John M. Leong

Insulin receptor tyrosine kinase substrate links the E. coli O157:H7 actin assembly effectors Tir and EspF(U) during pedestal formation (2009)

Vingadassalom, Didier F., Kazlauskas, Arunas, Skehan, Brian M., Cheng, Hui-Chun, Magoun, Loranne, Robbins, Douglas, ...

Enterohemorrhagic Escherichia coli O157:H7 translocates 2 effectors to trigger localized actin assembly in mammalian cells, resulting in filamentous actin "pedestals." One effector, the...

Targeting type III secretion in Yersinia pestis (2008)

Pan, Ning, Brady, Michael John, Leong, John M., Goguen, Jon D.

Yersinia pestis, the causative agent of plague, utilizes a plasmid-encoded type III secretion system (T3SS) to aid it with its resistance to host defenses. This system injects a set of effector...

Hierarchical regulation of WASP/WAVE proteins (2008)

Padrick, Shae B., Cheng, Hui-Chun, Ismail, Ayman M., Panchal, Sanjay C., Doolittle, Lynda K., Kim, Soyeon, ...

Members of the Wiskott-Aldrich syndrome protein (WASP) family control actin dynamics in eukaryotic cells by stimulating the actin nucleating activity of the Arp2/3 complex. The prevailing paradigm...

Repetitive N-WASP-binding elements of the enterohemorrhagic Escherichia coli effector EspF(U) synergistically activate actin assembly (2008)

Campellone, Kenneth Geno, Cheng, Hui-Chun, Robbins, Douglas, Siripala, Anosha D., McGhie, Emma J., Hayward, Richard D., ...

Enterohemorrhagic Escherichia coli (EHEC) generate F-actin-rich adhesion pedestals by delivering effector proteins into mammalian cells. These effectors include the translocated receptor Tir, along...

In vitro CpG methylation increases the transformation efficiency of Borrelia burgdorferi strains harboring the endogenous linear plasmid lp56 (2008)

Chen, Qiang, Fischer, Joshua Richard, Benoit, Vivian M., Dufour, Nicholas P., Youderian, Philip, Leong, John M.

Borrelia burgdorferi is the causative agent of Lyme disease, the most common vector-borne illness in the Northern hemisphere. Low-passage-number infectious strains of B. burgdorferi exhibit extremely...

Structural mechanism of WASP activation by the enterohaemorrhagic E. coli effector EspF(U) (2008)

Cheng, Hui-Chun, Skehan, Brian M., Campellone, Kenneth Geno, Leong, John M., Rosen, Michael K.

During infection, enterohaemorrhagic Escherichia coli (EHEC) takes over the actin cytoskeleton of eukaryotic cells by injecting the EspF(U) protein into the host cytoplasm. EspF(U) controls actin by...

EspFU, a type III-translocated effector of actin assembly, fosters epithelial association and late-stage intestinal colonization by E. coli O157:H7 (2007)

Ritchie, Jennifer M., Brady, Michael J., Riley, Kathleen N., Ho, Theresa Deland, Campellone, Kenneth Geno, Herman, Ira M., ...

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 induces filamentous actin-rich 'pedestals' on intestinal epithelial cells. Pedestal formation in vitro requires translocation of bacterial effectors...

Enterohaemorrhagic and enteropathogenic Escherichia coli Tir proteins trigger a common Nck-independent actin assembly pathway (2007)

Brady, Michael J., Campellone, Kenneth Geno, Ghildiyal, Megha, Leong, John M.

The Tir proteins of enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC respectively) are each translocated into the host plasma membrane where they promote F-actin pedestals in...

Increased adherence and actin pedestal formation by dam-deficient enterohaemorrhagic Escherichia coli O157:H7 (2007)

Campellone, Kenneth Geno, Roe, Andrew J., Lobner-Olesen, Anders, Murphy, Kenan C., Magoun, Loranne, Brady, Michael J., ...

Enterohaemorrhagic Escherichia coli (EHEC) are highly infectious pathogens capable of causing severe diarrhoeal illnesses. As a critical step during their colonization, EHEC adhere intimately to...

