ABSTRACT
Galectins are a family of beta-galactoside-binding proteins that are characterised by their carbohydrate recognition domain (CRD) and include galectin-1 and galectin-3. These galectins have been implicated in numerous diseases due to their pleiotropic nature, including cancer and fibrosis, with therapeutic inhibitors being clinically developed to block the CRD. One of the early methods developed to characterise these galectins was the hemagglutination of red blood cells. Although it is insightful, this approach has been hampered by a lack of sensitivity and accurate quantification of the agglutination observed. In this study, we aimed to validate a more precise and quantitative method to enable the further investigation of differences between galectins in respect to agglutination induction in different blood groups, as well as the characterisation of small molecule inhibitors. Quantification of hemagglutination was shown to be optimal using U-bottom plates imaged and analysed with FIJI ImageJ rather than flat-bottom plates read for absorbance on an optical density plate reader. Galectin-3-induced red blood cell agglutination efficacy increased significantly from blood group O to A to B. However, for both the galectin-1 monomer and concatemer, a more comparable effect was observed between blood group B and O, but with more potent effects than in blood group A. Inhibition assays for both galectin-3 and galectin-1 induced-hemagglutination were able to demonstrate clear concentration responses and expected selectivity profiles for a set of small-molecule glycomimetics, confirming the historical profiles obtained in biochemical binding and functional cellular assays.
Subject(s)
Erythrocytes , Galectin 1 , Galectins , Hemagglutination , Humans , Erythrocytes/metabolism , Erythrocytes/drug effects , Hemagglutination/drug effects , Galectins/antagonists & inhibitors , Galectins/metabolism , Galectin 1/antagonists & inhibitors , Galectin 1/metabolism , Galectin 3/antagonists & inhibitors , Galectin 3/metabolism , Agglutination Tests/methods , Hemagglutination Tests , Agglutination/drug effectsABSTRACT
Galectin-3 has a variety of important pathophysiological significance in the human body. Much evidence shows that the abnormal expression of galectin-3 is related to the formation and development of many diseases. Pectin is mostly obtained from processed citrus fruits and apples and is a known natural inhibitor of galactin-3. A large number of peels produced each year are discarded, and it is necessary to recycle some of the economically valuable active compounds in these by-products to reduce resource waste and environmental pollution. By binding with galectin-3, pectin can directly reduce the expression level of galectin-3 on the one hand, and regulate the expression level of cytokines by regulating certain signaling pathways on the other hand, to achieve the effect of treating diseases. This paper begins by presenting an overview of the basic structure of pectin, subsequently followed by a description of the structure of galectin-3 and its detrimental impact on human health when expressed abnormally. The health effects of pectin as a galectin-3 inhibitor were then summarized from the perspectives of anticancer, anti-inflammatory, ameliorating fibrotic diseases, and anti-diabetes. Finally, the challenges and prospects of future research on pectin are presented, which provide important references for expanding the application of pectin in the pharmaceutical industry or developing functional dietary supplements.
Subject(s)
Galectin 3 , Pectins , Animals , Humans , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/chemistry , Blood Proteins , Galectin 3/metabolism , Galectin 3/antagonists & inhibitors , Galectins/metabolism , Galectins/antagonists & inhibitors , Neoplasms/metabolism , Neoplasms/drug therapy , Pectins/pharmacology , Pectins/chemistryABSTRACT
As a result of our continued efforts to pursue Gal-3 inhibitors that could be used to fully evaluate the potential of Gal-3 as a therapeutic target, two novel series of benzothiazole derived monosaccharides as potent (against both human and mouse Gal-3) and orally bioavailable Gal-3 inhibitors, represented by 4 and 5, respectively, were identified. These discoveries were made based on proposals that the benzothiazole sulfur atom could interact with the carbonyl oxygen of G182/G196 in h/mGal-3, and that the anomeric triazole moiety could be modified into an N-methyl carboxamide functionality. The interaction between the benzothiazole sulfur and the carbonyl oxygen of G196 in mGal-3 was confirmed by an X-ray co-crystal structure of early lead 9, providing a rare example of using a S···O binding interaction for drug design. It was found that for both the series, methylation of 3-OH in the monosaccharides caused no loss in h & mGal-3 potencies but significantly improved permeability of the molecules.
