Structure‐Based Synthetic Mimicry of Discontinuous Protein Binding Sites: Inhibitors of the Interaction of Mena EVH1 Domain with Proline‐Rich Ligands

Hunke, Cornelia; Hirsch, Tatjana; Eichler, Jutta

doi:10.1002/cbic.200500465

Cited by 10 publications

(6 citation statements)

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“…The antibody responses to gag are not useful against HIV and do not constitute a viable vaccine strategy. However, given the strong and broad immune responses that the mice developed, a reasonable strategy could be modifying the vector to encode a defective env that induces neutralizing antibodies, or even to use a membrane-based protein that contains neutralizing antibody-inducing epitopes [52][53][54][55][56]. Such a strategy could generate potent T cell immunity against gagpol and potentially env as well as a neutralizing antibody response to envelope.…”

Section: Discussionmentioning

confidence: 99%

Induction of HIV‐specific T and B cell responses with a replicating and conditionally infectious lentiviral vaccine

2008

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The development of an HIV vaccine that induces broad and potent immunity is critically needed. Viruses, including lentiviruses, have been used as vectors for ex vivo transduction of antigens into dendritic cells (DC). We hypothesized that DC transduced with a vector that allows selective infection of DC could induce potent immunity by continually priming DC. A lentiviral vector encoding HIV gag-pol without env would form viral cores in transduced DC, but would release non-infectious particles by budding into endosomes and releasing apoptotic bodies or exosomes containing viral cores. DC function by endocytosing DCderived apoptotic bodies, and they are specialized in their ability to move endocytic contents into the cytoplasm. We postulated that endocytosis of vector cores could lead to transduction of a second round of DC. In this report, we demonstrate accumulation of viral cores inside transduced DC and show second-round transduction of immature DC that endocytose transduced DC in vitro. The effectiveness of immunization of mice with transduced DC to induce specific lymphocyte activation was assessed. Mice developed antigen-specific T cell responses and specific antibodies after immunization. Transduction of DC with a replication-competent but conditionally infectious lentivirus could be a novel vaccine strategy for HIV.Key words: Dendritic cell Á HIV Á Immune response Á Lentiviral vector Introduction A safe and effective vaccine for HIV is critically needed to combat the worldwide scourge of AIDS. While the correlates of immune protection have yet to be clearly defined, either for protective or therapeutic vaccines, it is widely believed that both CD4 + and CD8 + T cell as well as humoral immunity are important. How sufficiently broad, potent, and sustained responses can be elicited has yet to be determined, and this represents a critical gap in our understanding of how to generate an effective vaccine such that protective or therapeutic immunity can be achieved. Selection and activation of lymphocytes is a function of antigen presentation by dendritic cells (DC), making DC a logical vehicle for immunotherapy [1]. Early studies showed that DC loaded with tumor extracts [2,3] or antigenic peptides [2][3][4][5] induced anti-tumor immunity in both laboratory mice [2,4,5] and human melanoma patients [3]. More recently, viruses have been used as gene transfer vectors for the ex vivo transduction of DC with selected antigens. Lentiviral vectors have a number of advantages over adenoviruses, adeno-associated viruses, poxviruses, and alphaviruses. Transduction is stable due to chromosomal integration and non-dividing cells are efficiently transduced [6]. Lentivirally transduced DC have been studied for their ability to induce anti-tumor immunity. Breckpot et al. [7] demonstrated that murine DC transduced with a lentivirus encoding a truncated variant of ovalbumin (OVA) protected against tumor challenge with OVA-expressing cells. He et al. [8] recently described the transduction of murine DC with a lentiviral vector...