Enterohaemorrhagic Escherichia coli Tir requires a C-terminal 12-residue peptide to initiate EspF-mediated actin assembly and harbours N-terminal sequences that influence pedestal length (2006)

Campellone, Kenneth Geno, Brady, Michael J., Alamares, Judith G., Rowe, Daniel C., Skehan, Brian M., Tipper, Donald J., ...

Enterohaemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) both utilize type III secretion systems that translocate the effector protein Tir into the plasma membrane of mammalian...

Exploiting pathogenic Escherichia coli to model transmembrane receptor signalling (2006)

Hayward, Richard D., Leong, John M., Koronakis, Vassilis, Campellone, Kenneth Geno

Many microbial pathogens manipulate the actin cytoskeleton of eukaryotic target cells to promote their internalization, intracellular motility and dissemination. Enteropathogenic and...

Fibronectin binding protein BBK32 of the Lyme disease spirochete promotes bacterial attachment to glycosaminoglycans (2005)

Fischer, Joshua Richard, LeBlanc, Kimberly T., Leong, John M.

Borrelia burgdorferi, the agent of Lyme disease, causes a multisystemic illness that can affect the skin, heart, joints, and nervous system and is capable of attachment to diverse cell types. Among...

Solving a sticky problem: new genetic approaches to host cell adhesion by the Lyme disease spirochete (2005)

Coburn, Jenifer, Fischer, Joshua R., Leong, John M.

The Lyme disease spirochetes, comprised of at least three closely related species, Borrelia burgdorferi, Borrelia garinii and Borrelia afzelii, are fascinating and enigmatic bacterial pathogens. They...

Nck-independent actin assembly is mediated by two phosphorylated tyrosines within enteropathogenic Escherichia coli Tir (2005)

Campellone, Kenneth Geno, Leong, John M.

Enteropathogenic Escherichia coli (EPEC) stimulates tyrosine-kinase signalling cascades to trigger localized actin assembly within mammalian cells. During actin 'pedestal' formation, the EPEC...

EspFU is a translocated EHEC effector that interacts with Tir and N-WASP and promotes Nck-independent actin assembly (2004)

Campellone, Kenneth Geno, Robbins, Douglas, Leong, John M.

Several microbial pathogens including enteropathogenic E. coli (EPEC) exploit mammalian tyrosine-kinase signaling cascades to recruit Nck adaptor proteins and activate N-WASP-Arp2/3-mediated actin...

Clustering of Nck by a 12-residue Tir phosphopeptide is sufficient to trigger localized actin assembly (2004)

Campellone, Kenneth Geno, Rankin, Susannah, Pawson, Tony, Kirschner, Marc W., Tipper, Donald J., Leong, John M.

Enteropathogenic Escherichia coli (EPEC) translocates effector proteins into mammalian cells to promote reorganization of the cytoskeleton into filamentous actin pedestals. One effector, Tir, is a...

Spirochete-platelet attachment and thrombocytopenia in murine relapsing fever borreliosis (2003)

Alugupalli, Kishore R., Michelson, Alan D., Joris, Isabelle, Schwan, Tom G., Hodivala-Dilke, Kairbaan, Hynes, Richard O., ...

Thrombocytopenia is common in persons infected with relapsing fever Borreliae. We previously showed that the relapsing fever spirochete Borrelia hermsii binds to and activates human platelets in...

Decorin-binding proteins A and B confer distinct mammalian cell type-specific attachment by Borrelia burgdorferi, the Lyme disease spirochete (2003)

Fischer, Joshua Richard, Parveen, Nikhat, Magoun, Loranne, Leong, John M.

Host cell binding is an essential step in colonization by many bacterial pathogens, and the Lyme disease agent, Borrelia burgdorferi, which colonizes multiple tissues, is capable of attachment to...

