scholarly journals The selection of variable regions affects effector mechanisms of IgA antibodies against CD20

2021 ◽  
Author(s):  
Mitchell Evers ◽  
Thies Rösner ◽  
Anna Duenkel ◽  
J. H. Marco Marco Jansen ◽  
Niklas Baumann ◽  
...  
Keyword(s):  
Cell Killing ◽  
Lymphoma Cell ◽  
In Vivo Models ◽  
Variable Regions ◽  
Effector Cells ◽  
The Impact ◽  
Cd20 Antibodies ◽  
Selection Of ◽  
Effector Mechanisms

Blockade of the CD47-SIRPα axis improves lymphoma cell killing by myeloid effector cells, which is an important effector mechanism for CD20 antibodies in vivo. The approved CD20 antibodies rituximab, ofatumumab and obinutuzumab are of human IgG1 isotype. Here, we investigated the impact of the variable regions of these three CD20 antibodies, when they were expressed as human IgA2 isotype variants. We observed more effective direct tumor cell killing by OBI-IgA2 compared to RTX- and OFA-IgA2, which was caspase-independent and required a functional cytoskeleton. Furthermore, IgA2 variants of all three antibodies triggered complement dependent cytotoxicity, with OBI-IgA2 being less effective than RTX- and OFA-IgA2. All three IgA2 antibodies mediated antibody-dependent cellular phagocytosis (ADCP) by macrophages and antibody-dependent cellular cytotoxicity (ADCC) by PMN. Both effector mechanisms were significantly enhanced in the presence of a CD47 blocking antibody or by glutaminyl cyclase inhibition to interfere with CD47-SIRPα interactions. Interestingly, OBI-IgA2 was consistently more potent than RTX- and OFA-IgA2 in triggering ADCC. When we investigated the therapeutic efficacy of the CD20 IgA2 antibodies in different in vivo models, OBI-IgA2 was therapeutically more effective than RTX- or OFA-IgA2. In vivo efficacy required the presence of a functional IgA receptor on effector cells, and was independent of complement activation or direct lymphoma cell killing. These data characterize the functional activities of human IgA2 antibodies against CD20, which were affected by the selection of the respective variable regions. OBI-IgA2 proved particularly effective in vitro and in vivo, which is potentially relevant in the context of CD47-SIRPα blockade.

scholarly journals Alpha-Fetoprotein- and CD40Ligand-Expressing Dendritic Cells for Immunotherapy of Hepatocellular Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3375
Author(s):  
Annabelle Vogt ◽  
Farsaneh Sadeghlar ◽  
Tiyasha H. Ayub ◽  
Carlo Schneider ◽  
Christian Möhring ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
Dendritic Cells ◽  
Tumor Regression ◽  
Combined Therapy ◽  
Term Survival ◽  
Effector Cells ◽  
Tumor Environment ◽  
The Impact

