scholarly journals Engineered SIRPα Variants as Immunotherapeutic Adjuvants to Anticancer Antibodies

Science ◽  
2013 ◽  
Vol 341 (6141) ◽  
pp. 88-91 ◽  
Author(s):  
Kipp Weiskopf ◽  
Aaron M. Ring ◽  
Chia Chi M. Ho ◽  
Jens-Peter Volkmer ◽  
Aron M. Levin ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Immune Responses ◽  
Cancer Cells ◽  
Macrophage Activation ◽  
Universal Method ◽  
Wild Type ◽  
High Affinity ◽  
Macrophage Phagocytosis

CD47 is an antiphagocytic signal that cancer cells employ to inhibit macrophage-mediated destruction. Here, we modified the binding domain of human SIRPα, the receptor for CD47, for use as a CD47 antagonist. We engineered high-affinity SIRPα variants with about a 50,000-fold increased affinity for human CD47 relative to wild-type SIRPα. As high-affinity SIRPα monomers, they potently antagonized CD47 on cancer cells but did not induce macrophage phagocytosis on their own. Instead, they exhibited remarkable synergy with all tumor-specific monoclonal antibodies tested by increasing phagocytosis in vitro and enhancing antitumor responses in vivo. This “one-two punch” directs immune responses against tumor cells while lowering the threshold for macrophage activation, thereby providing a universal method for augmenting the efficacy of therapeutic anticancer antibodies.

scholarly journals Murine monoclonal antibodies against RBD of SARS-CoV-2 neutralize authentic wild type SARS-CoV-2 as well as B.1.1.7 and B.1.351 viruses and protect in vivo in a mouse model in a neutralization dependent manner

2021 ◽  
Author(s):  
Fatima Amanat ◽  
Shirin Strohmeier ◽  
Wen-Hsin Lee ◽  
Sandhya Bangaru ◽  
Andrew B Ward ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Severe Acute Respiratory Syndrome ◽  
Mouse Model ◽  
Neutralizing Antibodies ◽  
Dependent Manner ◽  
Receptor Binding Domain ◽  
Wild Type ◽  
Murine Monoclonal Antibodies

After first emerging in December 2019 in China, severe acute respiratory syndrome 2 (SARS-CoV-2) has since caused a pandemic leading to millions of infections and deaths worldwide. Vaccines have been developed and authorized but supply of these vaccines is currently limited. With new variants of the virus now emerging and spreading globally, it is essential to develop therapeutics that are broadly protective and bind conserved epitopes in the receptor binding domain (RBD) or the whole spike of SARS-CoV-2. In this study, we have generated mouse monoclonal antibodies (mAbs) against different epitopes on the RBD and assessed binding and neutralization against authentic SARS-CoV-2. We have demonstrated that antibodies with neutralizing activity, but not non-neutralizing antibodies, lower viral titers in the lungs when administered in a prophylactic setting in vivo in a mouse challenge model. In addition, most of the mAbs cross-neutralize the B.1.351 as well as the B.1.1.7 variants in vitro.

Disruption of SND1–MTDH Interaction by a High Affinity Peptide Results in SND1 Degradation and Cytotoxicity to Breast Cancer Cells In Vitro and In Vivo

2020 ◽  
Vol 20 (1) ◽  
pp. 76-84
Author(s):  
Peng Li ◽  
Yunjiao He ◽  
Teng Chen ◽  
Kit-Ying Choy ◽  
Tsun Sing Chow ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
High Affinity ◽  
Affinity Peptide

scholarly journals MGL1 Receptor Plays a Key Role in the Control of T. cruzi Infection by Increasing Macrophage Activation through Modulation of ERK1/2, c-Jun, NF-κB and NLRP3 Pathways

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 108
Author(s):  
Tonathiu Rodriguez ◽  
Thalia Pacheco-Fernández ◽  
Alicia Vázquez-Mendoza ◽  
Oscar Nieto-Yañez ◽  
Imelda Juárez-Avelar ◽  
...  
Keyword(s):  
Immune Responses ◽  
Macrophage Activation ◽  
Cell Activation ◽  
Wild Type ◽  
Mhc Ii ◽  
Adaptive Immune ◽  
Splenic Cell ◽  
Tnf Α ◽  
Cruzi Infection

