Selective Cathepsin S Inhibition with MIV-247 Attenuates Mechanical Allodynia and Enhances the Antiallodynic Effects of Gabapentin and Pregabalin in a Mouse Model of Neuropathic Pain.

Cathepsin S inhibitors attenuate mechanical allodynia in preclinical neuropathic pain models. The current study evaluated the effects when combining the selective cathepsin S inhibitor MIV-247 with gabapentin or pregabalin in a mouse model of neuropathic pain. Mice were rendered neuropathic by partial sciatic nerve ligation.

Solid-phase parallel synthesis and SAR of 4-amidofuran-3-one inhibitors of cathepsin S: effect of sulfonamides P3 substituents on potency and selectivity.

Highly potent and selective 4-amidofuran-3-one inhibitors of cathepsin S are described. The synthesis and structure-activity relationship of a series of inhibitors with a sulfonamide moiety in the P3 position is presented. Several members of the series show sub-nanomolar inhibition of the target enzyme as well as an excellent selectivity profile and good cellular potency.

Discovery of novel, potent and bioavailable proline-urea based macrocyclic HCV NS3/4A protease inhibitors.

A novel series of P3-truncated macrocyclic HCV NS3/4A protease inhibitors containing a P2 proline-urea or carbamate scaffold was synthesized. Very potent inhibitors were obtained through the optimization of the macrocycle size, urea and proline substitution, and bioisosteric replacement of the P1 carboxylic acid moiety. Variation of the lipophilicity by introduction of small lipophilic substituents resulted in improved PK profiles, ultimately leading to compound 13Bh, an extremely potent (K(i)=0.

Novel potent macrocyclic inhibitors of the hepatitis C virus NS3 protease: use of cyclopentane and cyclopentene P2-motifs.

Several highly potent novel HCV NS3 protease inhibitors have been developed from two inhibitor series containing either a P2 trisubstituted macrocyclic cyclopentane- or a P2 cyclopentene dicarboxylic acid moiety as surrogates for the widely used N-acyl-(4R)-hydroxyproline in the P2 position. These inhibitors were optimized for anti HCV activities through examination of different ring sizes in the macrocyclic systems and further by exploring the effect of P4 substituent removal on potency. The target molecules were synthesized from readily available starting materials, furnishing the inhibitor compounds in good overall yields.

The HLA A*0201-restricted hTERT(540-548) peptide is not detected on tumor cells by a CTL clone or a high-affinity T-cell receptor.

Tumor-associated human telomerase reverse transcriptase (hTERT) is expressed in >85% of human tumors but not in most normal cells. As a result, this antigen has received considerable attention from those interested in cancer immunotherapy. Specifically, there has been strong interest in MHC class I-associated peptides derived from hTERT because these are expressed on the cell surface and thus may enable the targeting of tumor cells.

A unique thymic fibroblast population revealed by the monoclonal antibody MTS-15.

T cell differentiation in the thymus is dependent upon signals from thymic stromal cells. Most studies into the nature of these signals have focused only on the support provided by the thymic epithelium, but there is an emerging view that other stromal cells such as mesenchymal fibroblasts may also be involved. Study of the latter has been hindered by a lack of appropriate markers, particularly those allowing their isolation.

Dendritic cells generated from patients with androgen-independent prostate cancer are not impaired in migration and T-cell stimulation.

Background: Dendritic cell (DC)-based vaccination has been investigated as immunotherapy for several types of cancer. A potential drawback to vaccination with autologous monocyte-derived DCs (MoDCs) could be that MoDCs from patients are functionally impaired. In case of androgen-independent prostate cancer (CaP), the cancer itself, diverse prior therapies, and the hormone manipulation may affect the immune system.

High-affinity small molecule inhibitors of T cell costimulation: compounds for immunotherapy.

Costimulatory molecules are important regulators of T cell activation and thus favored targets for therapeutic manipulation of immune responses. One of the key costimulatory receptors is CD80, which binds the T cell ligands, CD28, and CTLA-4. We describe a set of small compounds that bind with high specificity and low nanomolar affinity to CD80.

Symmetric fluoro-substituted diol-based HIV protease inhibitors. Ortho-fluorinated and meta-fluorinated P1/P1'-benzyloxy side groups significantly improve the antiviral activity and preserve binding efficacy.

