CLL-1 Is a Potential Target for the Treatment of Acute Myeloid Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2839-2839
Author(s):  
Wouter Korver ◽  
Xiaoxian Zhao ◽  
Shweta Singh ◽  
Eric D. Hsi ◽  
Arie Abo
Keyword(s):  
Flow Cytometry ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Normal Tissues ◽  
B Lymphoma Cells ◽  
293 Cells ◽  
Complement Dependent Cytotoxicity ◽  
Xenograft Models

Abstract CLL-1 (C-type Lectin-Like Molecule-1) is an inhibitory receptor expressed on myeloid cells. We have generated a series of monoclonal antibodies (mAbs) against CLL-1 and used these mAbs to assess expression of the receptor on normal and AML cells and their therapeutic potential in in vitro and ex vivo cytotoxicity assays. By Immunohistochemistry, normal tissues lacked expression of CLL-1, with the exception of spleen. Using flow cytometry, expression was demonstrated on monocytes, granulocytes and dendritic cells, but not on lymphocytes and platelets. Tissue micro-arrays revealed CLL-1 expression in 97.3% (37/38) of AML cases. Flow cytometry of AML blasts demonstrated expression of CLL-1 on 81% (17/21) of patient samples. No detectable expression was detected in ALL blasts (n=5). Selected anti-CLL-1 mAbs mediated dose-dependent Complement Dependent Cytotoxicity (CDC) in various AML-derived cell lines, while no cytotoxicity was observed in CLL-1 negative K562 (CML) or CA46 (B lymphoma) cells. Human embryonic kidney 293 cells only became susceptible to anti-CLL-1 mAb mediated killing after transfection with CLL-1, demonstrating specificity. Furthermore, anti-CLL-1 mAbs showed CDC activity against all AML blasts tested in ex vivo assays (n=10), while no activity was observed against ALL blasts. Our results demonstrate restricted expression of CLL-1 on cells from myeloid origin and AML blasts and specific cytotoxic activity in in vitro and ex vivo assays. We are currently undertaking xenograft models to evaluate the therapeutic potential of these mAbs in vivo.

The IL-15 Super-Agonist ALT-803 Promotes Superior Activation and Cytotoxicity of Ex Vivo Expanded NK Cells Against AML

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3090-3090 ◽  
Author(s):  
Folashade Otegbeye ◽  
Nathan Mackowski ◽  
Evelyn Ojo ◽  
Marcos De Lima ◽  
David N. Wald
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Nk Cells ◽  
Myeloid Leukemia ◽  
Nk Cell ◽  
Ex Vivo ◽  
Leukemia Cells ◽  
Activating Receptor