Subject(s)
Galectin 3 , Monosaccharides , Animals , Humans , Mice , Benzothiazoles/chemistry , Benzothiazoles/pharmacology , Drug Design , Galectin 3/antagonists & inhibitors , Galectins/antagonists & inhibitors , Monosaccharides/chemistry , Monosaccharides/pharmacology , Oxygen , SulfurABSTRACT
Toxoplasma gondii (T. gondii), one of the most important Apicomplexan protozoa, causes toxoplasmosis in human throughout the world. Galectin (Gal)-9 triggers a series of immune events via binding to its receptors, including T cell immunoglobulin and mucin-containing molecule 3, CD137, CD44, and protein disulfide isomerase. To examine the regulatory role of galectin-receptor interactions in anti-toxoplasmic activities, C57BL/6 mice were infected with T. gondii RH strain and intraperitoneally injected with alpha (α)-lactose to block the interactions of galectins and their receptors. Heatmaps showed upregulated values for Gal-9 and CD137 in the livers of T. gondii-infected mice and T. gondii-infected mice treated with α-lactose. Compared with T. gondii-infected mice, T. gondii-infected mice treated with α-lactose showed significantly increased survival rate, decreased tissue parasite burden, attenuated liver histopathology, increased mRNA expression levels of CD137, IFNγ, IL-4, and IL-10 in the liver, and increased Gal-9 mRNA expression level in the spleen. Correlation analysis showed that significant positive correlations existed between the mRNA expression levels of Gal-9 and CD137, Gal-9 and IFNγ, as well as between CD137 and IFNγ in the liver and spleen of T. gondii-infected mice; between CD137 and IFNγ in the liver of T. gondii-infected mice treated with α-lactose. In addition, blockage of galectin-receptor interactions showed enhanced M2 macrophage polarization in the liver of T. gondii-infected mice. Our data indicate that Gal-9-CD137 interaction may play an important role in T. gondii proliferation and liver inflammation in mice during acute T. gondii infection, through regulating T cell and macrophage immune responses.
Subject(s)
Galectins , Liver , Toxoplasma , Toxoplasmosis , Animals , Disease Models, Animal , Galectins/antagonists & inhibitors , Galectins/metabolism , Lactose/metabolism , Liver/metabolism , Liver/pathology , Mice , Mice, Inbred C57BL , RNA, Messenger/metabolism , Toxoplasmosis/complicationsABSTRACT
The growth of new blood vessels is a key event in many (patho) physiological processes, including embryogenesis, wound healing, inflammatory diseases, and cancer. Neovascularization requires different, well-coordinated actions of endothelial cells, i.e., the cells lining the luminal side of all blood vessels. Galectins are involved in several of these activities. In this chapter, we describe methods to study galectins in three key functions of endothelial cells during angiogenesis, i.e., endothelial cell migration, endothelial cell sprouting, and endothelial cell network formation.
Subject(s)
Endothelial Cells , Galectins , Neovascularization, Physiologic , Cell Movement , Endothelial Cells/physiology , Galectins/antagonists & inhibitors , Galectins/physiology , HumansABSTRACT
Galectins play relevant roles in tumor development, progression and metastasis. Accordingly, galectins are certainly enticing targets for medical intervention in cancer. To date, however, clinical trials based on galectin inhibitors reported inconclusive results. This review summarizes the galectin inhibitors currently being evaluated and discusses some of the biological challenges that need to be addressed to improve these strategies for the benefit of cancer patients.
Subject(s)
Antineoplastic Agents , Galectins , Neoplasms , Humans , Galectins/antagonists & inhibitors , Neoplasms/drug therapy , Neoplasms/metabolism , Antineoplastic Agents/therapeutic useABSTRACT
Immune profiling in patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM) provides the framework for developing novel immunotherapeutic strategies. Here, we demonstrate decreased CD4+ Th cells, increased Treg and G-type MDSC, and upregulation of immune checkpoints on effector/regulatory and CD138+ cells in MM patients, compared MGUS/SMM patients or healthy individuals. Among the checkpoints profiled, LAG3 was most highly expressed on proliferating CD4+ Th and CD8+ Tc cells in MM patients BMMC and PBMC. Treatment with antibody targeting LAG3 significantly enhanced T cells proliferation and activities against MM. XBP1/CD138/CS1-specific CTL generated in vitro displayed anti-MM activity, which was further enhanced following anti-LAG3 treatment, within the antigen-specific memory T cells. Treg and G-type MDSC weakly express LAG3 and were minimally impacted by anti-LAG3. CD138+ MM cells express GAL-3, a ligand for LAG3, and anti-GAL-3 treatment increased MM-specific responses, as observed for anti-LAG3. Finally, we demonstrate checkpoint inhibitor treatment evokes non-targeted checkpoints as a cause of resistance and propose combination therapeutic strategies to overcome this resistance. These studies identify and validate blockade of LAG3/GAL-3, alone or in combination with immune strategies including XBP1/CD138/CS1 multipeptide vaccination, to enhance anti-tumor responses and improve patient outcome in MM.