The resolution of relapsing fever borreliosis requires IgM and is concurrent with expansion of B1b lymphocytes (2003)

Alugupalli, Kishore R., Gerstein, Rachel M., Chen, Jianzhu, Szomolanyi-Tsuda, Eva, Woodland, Robert T., Leong, John M.

The rate of pathogen clearance is a critical determinant of morbidity and mortality. We sought to characterize the immune response responsible for the remarkably rapid clearance of individual...

Tails of two Tirs: actin pedestal formation by enteropathogenic E. coli and enterohemorrhagic E. coli O157:H7 (2003)

Campellone, Kenneth Geno, Leong, John M.

Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli O157:H7 (EHEC) form characteristic lesions on infected mammalian cells called actin pedestals. Each of these two pathogens...

Point mutants of EHEC intimin that diminish Tir recognition and actin pedestal formation highlight a putative Tir binding pocket (2002)

Liu, Hui, Radhakrishnan, Padhma, Magoun, Loranne, Prabu-Jeyabalan, Moses, Campellone, Kenneth Geno, Savage, Pamela Joyce, ...

Attachment to host cells by enterohaemorrhagic Escherichia coli (EHEC) is associated with the formation of a highly organized cytoskeletal structure containing filamentous actin, termed an attaching...

A tyrosine-phosphorylated 12-amino-acid sequence of enteropathogenic Escherichia coli Tir binds the host adaptor protein Nck and is required for Nck localization to actin pedestals (2002)

Campellone, Kenneth Geno, Giese, Andrew, Tipper, Donald J., Leong, John M.

Enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) each promote the reorganization of actin into filamentous pedestal structures beneath attached bacteria during...

The Tir-binding region of enterohaemorrhagic Escherichia coli intimin is sufficient to trigger actin condensation after bacterial-induced host cell signalling (1999)

Liu, Hui, Magoun, Loranne, Luperchio, Steven A., Schauer, David B., Leong, John M.

Enterohaemorrhagic Escherichia coli (EHEC) has emerged as an important agent of diarrhoeal disease. Attachment to host cells, an essential step during intestinal colonization by EHEC, is associated...

Strain variation in glycosaminoglycan recognition influences cell-type-specific binding by lyme disease spirochetes (1999)

Parveen, Nikhat, Robbins, Douglas, Leong, John M.

Lyme disease, a chronic multisystemic disorder that can affect the skin, heart, joints, and nervous system is caused by Borrelia burgdorferi sensu lato. Lyme disease spirochetes were previously shown...

beta1-chain integrins are not essential for intimin-mediated host cell attachment and enteropathogenic Escherichia coli-induced actin condensation (1999)

Liu, Hui, Magoun, Loranne, Leong, John M.

Intimin is a bacterial outer membrane protein required for intimate attachment of enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) to mammalian cells. beta1-chain integrins...

Structural requirements for glycosaminoglycan recognition by the Lyme disease spirochete, Borrelia burgdorferi (1998)

Leong, John M., Robbins, Douglas, Rosenfeld, Louis, Lahiri, Biswajit, Parveen, Nikhat

Borrelia burgdorferi, the Lyme disease agent, binds glycosaminoglycans (GAGs) such as heparin, heparan sulfate, and dermatan sulfate. Heparin or heparan sulfate fractions separated by size or charge...

Different classes of proteoglycans contribute to the attachment of Borrelia burgdorferi to cultured endothelial and brain cells (1998)

Leong, John M., Wang, Hong, Magoun, Loranne, Field, Jodie A., Morrissey, Pamela E., Robbins, Douglas, ...

The Lyme disease spirochete, Borrelia burgdorferi, infects multiple tissues, such as the heart, joint, skin, and nervous system and has been shown to recognize heparan sulfate and dermatan sulfate...

A natural variant of the cysteine protease virulence factor of group A Streptococcus with an arginine-glycine-aspartic acid (RGD) motif preferentially binds human integrins αvβ3 and αIIbβ3

Stockbauer, Kathryn E., Magoun, Loranne, Liu, Mengyao, Burns, Eugene H., Gubba, Siddeswar, Renish, Sarah, ...