Macrophage galactose-C type lectin (MGL)1 receptor is involved in the recognition of Trypanosoma cruzi (T. cruzi) parasites and is important for the modulation of the innate and adaptive immune responses. However, the mechanism by which MGL1 promotes resistance to T. cruzi remains unclear. Here, we show that MGL1 knockout macrophages (MGL1−/− Mφ) infected in vitro with T. cruzi were heavily parasitized and showed decreased levels of reactive oxygen species (ROS), nitric oxide (NO), IL-12 and TNF-α compared to wild-type macrophages (WT Mφ). MGL1−/− Mφ stimulated in vitro with T. cruzi antigen (TcAg) showed low expression of TLR-2, TLR-4 and MHC-II, which resulted in deficient splenic cell activation compared with similar co-cultured WT Mφ. Importantly, the activation of p-ERK1/2, p-c-Jun and p-NF-κB p65 were significantly reduced in MGL1−/− Mφ exposed to TcAg. Similarly, procaspase 1, caspase 1 and NLRP3 inflammasome also displayed a reduced expression that was associated with low IL-β production. Our data reveal a previously unappreciated role for MGL1 in Mφ activation through the modulation of ERK1/2, c-Jun, NF-κB and NLRP3 signaling pathways, and to the development of protective innate immunity against experimental T. cruzi infection.

scholarly journals A helminth-derived suppressor of ST2 blocks allergic responses

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Francesco Vacca ◽  
Caroline Chauché ◽  
Abhishek Jamwal ◽  
Elizabeth C Hinchy ◽  
Graham Heieis ◽  
...  
Keyword(s):  
Immune Responses ◽  
Heligmosomoides Polygyrus ◽  
Human Pbmc ◽  
Complement Control Protein ◽  
High Affinity ◽  
Intestinal Nematode ◽  
Control Protein

The IL-33-ST2 pathway is an important initiator of type 2 immune responses. We previously characterised the HpARI protein secreted by the model intestinal nematode Heligmosomoides polygyrus, which binds and blocks IL-33. Here, we identify H. polygyrus Binds Alarmin Receptor and Inhibits (HpBARI) and HpBARI_Hom2, both of which consist of complement control protein (CCP) domains, similarly to the immunomodulatory HpARI and Hp-TGM proteins. HpBARI binds murine ST2, inhibiting cell surface detection of ST2, preventing IL-33-ST2 interactions, and inhibiting IL-33 responses in vitro and in an in vivo mouse model of asthma. In H. polygyrus infection, ST2 detection is abrogated in the peritoneal cavity and lung, consistent with systemic effects of HpBARI. HpBARI_Hom2 also binds human ST2 with high affinity, and effectively blocks human PBMC responses to IL-33. Thus, we show that H. polygyrus blocks the IL-33 pathway via both HpARI which blocks the cytokine, and also HpBARI which blocks the receptor.

scholarly journals Microsomal prostaglandin E synthase-1 in both cancer cells and hosts contributes to tumour growth, invasion and metastasis

2009 ◽  
Vol 425 (2) ◽  
pp. 361-371 ◽  
Author(s):  
Daisuke Kamei ◽  
Makoto Murakami ◽  
Yuka Sasaki ◽  
Yoshihito Nakatani ◽  
Masataka Majima ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Tumour Growth ◽  
Matrix Metalloproteinase 2 ◽  
Prostaglandin E ◽  
Wild Type ◽  
Prostaglandin E Synthase ◽  
Lung Carcinoma Cells ◽  
Microsomal Prostaglandin E Synthase

mPGES-1 (microsomal prostaglandin E synthase-1) is a stimulus-inducible enzyme that functions downstream of COX (cyclo-oxygenase)-2 in the PGE2 (prostaglandin E2)-biosynthesis pathway. Although COX-2-derived PGE2 is known to play a role in the development of various tumours, the involvement of mPGES-1 in carcinogenesis has not yet been fully understood. In the present study, we used LLC (Lewis lung carcinoma) cells with mPGES-1 knockdown or overexpression, as well as mPGES-1-deficient mice to examine the roles of cancer cell- and host-associated mPGES-1 in the processes of tumorigenesis in vitro and in vivo. We found that siRNA (small interfering RNA) silencing of mPGES-1 in LLC cells decreased PGE2 synthesis markedly, accompanied by reduced cell proliferation, attenuated Matrigel™ invasiveness and increased extracellular matrix adhesion. Conversely, mPGES-1-overexpressing LLC cells showed increased proliferating and invasive capacities. When implanted subcutaneously into wild-type mice, mPGES-1-silenced cells formed smaller xenograft tumours than did control cells. Furthermore, LLC tumours grafted subcutaneously into mPGES-1-knockout mice grew more slowly than did those grafted into littermate wild-type mice, with concomitant decreases in the density of microvascular networks, the expression of pro-angiogenic vascular endothelial growth factor, and the activity of matrix metalloproteinase-2. Lung metastasis of intravenously injected LLC cells was also significantly less obvious in mPGES-1-null mice than in wild-type mice. Thus our present approaches provide unequivocal evidence for critical roles of the mPGES-1-dependent PGE2 biosynthetic pathway in both cancer cells and host microenvironments in tumour growth and metastasis.

