During organogenesis, immunosurveillance, and inflammation, chemokines selectively recruit leukocytes by activating seven-transmembrane-spanning receptors. It has been suggested that an important component of this process is the formation a haptotactic gradient immobilization on cell surface glycosaminoglycans (GAGs). However, hypothesis not experimentally demonstrated in vivo . In present study we investigated effect mutations GAG binding sites three chemokines, monocyte chemoattractant...

The reported structures of many CC chemokines show a conserved dimer interface along their N-terminal region, raising the possibility that quaternary arrangement these small immune proteins might influence function. We have produced and analyzed several mutants MIP-1β having range Kd values in order to determine significance dimerization receptor binding cellular activation. NMR analytical ultracentrifugation were used analyze oligomeric state mutants. Functional relevance was determined by...

Human cytomegalovirus (HCMV) is the causative agent of life-threatening systemic diseases in immunocompromised patients as well a risk factor for vascular pathologies, like atherosclerosis, immunocompetent individuals. HCMV encodes G-protein-coupled receptor (GPCR), referred to US28, that displays homology human chemokine CCR1 and binds several chemokines CC family CX3C fractalkine with high affinity. Most importantly, following infection, US28 activates intracellular pathways, either...

Chemokines (chemotactic cytokines) comprise a large family of proteins that recruit and activate leukocytes, giving chemokines major role in both immune response inflammation-related diseases. The poxvirus-encoded viral CC chemokine inhibitor (vCCI) binds to many with high affinity, acting as potent action. We have used heteronuclear multidimensional NMR determine the structure an orthopoxvirus vCCI complex human chemokine, MIP-1beta (macrophage inflammatory protein 1beta). 1:1...

Griffithsin (GRFT) is a lectin that has been shown to inhibit HIV infection by binding high mannose glycan structures on the surface of gp120, and it among most potent entry inhibitors reported so far. However, important biochemical details antiviral mechanism GRFT action remain unexplored. In order understand role three individual carbohydrate-binding sites (CBS) in GRFT, mutations were made at each site (D30A, D70A, D112A), resulting mutants investigated. NMR studies revealed variant was...

Chemokines direct immune cells toward sites of infection by establishing a gradient across the extracellular matrix tissue. This is thought to be stabilized ligation chemokines sulfated polysaccharides known as glycosaminoglycans (GAGs) that are found on surface endothelial and other well in tissue matrix. GAGs interact with some cases cause them aggregate. The interaction between cell has also been postulated play role anti-HIV activity chemokines, including MIP-1β. Since many proteins...

Chemokine dimerization has been the subject of much interest in recent years as evidence accumulated that different quaternary states chemokines play biological roles; monomer is believed to be receptor-binding unit, whereas dimer implicated binding cell surface glycosaminoglycans. However, although several studies have provided for this paradigm by making monomeric chemokine variants or dimer-impaired chemokines, few direct receptor function a dimer. We produced covalent CC macrophage...

Topical microbicides have the potential to provide effective protection against sexual transmission of HIV. Challenges in developing include their application resource-poor settings with high temperatures and a lack refrigeration, low user adherence rigorous daily regimen. Several protein-based HIV inhibitors show great promise as microbicides, being highly specific not expected lead resistance that would affect efficacy current antiretroviral treatments. We four potent protein inhibitors,...

Abstract Introduction The majority of new HIV infections occur through mucosal transmission. availability readily applicable and accessible platforms for anti‐retroviral (ARV) delivery is critical the prevention acquisition sexual transmission in both women men. There a compelling need developing topical systems that have advantages over pills, gels rings, which currently fail to guarantee protection against viral vulnerable populations due lack user compliance. silk fibroin (SF) platform...

Encoded by Kaposi's sarcoma-associated herpesvirus, viral macrophage-inflammatory protein-II (VMIP-II) is unique among CC chemokines in that it has been shown to bind the CXC chemokine receptor CXCR4 as well a variety of receptors. This binding ability allows vMIP-II block infection wide range human immunodeficiency virus type I (HIV-1) strains, but structural and dynamic basis for this broad not known. 15N T1, T2 15N[-HN] nuclear Overhauser effect (NOE) values vMIP-II, determined through...

Chemokines are important immune proteins, carrying out their function by binding to glycosaminoglycans (GAGs) on the endothelial surface and cell chemokine receptors. A unique viral analogue, macrophage inflammatory protein-II (vMIP-II), encoded human herpesvirus-8, has garnered interest because of its ability bind multiple receptors, including both HIV coreceptors. In addition, vMIP-II binds GAGs much more tightly than most chemokines, which may be key anti-inflammatory in vivo. The goal...

Chemokines play important roles in the immune system, not only recruiting leukocytes to site of infection and inflammation but also guiding cell homing development. The soluble poxvirus-encoded protein viral CC chemokine inhibitor (vCCI), a inhibitor, can bind human chemokines tightly impair host defense. This has no known homologs eukaryotes may represent potent method stop inflammation. Previously, our structure vCCI·MIP-1β (macrophage inflammatory protein-1β) complex indicated that vCCI...