The human pathogenic bacterium group A Streptococcus produces an extracellular cysteine protease [streptococcal pyrogenic exotoxin B (SpeB)] that is a critical virulence factor for invasive disease...

Strain Variation in Glycosaminoglycan Recognition Influences Cell-Type-Specific Binding by Lyme Disease Spirochetes

Parveen, Nikhat, Robbins, Douglas, Leong, John M.

Lyme disease, a chronic multisystemic disorder that can affect the skin, heart, joints, and nervous system is caused by Borrelia burgdorferi sensu lato. Lyme disease spirochetes were previously shown...

β1-Chain Integrins Are Not Essential for Intimin-Mediated Host Cell Attachment and Enteropathogenic Escherichia coli-Induced Actin Condensation

Liu, Hui, Magoun, Loranne, Leong, John M.

Intimin is a bacterial outer membrane protein required for intimate attachment of enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) to mammalian cells. β1-chain integrins have...

Different Classes of Proteoglycans Contribute to the Attachment of Borrelia burgdorferi to Cultured Endothelial and Brain Cells

Leong, John M., Wang, Hong, Magoun, Loranne, Field, Jodie A., Morrissey, Pamela E., Robbins, Douglas, ...

The Lyme disease spirochete, Borrelia burgdorferi, infects multiple tissues, such as the heart, joint, skin, and nervous system and has been shown to recognize heparan sulfate and dermatan sulfate...

Integrins αvβ3 and α5β1 Mediate Attachment of Lyme Disease Spirochetes to Human Cells

Coburn, Jenifer, Magoun, Loranne, Bodary, Sarah C., Leong, John M.

Borrelia burgdorferi (sensu lato), the agent of Lyme disease, is able to cause chronic, multisystemic infections in human and animal hosts. Attachment of the spirochete to host cells is likely to be...

Structural Requirements for Glycosaminoglycan Recognition by the Lyme Disease Spirochete, Borrelia burgdorferi†

Leong, John M., Robbins, Douglas, Rosenfeld, Louis, Lahiri, Biswajit, Parveen, Nikhat

Borrelia burgdorferi, the Lyme disease agent, binds glycosaminoglycans (GAGs) such as heparin, heparan sulfate, and dermatan sulfate. Heparin or heparan sulfate fractions separated by size or charge...

Opsonophagocytosis-Inhibiting Mac Protein of Group A Streptococcus: Identification and Characteristics of Two Genetic Complexes

Lei, Benfang, DeLeo, Frank R., Reid, Sean D., Voyich, Jovanka M., Magoun, Loranne, Liu, Mengyao, ...

Recently, it was reported that a streptococcal Mac protein (designated Mac5005) made by serotype M1 group A Streptococcus (GAS) is a homologue of human CD11b that inhibits opsonophagocytosis and...

Decorin-binding proteins A and B confer distinct mammalian cell type-specific attachment by Borrelia burgdorferi, the Lyme disease spirochete

Fischer, Joshua R., Parveen, Nikhat, Magoun, Loranne, Leong, John M.

Host cell binding is an essential step in colonization by many bacterial pathogens, and the Lyme disease agent, Borrelia burgdorferi, which colonizes multiple tissues, is capable of attachment to...

Relapsing Fever Spirochetes Contain Chromosomal Genes with Unique Direct Tandemly Repeated Sequences

Guyard, Cyril, Chester, Earl M., Raffel, Sandra J., Schrumpf, Merry E., Policastro, Paul F., Porcella, Stephen F., ...

Genome sequencing of the relapsing fever spirochetes Borrelia hermsii and Borrelia turicatae identified three open reading frames (ORFs) on the chromosomes that contained internal, tandemly repeated...

Fibronectin Binding Protein BBK32 of the Lyme Disease Spirochete Promotes Bacterial Attachment to Glycosaminoglycans

Fischer, Joshua R., LeBlanc, Kimberly T., Leong, John M.

Borrelia burgdorferi, the agent of Lyme disease, causes a multisystemic illness that can affect the skin, heart, joints, and nervous system and is capable of attachment to diverse cell types. Among...