Dendritic cells (DC) as professional antigen presenting cells are able to prime T-cells against the tumor-associated antigen α-fetoprotein (AFP) for immunotherapy of hepatocellular carcinoma (HCC). However, a strong immunosuppressive tumor environment limits their efficacy in patients. The co-stimulation with CD40Ligand (CD40L) is critical in the maturation of DC and T-cell priming. In this study, the impact of intratumoral (i.t.) CD40L-expressing DC to improve vaccination with murine (m)AFP-transduced DC (Ad-mAFP-DC) was analyzed in subcutaneous (s.c.) and orthotopic murine HCC. Murine DC were adenovirally transduced with Ad-mAFP or Ad-CD40L. Hepa129-mAFP-cells were injected into the right flank or the liver of C3H-mice to induce subcutaneous (s.c.) and orthotopic HCC. For treatments, 106 Ad-mAFP-transduced DC were inoculated s.c. followed by 106 CD40L-expressing DC injected intratumorally (i.t.). S.c. inoculation with Ad-mAFP-transduced DC, as vaccine, induced a delay of tumor-growth of AFP-positive HCC compared to controls. When s.c.-inoculation of Ad-mAFP-DC was combined with i.t.-application of Ad-CD40L-DC synergistic antitumoral effects were observed and complete remissions and long-term survival in 62% of tumor-bearing animals were achieved. Analysis of the tumor environment at different time points revealed that s.c.-vaccination with Ad-mAFP-DC seems to stimulate tumor-specific effector cells, allowing an earlier recruitment of effector T-cells and a Th1 shift within the tumors. After i.t. co-stimulation with Ad-CD40L-DC, production of Th1-cytokines was strongly increased and accompanied by a robust tumor infiltration of mature DC, activated CD4+-, CD8+-T-cells as well as reduction of regulatory T-cells. Moreover, Ad-CD40L-DC induced tumor cell apoptosis. Intratumoral co-stimulation with CD40L-expressing DC significantly improves vaccination with Ad-mAFP-DC in pre-established HCC in vivo. Combined therapy caused an early and strong Th1-shift in the tumor environment as well as higher tumor apoptosis, leading to synergistic tumor regression of HCC. Thus, CD40L co-stimulation represents a promising tool for improving DC-based immunotherapy of HCC.

Selection of Hydroxypyridin-4-Ones for the Treatment of Iron Overload Using In Vitro and In Vivo Models

Hemoglobin ◽  
1988 ◽  
Vol 12 (5-6) ◽  
pp. 593-600 ◽  
Author(s):  
E. R. Huehns ◽  
J. B. Porter ◽  
R. C. Hider
Keyword(s):  
Iron Overload ◽  
In Vivo Models ◽  
Selection Of

scholarly journals Anti-Inflammatory Activity of A Polyphenolic Extract from Arabidopsis thaliana in In Vitro and In Vivo Models of Alzheimer’s Disease

2019 ◽  
Vol 20 (3) ◽  
pp. 708 ◽  
Author(s):  
Roberto Mattioli ◽  
Antonio Francioso ◽  
Maria d’Erme ◽  
Maurizio Trovato ◽  
Patrizia Mancini ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Arabidopsis Thaliana ◽  
Heme Oxygenase 1 ◽  
Neuroprotective Effects ◽  
In Vivo Models ◽  
Polyphenolic Extract ◽  
Anti Inflammatory ◽  
The Impact

Alzheimer’s disease (AD) is the most common neurodegenerative disorder and the primary form of dementia in the elderly. One of the main features of AD is the increase in amyloid-beta (Aβ) peptide production and aggregation, leading to oxidative stress, neuroinflammation and neurodegeneration. Polyphenols are well known for their antioxidant, anti-inflammatory and neuroprotective effects and have been proposed as possible therapeutic agents against AD. Here, we investigated the effects of a polyphenolic extract of Arabidopsis thaliana (a plant belonging to the Brassicaceae family) on inflammatory response induced by Aβ. BV2 murine microglia cells treated with both Aβ25–35 peptide and extract showed a lower pro-inflammatory (IL-6, IL-1β, TNF-α) and a higher anti-inflammatory (IL-4, IL-10, IL-13) cytokine production compared to cells treated with Aβ only. The activation of the Nrf2-antioxidant response element signaling pathway in treated cells resulted in the upregulation of heme oxygenase-1 mRNA and in an increase of NAD(P)H:quinone oxidoreductase 1 activity. To establish whether the extract is also effective against Aβ-induced neurotoxicity in vivo, we evaluated its effect on the impaired climbing ability of AD Drosophila flies expressing human Aβ1–42. Arabidopsis extract significantly restored the locomotor activity of these flies, thus confirming its neuroprotective effects also in vivo. These results point to a protective effect of the Arabidopsis extract in AD, and prompt its use as a model in studying the impact of complex mixtures derived from plant-based food on neurodegenerative diseases.

scholarly journals IL1RAP antibodies block IL-1–induced expansion of candidate CML stem cells and mediate cell killing in xenograft models