Subject(s)
Antigens, CD/chemistry , Blood Proteins/antagonists & inhibitors , Galectins/antagonists & inhibitors , Immunosuppression Therapy/methods , Leukocytes, Mononuclear/immunology , Monoclonal Gammopathy of Undetermined Significance/immunology , Multiple Myeloma/immunology , T-Lymphocytes, Cytotoxic/immunology , Apoptosis , Case-Control Studies , Cell Proliferation , Follow-Up Studies , Humans , Leukocytes, Mononuclear/metabolism , Leukocytes, Mononuclear/pathology , Lymphocyte Activation , Monoclonal Gammopathy of Undetermined Significance/metabolism , Monoclonal Gammopathy of Undetermined Significance/pathology , Monoclonal Gammopathy of Undetermined Significance/therapy , Multiple Myeloma/metabolism , Multiple Myeloma/pathology , Multiple Myeloma/therapy , Prognosis , Tumor Cells, Cultured , Lymphocyte Activation Gene 3 ProteinABSTRACT
Hepatopathy is frequently observed in patients with severe malaria but its pathogenesis remains unclear. Galectins are evolutionarily conserved glycan-binding proteins with pleiotropic roles in innate and adaptive immune responses, and exhibit pivotal roles during Plasmodium spp. infection. Here, we analyzed the impact of blockage of galectin-receptor interactions by treatment with alpha (α)-lactose on liver immunopathology during the erythrocytic stage of malaria in mice infected with Plasmodium berghei ANKA (PbANKA). Our results found that compared with PbANKA-infected mice (malarial mice), blockage of galectin-receptor interactions led to decreased host survival rate and increased peripheral blood parasitemia; exacerbated liver pathology, increased numbers of CD68+ macrophages and apoptotic cells, and increased parasite burden in the livers on days 5 and 7 post infection (p.i.) as well as increased mRNA expression levels of galectin-9 (Gal-9) and its receptor, the T cell immunoglobulin domain and mucin domain protein 3 (Tim-3), interferon (IFN)α, IFNγ, and the triggering receptor expressed on myeloid cells (TREM)-1 in the livers or spleens of PbANKA-infected mice on day 7 p.i. Observed by transmission electron microscopy, the peritoneal macrophages isolated from malarial mice with α-lactose treatment had more pseudopodia than those from malarial mice. Measured by using quantitative real-time reverse transcription-polymerase chain reaction assay, the mRNA expression levels of Gal-9, IFNα, IFNß, IFNγ, and TREM-1 were increased in the peritoneal macrophages isolated from malarial mice with α-lactose treatment in comparison of those from malarial mice. Furthermore, significant positive correlations existed between the mRNA levels of Gal-9 and Tim-3/IFNγ/TREM-1 in both the livers and the peritoneal macrophages, and between Gal-9 and Tim-3/TREM-1 in the spleens of malarial mice; significant positive correlations existed between the mRNA levels of Gal-9 and IFNγ in the livers and between Gal-9 and IFNα in the peritoneal macrophages from malarial mice treated with α-lactose. Our data suggest a potential role of galectin-receptor interactions in limiting liver inflammatory response and parasite proliferation by down-regulating the expressions of IFNα, IFNγ, and TREM-1 during PbANKA infection.