Abstract Introduction: A crucial component of the innate immune response system, natural killer (NK) cells are uniquely competent to mediate anti-myeloid leukemia responses. NKG2D is an activating receptor on the surface of NK cells that engages stress ligands MICA and MICB, typically upregulated on myeloid leukemia cells. Adoptive transfer of NK cells is a promising treatment strategy for AML. Strategies to optimize the anti-leukemia effect of NK cell adoptive transfer are an area of active research. These include attempts to enhance NK cell activity and to maintain the activation status and proliferation of the NK cells in vivo. Traditionally, IL-2 has been used to maintain the in vivo proliferation of adoptively transferred NK cells, but it leads to unwanted proliferation of regulatory T cells and suboptimal NK cell proliferation. IL-15 may be superior to IL-2, without the effects on T regulatory cells. The IL-15 superagonist, ALT-803 exhibits >25 fold enhancement in biological activity as compared to IL-15. ALT-803 is a fusion protein of an IL-15 mutant and the IL-15Rα/Fc complex that has recently entered clinical trials as a direct immunomodulatory agent in cancer clinical trials We hypothesized ALT-803 would augment the activity and/or proliferation of adoptively transferred NK cells in vitro and in a mouse model system.. Methods: Human NK cells were isolated from healthy donor peripheral blood and were expanded over a 21-day period in co-culture with irradiated K562 cells genetically modified to express membrane-bound IL-21. (Somanchi et al. 2011 JoVE 48. doi: 10.3791/2540) The NK cells were expanded with IL-2 (50mU/mL) and/or ALT-803 (200ng/mL). On Day 21, NK cells were examined for cytotoxicity against AML cells as well as by flow cytometry for expression of known activating receptors. An NSG murine xenograft model of human AML was developed to test the in vivo function of NK cells expanded above. Briefly, NSG mice (n=5 per group) were non-lethally irradiated and each injected IV with 5 x106 OCI-AML3 leukemic cells. Two days later, each mouse received weekly NK cell infusions for 2 weeks. Mice that received NK cells expanded with IL2 got cytokine support with IL-2 (75kU IP three times a week). Mice infused with ALT-803 expanded cells (alone or in combination with IL2) received ALT-803 (0.2mg/kg IV weekly). One control group received OCI cells but were infused weekly only with 2% FBS vehicle, no NK cells. Leukemic burden in each mouse was assessed by flow cytometry of bone marrow aspirates on day 28 following start of NK cell infusions). This time point was chosen as the control mice appeared moribund. Results: ALT-803 did not have any differential effect on the proliferation of the NK cells ex vivo as compared to IL-2. However, the presence of ALT-803 either alone or in combination with IL-2 resulted in a significant increase (30% increase, p<0.0001) in the cytotoxic activity of the NK cells against leukemia cells as compared with IL-2 alone in vitro (figure 1). In addition, the percentages of NK cells that express the activating receptor NKG2D as well as CD16 were significantly higher (p<0.001 for both) after ALT-803 exposure (figure 1). Finally, in the murine xenograft AML model, ALT-803 expanded NK cells, which were also supported in vivo with ALT-803, resulted in an 8-fold reduction in disease burden in the bone marrow (p<0.0001). Importantly the efficacy of NK cells in the ALT-803 injected mice was significantly higher (3-fold, p= 0.0447) than IL-2 treated mice (figure 2). Discussion: Our results suggest that the presence of ALT-803 during ex-vivo expansion of NK cells results in increased activation and cytotoxicity against AML cells. In addition our results using a murine model of human AML show that the use of ALT-803 in combination with adoptively transferred NK cells provides a significant anti-leukemic benefit as compared to IL-2. Future studies to test larger panels of leukemia cells as well as other cancer cell lines are currently in progress. It is hoped that this work will lead to an improvement in the efficacy of adoptively transferred NK cells for AML patients due to an improvement in survival and activity of the NK cells. Disclosures Wald: Invenio Therapeutics: Equity Ownership.

T-cell redirected killing and cure of pancreatic and gastric cancer xenografts by targeting Trop-2.

2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 262-262
Author(s):  
David M. Goldenberg ◽  
Edmund A. Rossi ◽  
Diane L Rossi ◽  
Thomas M. Cardillo ◽  
Chien-Hsing Chang
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Control Group ◽  
Calcium Signal ◽  
Target Cells ◽  
Normal Tissues

