLL cells. Detailed two dimensional gel analysis of lysates from CD37-SMIP™drug treated and untreated CD19+ CLL cells revealed at least 6 potential tyrosine phosphorylated targets. Further experiments to identify the tyrosine phosphorylated proteins, using MALDI-TOF mass spectrometry, and to define the potential role of these target proteins in the apoptotic pathway are ongoing. We conclude that CD37 SMIP™drug may represent an exciting novel therapy for CLL and that direct cytotoxicity appears to be related to specific changes in protein tyrosine phosphorylation status. (SMIP trademark is owned by Trubion Pharmaceuticals).


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2672-2672
Author(s):  
Marion Leick ◽  
Julie Catusse ◽  
Meike Burger

Abstract Abstract 2672 Poster Board II-648 Introduction: Chemokines work as cellular recruitment molecules. Specific combinations of chemokines, receptors, and adhesion molecules determine which subgroups of leukocytes migrate and what their destinations are. Chemokine receptor expression and activation on malignant cells may be involved in the growth, survival and migration of cancer cells as well as in the tumor vascularisation. CCR7, by binding the chemokines CCL19 and CCL21, is centrally involved in B cell localisation to the secondary lymphoid organs and therefore implicated in lymphadenopathy of various non-hodgkin lymphomas (NHL). In addition to chemokine receptors that have been cloned and described, various orphan receptors with a chemokine receptor-like structure are still not characterized. Atypical, non-signaling chemokine receptors are members of a newly described class of receptors and have been implicated with chemokine clearance and influencing of other signalling receptors. They are consequently considered as potent immuno-modulators and as anti-inflammatory factors and are implicated in progression of cancer. Among these receptors, we are investigating the role of the orphan chemokine (C-C motif) receptor-like 2 (CCRL2), also known as CRAM, a receptor expressed on endothelial cells and B cells in a maturation stage dependent manner, but for which functions and ligands are poorly characterized so far. In an effort to elucidate the role of CRAM and its implication in neoplasias, we have focussed research on identification of ligands and the implication of CRAM in regulating B cell migration in samples from healthy donors and from non-Hodgkin lymphomas. Methods: We characterised the receptor's expression profile by flow cytometry in peripheral blood, bone marrow and lymph node sections of different B cell NHL and correlated it to expression levels of CCR7 and CXCR4. In addition, a screening for ligands was performed using radiolabelled binding assays. The role of CRAM was elucidated using various functional assays, internalisation and transcytosis experiments. Results: We show that CRAM is an alternative, but non-signaling receptor for the CCR7-activating chemokine CCL19. CRAM is constitutively recycling to and from the cell surface and internalizing the chemokine without degrading it. We found that the receptor is responsible for transcytosis of CCL19 through endothelial cell layers and subsequent presentation, a crucial step in homing of leukocytes to the lymph nodes. On the other hand, when expressed on B cells, CRAM interferes in CCL19 binding to CCR7. We thereby show that CRAM can act as an integrator of different signals, by binding different chemokines and controlling their activity toward surrounding ligands. Chemotaxis experiments demonstrate that CRAM is a negative modulator of CCL19 B cell recruitment. In addition, we have found increased expression in activated B cells, dendritic cells, and also in the B cell malignancies chronic lymphocytic leukemia (B-CLL) and pre-B cell acute lymphoblastic leukemia (pre-B ALL), and are currently evaluating CRAM as a possible prognostic marker in various B-NHLs. Conclusions: CRAM is a newly identified member of the silent or atypical chemokine receptor group, already known for modulating chemokine availability, together with D6, DARC and CCX-CKR. We have shown here that it contributes to lymphocyte recruitment into peripheral lymphoid tissue by presenting CCL19 on endothelium. It is also involved in CCR7 driven recruitment of B cells by regulating CCL19 availability. Expression of CRAM differs in B cell malignancies for which both CCR7 ligands, CCL19 and CCL21, have already been shown to be implicated in the development of lymphadenopathies. We therefore suggest that CRAM is an additional player and potential biomarker in determining outcome and development of disease. Disclosures: No relevant conflicts of interest to declare.


2017 ◽  
Vol 313 (5) ◽  
pp. L899-L915 ◽  
Author(s):  
Fumiaki Kato ◽  
Seiichiro Sakao ◽  
Takao Takeuchi ◽  
Toshio Suzuki ◽  
Rintaro Nishimura ◽  
...  