Subject(s)
Erythrocytes/parasitology , Galectins/physiology , Liver/pathology , Malaria/pathology , Parasitemia/pathology , Animals , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Female , Galectins/antagonists & inhibitors , Hepatitis A Virus Cellular Receptor 2/antagonists & inhibitors , Hepatitis A Virus Cellular Receptor 2/genetics , Hepatitis A Virus Cellular Receptor 2/metabolism , Interferon Type I/genetics , Interferon Type I/metabolism , Lactose/pharmacology , Lactose/toxicity , Liver/parasitology , Lung/metabolism , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/metabolism , Macrophages, Peritoneal/ultrastructure , Malaria/blood , Mice , Plasmodium berghei/growth & development , Pseudopodia/ultrastructure , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Receptors, Immunologic/biosynthesis , Receptors, Immunologic/genetics , Triggering Receptor Expressed on Myeloid Cells-1/biosynthesis , Triggering Receptor Expressed on Myeloid Cells-1/geneticsABSTRACT
Galectin-3 (Gal-3), a ß-galactoside-binding lectin, has been implicated in a plethora of pathological disorders including fibrosis, inflammation, cancer and metabolic diseases. TD139-a thio-digalactoside inhibitor developed by Galecto Biotech as a potential therapeutic for idiopathic pulmonary fibrosis-is the most advanced small-molecule Gal-3 inhibitor in clinical studies. It binds to human Gal-3 with high affinity but has lower affinity towards mouse and rat homologs, which is also manifested in the differential inhibition of Gal-3 function. Using biophysical methods and high-resolution X-ray co-crystal structures of TD139 and Gal-3 proteins, we demonstrate that a single amino acid change corresponding to A146 in human Gal-3 is sufficient for the observed reduction in the binding affinity of TD139 in rodents. Site-directed mutagenesis of A146V (in human Gal-3) and V160A (in mouse Gal-3) was sufficient to interchange the affinities, mainly by affecting the off rates of the inhibitor binding. In addition, molecular dynamics simulations of both wild-type and mutant structures revealed the sustained favorable noncovalent interactions between the fluorophenyl ring and the active site A146 (human Gal-3 and mouse V160A) that corroborate the finding from biophysical studies. Current findings have ramifications in the context of optimization of drug candidates against Gal-3.
Subject(s)
Blood Proteins , Galectins , Thiogalactosides , Humans , Binding Sites/drug effects , Blood Proteins/antagonists & inhibitors , Blood Proteins/metabolism , Galectins/antagonists & inhibitors , Galectins/metabolism , Thiogalactosides/metabolism , Thiogalactosides/pharmacologyABSTRACT
Oral squamous cell carcinoma (OSCC) is a cancer associated with high mortality (accounting for 3.1/100,000 deaths per year in Brazil in 2013) and a high frequency of amplification in the expression of the epidermal growth factor receptor (EGFR). Treatment with the EGFR inhibitor cetuximab leads to drug resistance in patients with OSCC due to unknown mechanisms. Galectin3 (Gal3) is a ßgalactoside binding lectin that regulates multiple signaling pathways in cells. The present study aimed to investigate the effect of Gal3 in cetuximabresistant (cetR) OSCC. The OSCC HSC3 cell line was selected to establish a mouse xenograft model, which was treated with cetuximab to induce resistance. Subsequently, a Gal3 inhibitor was used to treat cetR tumors, and the tumor volume was monitored. The expression of Gal3, phosphorylated (p)ERK1/2 and pAkt was assessed using immunohistochemistry. The combined effect of cetuximab and the Gal3 inhibitor on HSC3 tumor xenografts was also investigated. HSC3 cells were cultured in vitro to investigate the regulatory effects of Gal3 on ERK1/2 and Akt via western blotting. In addition, the effects of the Gal3 inhibitor on the proliferation, colony formation, invasion and apoptosis of HSC3 cells were investigated by performing Cell Counting Kit8, colony formation, Transwell and apoptosis assays, respectively. In cetR OSCC tumors, increased expression of Gal3, pERK1/2 and pAkt was observed. Further research demonstrated that Gal3 regulated the expression of both ERK1/2 and Akt in HSC3 cells by promoting phosphorylation. Moreover, the Gal3 inhibitor decreased the proliferation and invasion, but increased the apoptosis of cetR HSC3 cells. In addition, the Gal3 inhibitor suppressed the growth of cetR tumors. Collectively, the results indicated that the Gal3 inhibitor and cetuximab displayed a synergistic inhibitory effect on OSCC tumors. In summary, the present study demonstrated that Gal3 may serve an important role in cetR OSCC. The combination of cetuximab and the Gal3 inhibitor may display a synergistic antitumor effect, thereby inhibiting the development of cetuximab resistance in OSCC.
