Cathepsin S inhibitors as novel immunomodulators (original) (raw)
Related papers
Pharmacodynamic Monitoring of RO5459072, a Small Molecule Inhibitor of Cathepsin S
Frontiers in immunology, 2017
Major histocompatibility complex class II (MHCII)-restricted antigen priming of CD4(+) T cells is both involved in adaptive immune responses and the pathogenesis of autoimmune diseases. Degradation of invariant chain Ii, a protein that prevents premature peptide loading, is a prerequisite for nascent MHCII-peptide complex formation. A key proteolytic step in this process is mediated by cathepsin S. Inhibition of this cysteine protease is known to result in the intracellular accumulation of Lip10 in B cells. Here, we describe the development and application of a neoepitope-based flow cytometry assay measuring accumulation of Lip10. This novel method enabled the investigation of cathepsin S-dependent MHCII maturation in professional antigen-presenting cell (APC) subsets. Inhibition of cathepsin S by a specific inhibitor, RO5459072, in human PBMC ex vivo resulted in accumulation of Lip10 in B cells and myeloid dendritic cells, but not in plasmacytoid dendritic cells and only to a minor...
Cathepsin S activity regulates antigen presentation and immunity
Journal of Clinical Investigation, 1998
MHC class II molecules display antigenic peptides on cell surfaces for recognition by CD4 ϩ T cells. Proteolysis is required in this process both for degradation of invariant chain (Ii) from class II-Ii complexes to allow subsequent binding of peptides, and for generation of the antigenic peptides. The cysteine endoprotease, cathepsin S, mediates Ii degradation in human and mouse antigen-presenting cells.
Thiol-Dependent Cathepsins: Pathophysiological Implications and Recent Advances in Inhibitor Design
Current Pharmaceutical Design, 2002
Thirteen papain-like cysteine proteases (cathepsins) are coded in the human genome from which two represent pseudogenes. Initially it was believed that lysosomal cysteine proteases primarily fulfill housekeeping functions which would exclude them as potential drug targets. Within the last decade, this view has dramatically changed and highly specific and therapeutically relevant functions have been assigned to individual cathepsins. Cathepsins are critical for osteoclast-mediated bone resorption and cartilage erosion in arthritis. They are involved in various aspects of immune responses, in the development and proliferation of various cell types, as well as in tumor invasion and metastasis. Cathepsins qualify as pharmaceutical targets for the treatment of osteoporosis, arthritis, asthma, autoimmune diseases, and potentially for certain forms of cancer. The major challenge in using cysteine protease inhibitors will be the design of highly selective, potent, and bioavailable compounds. Emerging novel functions of long-known and recently discovered cathepsins will require more emphasis on the selectivity of drug candidates to avoid adverse side effects. This review will focus on the discussion of presently known functions of papain-like cathepsins and on recent advances in the design of cysteine protease inhibitors.
Quantifying Cathepsin S Activity in Antigen Presenting Cells Using a Novel Specific Substrate
Journal of Biological Chemistry, 2008
Cathepsin S (CatS) is a lysosomal cysteine protease belonging to the papain superfamily. Because of the relatively broad substrate specificity of this family, a specific substrate for CatS is not yet known. Based on a detailed study of the CatS endopeptidase specificity, using six series of internally quenched fluorescent peptides, we were able to design a specific substrate for CatS. The peptide series was based on the sequence GRWHTVGL-RWE-Lys(Dnp)-DArg-NH 2 , which shows only one single cleavage site between Gly and Leu and where every substrate position between P-3 and P-3 was substituted with up to 15 different amino acids. The endopeptidase specificity of CatS was mainly determined by the P-2, P-1, and the P-3 substrate positions.
Cathepsin S: therapeutic, diagnostic, and prognostic potential
Cathepsin S is a member of the cysteine cathep-sin protease family. It is a lysosomal protease which can promote degradation of damaged or unwanted proteins in the endo-lysosomal pathway. Additionally, it has more specific roles such as MHC class II antigen presentation, where it is important in the degradation of the invariant chain. Unsurprisingly, mis-regulation has implicated cathepsin S in a variety of pathological processes including arthritis, cancer, and cardiovascular disease, where it becomes secreted and can act on extracellular sub-strates. In comparison to many other cysteine cathepsin family members, cathepsin S has uniquely restricted tissue expression and is more stable at a neutral pH, which supports its involvement and importance in localised disease microenvironments. In this review, we examine the known involvement of cathepsin S in disease, particularly with respect to recent work indicating its role in mediating pain, diabetes, and cystic fibrosis. We provide an overview of current literature with regards cathepsin S as a therapeutic target, as well as its role and potential as a predictive diagnostic and/or prognostic marker in these diseases.
