scholarly journals A quantitative view of strategies to engineer cell-selective ligand binding

2021 ◽  
Author(s):  
Zhixin Cyrillus Tan ◽  
Brian T Orcutt-Jahns ◽  
Aaron S Meyer
Keyword(s):  
Specific Binding ◽  
Cell Types ◽  
Target Cells ◽  
Binding Model ◽  
Combinatorial Explosion ◽  
Model Driven ◽  
Target Populations ◽  
Proposed Model ◽  
Selective Ligand ◽  
Receptor Interactions

Abstract A critical property of many therapies is their selective binding to target populations. Exceptional specificity can arise from high-affinity binding to surface targets expressed exclusively on target cell types. In many cases, however, therapeutic targets are only expressed at subtly different levels relative to off-target cells. More complex binding strategies have been developed to overcome this limitation, including multi-specific and multivalent molecules, creating a combinatorial explosion of design possibilities. Guiding strategies for developing cell-specific binding are critical to employ these tools. Here, we employ a uniquely general multivalent binding model to dissect multi-ligand and multi-receptor interactions. This model allows us to analyze and explore a series of mechanisms to engineer cell selectivity, including mixtures of molecules, affinity adjustments, valency changes, multi-specific molecules and ligand competition. Each of these strategies can optimize selectivity in distinct cases, leading to enhanced selectivity when employed together. The proposed model, therefore, provides a comprehensive toolkit for the model-driven design of selectively binding therapies.

scholarly journals A quantitative view of strategies to engineer cell-selective ligand binding

2020 ◽  
Author(s):  
Zhixin Cyrillus Tan ◽  
Brian Orcutt-Jahns ◽  
Aaron S. Meyer
Keyword(s):  
Specific Binding ◽  
Quantitative Model ◽  
Design Guidelines ◽  
Target Cells ◽  
List Type ◽  
Binding Model ◽  
Selective Ligand ◽  
Unique Cell ◽  
Development Literature ◽  
Enhanced Selectivity

AbstractA critical property of many therapies is their selective binding to specific target populations. Exceptional specificity can arise from high-affinity binding to unique cell surface targets. In many cases, however, therapeutic targets are only expressed at subtly different levels relative to off-target cells. More complex binding strategies have been developed to overcome this limitation, including multi-specific and multi-valent molecules, but these create a combinatorial explosion of design possibilities. Therefore, guiding strategies for developing cell-specific binding are critical to employ these tools. Here, we extend a multi-valent binding model to multi-ligand and multi-receptor interactions. Using this model, we explore a series of mechanisms to engineer cell selectivity, including mixtures of molecules, affinity adjustments, and valency changes. Each of these strategies maximizes selectivity in distinct cases, leading to synergistic improvements when used in combination. Finally, we identify situations in which selectivity cannot be derived through passive binding alone to highlight areas in need of new developments. In total, this work uses a quantitative model to unify a comprehensive set of design guidelines for engineering cell-specific therapies.Summary pointsAffinity, valency, and other alterations to target cell binding provide enhanced selectivity in specific situations.Evidence for the effectiveness and limitations of each strategy are abundant within the drug development literature.Combining strategies can offer enhanced selectivity.A simple, multivalent ligand-receptor binding model can help to direct therapeutic engineering.

Comparative studies of insulin binding to receptor from adipocytes, hepatocytes, monocytes and erythrocytes from the pig

1988 ◽  
Vol 118 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Elisabeth Hjøllund ◽  
Bjørn Richelsen ◽  
Oluf Pedersen
Keyword(s):  
Steady State ◽  
Receptor Binding ◽  
Specific Binding ◽  
Insulin Binding ◽  
Cell Types ◽  
Target Cells ◽  
Suitable Model ◽  
The Individual ◽  
Different Cell Types ◽  
Specific Insulin