Blood ◽  
2016 ◽  
Vol 128 (23) ◽  
pp. 2683-2693 ◽  
Author(s):  
Helena Ågerstam ◽  
Nils Hansen ◽  
Sofia von Palffy ◽  
Carl Sandén ◽  
Kristian Reckzeh ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Killing ◽  
Blast Phase ◽  
In Vivo Models ◽  
Key Points ◽  
Xenograft Models ◽  
Mediate Cell

Key Points IL-1 activates signaling and promotes proliferation of primitive CML cells. IL1RAP antibodies block IL-1–induced effects and mediate cell killing in chronic and blast phase CML in vivo models.

scholarly journals Knockdown of Leptin Receptor Affects Macrophage Phenotype in the Tumor Microenvironment Inhibiting Breast Cancer Growth and Progression

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2078
Author(s):  
Luca Gelsomino ◽  
Giuseppina Daniela Naimo ◽  
Rocco Malivindi ◽  
Giuseppina Augimeri ◽  
Salvatore Panza ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Microenvironment ◽  
Leptin Receptor ◽  
Macrophage Phenotype ◽  
In Vivo Models ◽  
Monocyte Chemoattractant Protein 1 ◽  
Arginase 1 ◽  
The Impact

Aberrant leptin (Ob) signaling, a hallmark of obesity, has been recognized to influence breast cancer (BC) biology within the tumor microenvironment (TME). Here, we evaluated the impact of leptin receptor (ObR) knockdown in affecting BC phenotype and in mediating the interaction between tumor cells and macrophages, the most abundant immune cells within the TME. The stable knockdown of ObR (ObR sh) in ERα-positive and ERα-negative BC cells turned the tumor phenotype into a less aggressive one, as evidenced by in vitro and in vivo models. In xenograft tumors and in co-culture experiments between circulating monocytes and BC cells, the absence of ObR reduced the recruitment of macrophages, and also affected their cytokine mRNA expression profile. This was associated with a decreased expression and secretion of monocyte chemoattractant protein-1 in ObR sh clones. The loss of Ob/ObR signaling modulated the immunosuppressive TME, as shown by a reduced expression of programmed death ligand 1/programmed cell death protein 1/arginase 1. In addition, we observed increased phagocytic activity of macrophages compared to control Sh clones in the presence of ObR sh-derived conditioned medium. Our findings, addressing an innovative role of ObR in modulating immune TME, may open new avenues to improve BC patient health care.

scholarly journals In vivo studies on antibiotic combination for the treatment of carbapenem-resistant Gram-negative bacteria: a systematic review and meta-analysis protocol

2020 ◽  
Vol 4 (1) ◽  
pp. e100055
Author(s):  
Elda Righi ◽  
Luigia Scudeller ◽  
Margherita Chiamenti ◽  
Kamilia Abdelraouf ◽  
Thomas Lodise ◽  
...  
Keyword(s):  
Systematic Review ◽  
Meta Analysis ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
In Vivo Models ◽  
Gram Negative ◽  
Carbapenem Resistant ◽  
The Impact ◽  
Antibiotic Combination

ObjectiveThere is poor evidence to determine the superiority of combination regimens versus monotherapy against infections due to carbapenem-resistant (CR) Gram-negative bacteria. In vivo models can simulate the pathophysiology of infections in humans and assess antibiotic efficacy. We aim to investigate in vivo effects of antibiotic combination on mortality and disease burden for infections due to CR Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacteriaceae and provide an unbiased overview of existing knowledge. The results of the study can help prioritising future research on the most promising therapies against CR bacteria.Methods and analysisThis protocol was formulated using the Systematic Review Protocol for Animal Intervention Studies (SYRCLE) Checklist. Publications will be collected from PubMed, Scopus, Embase and Web of Science. Quality checklists adapted by Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies and SYRCLE’s risk of bias tool will be used. If the meta-analysis seems feasible, the ES and the 95% CI will be analysed. The heterogeneity between studies will be assessed by I2 test. Subgroup meta-analysis will be performed when possible to assess the impact of the studies on efficacy of the treatments. Funnel plotting will be used to evaluate the risk of publication bias.DisseminationThis systematic review and meta-analysis is part of a wider research collaboration project, the COmbination tHErapy to treat sepsis due to carbapenem-Resistant bacteria in adult and paediatric population: EvideNCE and common practice (COHERENCE) study that includes also the analyses of in vitro and human studies. Data will be presented at international conferences and the results will be published in peer-reviewed journals.PROSPERO registration numberCRD42019128104(available at: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019128104).