Pulmonary arterial hypertension (PAH) is characterized by progressive obstructive remodeling of pulmonary arteries. However, no reports have described the causative role of the autophagic pathway in pulmonary vascular endothelial cell (EC) alterations associated with PAH. This study investigated the time-dependent role of the autophagic pathway in pulmonary vascular ECs and pulmonary vascular EC kinesis in a severe PAH rat model (Sugen/hypoxia rat) and evaluated whether timely induction of the autophagic pathway by rapamycin improves PAH. Hemodynamic and histological examinations as well as flow cytometry of pulmonary vascular EC-related autophagic pathways and pulmonary vascular EC kinetics in lung cell suspensions were performed. The time-dependent and therapeutic effects of rapamycin on the autophagic pathway were also assessed. Sugen/hypoxia rats treated with the vascular endothelial growth factor receptor blocker SU5416 showed increased right ventricular systolic pressure (RVSP) and numbers of obstructive vessels due to increased pulmonary vascular remodeling. The expression of the autophagic marker LC3 in ECs also changed in a time-dependent manner, in parallel with proliferation and apoptotic markers as assessed by flow cytometry. These results suggest the presence of cross talk between pulmonary vascular remodeling and the autophagic pathway, especially in small vascular lesions. Moreover, treatment of Sugen/hypoxia rats with rapamycin after SU5416 injection activated the autophagic pathway and improved the balance between cell proliferation and apoptosis in pulmonary vascular ECs to reduce RVSP and pulmonary vascular remodeling. These results suggested that the autophagic pathway can suppress PAH progression and that rapamycin-dependent activation of the autophagic pathway could ameliorate PAH.


2020 ◽  
Author(s):  
Jun Sun ◽  
Xiaofeng Tang ◽  
Feifei Zhang ◽  
Cheng Ju ◽  
Renfeng Liu ◽  
...  

Abstract Background: WT161 as a new selective HDAC6 inhibitor has been shown to play anti-tumor effects on multiple myeloma and breast cancer. However, the role of WT161 in osteosarcoma remains unclear. The aim of this study is to explore the role of WT161 in osteosarcoma and its underlying mechanisms.Methods: The anti-proliferative effect of WT161 on osteosarcoma cells was examined using MTT assay and colony formation assay. Cell apoptosis was analyzed using flow cytometer. The synergistic effect was evaluated by isobologram analysis using CompuSyn software. The osteosarcoma xenograft models were esatablished to evaluate the anti-proliferative effect of WT161 in vivo.Results: WT161 suppressed the cell growth and induced apoptosis of osteosarcoma cells in a dose- and time-dependent manner. Mechanistically, we found that WT161 treatment obviously increased the protein expression level of PTEN and decreased the phosphorylation level of AKT. Notably, WT161 shows synergistically inhibitory effects on osteosarcoma cell combined with 5-FU. Animal experiment results show WT161 inhibits the growth of osteosarcoma tumor and further illustrates that WT161 and 5-FU have a synergistic efficiency in osteosarcoma.Conclusions: These results indicate that WT161 inhibiting the growth of osteosarcoma through PTEN and has a synergistic efficiency with 5-FU.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1734-1734
Author(s):  
Orit Uziel ◽  
Zinab Sarsur- Amer ◽  
Einat Beery ◽  
Pia Raanani ◽  
Uri Rozovski

Studies from recent years unraveled the role of monocytes and T-cells in the pathogenesis of chronic lymphocytic leukemia (CLL). The role of other immune cells in the pathobiology of CLL is less known. Specifically, whether B-cells, the normal counterpart of CLL cells play a role in CLL is unknown. Nevertheless, since both CLL cells and wild type B-cells reside in lymphatic organs and travel in blood, they either share or compete over common environmental resources. According to the cell competition theory, a sensing mechanism measures the relative fitness of a cell and ensures the elimination of cells deemed to be less fit then their neighbors. Since constitutive activation of intracellular pathways protect CLL cells from apoptosis, the cell competition theory predicts that compared with normal B-cells these cells are sensed as "super fit" and B-cells, the less fit counterparts, are eliminated. Yet, what delivers this massage across a population of cells is unknown. Exosomes are nanosized particles that are secreted by various types of cells. Exosomes carry a cargo of proteins and different types of RNA. They travel in body fluids and are taken up by cells in their vicinity. Since cancer cells including CLL cells secrete exosomes, we have formulated our hypothesis, namely, that exosomes derived from CLL cells are the vehicles that carry a death massage to wild type B-cells. To test this hypothesis, we isolated CLL cells from 3 previously untreated patients with CLL. We then grew these cells in exosome free media for 72 hours and harvested the exosomes by ultracentrifugation. We used NanoSight tracking analysis, Western immunoblotting for CD63, a common exosomal marker, and electron microscopy imaging studies to ensure that our pellet include the typical 100nm exosomal particles. Subsequently, we subjected normal B-cells derived from healthy volunteers to CLL derived exosomes stained by FM-143 dye. Using flow cytometry we found that exosomes are taken up by normal B-cells in a dose- and time- dependent manner. Double staining of the recipient B-cells to Annexin/PI revealed that exosomes induce apoptosis of these cells in a dose- and time- dependent manner. We then used RNA-seq to trace the changes in the molecular makeup of B-cells after exosomal uptake?? they took up exosomes. We found 24 transcripts that were differentially expressed (11 that were upregulated and 13 that were downregulated). We then verified the array results by quantitative real-time PCR for four of these genes. Among the top transcripts that were upregulated in exosome-positive B-cells is SMAD6. Because the upregulation of the SMAD family members including SMAD6 is associated with the induction of apoptosis in various malignant and non-malignant cells we wondered whether the upregulation of SMAD6 also induces apoptosis in normal B-cells. To test this, we transfected normal B-cells with SMAD6 containing vector and verified by RT-PCR that level of SMAD6 transcript were upregulated and by Western immunoblotting that levels of SMAD6 protein are upregulated as well. As expected, the rate of apoptosis was higher, and the rates of viable cells and proliferating cells were significantly lower in SMAD6-transfected B-cells. Taken together, we show here that CLL cells secrete exosomes that function as "Trojan horses". Once they are taken up by normal B-cells they induce SMAD6-dependent apoptosis. In this way the neoplastic cells may actively eliminate their competitors and take over the common environmental resources. Disclosures No relevant conflicts of interest to declare.