262 Background: Trop-2 [also called tumor-associated calcium signal transducer 2 (TACSTD2), EGP-1 (epithelial glycoprotein-1), GA733-1, or M1S1]is a 35 kDa transmembrane glycoprotein that is overexpressed relative to normal tissues in a variety of human cancers, including pancreatic and gastric carcinomas, where increased expression correlates with poor prognosis. Trop-2 appears to be more tumor-specific than the related molecule, EpCAM (Trop-1). MT110, the EpCAM antibody x CD3 bispecific T-cell engager (BiTE), is currently undergoing a Phase I study in various solid tumors, including lung, gastric, colorectal, breast, prostate, and ovarian cancers. We produced a similar T-cell redirecting bispecific tandem scFv, E1-3, using the variable domains of hRS7 (humanized anti-Trop-2 mAb) and Okt-3 (anti-CD3 mAb). Methods: T-cell activation, cytokine induction and cytotoxicity were evaluated ex vivo using PBMCs or purified T cells with human pancreatic (Capan-1 and BxPC3) and gastric (NCI-N87) cancer cell lines as target cells. In vivo activity was assayed with NCI-N87 xenografts that were inoculated s.c. in a mixture with twice the number of human PBMCs and matrigel. Results: In the presence of target cells and PBMCs, E1-3 potently induced T-cell activation, proliferation, and dose-dependent cytokine production of IL-2 (>2 ng/mL), IL-6 (>1 ng/mL), IL-10 (>7 ng/mL), TNF-α (>1 ng/mL) and IFN-γ (>50 ng/mL). In vitro, E1-3 mediated a highly potent T-cell lysis of BxPC3 [IC50=0.09(±0.04) pM], Capan-1 [IC50=1.2(±1.1) pM] and NCI-N87 [IC50=1.2(±1.2) pM] target cells. In vivo, two 50-µg doses of E1-3 given three days apart cured all of the mice (N=8) bearing NCI-N87 xenografts (P=0.0005; Log-Rank). Tumors in the control group (PBMCs only) reached the endpoint (TV>1 cm3) with a median of 39.5 days. All mice remained tumor-free in the E1-3 group at 78 days. Conclusions: Trop-2 is an attractive target for T-cell-mediated killing of pancreatic, gastric and other epithelial cancers.

scholarly journals Lasia spinosa Chemical Composition and Therapeutic Potential: A Literature-Based Review

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Rajib Hossain ◽  
Cristina Quispe ◽  
Jesús Herrera-Bravo ◽  
Md. Shahazul Islam ◽  
Chandan Sarkar ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Human Subjects ◽  
Uterine Cancer ◽  
Safety Data ◽  
Volatile Oil ◽  
Stomach Pain

Lasia spinosa (L.) is used ethnobotanically for the treatment of various diseases, including rheumatoid arthritis, inflammation of the lungs, bleeding cough, hemorrhoids, intestinal diseases, stomach pain, and uterine cancer. This review is aimed at summarizing phytochemistry and pharmacological data with their molecular mechanisms of action. A search was performed in databases such as PubMed, Science Direct, and Google Scholar using the keywords: “Lasia spinosa,” then combined with “ethnopharmacological use,” “phytochemistry,” and “pharmacological activity.” This updated review included studies with in vitro, ex vivo, and in vivo experiments with compounds of known concentration and highlighted pharmacological mechanisms. The research results showed that L. spinosa contains many important nutritional and phytochemical components such as alkanes, aldehydes, alkaloids, carotenoids, flavonoids, fatty acids, ketones, lignans, phenolics, terpenoids, steroids, and volatile oil with excellent bioactivity. The importance of this review lies in the fact that scientific pharmacological evidence supports the fact that the plant has antioxidant, anti-inflammatory, antimicrobial, cytotoxic, antidiarrheal, antihelminthic, antidiabetic, antihyperlipidemic, and antinociceptive effects, while protecting the gastrointestinal system and reproductive. Regarding future toxicological and safety data, more research is needed, including studies on human subjects. In light of these data, L. spinosa can be considered a medicinal plant with effective bioactives for the adjuvant treatment of various diseases in humans.

scholarly journals Five-Decade Update on Chemopreventive and Other Pharmacological Potential of Kurarinone: a Natural Flavanone

2021 ◽  
Vol 12 ◽  
Author(s):  
Shashank Kumar ◽  
Kumari Sunita Prajapati ◽  
Mohd Shuaib ◽  
Prem Prakash Kushwaha ◽  
Hardeep Singh Tuli ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cell Cycle Progression ◽  
Therapeutic Potential ◽  
Experimental Models ◽  
Xenograft Models ◽  
Inhibitory Potential ◽  
Pharmacological Potential

