Replicating adenovirus HIV/SIV recombinant priming alone or in combination with a gp140 protein boost results in significant control of viremia following a SHIV89.6P challenge in Mamu-A*01 negative rhesus macaques.

Previously, replicating adenovirus type 5 host range (Ad5hr)-HIV/SIV recombinant priming in combination with SIV envelope boosting, resulted in significant, durable protection in 39% of rhesus macaques after SIVmac251 challenge. Both Env-specific antibody mediating ADCC, and cellular immunity correlated with protection. Here we evaluate the relative immunogenicities of novel HIV proteins and their contribution to protection in a SHIV89.

Protection against mucosal simian immunodeficiency virus SIV(mac251) challenge by using replicating adenovirus-SIV multigene vaccine priming and subunit boosting.

Whereas several recent AIDS vaccine strategies have protected rhesus macaques against a pathogenic simian/human immunodeficiency virus (SHIV)(89.6P) challenge, similar approaches have provided only modest, transient reductions in viral burden after challenge with virulent, pathogenic SIV, which is more representative of HIV infection of people. We show here that priming with replicating adenovirus recombinants encoding SIV env/rev, gag, and/or nef genes, followed by boosting with SIV gp120 or an SIV polypeptide mimicking the CD4 binding region of the envelope, protects rhesus macaques from intrarectal infection with the highly pathogenic SIV(mac251).

A conformational C4 peptide polymer vaccine coupled with live recombinant vector priming is immunogenic but does not protect against rectal SIV challenge.

The conserved, immunogenic CD4 binding site on the viral envelope is an attractive HIV or SIV vaccine candidate. Polymerization of an 18 amino acid segment derived from the C4 domain of SIV gp120 produced a peptide polymer or "peptomer," having an alpha-helical conformation possibly mimicking a proposed structure of the C4 domain in the unbound native protein. The SIV peptomer and native gp120 were compared as subunit boosts following two adenovirus type 5 host range (Ad5hr)-SIVenv recombinant priming immunizations.

A defined conformational epitope from the C4 domain of HIV type 1 glycoprotein 120: anti-cyclic C4 antibodies from HIV-positive donors magnify glycoprotein 120 suppression of interleukin 2 produced by T cells.

The C4 domain of HIV gp120 plays a functionally vital role in the binding of gp120 to CD4 receptors on target cells. Antibodies to an 11-amino acid cyclic C4 peptide were obtained from immunized rabbits and from the serum of an HIV-positive human and were found to recognize gp120 bound to CD4. Anti-cyclic C4 antibodies magnified gp120-induced suppression of IL-2 produced by T cells in vitro.

Selective and facile cyclization of N-chloroacetylated peptides from the C4 domain of HIV Gp120 in LiCl/DMF solvent systems.

Lithium salts have been reported to mediate the solubilization of peptides in organic solvents in 1989 (Seebach, D., Thaler, A. & Beck, A.

Bone sialoprotein mediates human endothelial cell attachment and migration and promotes angiogenesis.

Bone sialoprotein (BSP) is a secreted glycoprotein primarily found in sites of biomineralization. Recently, we demonstrated that BSP is strongly upregulated in osteotropic cancers and particularly those that exhibit microcalcifications. BSP contains an Arg-Gly-Asp (RGD) motif found in other adhesive molecules that interact with cellular integrins.

Immunization of mice with peptomers covalently coupled to aluminum oxide nanoparticles.

Subunit vaccines generally require adjuvants to elicit immune responses, but adjuvants may alter the conformation of critical epitopes and reduce vaccine efficacy. We therefore tested an immunization strategy in which antigen is covalently coupled to aluminum oxide nanoparticles using a method that favors preservation of the native conformation. The test antigen consisted of "peptomers" (head-to-tail-linked peptide homopolymers) derived from the 4th conserved region (C4) of HIV-1 gp120 which is believed to be in an alpha-helical conformation prior to binding to CD4.

Tyrosine phosphorylation induced by C4 peptide constructs from HIV Gp120.

Treatment of HUT78 cells with CD4-binding peptide constructs derived from the C4 domain of HIV-1 gp120 results in autophosphorylation of a src-related kinase, p56lck. This leads to p56lck activation and the subsequent phosphorylation of tyrosine residues in several intracellular proteins. The phosphorylation is specific to the C4 peptides as no new phosphorylation occurs when the cells are treated with control peptides or polymers.