2006 ◽  
Vol 203 (1) ◽  
pp. 189-201 ◽  
Author(s):  
Ronit Vogt Sionov ◽  
Orly Cohen ◽  
Shlomit Kfir ◽  
Yael Zilberman ◽  
Eitan Yefenof

The mechanisms by which glucocorticoid receptor (GR) mediates glucocorticoid (GC)-induced apoptosis are unknown. We studied the role of mitochondrial GR in this process. Dexamethasone induces GR translocation to the mitochondria in GC-sensitive, but not in GC-resistant, T cell lines. In contrast, nuclear GR translocation occurs in all cell types. Thymic epithelial cells, which cause apoptosis of the PD1.6 T cell line in a GR-dependent manner, induce GR translocation to the mitochondria, but not to the nucleus, suggesting a role for mitochondrial GR in eliciting apoptosis. This hypothesis is corroborated by the finding that a GR variant exclusively expressed in the mitochondria elicits apoptosis of several cancer cell lines. A putative mitochondrial localization signal was defined to amino acids 558–580 of human GR, which lies within the NH2-terminal part of the ligand-binding domain. Altogether, our data show that mitochondrial and nuclear translocations of GR are differentially regulated, and that mitochondrial GR translocation correlates with susceptibility to GC-induced apoptosis.


1998 ◽  
Vol 275 (5) ◽  
pp. L942-L949 ◽  
Author(s):  
Beek Yoke Chin ◽  
Mary E. Choi ◽  
Marie D. Burdick ◽  
Robert M. Strieter ◽  
Terence H. Risby ◽  
...  

Particulate matter (PM) is a major by-product from the combustion of fossil fuels. The biological target of inhaled PM is the pulmonary epithelium and resident macrophages. In this study, we demonstrate that cultured macrophages (RAW 264.7 cells) exposed continously to a well-defined model of PM [benzo[ a]pyrene adsorbed on carbon black (CB+BaP)] exhibit a time-dependent expression and release of the cytokine tumor necrosis factor-α (TNF-α). CB+BaP also evoked programmed cell death or apoptosis in cultured macrophages as assessed by genomic DNA-laddering assays. The CB+BaP-induced apoptosis was inhibited when macrophages were treated with CB+BaP in the presence of a neutralizing antibody to TNF-α, suggesting that TNF-α plays an important role in mediating CB+BaP-induced apoptosis in macrophages. Interestingly, neither untreated carbon black nor benzo[ a]pyrene alone induced apoptosis or caused the release of TNF-α in RAW 264.7 cells. Moreover, we observed that TNF-α activates mitogen-activated protein kinase (MAPK) activity, the extracellular signal-regulated kinases p42/p44, in a time-dependent manner. RAW 264.7 cells treated with PD-098059, a selective inhibitor of MAPK kinase activity, did not exhibit CB+BaP-induced apoptosis and TNF-α secretion. Furthermore, cells treated with the MAPK kinase inhibitor did not undergo TNF-α-induced apoptosis. Taken together, our data suggest that TNF-α mediates PM-induced apoptosis and that the MAPK pathway may play an important role in regulating this pathway.


Sign in / Sign up

Export Citation Format

Share Document