Abstract. We have described the receptor binding of A 14-labelled [125I]insulin to viable adipocytes, hepatocytes, monocytes and erythrocytes from the pig. For all cell types the binding was of high affinity, specific for insulin, the non-specific binding low and degradation of insulin in the medium was minimal. At 24°C, steady state insulin binding was achieved in all four cell types. At 37°C, steady state insulin binding could be measured to adipocytes and hepatocytes. Specific insulin binding levels and receptor affinity for blood and fat cells from the pig are comparable to that in human cells, whereas differences, especially according to affinity, exist between pig and rat cell insulin receptor binding. It is therefore concluded that the pig is a more suitable model for studies of insulin binding in man than rodents. Finally, no correlations between the individual binding levels to the different cell types were observed. Hence, measurement of insulin binding to the easier available blood cells cannot replace studies of insulin binding to target cells of insulin.

scholarly journals Exosome Traceability and Cell Source Dependence on Composition and Cell-Cell Cross Talk

2021 ◽  
Vol 22 (10) ◽  
pp. 5346
Author(s):  
Rabab N. Hamzah ◽  
Karrer M. Alghazali ◽  
Alexandru S. Biris ◽  
Robert J. Griffin
Keyword(s):  
Donor Cell ◽  
Average Diameter ◽  
Cell Types ◽  
Cell Interaction ◽  
Target Cells ◽  
Remote Communication ◽  
Normal Cells ◽  
Growth Environment ◽  
Cell Components ◽  
The Impact

Exosomes are small vesicles with an average diameter of 100 nm that are produced by many, if not all, cell types. Exosome cargo includes lipids, proteins, and nucleic acids arranged specifically in the endosomes of donor cells. Exosomes can transfer the donor cell components to target cells and can affect cell signaling, proliferation, and differentiation. Important new information about exosomes’ remote communication with other cells is rapidly being accumulated. Recent data indicates that the results of this communication depend on the donor cell type and the environment of the host cell. In the field of cancer research, major questions remain, such as whether tumor cell exosomes are equally taken up by cancer cells and normal cells and whether exosomes secreted by normal cells are specifically taken up by other normal cells or also tumor cells. Furthermore, we do not know how exosome uptake is made selective, how we can trace exosome uptake selectivity, or what the most appropriate methods are to study exosome uptake and selectivity. This review will explain the effect of exosome source and the impact of the donor cell growth environment on tumor and normal cell interaction and communication. The review will also summarize the methods that have been used to label and trace exosomes to date.

scholarly journals Single-cell analysis reveals cell communication triggered by macrophages associated with the reduction and exhaustion of CD8+ T cells in COVID-19

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lei He ◽  
Quan Zhang ◽  
Yue Zhang ◽  
Yixian Fan ◽  
Fahu Yuan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Cell Communication ◽  
Cell Types ◽  
Trial Registration ◽  
T Cell Subsets ◽  
Disease Group ◽  
Communication Analysis ◽  
Receptor Interactions

Abstract Background The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) has become an ongoing pandemic. Understanding the respiratory immune microenvironment which is composed of multiple cell types, together with cell communication based on ligand–receptor interactions is important for developing vaccines, probing COVID-19 pathogenesis, and improving pandemic control measures. Methods A total of 102 consecutive hospitalized patients with confirmed COVID-19 were enrolled in this study. Clinical information, routine laboratory tests, and flow cytometry analysis data with different conditions were collected and assessed for predictive value in COVID-19 patients. Next, we analyzed public single-cell RNA-sequencing (scRNA-seq) data from bronchoalveolar lavage fluid, which offers the closest available view of immune cell heterogeneity as encountered in patients with varying severity of COVID-19. A weighting algorithm was used to calculate ligand–receptor interactions, revealing the communication potentially associated with outcomes across cell types. Finally, serum cytokines including IL6, IL1β, IL10, CXCL10, TNFα, GALECTIN-1, and IGF1 derived from patients were measured. Results Of the 102 COVID-19 patients, 42 cases (41.2%) were categorized as severe. Multivariate logistic regression analysis demonstrated that AST, D-dimer, BUN, and WBC were considered as independent risk factors for the severity of COVID-19. T cell numbers including total T cells, CD4+ and CD8+ T cells in the severe disease group were significantly lower than those in the moderate disease group. The risk model containing the above mentioned inflammatory damage parameters, and the counts of T cells, with AUROCs ranged from 0.78 to 0.87. To investigate the molecular mechanism at the cellular level, we analyzed the published scRNA-seq data and found that macrophages displayed specific functional diversity after SARS-Cov-2 infection, and the metabolic pathway activities in the identified macrophage subtypes were influenced by hypoxia status. Importantly, we described ligand–receptor interactions that are related to COVID-19 serverity involving macrophages and T cell subsets by communication analysis. Conclusions Our study showed that macrophages driving ligand–receptor crosstalk contributed to the reduction and exhaustion of CD8+ T cells. The identified crucial cytokine panel, including IL6, IL1β, IL10, CXCL10, IGF1, and GALECTIN-1, may offer the selective targets to improve the efficacy of COVID-19 therapy. Trial registration: This is a retrospective observational study without a trial registration number.