Subject(s)
Blood Proteins/antagonists & inhibitors , Carcinoma, Squamous Cell/drug therapy , Drug Resistance, Neoplasm , Galectins/antagonists & inhibitors , Mouth Neoplasms/drug therapy , Animals , Antineoplastic Agents, Immunological/pharmacology , Apoptosis/drug effects , Blood Proteins/genetics , Carcinoma, Squamous Cell/metabolism , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Cetuximab/pharmacology , Drug Resistance, Neoplasm/drug effects , Drug Synergism , Galectins/genetics , Gene Knockdown Techniques , Humans , Mice, Inbred BALB C , Mice, Nude , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3/antagonists & inhibitors , Mouth Neoplasms/metabolism , Mouth Neoplasms/pathology , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Signal Transduction/drug effects , Up-Regulation/drug effects , Xenograft Model Antitumor AssaysABSTRACT
Leukocyte recruitment to the site of injury is a crucial event in the regulation of an inflammatory response. Tight regulation of interactions between the endothelium and circulating leukocytes is necessary to ensure a protective response to injury does not result in inflammatory disease. Rising interest in the broad immunoregulatory roles displayed by members of the glycan-binding galectin family suggests that these proteins could be an attractive target for therapeutic intervention, since their expression is significantly altered in disease. The focus of this review is to summarize current knowledge on the role of galectins in leukocyte trafficking during inflammation and the clinical approaches being taken to target these interactions for treatment of inflammatory disease.
Subject(s)
Cell Adhesion , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Galectins/metabolism , Inflammation/metabolism , Leukocyte Rolling , Leukocytes/metabolism , Animals , Anti-Inflammatory Agents/therapeutic use , Cell Adhesion/drug effects , Endothelial Cells/drug effects , Endothelial Cells/immunology , Endothelium, Vascular/drug effects , Endothelium, Vascular/immunology , Galectins/antagonists & inhibitors , Humans , Inflammation/drug therapy , Inflammation/immunology , Leukocyte Rolling/drug effects , Leukocytes/drug effects , Leukocytes/immunology , Signal TransductionABSTRACT
Lectins are a family of glycan-binding proteins, many of which have been established as key targets for therapeutic intervention. They play a central role in many physiological and cellular processes. With the advances in protein crystallography, NMR spectroscopy and computational power over the past couple of decades, the carbohydrate-receptor interactions are now well understood and characterized. Nevertheless, designing efficient carbohydrate inhibitors is a laborious endeavour. They are known to have weak affinities, unsuitable pharmacokinetic properties and highly cumbersome/complex synthetic routes. To circumvent these issues many non-carbohydrate strategies have been reported. Galectins are a sub-family of lectin proteins which have been recognized as crucial targets for a wide variety of diseases. Many candidates targeting galectins are currently in advanced stages of clinical trials. There have been a few reports of non-carbohydrate inhibitors targeting galectins which comprise of peptide-based inhibitors and a recent flourish of heterocyclic inhibitors. In this review, we have briefly highlighted the strategies like fragment-based drug-design and high-throughput screens utilized to identify non-carbohydrate based antagonists for proteins wherein the presence of a sugar was believed to be essential. Additionally, we have described the literature pertaining to non-carbohydrate inhibitors of galectins and how previous reports on rational substitution of a sugar motif could aid in design of heterocyclics that inhibit lectins/galectins. We have concluded with remarks on challenges, gap in our understanding and future perspectives concerned with rational design of non-carbohydrate molecules targeting lectins/galectins.
Subject(s)
Galectins/antagonists & inhibitors , Peptides/pharmacology , Dose-Response Relationship, Drug , Galectins/metabolism , Molecular Structure , Peptides/chemistry , Structure-Activity RelationshipABSTRACT
Galectin-3 plays a crucial role in cancerogenesis; its targeting is a prospective pathway in cancer diagnostics and therapy. Multivalent presentation of glycans was shown to strongly increase the affinity of glycoconjugates to galectin-3. Further strengthening of interaction with galectin-3 may be accomplished using artificial glycomimetics with apt aryl substitutions. We established a new, as yet undescribed chemoenzymatic method to produce selective C-3-substituted N,N'-diacetyllactosamine glycomimetics and coupled them to human serum albumin. From a library of enzymes, only ß-N-acetylhexosaminidase from Talaromyces flavus was able to efficiently synthesize the C-3-propargylated disaccharide. Various aryl residues were attached to the functionalized N,N'-diacetyllactosamine via click chemistry to assess the impact of the aromatic substitution. In ELISA-type assays with galectin-3, free glycomimetics exhibited up to 43-fold stronger inhibitory potency to Gal-3 than the lactose standard. Coupling to human serum albumin afforded multivalent neo-glycoproteins with up to 4209-fold increased inhibitory potency per glycan compared to the monovalent lactose standard. Surface plasmon resonance brought further information on the kinetics of galectin-3 inhibition. The potential of prepared neo-glycoproteins to target galectin-3 was demonstrated on colorectal adenocarcinoma DLD-1 cells. We investigated the uptake of neo-glycoproteins into cells and observed limited non-specific transport into the cytoplasm. Therefore, neo-glycoproteins primarily act as efficient scavengers of exogenous galectin-3 of cancer cells, inhibiting its interaction with the cell surface, and protecting T-lymphocytes against galectin-3-induced apoptosis. The present neo-glycoproteins combine the advantage of a straightforward synthesis, selectivity, non-toxicity, and high efficiency for targeting exogenous galectin-3, with possible application in the immunomodulatory treatment of galectin-3-overexpressing cancers.