In the present article we present an update on the role of chemoprevention and other pharmacological activities reported on kurarinone, a natural flavanone (from 1970 to 2021). To the best of our knowledge this is the first and exhaustive review of kurarinone. The literature was obtained from different search engine platforms including PubMed. Kurarinone possesses anticancer potential against cervical, lung (non-small and small), hepatic, esophageal, breast, gastric, cervical, and prostate cancer cells. In vivo anticancer potential of kurarinone has been extensively studied in lungs (non-small and small) using experimental xenograft models. In in vitro anticancer studies, kurarinone showed IC50 in the range of 2–62 µM while in vivo efficacy was studied in the range of 20–500 mg/kg body weight of the experimental organism. The phytochemical showed higher selectivity toward cancer cells in comparison to respective normal cells. kurarinone inhibits cell cycle progression in G2/M and Sub-G1 phase in a cancer-specific context. It induces apoptosis in cancer cells by modulating molecular players involved in apoptosis/anti-apoptotic processes such as NF-κB, caspase 3/8/9/12, Bcl2, Bcl-XL, etc. The phytochemical inhibits metastasis in cancer cells by modulating the protein expression of Vimentin, N-cadherin, E-cadherin, MMP2, MMP3, and MMP9. It produces a cytostatic effect by modulating p21, p27, Cyclin D1, and Cyclin A proteins in cancer cells. Kurarinone possesses stress-mediated anticancer activity and modulates STAT3 and Akt pathways. Besides, the literature showed that kurarinone possesses anti-inflammatory, anti-drug resistance, anti-microbial (fungal, yeast, bacteria, and Coronavirus), channel and transporter modulation, neuroprotection, and estrogenic activities as well as tyrosinase/diacylglycerol acyltransferase/glucosidase/aldose reductase/human carboxylesterases 2 inhibitory potential. Kurarinone also showed therapeutic potential in the clinical study. Further, we also discussed the isolation, bioavailability, metabolism, and toxicity of Kurarinone in experimental models.

scholarly journals A Novel, Nonpeptidic, Orally Active Bivalent Inhibitor of Human β-Tryptase

Pharmacology ◽  
2018 ◽  
Vol 102 (5-6) ◽  
pp. 233-243 ◽  
Author(s):  
Sarah F. Giardina ◽  
Douglas S. Werner ◽  
Maneesh Pingle ◽  
Donald E. Bergstrom ◽  
Lee D. Arnold ◽  
...  
Keyword(s):  
Active Sites ◽  
Rational Design ◽  
Therapeutic Potential ◽  
X Ray Crystallography ◽  
Inflammatory Stimuli ◽  
Invaluable Tool ◽  
Xenograft Models ◽  
Orally Bioavailable

β-Tryptase is released from mast cells upon degranulation in response to allergic and inflammatory stimuli. Human tryptase is a homotetrameric serine protease with 4 identical active sites directed toward a central pore. These active sites present an optimized scenario for the rational design of bivalent inhibitors, which bridge 2 adjacent active sites. Using (3-[1-acylpiperidin-4-yl]phenyl)methanamine as the pharmacophoric core and a disiloxane linker to span 2 active sites we have successfully produced a novel bivalent tryptase inhibitor, compound 1a, with a comparable profile to previously described inhibitors. Pharmacological properties of compound 1a were studied in a range of in vitro enzymic and cellular screening assays, and in vivo xenograft models. This non-peptide inhibitor of tryptase demonstrated superior activity (IC50 at 100 pmol/L tryptase = 1.82 nmol/L) compared to monomeric modes of inhibition. X-ray crystallography validated the dimeric mechanism of inhibition, and 1a demonstrated good oral bioavailability and efficacy in HMC-1 xenograft models. Furthermore, compound 1a demonstrated extremely slow off rates and high selectivity against-related proteases. This highly potent, orally bioavailable and selective inhibitor of human tryptase will be an invaluable tool in future studies to explore the therapeutic potential of attenuating the activity of this elusive target.

scholarly journals Nanocurcumin-Loaded UCNPs for Cancer Theranostics: Physicochemical Properties, In Vitro Toxicity, and In Vivo Imaging Studies