Cathepsin S inhibition suppresses autoimmune-triggered inflammatory responses in macrophages
Biochemical pharmacology, 2017
In several types of antigen-presenting cells (APCs), Cathepsin S (CatS) plays a crucial role in the regulation of MHC class II surface expression and consequently influences antigen (Ag) presentation of APCs to CD4(+) T cells. During the assembly of MHC class II-Ag peptide complexes, CatS cleaves the invariant chain p10 (Lip10) - a fragment of the MHC class II-associated invariant chain peptide. In this report, we used a selective, high-affinity CatS inhibitor to suppress the proteolytic activity of CatS in lymphoid and myeloid cells. CatS inhibition resulted in a concentration-dependent Lip10 accumulation in B cells from both healthy donors and patients with systemic lupus erythematosus (SLE). Furthermore, CatS inhibition led to a decreased MHC class II expression on B cells, monocytes, and proinflammatory macrophages. In SLE patient-derived peripheral blood mononuclear cells, CatS inhibition led to a suppressed secretion of IL-6, TNFα, and IL-10. In a second step, we tested the ef...
1996
is the proteolytic destruction of Ii, as intact ␣Ii trimers and Harold A. Chapman* themselves are unable to bind peptides (Roche and *Department of Medicine Cresswell, 1990). In vivo, inhibition of all cysteine class Brigham and Women's Hospital proteases impairs Ii breakdown and induces accumulaand Harvard Medical School tion of class II-associated Ii fragments in B lymphoblas-Boston, Massachusetts 02115 toid cells (Blum and Cresswell, 1988; Nguyen et al., 1988; † Center for Cancer Research Newcomb and Cresswell, 1993). Consequently, acquisi-Department of Biology tion of antigenic peptide by class II ␣ dimers is pre-Massachusetts Institute of Technology vented (Neefjes and Ploegh, 1992), expression of class Cambridge, Massachusetts 02139 II molecules at the cell surface is decreased (Neefjes ‡ Arris Pharmaceuticals, Incorporated and Ploegh, 1992; Bé naroch et al., 1995), and antigen-385 Oyster Point Boulevard stimulated T cell proliferation is attenuated (Buus and South San Francisco, California 94080 Werdelin, 1986; Diment, 1990). Despite the absolute requirement for Ii destruction to render class II molecules capable of binding peptide, the primary proteases that perform this task remain unidentified. Previous attempts Summary at identifying these proteases are difficult to interpret, owing to the rather nonspecific action of the inhibitors Destruction of Ii by proteolysis is required for MHC used and possible contamination of commercially availclass II molecules to bind antigenic peptides, and for able protease preparations with other proteases. For transport of the resulting complexes to the cell surexample, leupeptin, a commonly utilized protease inhibiface. The cysteine protease cathepsin S is highly tor (Nguyen et al., 1988), acts on many proteases of the expressed in spleen, lymphocytes, monocytes, and cysteine and serine class. Lysosomotropic agents, such other class II-positive cells, and is inducible with as quinidine (Humbert et al., 1993) and concanamycin interferon-␥. Specific inhibition of cathepsin S in B B (Bé naroch et al., 1995), neutralize acidic compartlymphoblastoid cells prevented complete proteolysis ments in a nonspecific manner. Also, analysis of some of Ii, resulting in accumulation of a class II-associated commercially available cathepsin B preparations in our 13 kDa Ii fragment in vivo. Consequently, the formation laboratory have demonstrated the presence of addiof SDS-stable complexes was markedly reduced. Puritional cysteine proteases (H. A. C., unpublished data). fied cathepsin S, but not cathepsin B, H, or D, specifi-Cathepsin S, a cysteine protease originally cloned cally digested Ii from ␣Ii trimers, generating ␣-CLIP from human alveolar macrophages, is highly expressed complexes capable of binding exogenously added in the spleen and professional antigen-presenting cells, peptide in vitro. Thus, cathepsin S is essential in B including B lymphocytes, macrophages, and other class cells for effective Ii proteolysis necessary to render II-positive cells (Shi et al., 1992, 1994; Morton et al., class II molecules competent for binding peptides. 1995). Moreover, it is inducible with interferon-␥ (IFN␥), it is a potent endoprotease, and it has a broad pH activity profile (Shi et al.