Subject(s)
Biomimetic Materials/pharmacology , Blood Proteins/antagonists & inhibitors , Galectins/antagonists & inhibitors , Glycoproteins/metabolism , Biomimetic Materials/chemical synthesis , Biomimetic Materials/chemistry , Blood Proteins/genetics , Blood Proteins/metabolism , Dose-Response Relationship, Drug , Galectins/genetics , Galectins/metabolism , Glycoproteins/chemistry , Humans , Kinetics , Molecular Structure , Structure-Activity RelationshipABSTRACT
BACKGROUND: PD-1/PD-L1 engagement and overexpression of galectin-3 (Gal-3) are critical mechanisms of tumor-induced immune suppression that contribute to immunotherapy resistance. We hypothesized that Gal-3 blockade with belapectin (GR-MD-02) plus anti-PD-1 (pembrolizumab) would enhance tumor response in patients with metastatic melanoma (MM) and head and neck squamous cell carcinoma (HNSCC). METHODS: We performed a phase I dose escalation study of belapectin+pembrolizumab in patients with advanced MM or HNSCC (NCT02575404). Belapectin was administered at 2, 4, or 8 mg/kg IV 60 min before pembrolizumab (200 mg IV every 3 weeks for five cycles). Responding patients continued pembrolizumab monotherapy for up to 17 cycles. Main eligibility requirements were a functional Eastern Cooperative Oncology Group status of 0-2, measurable or assessable disease, and no active autoimmune disease. Prior T-cell checkpoint antibody therapy was permitted. RESULTS: Objective response was observed in 50% of MM (7/14) and and 33% of HNSCC (2/6) patients. Belapectin+pembrolizumab was associated with fewer immune-mediated adverse events than anticipated with pembrolizumab monotherapy. There were no dose-limiting toxicities for belapectin within the dose range investigated. Significantly increased effector memory T-cell activation and reduced monocytic myeloid-derived suppressor cells (M-MDSCs) were observed in responders compared with non-responders. Increased baseline expression of Gal-3+ tumor cells and PD-1+CD8+ T cells in the periphery correlated with response as did higher serum trough levels of pembrolizumab. CONCLUSIONS: Belapectin+pembrolizumab therapy has activity in MM and HNSCC. Increased Gal-3 expression, expansion of effector memory T cells, and decreased M-MDSCs correlated with clinical response. Further investigation is planned.
Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Blood Proteins/antagonists & inhibitors , Galectins/antagonists & inhibitors , Head and Neck Neoplasms/drug therapy , Immune Checkpoint Inhibitors/therapeutic use , Multiple Myeloma/drug therapy , Pectins/therapeutic use , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Squamous Cell Carcinoma of Head and Neck/drug therapy , Adult , Aged , Antibodies, Monoclonal, Humanized/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Blood Proteins/immunology , Female , Galectins/immunology , Head and Neck Neoplasms/diagnosis , Head and Neck Neoplasms/immunology , Humans , Immune Checkpoint Inhibitors/adverse effects , Male , Memory T Cells/drug effects , Memory T Cells/immunology , Middle Aged , Multiple Myeloma/diagnosis , Multiple Myeloma/immunology , Myeloid-Derived Suppressor Cells/drug effects , Myeloid-Derived Suppressor Cells/immunology , Pectins/adverse effects , Programmed Cell Death 1 Receptor/immunology , Squamous Cell Carcinoma of Head and Neck/diagnosis , Squamous Cell Carcinoma of Head and Neck/immunology , Time Factors , Treatment OutcomeABSTRACT
Here, we compare the content and composition of polysaccharides derived from the mycelium (40.4 kDa intracellular polysaccharide, IPS) and culture (27.2 kDa extracellular polysaccharide, EPS) of Penicillium oxalicum. Their chemical structures investigated by IR, NMR, enzymolysis and methylation analysis indicate that both IPS and EPS are galactomannans composed of α-1,2- mannopyranose (Manp) and α-1,6-Manp in a backbone ratio of ~3:1, respectively, both decorated with ß-l,5-galactofuranose (Galf) side chains. A few ß-l,6-Galf residues were also detected in the IPS fraction. EPS and IPS have different molecular weights (Mw) and degrees of branching. IPS obtained by alkaline extraction of P. oxalicum have been reported to be galactofuranans, a composition different from our IPS. Up to now, there have been no reports on the fine structure of EPS. Our results of galectin-mediated hemagglutination demonstrate that IPS exhibits greater inhibitory effects on five galectins compared with EPS. In addition, we find that Galf, a five-membered ring form of galactose, can also inhibit galectins. IPS may provide a new source of galectin inhibitors. These results increase our understanding of structure-activity relationships of polysaccharides as galectin inhibitors.