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2234
Author(s):  
Anbharasi Lakshmanan ◽  
Roman A. Akasov ◽  
Natalya V. Sholina ◽  
Polina A. Demina ◽  
Alla N. Generalova ◽  
...  
Keyword(s):  
Near Infrared ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Laboratory Animals ◽  
In Vitro Toxicity ◽  
Upconversion Nanoparticles ◽  
Lewis Lung Cancer ◽  
Spectral Bands

Formulation of promising anticancer herbal drug curcumin as a nanoscale-sized curcumin (nanocurcumin) improved its delivery to cells and organisms both in vitro and in vivo. We report on coupling nanocurcumin with upconversion nanoparticles (UCNPs) using Poly (lactic-co-glycolic Acid) (PLGA) to endow visualisation in the near-infrared transparency window. Nanocurcumin was prepared by solvent-antisolvent method. NaYF4:Yb,Er (UCNP1) and NaYF4:Yb,Tm (UCNP2) nanoparticles were synthesised by reverse microemulsion method and then functionalized it with PLGA to form UCNP-PLGA nanocarrier followed up by loading with the solvent-antisolvent process synthesized herbal nanocurcumin. The UCNP samples were extensively characterised with XRD, Raman, FTIR, DSC, TGA, UV-VIS-NIR spectrophotometer, Upconversion spectrofluorometer, HRSEM, EDAX and Zeta Potential analyses. UCNP1-PLGA-nanocurcumin exhibited emission at 520, 540, 660 nm and UCNP2-PLGA-nanocurmin showed emission at 480 and 800 nm spectral bands. UCNP-PLGA-nanocurcumin incubated with rat glioblastoma cells demonstrated moderate cytotoxicity, 60–80% cell viability at 0.12–0.02 mg/mL marginally suitable for therapeutic applications. The cytotoxicity of UCNPs evaluated in tumour spheroids models confirmed UCNP-PLGA-nanocurcumin therapeutic potential. As-synthesised curcumin-loaded nanocomplexes were administered in tumour-bearing laboratory animals (Lewis lung cancer model) and showed adequate contrast to enable in vivo and ex vivo study of UCNP-PLGA-nanocurcumin bio distribution in organs, with dominant distribution in the liver and lungs. Our studies demonstrate promise of nanocurcumin-loaded upconversion nanoparticles for theranostics applications.

scholarly journals The Potential of CRISPR/Cas9 Gene Editing as a Treatment Strategy for Inherited Diseases

2021 ◽  
Vol 9 ◽  
Author(s):  
Sameh A. Abdelnour ◽  
Long Xie ◽  
Abdallah A. Hassanin ◽  
Erwei Zuo ◽  
Yangqing Lu
Keyword(s):  
Therapeutic Potential ◽  
Ex Vivo ◽  
Genetic Diseases ◽  
Patient Specific ◽  
Innovative Technology ◽  
Rna Molecules ◽  
Inherited Diseases ◽  
Genomic Editing

Clustered regularly interspaced short palindromic repeats (CRISPR) is a promising innovative technology for genomic editing that offers scientists the chance to edit DNA structures and change gene function. It has several possible uses consisting of editing inherited deficiencies, treating, and reducing the spread of disorders. Recently, reports have demonstrated the creation of synthetic RNA molecules and supplying them alongside Cas9 into genome of eukaryotes, since distinct specific regions of the genome can be manipulated and targeted. The therapeutic potential of CRISPR/Cas9 technology is great, especially in gene therapy, in which a patient-specific mutation is genetically edited, or in the treating of human disorders that are untreatable with traditional treatments. This review focused on numerous, in vivo, in vitro, and ex vivo uses of the CRISPR/Cas9 technology in human inherited diseases, discovering the capability of this versatile in medicine and examining some of the main limitations for its upcoming use in patients. In addition to introducing a brief impression of the biology of the CRISPR/Cas9 scheme and its mechanisms, we presented the utmost recent progress in the uses of CRISPR/Cas9 technology in editing and treating of human genetic diseases.