INTERACTION OF S PROTEIN/VITRONECTIN WITH CULTURED ENDOTHELIAL CELLS: PROMOTION OF ATTACHMENT AND SPECIFIC BINDING

1987 ◽  
Author(s):  
K T Preissner ◽  
E Anders ◽  
G Müller-Berghaus
Keyword(s):  
Endothelial Cells ◽  
Cell Attachment ◽  
Specific Binding ◽  
Umbilical Vein ◽  
Attachment Site ◽  
Cell Types ◽  
S Protein ◽  
Specific Association ◽  
Umbilical Vein Endothelial Cells ◽  
Adhesive Proteins

The interaction of the complement inhibitor S protein, which is identical to the serum spreading factor, vitronectin, with cultured human endothelial cells of macro- and microvas- cular origin was investigated. Purified S protein, coated for 2 h on polystyrene petri dishes, induced concentration- and time-dependent attachment and spreading of human umbilical vein endothelial cells (HUVEC) as well as human omental tissqe microvasular endothelial cells (HOTMEC) at 37°C. With 3 × 105 cells/ml (final concentration) more than 50% of the cells attached within 2 h incubation at 0.3 - 3 μg/ml S protein. The effect of S protein was specific, since only monospecific antibodies against S protein prevented attachment of cells, while antibodies against fibronectin, fibrinogen or von Wille-brand factor were uneffective. The pentapeptide Gly-Arg-Gly-Asp-Ser, which contains the cell-attachment site of these adhesive proteins including S protein, inhibited the activity of S protein to promote attachment of endothelial cells in a concentration-dependent fashion; at 200 μM peptide, less than 10% of the cells became attached. Direct binding of S protein to HUVEC and HOTMEC was studied with cells in suspension at a concentration of 1 × 106 cells/ml in the presence of 1% (w/v) human serum albumin and 1 mM CaCl2 and was maximal after 120 min. Both cell types bound S protein in a concentration-dependent fashion with an estimated dissociation constant KD=0.2pM. More than 80% of bound radiolabelled S protein was displaced by unlabelled S protein, whereas binding was reduced to about 50% by the addition in excess of either fibronectin, fibrinogen, von Willebrand factor or the pentapeptide. These findings provide evidence for the specific association of S protein with endothelial cells, ultimately leading to attachment and spreading of cells. Although the promotion of attachment was highly specific for S protein, other adhesive proteins than S protein, also known to associate with endothelial cells, may in part compete with direct S protein binding.

scholarly journals The plasminogen system and cell surfaces: evidence for plasminogen and urokinase receptors on the same cell type.

1986 ◽  
Vol 103 (6) ◽  
pp. 2411-2420 ◽  
Author(s):  
E F Plow ◽  
D E Freaney ◽  
J Plescia ◽  
L A Miles
Keyword(s):  
Cell Line ◽  
Plasminogen Activator ◽  
Cell Lines ◽  
Specific Binding ◽  
High Capacity ◽  
Fetal Lung ◽  
Fibroblast Cell ◽  
Cell Types ◽  
Cell Surfaces ◽  
Catalytically Active