Subject(s)
Extracellular Space/chemistry , Fungal Polysaccharides/pharmacology , Galectins/antagonists & inhibitors , Intracellular Space/chemistry , Penicillium/chemistry , Animals , Carbon-13 Magnetic Resonance Spectroscopy , Enzyme Assays , Galectins/metabolism , Hemagglutination/drug effects , Hydrolysis , Methylation , Molecular Weight , Proton Magnetic Resonance Spectroscopy , Sheep , Spectroscopy, Fourier Transform InfraredABSTRACT
INTRODUCTION: Galectins are ubiquitous in nature. They have established themselves as a protein family of high therapeutic potential and play a role in a wide variety of diseases like cancer, fibrosis, and Alzheimer's. Within the galectin family, galectin- 1 and galectin- 3 have been widely studied and their roles and functions have now been well established. AREAS COVERED: In this review, we discuss the important advancements in the development of galectin-1 & 3 inhibitors. All patents filed detailing the divergent strategies to inhibit galectin-1 & 3 from 2016 to present have been covered and discussed. EXPERT OPINION: Over the past couple of decades, distinct galectin inhibitors have been synthesized, reported and studied. Among all, the mono and disaccharide-based antagonists have been found to be considerably successful. However, the cumbersome synthetic route followed to develop this class of inhibitors, in addition to complexity involved in making selective modifications within these molecules has posed a significant challenge. Recently, there have been numerous reports on heterocyclic-based galectin inhibitors. If these are established as potent galectin inhibitors, their ease of synthesis and tunability could overcome the potential drawbacks of carbohydrate-based inhibitors and could thus be exploited to develop efficient and highly specific galectin inhibitors.
Subject(s)
Blood Proteins/antagonists & inhibitors , Galectin 1/antagonists & inhibitors , Galectins/antagonists & inhibitors , Alzheimer Disease/drug therapy , Alzheimer Disease/physiopathology , Blood Proteins/metabolism , Drug Development , Fibrosis/drug therapy , Fibrosis/pathology , Galectin 1/metabolism , Galectins/metabolism , Humans , Neoplasms/drug therapy , Neoplasms/pathology , Patents as TopicABSTRACT
Over the past few years, tumor immunotherapy has emerged as an innovative tumor treatment and owned incomparable advantages over other tumor therapy. With unique complexity and uncertainty, immunotherapy still need helper to apply in the clinic. Galectins, modulated in tumor microenvironment, can regulate the disorders of innate and adaptive immune system resisting tumor growth. Considering the role of galectins in tumor immunosuppression, combination therapy of targeted anti-galectins and immunotherapy may be a promising tumor treatment. This brief review summarizes the expression and immune functions of different galectins in tumor microenvironment and discusses the potential value of anti-galectins in combination with checkpoint inhibitors in tumor immunotherapy.
Subject(s)
Galectins/antagonists & inhibitors , Immunotherapy/methods , Neoplasms/therapy , T-Lymphocytes/immunology , Tumor Microenvironment/immunology , Animals , Humans , Neoplasms/immunology , Neoplasms/metabolism , Neoplasms/pathologyABSTRACT
Fluorescent biosensors are indispensable tools for molecular imaging, detection, and drug screening. Conventionally, fluorescent biosensors were constructed by incorporating fluorophores into ligands. Here, to develop ligand-independent biosensors, we demonstrated biosensor selection from a fluorophore-modified peptide phage library. In this library, the peptides were designed to form α-helical structures, and one cysteine, the probe modification site, was located at the center of four randomized residues on the same face of the helix. By conjugation with 4-nitrobenzoxadiazole (NBD), we constructed an NBD-modified phage library. We conducted selection against galectin-3 (Gal-3), a galactose-specific lectin associated with various biological events such as tumor metastasis and insulin resistance. After biopanning, we obtained NBD-modified peptides that selectively bind to Gal-3 from the library. The fluorescence intensity of the hit biosensors increased with the concentration of Gal-3, and this fluorescent response was visually observed.