scholarly journals Targeted photodynamic therapy selectively kills activated fibroblasts in experimental arthritis

Rheumatology ◽  
2020 ◽  
Vol 59 (12) ◽  
pp. 3952-3960 ◽  
Author(s):  
Daphne N Dorst ◽  
Mark Rijpkema ◽  
Marti Boss ◽  
Birgitte Walgreen ◽  
Monique M A Helsen ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Synovial Fibroblasts ◽  
Knee Joints ◽  
Specific Cell ◽  
Collagen Induced Arthritis ◽  
Targeted Photodynamic Therapy

Abstract Objective In RA, synovial fibroblasts become activated. These cells express fibroblast activation protein (FAP) and contribute to the pathogenesis by producing cytokines, chemokines and proteases. Selective depletion in inflamed joints could therefore constitute a viable treatment option. To this end, we developed and tested a new therapeutic strategy based on the selective destruction of FAP-positive cells by targeted photodynamic therapy (tPDT) using the anti-FAP antibody 28H1 coupled to the photosensitizer IRDye700DX. Methods After conjugation of IRDye700DX to 28H1, the immunoreactive binding and specificity of the conjugate were determined. Subsequently, tPDT efficiency was established in vitro using a 3T3 cell line stably transfected with FAP. The biodistribution of [111In]In-DTPA-28H1 with and without IRDye700DX was assessed in healthy C57BL/6N mice and in C57BL/6N mice with antigen-induced arthritis. The potential of FAP-tPDT to induce targeted damage was determined ex vivo by treating knee joints from C57BL/6N mice with antigen-induced arthritis 24 h after injection of the conjugate. Finally, the effect of FAP-tPDT on arthritis development was determined in mice with collagen-induced arthritis. Results 28H1-700DX was able to efficiently induce FAP-specific cell death in vitro. Accumulation of the anti-FAP antibody in arthritic knee joints was not affected by conjugation with the photosensitizer. Arthritis development was moderately delayed in mice with collagen-induced arthritis after FAP-tPDT. Conclusion Here we demonstrate the feasibility of tPDT to selectively target and kill FAP-positive fibroblasts in vitro and modulate arthritis in vivo using a mouse model of RA. This approach may have therapeutic potential in (refractory) arthritis.

Abstract 12236: A Novel Particulate Guanylyl Cyclase B Agonist With Therapeutic Potential Targeting Fibrosis via cGMP Generation for Cardiorenal Disease

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
S. J Sangaralingham ◽  
Brenda K Huntley ◽  
Tomoko Ichiki ◽  
Gerald E Harders ◽  
John C Burnett
Keyword(s):  
Guanylyl Cyclase ◽  
Therapeutic Potential ◽  
Human Fibroblasts ◽  
Active Form ◽  
Hek 293 ◽  
Hek Cells ◽  
293 Cells ◽  
No Activation