The SARS-CoV-2 virion has shown remarkable resilience, capable of mutating to escape immune detection and re-establishing infectious capabilities despite new vaccine rollouts. Therefore, there is a critical need identify relatively immutable epitopes on the that are resistant future mutations virus may accumulate. While hACE2 been identified as receptor mediates susceptibility, it only modestly expressed in lung tissue. C-type lectin receptors like DC-SIGN can act attachment sites enhance...

Chemokines (chemotactic cytokines) are a family of immune system proteins, several which have been shown to block human immunodeficiency virus (HIV) infection in various cell types. While the solved structures most chemokines reveal protein dimers, evidence has accumulated for biological activity individual chemokine monomers, and debate arisen regarding role dimer. Concurrent with this debate, N-terminal truncations modifications CC subfamily functional significance, many cases antagonizing...

Abstract We report the solution structure of chemotactic cytokine (chemokine) vMIP‐II. This protein has unique biological activities in that it blocks infection by several different human immunodeficiency virus type 1 (HIV‐1) strains. occurs because vMIP‐II binds to a wide range chemokine receptors, some which are used HIV gain cell entry. is monomeric protein, unlike most members family, and its consists disordered N‐terminus, followed helical turn (Gln25‐Leu27), leads into first strand...

MIP-1beta is a CC-chemokine that plays role in inflammation and host defense mechanisms by interacting with its specific receptor CCR5. CCR5 major coreceptor for macrophage-tropic human immunodeficiency virus (HIV), as consequence, can inhibit HIV entry. It therefore of interest to understand how other ligands bind their receptor, such understanding could lead the rational design more efficient entry blockers. We have previously demonstrated importance Phe13, basic residues 40's loop,...

Abstract The N‐terminal region of the chemokine RANTES is critical for its function. A synthesized N‐terminally modified analog RANTES, P2‐RANTES, was discovered using a phage display selection against living CCR5‐expressing cells, and has been reported to inhibit HIV‐1 env‐mediated cell–cell fusion at subnanomolar levels (Hartley et al. J Virol 2003;77:6637–6644). In present study we produced this protein E. coli overexpression extensively studied structure x‐ray crystal P2‐RANTES solved...

Chemokines comprise a family of proteins that function in the immune response to recruit leukocytes sites infection. This recruitment is believed be carried out by establishment chemokine gradient binding chemokines sulfated polysaccharides known as glycosaminoglycans (GAGs) located on extracellular surface endothelial cells. In present studies, multidimensional NMR spectroscopy was used study interaction monomeric and dimeric macrophage inflammatory protein (MIP)-1β variants with series...

Chemokines are immune system proteins that recruit and activate leukocytes to sites of infection. This recruitment is believed involve the establishment a chemokine concentration gradient by binding chemokines glycosaminoglycans (GAGs). In previous studies, we elucidated GAG site MIP-1β implicated involvement dimer in through residues across interface. present nuclear magnetic resonance spectroscopy was used investigate effect on dimerization. Using several dimerization-impaired variants...

The protein Griffithsin (Grft) is a lectin that tightly binds to high-mannose glycosylation sites on viral surfaces. This property allows Grft potently inhibit many viruses, including HIV-1. major route of HIV infection through sexual activity, so an important tool for reducing the risk would be film could inserted vaginally or rectally transmission virus. We have previously shown silk fibroin can encapsulate, stabilize, and release various antiviral proteins, Grft. However, broad utility as...

MIP-1beta, a member of the chemokine family proteins, tightly binds receptor CCR5 as part its natural function in immune response, and doing so also blocks ability many strains HIV to enter cell. The single most important MIP-1beta residue known contribute interaction with is Phe13, which when mutated reduces bind by more than 1000-fold. To obtain structural understanding dramatic effect absence Phe13 we used multidimensional heteronuclear NMR determine three-dimensional structure F13A...

Certain viruses have the ability to subvert mammalian immune response, including interference in chemokine system. Poxviruses produce binding protein vCCI (viral CC inhibitor; also called 35K), which tightly binds chemokines. To facilitate study of vCCI, we first provide a protocol folded from Escherichia coli (E. coli.) It is shown here that with unusually high affinity viral Macrophage Inflammatory Protein-II (vMIP-II), analog produced by virus, human herpesvirus 8 (HHV-8). Fluorescence...

Due to the immense societal and economic impact that COVID-19 pandemic has caused, limiting spread of SARS-CoV-2 is one most important priorities at this time. The global interconnectedness food industry makes it biggest concerns for outbreaks. Although fomites are currently considered a low-risk route transmission SARS-CoV-2, new variants virus can potentially alter dynamics. In study, we compared survival rate pseudotyped on plastic with some commonly used samples (i.e., apple, strawberry,...