Subject(s)
Biosensing Techniques , Blood Proteins/antagonists & inhibitors , Fluorescent Dyes/pharmacology , Galectins/antagonists & inhibitors , Nitro Compounds/pharmacology , Oxadiazoles/pharmacology , Peptides/pharmacology , Blood Proteins/metabolism , Dose-Response Relationship, Drug , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/chemistry , Galectins/metabolism , Humans , Molecular Structure , Nitro Compounds/chemistry , Oxadiazoles/chemistry , Peptides/chemical synthesis , Peptides/chemistry , Structure-Activity RelationshipABSTRACT
The two T cell inhibitory receptors PD-1 and TIM-3 are co-expressed during exhausted T cell differentiation, and recent evidence suggests that their crosstalk regulates T cell exhaustion and immunotherapy efficacy; however, the molecular mechanism is unclear. Here we show that PD-1 contributes to the persistence of PD-1+TIM-3+ T cells by binding to the TIM-3 ligand galectin-9 (Gal-9) and attenuates Gal-9/TIM-3-induced cell death. Anti-Gal-9 therapy selectively expands intratumoral TIM-3+ cytotoxic CD8 T cells and immunosuppressive regulatory T cells (Treg cells). The combination of anti-Gal-9 and an agonistic antibody to the co-stimulatory receptor GITR (glucocorticoid-induced tumor necrosis factor receptor-related protein) that depletes Treg cells induces synergistic antitumor activity. Gal-9 expression and secretion are promoted by interferon ß and γ, and high Gal-9 expression correlates with poor prognosis in multiple human cancers. Our work uncovers a function for PD-1 in exhausted T cell survival and suggests Gal-9 as a promising target for immunotherapy.
Subject(s)
Adenocarcinoma/therapy , Colonic Neoplasms/therapy , Galectins/immunology , Gene Expression Regulation, Neoplastic/immunology , Glucocorticoid-Induced TNFR-Related Protein/immunology , Hepatitis A Virus Cellular Receptor 2/immunology , Programmed Cell Death 1 Receptor/immunology , Adenocarcinoma/genetics , Adenocarcinoma/immunology , Adenocarcinoma/mortality , Animals , Antibodies/pharmacology , Antineoplastic Agents, Immunological/pharmacology , Colonic Neoplasms/genetics , Colonic Neoplasms/immunology , Colonic Neoplasms/mortality , Galectins/antagonists & inhibitors , Galectins/genetics , Glucocorticoid-Induced TNFR-Related Protein/agonists , Glucocorticoid-Induced TNFR-Related Protein/genetics , Hepatitis A Virus Cellular Receptor 2/genetics , Humans , Immunotherapy/methods , Jurkat Cells , Melanoma, Experimental/genetics , Melanoma, Experimental/immunology , Melanoma, Experimental/mortality , Melanoma, Experimental/therapy , Mice , Mice, Inbred BALB C , Programmed Cell Death 1 Receptor/genetics , Protein Binding , Signal Transduction , Skin Neoplasms/genetics , Skin Neoplasms/immunology , Skin Neoplasms/mortality , Skin Neoplasms/therapy , Survival Analysis , T-Lymphocytes, Cytotoxic/drug effects , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Cytotoxic/pathology , T-Lymphocytes, Regulatory/drug effects , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/pathologyABSTRACT
A sequence of interconnected events known as the metastatic cascade promotes tumor progression by regulating cellular and molecular interactions between tumor, stromal, endothelial, and immune cells both locally and systemically. Recently, a new concept has emerged to better describe this process by defining four attributes that metastatic cells should undergo. Every individual hallmark represents a unique trait of a metastatic cell that impacts directly in the outcome of the metastasis process. These critical features, known as the hallmarks of metastasis, include motility and invasion, modulation of the microenvironment, cell plasticity and colonization. They are hierarchically regulated at different levels by several factors, including galectins, a highly conserved family of ß-galactoside-binding proteins abundantly expressed in tumor microenvironments and sites of metastasis. In this review, we discuss the role of galectins in modulating each hallmark of metastasis, highlighting novel therapeutic opportunities for treating the metastatic disease.