Introduction: Fibrosis is a hallmark of cardiorenal diseases, including heart failure, for which there are few effective therapies. C-type natriuretic peptide (CNP) is a cardiorenal-derived peptide whose mature active form, CNP-22, possesses potent anti-fibrotic actions through the activation of guanylyl cyclase receptor B (GC-B) and its second messenger, cGMP. However, CNP-22’s therapeutic potential is limited due to its short half-life. We recently identified a 53 amino acid (AA) peptide, CNP-53, whose structure consists of CNP-22 with an additional 31 AA on the N-terminus. Herein, we investigated the cGMP generating actions of CNP-53 (compared to CNP-22) in vivo and in vitro, with the goal of advancing a potential anti-fibrotic strategy for cardiorenal disease. Hypotheses: We hypothesized that CNP-53 would elevate circulating CNP levels as well as have greater cGMP activating actions compared to CNP-22 in vivo. We also hypothesized that CNP-53 would stimulate GC-B specific cGMP production in vitro. Methods: In vivo, two groups of anesthetized normal rats (n=8) received a 75-minute intravenous infusion of an equimolar dose of CNP-53 or CNP-22. Mean arterial pressure (MAP), plasma CNP and plasma and urinary cGMP were assessed. In vitro, HEK 293 cells over-expressing GC-A and GC-B and human fibroblasts (hFs), where GC-B is abundant, were stimulated with CNP-53 or CNP-22 for 10 minutes at a dose of (10-8M). Data are mean ± SE, *p<0.05. Results: In vivo, plasma CNP (CNP-53: 311±66, CNP-22: 153±16 pg/ml*) and cGMP (CNP-53: 21±2, CNP-22: 11±1 pmol/ml*) and urinary cGMP excretion (CNP-53: 75±4, CNP-22: 38±1 pmol/min*) were greater with CNP-53 infusion than CNP-22. MAP was similar between the 2 groups (CNP-53: 85±2, CNP-22: 88±4 mmHg). In vitro, both CNP-53 and CNP-22 activated cGMP in GC-B HEK cells and in hFs, with no activation of cGMP in GC-A HEK cells. Conclusions: These findings demonstrate that CNP-53 is superior to CNP-22 in activating cGMP in vivo, without inducing hypotension. Additionally, CNP-53 is a GC-B specific cGMP activating peptide that potently increases cGMP in hFs. Thus, CNP-53 may represent a novel first in class GC-B agonist with therapeutic potential targeting fibrosis and preventing the progression of cardiorenal disease.

FTY720 Abrogates the Therapeutic Potential of Adoptively Transferred Treg Via Inhibition of IL-2 Induced in Vivo Expansion

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2584-2584
Author(s):  
Anna Maria Wolf ◽  
Kathrin Hochegger ◽  
Robert Zeiser ◽  
Christoph Duerr ◽  
Michael Sixt ◽  
...  
Keyword(s):  
T Cells ◽  
Adoptive Transfer ◽  
Chemokine Receptors ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Effective Means ◽  
Effector T Cells ◽  
Target Tissue

Abstract CD4+CD25+ T cells (Treg) entry into secondary lymphoid organs (SLO) and local expansion after activation is at least in part responsible for their immunosuppressive action. Thus we hypothesized that trapping of adoptively transferred Treg in SLO would be an effective means to tip the balance towards a more immunosuppressive milieu within the LN microenvironment. Systemic application of the sphingosine-phosphate receptor agonist FTY720 has been proven to trap harmful effector T cells in SLO, thereby inhibiting their migration and destruction of target tissue. Here we provide first evidence that selective entrapment of adoptively transferred Treg in inflammatory LN can be achieved by blockade of SP-receptors upon ex vivo exposure of Treg to FTY720 before adoptive transfer. FTY720 exposure did not interfere with proper Treg localization within the T-cell areas of SLO as determined by immunofluorescent microscopy after co-transfer of either FTY720- or solvent exposed and subsequently differentially labelled Treg. However, despite the fact that the in vitro phenotype (including expression of adhesion and chemokine receptors), function (including anergy and suppressive activity) and survival (determined by Annexin/PI staining) of Treg remained unaltered by FTY720, it abrogated their protective effect after adoptive transfer in a murine model of acute experimental glomerulonephritis (determined by quantification of proteinuria and histological analysis) as well as in an acute GvHD model (determined by survival analysis and quantification of the in vivo expansion of luciferase-transgenic effector T cells by bioluminiscence technology). Notably, adoptive transfer of CFSE-labelled Treg revealed a markedly impaired proliferation of Treg in inflammatory SLO when pre-exposed to FTY720 ex vivo. Accordingly, FTY720 blocked Treg-proliferation induced by TCR-stimulation in combination with IL-2 in vitro. In line with this observation, FTY720 completely abolishes IL-2 induced phosphorylation of STAT-5. Thus, SP-1P receptors induce Treg trapping in inflammatory SLO but abrogate their in vivo immunosuppressive potential by inhibition of local Treg expansion.

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