Bgp, a Secreted Glycosaminoglycan-Binding Protein of Borrelia burgdorferi Strain N40, Displays Nucleosidase Activity and Is Not Essential for Infection of Immunodeficient Mice†

Parveen, Nikhat, Cornell, Kenneth A., Bono, James L., Chamberland, Christen, Rosa, Patricia, Leong, John M.

Bgp, one of the surface-localized glycosaminoglycan-binding proteins of the Lyme disease spirochete, Borrelia burgdorferi, exhibited nucleosidase activity. Infection of SCID mice with B. burgdorferi...

A natural variant of the cysteine protease virulence factor of group A Streptococcus with an arginine-glycine-aspartic acid (RGD) motif preferentially binds human integrins αvβ3 and αIIbβ3

Stockbauer, Kathryn E., Magoun, Loranne, Liu, Mengyao, Burns, Eugene H., Gubba, Siddeswar, Renish, Sarah, ...

The human pathogenic bacterium group A Streptococcus produces an extracellular cysteine protease [streptococcal pyrogenic exotoxin B (SpeB)] that is a critical virulence factor for invasive disease...

Strain Variation in Glycosaminoglycan Recognition Influences Cell-Type-Specific Binding by Lyme Disease Spirochetes

Parveen, Nikhat, Robbins, Douglas, Leong, John M.

Lyme disease, a chronic multisystemic disorder that can affect the skin, heart, joints, and nervous system is caused by Borrelia burgdorferi sensu lato. Lyme disease spirochetes were previously shown...

β1-Chain Integrins Are Not Essential for Intimin-Mediated Host Cell Attachment and Enteropathogenic Escherichia coli-Induced Actin Condensation

Liu, Hui, Magoun, Loranne, Leong, John M.

Intimin is a bacterial outer membrane protein required for intimate attachment of enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) to mammalian cells. β1-chain integrins have...

Different Classes of Proteoglycans Contribute to the Attachment of Borrelia burgdorferi to Cultured Endothelial and Brain Cells

Leong, John M., Wang, Hong, Magoun, Loranne, Field, Jodie A., Morrissey, Pamela E., Robbins, Douglas, ...

The Lyme disease spirochete, Borrelia burgdorferi, infects multiple tissues, such as the heart, joint, skin, and nervous system and has been shown to recognize heparan sulfate and dermatan sulfate...

Integrins αvβ3 and α5β1 Mediate Attachment of Lyme Disease Spirochetes to Human Cells

Coburn, Jenifer, Magoun, Loranne, Bodary, Sarah C., Leong, John M.

Borrelia burgdorferi (sensu lato), the agent of Lyme disease, is able to cause chronic, multisystemic infections in human and animal hosts. Attachment of the spirochete to host cells is likely to be...

Structural Requirements for Glycosaminoglycan Recognition by the Lyme Disease Spirochete, Borrelia burgdorferi†

Leong, John M., Robbins, Douglas, Rosenfeld, Louis, Lahiri, Biswajit, Parveen, Nikhat

Borrelia burgdorferi, the Lyme disease agent, binds glycosaminoglycans (GAGs) such as heparin, heparan sulfate, and dermatan sulfate. Heparin or heparan sulfate fractions separated by size or charge...

Opsonophagocytosis-Inhibiting Mac Protein of Group A Streptococcus: Identification and Characteristics of Two Genetic Complexes

Lei, Benfang, DeLeo, Frank R., Reid, Sean D., Voyich, Jovanka M., Magoun, Loranne, Liu, Mengyao, ...

Recently, it was reported that a streptococcal Mac protein (designated Mac5005) made by serotype M1 group A Streptococcus (GAS) is a homologue of human CD11b that inhibits opsonophagocytosis and...

Decorin-binding proteins A and B confer distinct mammalian cell type-specific attachment by Borrelia burgdorferi, the Lyme disease spirochete

Fischer, Joshua R., Parveen, Nikhat, Magoun, Loranne, Leong, John M.