The capacity of cells to interact with the plasminogen activator, urokinase, and the zymogen, plasminogen, was assessed using the promyeloid leukemic U937 cell line and the diploid fetal lung GM1380 fibroblast cell line. Urokinase bound to both cell lines in a time-dependent, specific, and saturable manner (Kd = 0.8-2.0 nM). An active catalytic site was not required for urokinase binding to the cells, and 55,000-mol-wt urokinase was selectively recognized. Plasminogen also bound to the two cell lines in a specific and saturable manner. This interaction occurred with a Kd of 0.8-0.9 microM and was of very high capacity (1.6-3.1 X 10(7) molecules bound/cell). The interaction of plasminogen with both cell types was partially sensitive to trypsinization of the cells and required an unoccupied high affinity lysine-binding site in the ligand. When plasminogen was added to the GM1380 cells, a line with high intrinsic plasminogen activator activity, the bound ligand was comprised of both plasminogen and plasmin. Urokinase, in catalytically active or inactive form, enhanced plasminogen binding to the two cell lines by 1.4-3.3-fold. Plasmin was the predominant form of the bound ligand when active urokinase was added, and preformed plasmin can also bind directly to the cells. Plasmin on the cell surface was also protected from its primary inhibitor, alpha 2-antiplasmin. These results indicate that the two cell lines possess specific binding sites for plasminogen and urokinase, and a family of widely distributed cellular receptors for these components may be considered. Endogenous or exogenous plasminogen activators can generate plasmin on cell surfaces, and such activation may provide a mechanism for arming cell surfaces with the broad proteolytic activity of this enzyme.

scholarly journals Human Dendritic Cells Mediate Cellular Apoptosis via Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand (Trail)

1999 ◽  
Vol 190 (8) ◽  
pp. 1155-1164 ◽  
Author(s):  
Neil A. Fanger ◽  
Charles R. Maliszewski ◽  
Ken Schooley ◽  
Thomas S. Griffith
Keyword(s):  
Dendritic Cells ◽  
Tumor Cells ◽  
Cell Types ◽  
Target Cells ◽  
Functional Difference ◽  
Cellular Apoptosis ◽  
Soluble Trail ◽  
Innate Effector ◽  
Human Dendritic Cells ◽  
Necrosis Factor

TRAIL (TNF-related apoptosis-inducing ligand) is a member of the TNF family that induces apoptosis in a variety of cancer cells. In this study, we demonstrate that human CD11c+ blood dendritic cells (DCs) express TRAIL after stimulation with either interferon (IFN)-γ or -α and acquire the ability to kill TRAIL-sensitive tumor cell targets but not TRAIL-resistant tumor cells or normal cell types. The DC-mediated apoptosis was TRAIL specific, as soluble TRAIL receptor blocked target cell death. Moreover, IFN-stimulated interleukin (IL)-3 receptor (R)α+ blood precursor (pre-)DCs displayed minimal cytotoxicity toward the same target cells, demonstrating a clear functional difference between the CD11c+ DC and IL-3Rα+ pre-DC subsets. These results indicate that TRAIL may serve as an innate effector molecule on CD11c+ DCs for the elimination of spontaneously arising tumor cells and suggest a means by which TRAIL-expressing DCs may regulate or eliminate T cells responding to antigen presented by the DCs.

scholarly journals Chimeric Maternal Cells with Tissue-Specific Antigen Expression and Morphology Are Common in Infant Tissues

2009 ◽  
Vol 12 (5) ◽  
pp. 337-346 ◽  
Author(s):  
Anne M. Stevens ◽  
Heidi M. Hermes ◽  
Meghan M. Kiefer ◽  
Joe C. Rutledge ◽  
J. Lee Nelson
Keyword(s):  
Islet Cells ◽  
Tissue Injury ◽  
Specific Antigen ◽  
Antigen Expression ◽  
Cell Types ◽  
Target Cells ◽  
Specific Cell ◽  
Tissue Specific ◽  
Renal Tubular Cells ◽  
Parenchymal Cells