The atypical chemokine receptor CCX-CKR scavenges homeostatic chemokines in circulation and tissues and suppresses Th17 responses

Blood ◽  
2010 ◽  
Vol 116 (20) ◽  
pp. 4130-4140 ◽  
Author(s):  
Iain Comerford ◽  
Robert J. B. Nibbs ◽  
Wendel Litchfield ◽  
Mark Bunting ◽  
Yuka Harata-Lee ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Chemokine Receptor ◽  
Fold Increase ◽  
Wild Type ◽  
Peripheral Lymph ◽  
The Central Nervous System

Abstract Our previous in vitro studies led to proposals that the atypical chemokine receptor CCX-CKR is a scavenger of CCR7 ligand homeostatic chemokines. In the present study, we generated CCX-CKR−/− mice and confirm this scavenger function in vivo. Compared with wild-type mice, CCX-CKR−/− have a 5-fold increase in the level of CCL21 protein in blood, and 2- to 3-fold increases in CCL19 and CCL21 in peripheral lymph nodes. The effect of these protein increases on immunity was investigated after immunization with MOG35-55 peptide emulsified in complete Freund adjuvant (CFA). The subsequent characteristic paralysis develops with enhanced kinetics and severity in CCX-CKR−/− versus wild-type mice. Despite this effect, antigen-specific immune responses in the draining lymph nodes are diminished in CCX-CKR−/− mice. Instead, the earlier onset of disease is associated with enhanced T-cell priming in the CCX-CKR−/− spleen and a skewing of CD4+ T-cell responses toward Th17 rather than Th1. This observation correlates with increased expression of IL-23 in the CCX-CKR−/− spleen and increased CCL21 levels in the central nervous system postimmunization. The early onset of disease in CCX-CKR−/− mice is reversed by systemic administration of neutralizing anti-CCL21 antibodies. Thus, by regulating homeostatic chemokine bioavailability, CCX-CKR influences the localization, kinetics, and nature of adaptive immune responses in vivo.

Cell cycle arrest and senescence in P53-wild type renal carcinoma by enhancer RNA - P53-bound enhancer regions 2(p53BER2) through p53-dependent pathway

2020 ◽  
Author(s):  
HAIBIAO XIE ◽  
Kaifang Ma ◽  
Kenan Zhang ◽  
Jingcheng Zhou ◽  
Lei Li ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cancer Cells ◽  
Cell Lines ◽  
Kidney Cancer ◽  
Renal Cancer ◽  
G1 Arrest ◽  
Wild Type ◽  
Enhancer Rna

Abstract Background P53 is a classic tumor suppressor, but its role in kidney cancer remains unclear. In our study, we tried to explain the role of p53 in kidney cancer through p53 enhancer RNA-related pathway. Methods qPCR and luciferase reporters were used to detect the expression of p53-related enhancer RNA. Nutlin3 and artificial "microRNA" were used to induce and inhibit the expression of p53 enhancer RNA, respectively. Cycle analysis and β-galactosidase assay were used to explore whether P53-bound enhancer regions 2(p53BER2) plays a role in the cell cycle and senescence response of p53-wild type (WT) renal cancer cells. The function of p53BER2 was further analyzed in vivo by nude mice. RNA sequencing was used to identify the potential target of p53BER2. Results The results showed that P53BER2 expression was down-regulated in renal cancer tissues and cell lines and could specifically express in p53-WT renal cancer cell lines. Knockdown p53BER2 could reverse nutlin-3-induced cytotoxic effect in p53-WT cell lines. Further, downregulation of p53BER2 could reverse nutlin-3-induced G1 arrest and senescence in p53-WT cell lines. What is more, knockdown of p53BER2 showed a resistance to nutlin-3 treatment in Vivo. Additionally, we found BRCA2 could be regulated by p53BER2 in vitro and vivo, which suggested BRCA2 might mediate the function of p53BER2 in RCC. Conclusions The p53-associated enhancer RNA-p53BER2 mediates the cell cycle and senescence of p53 in p53-WT renal cancer cells. This further provides a novel approach and insight for the RCC and p53 research in renal cancer.