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Section: Discussionmentioning

confidence: 99%

Induction of HIV‐specific T and B cell responses with a replicating and conditionally infectious lentiviral vaccine

2008

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“…Since the inhibition of this interaction may provide a strategy to hamper the motility of the pathogen and to prevent its spread in the host organism, many efforts are currently devoted to the development of peptides able to interfere with ActA/Mena interaction [41]. In this scenario many efforts are currently made to fully elucidate the structural and energetic details of this protein-protein interaction.…”

Section: Polyproline Helices In Host-pathogen Recognitionmentioning

confidence: 99%

Polyproline and Triple Helix Motifs in Host-Pathogen Recognition

Berisio¹,

Vitagliano

2012

CPPS

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Secondary structure elements often mediate protein-protein interactions. Despite their low abundance in folded proteins, polyproline II (PPII) and its variant, the triple helix, are frequently involved in protein-protein interactions, likely due to their peculiar propensity to be solvent-exposed. We here review the role of PPII and triple helix in mediating host-pathogen interactions, with a particular emphasis to the structural aspects of these processes. After a brief description of the basic structural features of these elements, examples of host-pathogen interactions involving these motifs are illustrated. Literature data suggest that the role played by PPII motif in these processes is twofold. Indeed, PPII regions may directly mediate interactions between proteins of the host and the pathogen. Alternatively, PPII may act as structural spacers needed for the correct positioning of the elements needed for adhesion and infectivity. Recent investigations have highlighted that collagen triple helix is also a common target for bacterial adhesins. Although structural data on complexes between adhesins and collagen models are rather limited, experimental and theoretical studies have unveiled some interesting clues of the recognition process. Interestingly, very recent data show that not only is the triple helix used by pathogens as a target in the host-pathogen interaction but it may also act as a bait in these processes since bacterial proteins containing triple helix regions have been shown to interact with host proteins. As both PPII and triple helix expose several main chain non-satisfied hydrogen bond acceptors and donors, both elements are highly solvated. The preservation of the solvation state of both PPII and triple helix upon protein-protein interaction is an emerging aspect that will be here thoroughly discussed.

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“…Moreover, the peptide was also found to be a specific ligand for a synthetic Mena EVH1 mimetic. This receptor fragment presents the conserved aromatic triad of Mena EVH1 in a sequence context which constitutes the binding site for proline-rich ligands (Hunke et al, 2006). Nevertheless, no experimentally determined structure of pGolemi is available yet.…”

Section: Introductionmentioning

confidence: 99%

The solution structure of pGolemi, a high affinity Mena EVH1 binding miniature protein, suggests explanations for paralog-specific binding to Ena/VASP homology (EVH) 1 domains

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Hunke

Mueller

et al. 2009

Biological Chemistry

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Ena/VASP homology 1 (EVH1) domains are polyproline binding domains that are present in a wide range of adaptor proteins, among them Ena/VASP proteins involved in actin remodeling and axonal guidance. The interaction of ActA, a transmembrane protein from the food-borne pathogen Listeria monocytogenes, with EVH1 domains has been shown to be crucial for recruitment of the host's actin skeleton and, as a consequence, for the infectivity of this bacterium. We present the structure of a synthetic high-affinity Mena EVH1 ligand, pGolemi, capable of paralog-specific binding, solved by NMR spectroscopy. This peptide shares the common pancreatic peptide fold with its scaffold, avian pancreatic peptide, but shows pivotal differences in the aminoterminus. The interplay of spatial fixation and flexibility appears to be the reason for its high affinity towards Mena EVH1. Combined with earlier investigations, our structural data shed light on the specificity determinants of pGolemi and the importance of additional binding epitopes around the residues Thr74 and Phe32 on EVH1 domains regulating paralog specificity. Our results are expected to facilitate the design of other high-affinity, paralog-specific EVH1 domain ligands, and serve as a fundament for the investigation of the molecular mode of action of EVH1 domains.

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Structure‐Based Synthetic Mimicry of Discontinuous Protein Binding Sites: Inhibitors of the Interaction of Mena EVH1 Domain with Proline‐Rich Ligands

Cited by 10 publications

References 57 publications

Induction of HIV‐specific T and B cell responses with a replicating and conditionally infectious lentiviral vaccine

Induction of HIV‐specific T and B cell responses with a replicating and conditionally infectious lentiviral vaccine

Polyproline and Triple Helix Motifs in Host-Pathogen Recognition

The solution structure of pGolemi, a high affinity Mena EVH1 binding miniature protein, suggests explanations for paralog-specific binding to Ena/VASP homology (EVH) 1 domains

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