HIV-1 protease is a pivotal enzyme in the later stages of the viral life cycle which is responsible for the processing and maturation of the virus particle into an infectious virion. As such, HIV-1 protease has become an important target for the treatment of AIDS, and efficient drugs have been developed. However, negative side effects and fast emerging resistance to the current drugs have necessitated the development of novel chemical entities in order to exploit different pharmacokinetic properties as well as new interaction patterns.

Optimization of P1-P3 groups in symmetric and asymmetric HIV-1 protease inhibitors.

HIV-1 protease is an important target for treatment of AIDS, and efficient drugs have been developed. However, the resistance and negative side effects of the current drugs has necessitated the development of new compounds with different binding patterns. In this study, nine C-terminally duplicated HIV-1 protease inhibitors were cocrystallised with the enzyme, the crystal structures analysed at 1.

O-glycan sialylation and the structure of the stalk-like region of the T cell co-receptor CD8.

Studies of mucins suggest that the structural effects of O-glycans are restricted to steric interactions between peptide-linked GalNAc residues and adjacent polypeptide residues. It has been proposed, however, that differential O-glycan sialylation alters the structure of the stalk-like region of the T cell co-receptor, CD8, and that this, in turn, modulates ligand binding (Daniels, M. A.

Essential role for the lymphostromal plasma membrane Ly-6 superfamily molecule thymic shared antigen 1 in development of the embryonic adrenal gland.

Thymic shared antigen 1 (TSA-1) is a plasma membrane protein of the Ly-6 superfamily expressed on thymocytes, thymic stromal cells, and other cells of the hematopoietic system. TSA-1 is also expressed in other nonhematopoietic tissues, in particular, embryonic and adult adrenal glands. To address the function of TSA-1, we generated mutant mice in which TSA-1 expression was inactivated by gene targeting.

Synthesis of novel, potent, diol-based HIV-1 protease inhibitors via intermolecular pinacol homocoupling of (2S)-2-benzyloxymethyl-4-phenylbutanal.

The synthesis of novel, potent, diol-based HIV-1 protease inhibitors, having phenethyl groups (-CH(2)CH(2)Ph) in P1/P1' position is described. An intermolecular pinacol homocoupling of (2S)-2-benzyloxymethyl-4-phenylbutanal 16 was the key step in the synthesis. From this reaction sequence four carba analogues, compounds 8a, 8b, 9a, and 9b, were prepared, having the inverted configuration of one or both of the stereogenic centers carrying the diol hydroxyls as compared to the parent series represented by inhibitors 6 and 7.

Synthesis of potent C(2)-symmetric, diol-based hiv-1 protease inhibitors. Investigation of thioalkyl and thioaryl P1/P1' substituents.

The synthesis of novel, potent diol-based HIV-1 protease inhibitors, having either -SAr, -SCH(2)Ar, or -SCH(2)R groups as P1/P1' substituents is described. They can be prepared using a straightforward synthesis involving a thiol nucleophilic ring opening of a diepoxide. Inhibitor 13 was found to be a potent inhibitor of HIV-1 PR, showing good antiviral activity in a cell-based assay.

Design and synthesis of potent C(2)-symmetric diol-based HIV-1 protease inhibitors: effects of fluoro substitution.

Implementation of derivatized carbohydrates as C(2)-symmetric HIV-1 protease inhibitors has previously been reported. With the objective of improving the anti-HIV activity of such compounds, we synthesized a series of fluoro substituted P1/P1' analogues. These compounds were evaluated for antiviral activity toward both wild type and mutant virus.

P1/P1' modified HIV protease inhibitors as tools in two new sensitive surface plasmon resonance biosensor screening assays.

The commonly used HIV-1 protease assays rely on measurements of the effect of inhibitions on the hydrolysis rate of synthetic peptides. Recently an assay based on surface plasmon resonance (SPR) was introduced. We have taken advantage of the fact that the SPR signal is proportional to the mass of the analyte interacting with the immobilised molecule and developed two new improved efficient competition assay methods.

Synthesis and comparative molecular field analysis (CoMFA) of symmetric and nonsymmetric cyclic sulfamide HIV-1 protease inhibitors.

We have previously reported on the unexpected flipped conformation in the cyclic sulfamide class of inhibitors. An attempt to induce a symmetric binding conformation by introducing P2/P2' substituents foreseen to bind preferentially in the S2/S2' subsite was unsuccessful. On the basis of the flipped conformation we anticipated that nonsymmetric sulfamide inhibitors, with P2/P2' side chains modified individually for the S1' and S2 subsites, should be more potent than the corresponding symmetric analogues.