Naive and Ex Vivo Activated Human T Cells Generate Consistent Engraftment and Lethal Graft-Versus-Host Disease (GvHD) in NOD SCID β 2M Null Mice: A New Xenogeneic Model for GvHD.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3106-3106
Author(s):  
Bruno Nervi ◽  
Michael P. Rettig ◽  
Julie K. Ritchey ◽  
Gerhard Bauer ◽  
Jon Walker ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
Conditioning Regimen ◽  
Activation Markers ◽  
In Vivo Models ◽  
Hematopoietic Stem ◽  
Human T Cells ◽  
The Impact

Abstract GvHD remains a major cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation and donor lymphocyte infusion. The human GvHD pathophysiology includes recipient tissue destruction and proinflammatory cytokine production associated with the conditioning regimen; donor T cells become allo-activated, proliferate, and mediate tissue injury in various organs, including the liver, skin, and gut. Modern therapeutic strategies to control GvHD while maintaining the beneficial graft-versus-leukemia effects require ex vivo T cell stimulation and expansion. Multiple studies have demonstrated that these ex vivo expanded T cells exhibit decreased survival and function in vivo, including reduced alloreactivity and GvHD potential. Unfortunately no in vivo models exist to consistently examine the impact of ex vivo manipulation of human T cells (HuT) on T cell function. Naive HuT were compared to HuT activated using CD3/28 beads (XcyteTMDynabeads) with 50 U/ml IL-2 for 4 days (Act). We initially evaluated the HuT engraftment and GvHD potential of naive and Act in RAG2γ null mice (n=22) conditioned with clodronate liposomes on day −1 and 350cGy on day 0, as previously described by others. We injected 107 and 1.5x107 naive or Act HuT intravenously (iv). All mice exhibited low HuT engraftment and no lethal GvHD. NOD SCIDβ 2M null mice (β 2M) were next conditioned with 250cGy on day −1 (n=34), or 300cGy on day 0 (n=21). 107 naive vs Act HuT were injected retroorbitaly (ro). Lower HuT doses or iv injection resulted in no expansion or GvHD. Engraftment of HuT in peripheral blood of recipient mice was evaluated weekly by FACS and euthanasia was performed if mice lost > 20% body weight. 60% of the mice conditioned with 250cGy that received naive HuT developed lethal GvHD, in comparison to 75% of mice that received 300cGy and nave HuT, and 100% of mice that received 300cGy and Act HuT. Table 1 250cGy 300cGy Naive (n=34) Naive (n=8) Activated (n=13) *p<0.02 PB engraftment (%HuT) 20%±15 33%±21 59%±19 Lethal GvHD 60% 75% 100% All mice receiving 300cGy had well preserved CD4/CD8 ratios (1–1.5). Tissue infiltration was greatest in mice that had received 300cGy and Act HuT (spleen, liver, lung, kidney: 50–70%). Of interest, serum levels of hu IFNγ dramatically increased over time in all mice who went on to develop lethal GvHD (day 3=270 ug/ml and day 15=36,000 ug/ml) compared to mice that did not develop lethal GvHD (day 10=40 ug/ml and day 17=1,020 ug/ml)(p<0.05). Interestingly, the up-regulation of the activation markers CD25 and CD30 in HuT, and IFNγ production predicted lethal GvHD in β 2M null mice. In summary, we developed a xenogeneic model of lethal GvHD where naive or ex vivo Act HuT injected ro in sublethaly irradiated β 2M not only engraft, expand in vivo, but also infiltrate and damage different mouse target organs. HuT are allo-activated against mouse antigens and damage the target tissues, sharing the major characteristics of human GvHD and causing the death of mice. This model will allow us to study the effects of specific ex vivo T cell manipulation including transduction, selection, expansion, and the depletion or addition of various T cells and other cellular subsets on the outcome of GvHD, to determine improved therapeutic interventions.