Interleukin 27 inhibits atherosclerosis via immunoregulation of macrophages in mice

2013 ◽  
Vol 305 (3) ◽  
pp. H420-H429 ◽  
Author(s):  
Tetsuaki Hirase ◽  
Hiromitsu Hara ◽  
Yoshiyuki Miyazaki ◽  
Noriko Ide ◽  
Ai Nishimoto-Hazuku ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Macrophage Activation ◽  
Density Lipoprotein ◽  
Cell Polarization ◽  
High Cholesterol Diet ◽  
Wild Type ◽  
Interleukin 27 ◽  
Significant Difference

Chronic inflammation in arterial wall that is driven by immune cells and cytokines plays pivotal roles in the development of atherosclerosis. Interleukin 27 (IL-27) is a member of the IL-12 family of cytokines that consists of IL-27p28 and Epstein-Barr virus induced gene 3 (EBI3) and has anti-inflammatory properties that regulate T cell polarization and cytokine production. IL-27-deficient ( Ldlr−/− Ebi3−/−) and IL-27 receptor-deficient ( Ldlr−/− WSX-1−/−) Ldlr−/− mice were generated and fed with a high-cholesterol diet to induce atherosclerosis. Roles of bone marrow-derived cells in vivo and macrophages in vitro were studied using bone marrow reconstitution by transplantation and cultured peritoneal macrophages, respectively. We demonstrate that mice lacking IL-27 or IL-27 receptor are more susceptible to atherosclerosis compared with wild type due to enhanced accumulation and activation of macrophages in arterial walls. The number of circulating proinflammatory Ly6Chi monocytes showed no significant difference between wild-type mice and mice lacking IL-27 or IL-27 receptor. Administration of IL-27 suppressed the development of atherosclerosis in vivo and macrophage activation in vitro that was indicated by increased uptake of modified low-density lipoprotein and augmented production of proinflammatory cytokines. These findings define a novel inhibitory role for IL-27 in atherosclerosis that regulates macrophage activation in mice.

scholarly journals Novel Human Anti-PD-L1 mAbs Inhibit Immune-Independent Tumor Cell Growth and PD-L1 Associated Intracellular Signalling

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Margherita Passariello ◽  
Anna Morena D’Alise ◽  
Annachiara Esposito ◽  
Cinzia Vetrei ◽  
Guendalina Froechlich ◽  
...  
Keyword(s):  
Cell Growth ◽  
Tumor Cell ◽  
Cancer Cells ◽  
Mapk Pathway ◽  
Immune Checkpoints ◽  
Tumor Cell Growth ◽  
Potent Effect ◽  
High Affinity

Abstract The novel antibody-based immunotherapy in oncology exploits the activation of immune system mediated by immunomodulatory antibodies specific for immune checkpoints. Among them, the programmed death ligand-1 (PD-L1) is of particular interest as it is expressed not only on T-cells, but also on other immune cells and on a large variety of cancer cells, such as breast cancer cells, considering its high expression in both ErbB2-positive and Triple Negative Breast Cancers. We demonstrate here that PD-L1_1, a novel anti-PD-L1 T -cell stimulating antibody, inhibits PD-L1-tumor cell growth also by affecting the intracellular MAPK pathway and by activating caspase 3. Similar in vitro results were obtained for the first time here also with the clinically validated anti-PD-L1 mAb Atezolizumab and in vivo with another validated anti-mouse anti-PD-L1 mAb. Moreover, we found that two high affinity variants of PD-L1_1 inhibited tumor cell viability more efficiently than the parental PD-L1_1 by affecting the same MAPK pathways with a more potent effect. Altogether, these results shed light on the role of PD-L1 in cancer cells and suggest that PD-L1_1 and its high affinity variants could become powerful antitumor weapons to be used alone or in combination with other drugs such as the anti-ErbB2 cAb already successfully tested in in vitro combinatorial treatments.

scholarly journals In vitro and in vivo efficacy of anti‐chikungunya virus monoclonal antibodies produced in wild‐type and glycoengineered Nicotiana benthamiana plants

2019 ◽  
Vol 18 (1) ◽  
pp. 266-273 ◽  
Author(s):  
Jonathan Hurtado ◽  
Dhiraj Acharya ◽  
Huafang Lai ◽  
Haiyan Sun ◽  
Somanath Kallolimath ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Nicotiana Benthamiana ◽  
Chikungunya Virus ◽  
Wild Type ◽  
In Vivo Efficacy
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