Discovery of selective and nonpeptidic cathepsin S inhibitors
Bioorganic & Medicinal Chemistry Letters, 2008
Nonpeptidic, selective, and potent cathepsin S inhibitors were derived from an in-house pyrrolopyrimidine cathepsin K inhibitor by modification of the P2 and P3 moieties. The pyrrolopyrimidine-based inhibitors show nanomolar inhibition of cathepsin S with over 100-fold selectivity against other cysteine proteases, including cathepsin K and L. Some of the inhibitors showed cellular activities in mouse splenocytes as well as oral bioavailabilities in rats.
Inhibition of Cathepsin K with Lysosomotropic Macromolecular Inhibitors †
Biochemistry, 2002
Cathepsin K is the major enzyme responsible for the degradation of the protein matrix of bone and probably for the destruction of articular cartilage in rheumatoid arthritis joints. These processes occur mainly in the resorption lacuna and within the lysosomal compartment. Here, we have designed, synthesized, and evaluated new lysosomotropic (water-soluble) polymer-cathepsin K inhibitor conjugates. In particular, we characterized the relationship between conjugate structures and their activity to inhibit cathepsins K, B, L, and papain. A potent selective cathepsin K inhibitor, 1,5-bis(N-benzyloxycarbonylleucyl)carbohydrazide, was modified to 1-(N-benzyloxycarbonylleucyl)-5-(phenylalanylleucyl)carbohydrazide (I) to facilitate polymer conjugation. It was conjugated to the polymer chain termini of two watersoluble polymers {R-methoxy poly(ethylene glycol), abbreviated as mPEG-I; semitelechelic poly[N-(2hydroxypropyl)methacrylamide], abbreviated as ST-PHPMA-I}. The conjugation of inhibitor I to N-(2hydroxypropyl)methacrylamide (HPMA) copolymer side chains was accomplished via either a Gly-Gly spacer (PHPMA-GG-I) or with no spacer between I and the copolymer backbone (PHPMA-I). Kinetic analysis revealed that free inhibitor I possessed an apparent second-order rate constant against cathepsin K (k obs /[I] ) 1.3 × 10 6 M -1 s -1 ) similar to that of unmodified 1,5-bis(Cbz-Leu) carbohydrazide, while I conjugated to the chain termini of mPEG and ST-PHPMA-COOH had slightly lower values (about 5 × 10 5 M -1 s -1 ). The k obs /[I] values for I attached to the side chains of HPMA copolymers (PHPMA-GG-I and PHPMA-I) were about 3 × 10 4 M -1 s -1 . When tested against cathepsin L, inhibitor I and all its polymer conjugates produced k obs /[I] values 1-2 orders of magnitude less than those determined for cathepsin K, while for cathepsin B and papain, the values were 2-4 orders of magnitude lower. The ability of mPEG-I and ST-PHPMA-I to inhibit cathepsin K activity in synovial fibroblasts was also evaluated. Both polymer-bound inhibitors were internalized by endocytosis and were ultimately trafficked to the lysosomal compartment. ST-PHPMA-I was internalized faster than mPEG-I. The inhibitory activity in the synovial fibroblast assay correlated with the rate of internalization. †
Journal of Biological Chemistry, 2005
Certain leukocytes release serine proteases that sustain inflammatory processes and cause disease conditions, such as asthma and chronic obstructive pulmonary disease. We identified -ketophosphonate 1 (JNJ-10311795; RWJ-355871) as a novel, potent dual inhibitor of neutrophil cathepsin G (K i ؍ 38 nM) and mast cell chymase (K i ؍ 2.3 nM). The x-ray crystal structures of 1 complexed with human cathepsin G (1.85 Å) and human chymase (1.90 Å) reveal the molecular basis of the dual inhibition. Ligand 1 occupies the S 1 and S 2 subsites of cathepsin G and chymase similarly, with the 2-naphthyl in S 1 , the 1-naphthyl in S 2 , and the phosphonate group in a complex network of hydrogen bonds. Surprisingly, however, the carboxamido-N-(naphthalene-2-carboxyl)piperidine group is found to bind in two distinct conformations. In cathepsin G, this group occupies the hydrophobic S 3 /S 4 subsites, whereas in chymase, it does not; rather, it folds onto the 1-naphthyl group of the inhibitor itself. Compound 1 exhibited noteworthy antiinflammatory activity in rats for glycogen-induced peritonitis and lipopolysaccharide-induced airway inflammation. In addition to a marked reduction in neutrophil influx, 1 reversed increases in inflammatory mediators interleukin-1␣, interleukin-1, tissue necrosis factor-␣, and monocyte chemotactic protein-1 in the glycogen model and reversed increases in airway nitric oxide levels in the lipopolysaccharide model. These findings demonstrate that it is possible to inhibit both cathepsin G and chymase with a single molecule and suggest an exciting opportunity in the treatment of asthma and chronic obstructive pulmonary disease.