Expression and purification of antigenically active soluble derivatives of the heterodimeric and homodimeric forms of the mouse CD8 lymphocyte membrane glycoprotein.

The T lymphocyte membrane glycoprotein CD8 enhances antigen recognition by class I-restricted T cells. There are two naturally occurring forms of CD8, an alphabeta heterodimer expressed by the majority of CD8(+) T cells, and a less abundant alphaalpha homodimer found on specialised T cell subsets. An expression strategy was developed for production of soluble CD8alphaalpha and CD8alphabeta extracellular domains for use in ligand binding studies.

Characterization of a set of HIV-1 protease inhibitors using binding kinetics data from a biosensor-based screen.

The interaction between 290 structurally diverse human immunodeficiency virus type 1 (HIV-1) protease inhibitors and the immobilized enzyme was analyzed with an optical biosensor. Although only a single concentration of inhibitor was used, information about the kinetics of the interaction could be obtained by extracting binding signals at discrete time points. The statistical correlation between the biosensor binding data, inhibition of enzyme activity (K(i)), and viral replication (EC(50)) revealed that the association and dissociation rates for the interaction could be resolved and that they were characteristic for the compounds.

Inhibitors of the C(2)-symmetric HIV-1 protease: nonsymmetric binding of a symmetric cyclic sulfamide with ketoxime groups in the P2/P2' side chains.

Symmetric cyclic sulfamides, substituted in the P2/P2' position with functional groups foreseen to bind preferentially to the S2/S2' subsites of HIV-1 protease, have been prepared. Despite efforts to promote a symmetric binding, the sulfamides seemed prone to bind nonsymmetrically, as deduced from X-ray crystal structure analysis of one of the most potent inhibitors, possessing ketoxime groups in the P2/P2' side chains. Ab initio calculations suggested that the nonsymmetric conformation of the cyclic sulfamide scaffold had lower energy than the corresponding symmetric, cyclic urea-like conformation.

Design and fast synthesis of C-terminal duplicated potent C(2)-symmetric P1/P1'-modified HIV-1 protease inhibitors.

An analysis of the X-ray structure of a complex of HIV-1 protease with a linear C(2)-symmetric C-terminal duplicated inhibitor guided the selection of a series of diverse target compounds. These were synthesized with the objective to identify suitable P1/P1' substituents to provide inhibitors with improved antiviral activity. Groups with various physical properties were attached to the para-positions of the P1/P1' benzyloxy groups in the parent inhibitor.

Thymic shared antigen-2: a novel cell surface marker associated with T cell differentiation and activation.

Thymic shared Ag-2 (TSA-2) is a 28-kDa, glycophosphatidylinitosol-linked cell surface molecule expressed on various T cell and thymic stromal cell subsets. It is expressed on most CD3-CD4-CD8-, CD4+CD8+, and CD3highCD4-CD8+ thymocytes but is down-regulated on approximately 40% of CD3highCD4+CD8- thymocytes. Expression on peripheral TCR-alphabeta+ T cells is similar to that of CD3+ thymocytes, although a transient down-regulation occurs with cell activation.

Design and synthesis of new potent C2-symmetric HIV-1 protease inhibitors. Use of L-mannaric acid as a peptidomimetic scaffold.

A study on the use of derivatized carbohydrates as C2-symmetric HIV-1 protease inhibitors has been undertaken. L-Mannaric acid (6) was bis-O-benzylated at C-2 and C-5 and subsequently coupled with amino acids and amines to give C2-symmetric products based on C-terminal duplication. Potent HIV protease inhibitors, 28 Ki = 0.

Thymic-shared antigen-1 (TSA-1). A lymphostromal cell membrane Ly-6 superfamily molecule with a putative role in cellular adhesion.

The seeding and colonization of the thymus by bone marrow stem cells and the maturation of these cells into mature T lymphocytes are dependent on cell-surface recognition events between different cell lineages within the thymic microenvironment. Positive and negative selection processes within the thymus produce a peripheral T-cell repertoire capable of recognizing peptides derived from foreign antigen bound to self MHCmolecules. In addition to the TCR/MHC-peptide interaction, many other cell-surface molecules act in concert to regulate the kinetics of cellular interactions and intracellular signaling events during thymopoiesis.