Specific interaction of conformational polypeptides derived from HIV gp120 with human T lymphocyte CD4 receptor.

Specifically cross-linked peptides (peptomers) have been prepared from the repeating sequences of the C4 domains of glycoproteins 120 present in different isolates of human immunodeficiency virus (HIV). In order to investigate if the HIV C4 peptomers could function as gp120 protein, we have used a novel protein-binding assay to examine if and which components of the peptomers could interact with CD4 receptor in vitro. Here, we demonstrate that all the polymeric components of the HIV-1 C4 peptomer could bind to recombinant soluble CD4 protein.

Synthetic integrin-binding peptides promote adhesion and proliferation of human periodontal ligament cells in vitro.

Periodontal ligament (PDL) cells have been shown to express several integrins (alphav, alpha5, beta1, beta3) that use RGD (arginine-glycine-aspartic Acid)-dependent mechanisms for the recognition and binding of their ligands. The objective of this study was to evaluate the effects of certain integrin-binding cyclic and linear synthetic RGD-containing peptides on PDL cells' adhesion, proliferation, and de novo protein synthesis in vitro. Fifth passages of normal human PDL cells established from teeth extracted from patients (ages 12 to 14) for orthodontic reasons were used for all experiments.

Peptomer aluminum oxide nanoparticle conjugates as systemic and mucosal vaccine candidates: synthesis and characterization of a conjugate derived from the C4 domain of HIV-1MN gp120.

Peptomers are polymers composed of peptides that are specifically cross-linked in a head-to-tail fashion. Recently, a peptomer composed of an amphipathic peptide from the C4 domain of HIV-1MN gp120 was shown to display a prominent alpha-helical conformation that, as an immunogen, elicited rabbit antibodies recognizing native and recombinant gp120 [Robey et al. (1995) J.

Effective use of free thiols as scavengers for HF cocktails to deprotect bromo- and chloroacetylated synthetic peptides.

A variety of thiol-containing compounds, in combination with m-cresol, were tested as scavengers in hydrogen fluoride (HF) cocktails that are used to deprotect haloacetylated peptidyl resins. Our results indicate that brome and chloroacetyl moieties on a synthetic peptide remain intact following HF treatment when the HF cocktail contains m-cresol along with either thiophenol, m-thiocresol or 1,2-ethanedithiol. The free thiols prevent the formation of a number of impurities in the preparation of bromo- and chloroacetylated peptides that contain amino acids that could be oxidized in a nonreducing HF environment.

Ligand-binding sites in human serum amyloid P component.

Amyloid P component (AP) is a naturally occurring glycoprotein that is found in serum and basement membranes. AP is also a component of all types of amyloid, including that found in individuals who suffer from Alzheimer's disease and Down's syndrome. Because AP has been found to bind strongly and specifically to certain glycosaminoglycans that are components of amyloid deposits, AP may play an important role in the maintenance of amyloid.

A synthetic conformational epitope from the C4 domain of HIV Gp120 that binds CD4.

The fourth conserved domain of the human immunodeficiency virus type 1 (HIV-1) envelope, the C4 region of glycoprotein 120 (gp120), is believed to be a major part of gp120 that is necessary for binding to CD4. Recently, we found that C4 in gp120 is probably an alpha-helix, because antibodies made against helical constructs of C4 react with native and recombinant gp120 but antibodies against linear C4 constructs do not. For the present study, we performed experiments to determine, first, if CD4 could bind to the helical C4 constructs and, second, if the binding was comparable with CD4 binding to gp120.

Bone sialoprotein peptides are potent inhibitors of breast cancer cell adhesion to bone.

Bone and bone marrow are important sites of metastasis formation in breast cancer. Extracellular matrix proteins with attachment properties are generally believed to play a key role in tumorigenesis and metastasis formation. We have investigated whether mammary carcinoma cells (MDA-MB-231) can recognize constructs of the fairly bone-specific human bone sialoprotein, which encompass the RGD sequence (EPRGD-NYR).

Long-term sun exposure alters the collagen of the papillary dermis. Comparison of sun-protected and photoaged skin by northern analysis, immunohistochemical staining, and confocal laser scanning microscopy.