Maternal microchimerism (MMc) has been purported to play a role in the pathogenesis of autoimmunity, but how a small number of foreign cells could contribute to chronic, systemic inflammation has not been explained. Reports of peripheral blood cells differentiating into tissue-specific cell types may shed light on the problem in that chimeric maternal cells could act as target cells within tissues. We investigated MMc in tissues from 7 male infants. Female cells, presumed maternal, were characterized by simultaneous immunohistochemistry and fluorescence in situ hybridization for X- and Y-chromosomes. Maternal cells constituted 0.017% to 1.9% of parenchymal cells and were found in all infants in liver, pancreas, lung, kidney, bladder, skin, and spleen. Maternal cells were differentiated: maternal hepatocytes in liver, renal tubular cells in kidney, and β-islet cells in pancreas. Maternal cells were not found in areas of tissue injury or inflammatory infiltrate. Maternal hematopoietic cells were found only in hearts from patients with neonatal lupus. Thus, differentiated maternal cells are present in multiple tissue types and occur independently of inflammation or tissue injury. Loss of tolerance to maternal parenchymal cells could lead to organ-specific “auto” inflammatory disease and elimination of maternal cells in areas of inflammation.

scholarly journals Cellular Receptors Involved in KSHV Infection

Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 118
Author(s):  
Emma van der Meulen ◽  
Meg Anderton ◽  
Melissa J. Blumenthal ◽  
Georgia Schäfer
Keyword(s):  
Virus Infection ◽  
Cell Surface ◽  
Kaposi's Sarcoma ◽  
Kaposi’S Sarcoma ◽  
Cell Types ◽  
Target Cells ◽  
Specific Cell ◽  
Cellular Receptors ◽  
Diverse Range ◽  
Kshv Infection

The process of Kaposi’s Sarcoma Herpes Virus’ (KSHV) entry into target cells is complex and engages several viral glycoproteins which bind to a large range of host cell surface molecules. Receptors for KSHV include heparan sulphate proteoglycans (HSPGs), several integrins and Eph receptors, cystine/glutamate antiporter (xCT) and Dendritic Cell-Specific Intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN). This diverse range of potential binding and entry sites allows KSHV to have a broad cell tropism, and entry into specific cells is dependent on the available receptor repertoire. Several molecules involved in KSHV entry have been well characterized, particularly those postulated to be associated with KSHV-associated pathologies such as Kaposi’s Sarcoma (KS). In this review, KSHV infection of specific cell types pertinent to its pathogenesis will be comprehensively summarized with a focus on the specific cell surface binding and entry receptors KSHV exploits to gain access to a variety of cell types. Gaps in the current literature regarding understanding interactions between KSHV glycoproteins and cellular receptors in virus infection are identified which will lead to the development of virus infection intervention strategies.

An Overview of the Latest Applications of Platelet-Derived Microparticles and Nanoparticles in Medical Technology 2010-2020

2021 ◽  
Vol 21 ◽  
Author(s):  
Tahereh Zadeh Mehrizi
Keyword(s):  
Drug Delivery ◽  
Cell Types ◽  
Current Status ◽  
Target Cells ◽  
Interesting Point ◽  
Large Size ◽  
Review Study ◽  
Cellular Pathways ◽  
Different Cell Types

: Today, Platelets and platelet-derived nanoparticles and microparticles have found many applications in nanomedical technology. The results of our review study show that no article has been published in this field to review the current status of applications of these platelet derivatives so far. Therefore, in present study, our goal is to compare the applications of platelet derivatives and review their latest status between 2010 and 2020 to present the latest findings to researchers. A very interesting point about the role of platelet derivatives is the presence of molecules on their surface which makes them capable of hiding from the immune system, reaching different target cells, and specifically attaching to different cell types. According to the results of this study, most of their applications include drug delivery, diagnosis of various diseases, and tissue engineering. However, their application in drug delivery is limited due to heterogeneity, large size, and the possibility of interference with cellular pathways in microparticles derived from other cells. On the other hand, platelet nanoparticles are more controllable and have been widely used for drug delivery in treatment of cancer, atherosclerosis, thrombosis, infectious diseases, repair of damaged tissue, and photothermal therapy. The results of this study show that platelet nanoparticles are more controllable than platelet microparticles and have a higher potential for use in medicine.

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