CD30/CD16A Tandab AFM13-Induced Target Cell Lysis By NK-Cells Is Enhanced By CD137 Co-Stimulation and Blocking PD-1

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2747-2747 ◽  
Author(s):  
Xing Zhao ◽  
Narendiran Rajasekaran ◽  
Uwe Reusch ◽  
Jens-Peter Marschner ◽  
Martin Treder ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Nk Cells ◽  
Target Cell ◽  
Tumor Size ◽  
Target Cells ◽  
In Vivo Models ◽  
Effector Cells ◽  
Cytotoxicity Assays

Abstract Introduction: AFM13 is a CD30/CD16A bispecific tetravalent TandAb antibody that recruits and activates NK-cells by specific binding to CD16A for targeted lysis of CD30+ tumor cells. Given promising clinical activity and safety profile of AFM13 and proof-of-mechanism demonstrating dependence on the immune response, potential synergy of AFM13 and checkpoint modulators was evaluated. Methods: Efficacy of AFM13 alone or in combination with anti-CTLA-4, anti-PD-1, or anti-CD137 antibodies was assessed by in vitro cytotoxicity assays with human PBMCs or enriched NK-cells and CD30+ target cells as well as patient-derived xenograft in vivo models with autologous PBMC. To evaluate NK-cell-mediated lysis of CD30+ lymphoma cell lines, 4 hour cytotoxicity assays were performed with PBMCs or enriched NK-cells as effector cells in the presence of suboptimal concentrations of AFM13 alone, and in combination with anti-CTLA-4, anti-PD-1, or anti-CD137 antibodies. For the in vivo model tumor fragments derived from surgical specimens of newly diagnosed patients with CD30+ Hodgkin Lymphoma were xenografted (PDX) in immuno-deficient mice. After 28 days mice were reconstituted with autologous patient-derived PBMC and treated with AFM13 alone and in combination with anti-CTLA-4, anti-PD-1, or anti-CD137 antibodies weekly for a total of three weeks. Tumor size, tumor-infiltrating human lymphocytes and intra-tumoral cytokines were evaluated on day 58. Results: AFM13 as a single agent at suboptimal concentrations induced effector-to-target cell-dependent lysis of CD30+ lymphoma cells up to 40% using enriched NK-cells as effector cells in a 4 hour in vitro assay. Immune-modulating antibodies alone mediated substantially lower lysis (<25%). However, the addition of anti-PD-1 or anti-CD137 to AFM13 strongly enhanced specific lysis up to 70%, whereas the addition of anti-CTLA-4 to AFM13 showed no beneficial effect. The most impressive increase of efficacy was observed when AFM13 was applied together with a combination of anti-PD-1 and anti-CD137. In vivo, reduction of tumor growth was observed when AFM13 and anti-PD-1 were used as single agents or when AFM13 was combined with anti-CD137. Synergy was most impressive in these PDX models for the combination of AFM13 and anti-PD-1 which led to a very strong reduction of tumor size. Of note, reduction of tumor growth was strongly correlated with infiltrating NK- and T-cells and intra-tumoral cytokines. Conclusions: The combination trials performed with companion intra-tumoral assessment of lymphocytes and cytokines may enhance the efficacy of AFM13 in patients. This may be explained by a potential cross-talk between NK-cells and T-cell which was enhanced when AFM13 was used in combination with checkpoint modulators. Disclosures No relevant conflicts of interest to declare.

scholarly journals Considerations and Pitfalls in Selecting the Drug Vehicles for Evaluation of New Drug Candidates: Focus on in vivo Pharmaco-Toxicological Assays Based on the Rotarod Performance Test