Background: Long-term solar irradiation produces both morphologic and functional changes in affected skin. Because collagen is the major structural component of skin, any alteration in its production or degradation could have profound effects on cutaneous functional integrity.

Objective: Our purpose was to investigate alterations in the production and morphology of collagen fibers brought about by long-term sun exposure.

A helical epitope in the C4 domain of HIV glycoprotein 120.

The fourth conserved domain of the human immunodeficiency virus type 1 (HIV-1) envelope, the C4 region of glycoprotein 120 (gp120), is an amphipathic stretch of amino acids that, based on mutational analyses, constitutes a major component of the CD4 binding region in gp120. In the absence of crystallographic and NMR data on C4 in intact gp120, we sought to gain insight into C4's conformation and accessibility in gp120 by taking an immunochemical approach. In this study, a peptomer composed of a repeat peptide of C4 amino acids 419-436 from gp120 of HIV-1MN was synthesized for use as a conformationally constrained immunogen.

Synthesis and use of a new bromoacetyl-derivatized heterotrifunctional amino acid for conjugation of cyclic RGD-containing peptides derived from human bone sialoprotein.

A new amino acid derivative, N alpha-(tert-butyloxycarbonyl)-N beta-(bromoacetyl)diaminopropionic acid (BBDap), has been synthesized as a reagent for introducing side-chain bromaocetyl groups into any position of a peptide sequence during solid-phase peptide synthesis. By using minor modifications to the protocol of the automated peptide synthesizer and a two-step in situ neutralization procedure, the syntheses of (bromoacetyl)diaminopropionic acid (BDap) in Arg-Gly-Asp-containing peptides from human bone sialoprotein were optimized and completed. Following HPLC purification, the BDap-derivatized peptides were cyclized or/and conjugated to carrier protein or to glass cover slips.

A capillary electrophoresis-based assay for the binding of Ca2+ and phosphorylcholine to human C-reactive protein.

Affinity capillary electrophoresis was performed to quantitate the binding of Ca2+ and phosphorylcholine to human C-reactive protein (CRP). The assay requires no modifications of any of the molecules involved, uses minuscule amounts of protein (8.5 x 10(-15) mol per analysis, i.

DNA binds and activates complement via residues 14-26 of the human C1q A chain.

The mechanism by which DNA activates the classical complement pathway was investigated, with emphasis upon the C1q binding sites involved. DNA bound to both the collagen-like and globular regions of C1q. Binding reactivity with DNA was retained after reduction/alkylation and sodium dodecyl sulfate treatment of C1q.

Use of capillary zone electrophoresis to evaluate the binding of anionic carbohydrates to synthetic peptides derived from human serum amyloid P component.

Capillary zone electrophoresis was used to study interactions between anionic carbohydrates and synthetic peptides derived from the heparin-binding region of human serum amyloid P component. The method involves quantitation of unbound peptides after a charge-dependent electrophoretic separation of the peptide-carbohydrate mixture. The concentrations of free peptide were determined by extrapolating the obtained peak areas of the peptide in the presence of ligand to a standard curve.

Localization of sites through which C-reactive protein binds and activates complement to residues 14-26 and 76-92 of the human C1q A chain.

Studies were initiated to localize the C-reactive protein (CRP) binding site on the collagen-like region (CLR) of C1q. CRP bound preferentially to the A chain of reduced C1q, in contrast to aggregated immunoglobulin G (Agg-IgG), which reacted preferentially with the C chain. A group of C1q A chain peptides, including peptides identical to residues 81-97, 76-92, and 14-26, respectively, were synthesized from predicted binding regions.

The V3 region of the envelope glycoprotein of human immunodeficiency virus type 1 binds sulfated polysaccharides and CD4-derived synthetic peptides.

gp120 is the envelope glycoprotein found on the surface of human immunodeficiency virus type 1 (HIV-1), and it binds to human cell surface CD4 receptors to initiate the HIV-1 infection process. It is now well-established that synthetic peptides from the V3 region on gp120 elicit antibodies that block HIV-1 infection and HIV-1-mediated cell fusion. Here we show that synthetic peptides derived from similar V3 regions of several isolates of HIV-1 bind [3H]heparin, and we also demonstrate that [3H]heparin binds to recombinant gp120 IIIB.