2018 ◽  
Vol 21 ◽  
pp. 110-118 ◽  
Author(s):  
Mariana Matias ◽  
Samuel Silvestre ◽  
Amílcar Falcão ◽  
Gilberto Alves
Keyword(s):  
Performance Test ◽  
Motor Impairment ◽  
New Drugs ◽  
Motor Deficit ◽  
Early Evaluation ◽  
Rotarod Performance ◽  
Peg 400 ◽  
The Impact ◽  
Selection Of

Purpose - During the discovery and development of new drugs, compounds with low aqueous solubility pose special challenges in their pharmacological evaluation and, therefore, the selection of appropriate vehicles to administer the compounds of interest is determinant for the quality of the results generated during the in vivo non-clinical studies. This work aimed to evaluate the motor deficit (as a surrogate of neurotoxicity) of several administration/delivery vehicles through the rotarod performance test. Methods - Trained male CD-1 mice were intraperitoneally administered with the following vehicles: dimethyl sulfoxide (DMSO), aqueous sodium chloride (NaCl) 0.9%, aqueous carboxymethylcellulose (CMC) 0.5%, polyethylene glycol (PEG)-400, propylene glycol (PG), and solutions of these vehicles containing 5% and 10% DMSO. Results - It was observed that the aqueous vehicles (NaCl 0.9% and CMC 0.5%) did not affect the performance of the animals on the rod. On the other hand, a vehicle consisting solely of DMSO led to significant motor impairment and only a small improvement was recorded over time. Additionally, a strong neuromotor toxicity was observed in the early evaluation points of the experiment using vehicles constituted by PG and PEG-400 or by mixtures of PG/DMSO (5% and 10%) and PEG-400/DMSO (5% and 10%). Conclusion - This study provides useful data about the neurotoxicity inherent to several vehicles frequently used in non-clinical pharmaco-toxicological assays, aiming to draw especial attention to the need of a careful selection of drug vehicles in order to avoid the impact of such confounding variables on the accuracy of the results and in decision-making processes. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Epithelial to mesenchymal plasticity and differential response to therapies in pancreatic ductal adenocarcinoma

2019 ◽  
Vol 116 (52) ◽  
pp. 26835-26845 ◽  
Author(s):  
Rebecca L. Porter ◽  
Neelima K. C. Magnus ◽  
Vishal Thapar ◽  
Robert Morris ◽  
Annamaria Szabolcs ◽  
...  
Keyword(s):  
Pancreatic Ductal Adenocarcinoma ◽  
Clinical Investigation ◽  
Transcriptional Profiling ◽  
Response To Therapy ◽  
Ductal Adenocarcinoma ◽  
Transcriptional Responses ◽  
In Vivo Models ◽  
Functional Changes ◽  
The Impact

Transcriptional profiling has defined pancreatic ductal adenocarcinoma (PDAC) into distinct subtypes with the majority being classical epithelial (E) or quasi-mesenchymal (QM). Despite clear differences in clinical behavior, growing evidence indicates these subtypes exist on a continuum with features of both subtypes present and suggestive of interconverting cell states. Here, we investigated the impact of different therapies being evaluated in PDAC on the phenotypic spectrum of the E/QM state. We demonstrate using RNA-sequencing and RNA-in situ hybridization (RNA-ISH) that FOLFIRINOX combination chemotherapy induces a common shift of both E and QM PDAC toward a more QM state in cell lines and patient tumors. In contrast, Vitamin D, another drug under clinical investigation in PDAC, induces distinct transcriptional responses in each PDAC subtype, with augmentation of the baseline E and QM state. Importantly, this translates to functional changes that increase metastatic propensity in QM PDAC, but decrease dissemination in E PDAC in vivo models. These data exemplify the importance of both the initial E/QM subtype and the plasticity of E/QM states in PDAC in influencing response to therapy, which highlights their relevance in guiding clinical trials.

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