Host cell binding is an essential step in colonization by many bacterial pathogens, and the Lyme disease agent, Borrelia burgdorferi, which colonizes multiple tissues, is capable of attachment to...

Relapsing Fever Spirochetes Contain Chromosomal Genes with Unique Direct Tandemly Repeated Sequences

Guyard, Cyril, Chester, Earl M., Raffel, Sandra J., Schrumpf, Merry E., Policastro, Paul F., Porcella, Stephen F., ...

Genome sequencing of the relapsing fever spirochetes Borrelia hermsii and Borrelia turicatae identified three open reading frames (ORFs) on the chromosomes that contained internal, tandemly repeated...

Fibronectin Binding Protein BBK32 of the Lyme Disease Spirochete Promotes Bacterial Attachment to Glycosaminoglycans

Fischer, Joshua R., LeBlanc, Kimberly T., Leong, John M.

Borrelia burgdorferi, the agent of Lyme disease, causes a multisystemic illness that can affect the skin, heart, joints, and nervous system and is capable of attachment to diverse cell types. Among...

Bgp, a Secreted Glycosaminoglycan-Binding Protein of Borrelia burgdorferi Strain N40, Displays Nucleosidase Activity and Is Not Essential for Infection of Immunodeficient Mice†

Parveen, Nikhat, Cornell, Kenneth A., Bono, James L., Chamberland, Christen, Rosa, Patricia, Leong, John M.

Bgp, one of the surface-localized glycosaminoglycan-binding proteins of the Lyme disease spirochete, Borrelia burgdorferi, exhibited nucleosidase activity. Infection of SCID mice with B. burgdorferi...

Clustering of Nck by a 12-residue Tir phosphopeptide is sufficient to trigger localized actin assembly

Campellone, Kenneth G., Rankin, Susannah, Pawson, Tony, Kirschner, Marc W., Tipper, Donald J., Leong, John M.

Enteropathogenic Escherichia coli (EPEC) translocates effector proteins into mammalian cells to promote reorganization of the cytoskeleton into filamentous actin pedestals. One effector, Tir, is a...

Repetitive N-WASP–Binding Elements of the Enterohemorrhagic Escherichia coli Effector EspFU Synergistically Activate Actin Assembly

Campellone, Kenneth G., Cheng, Hui-Chun, Robbins, Douglas, Siripala, Anosha D., McGhie, Emma J., Hayward, Richard D., ...

Enterohemorrhagic Escherichia coli (EHEC) generate F-actin–rich adhesion pedestals by delivering effector proteins into mammalian cells. These effectors include the translocated receptor Tir, along...

Cortactin Recruitment by Enterohemorrhagic Escherichia coli O157:H7 during Infection In Vitro and Ex Vivo▿

Mousnier, Aurelie, Whale, Andrew D., Schüller, Stephanie, Leong, John M., Phillips, Alan D., Frankel, Gad

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important human pathogen that colonizes the gut mucosa via attaching and effacing (A/E) lesions; A/E lesion formation in vivo and ex vivo is...

Borrelia burgdorferi Lacking DbpBA Exhibits an Early Survival Defect during Experimental Infection▿

Weening, Eric H., Parveen, Nikhat, Trzeciakowski, Jerome P., Leong, John M., Höök, Magnus, Skare, Jonathan T.

Several Borrelia burgdorferi genes induced under mammalian host conditions have been purported to be important in Lyme disease pathogenesis based on their binding to host structures. These genes...

In Vitro CpG Methylation Increases the Transformation Efficiency of Borrelia burgdorferi Strains Harboring the Endogenous Linear Plasmid lp56▿

Chen, Qiang, Fischer, Joshua R., Benoit, Vivian M., Dufour, Nicholas P., Youderian, Philip, Leong, John M.

Borrelia burgdorferi is the causative agent of Lyme disease, the most common vector-borne illness in the Northern hemisphere. Low-passage-number infectious strains of B. burgdorferi exhibit extremely...

Targeting Type III Secretion in Yersinia pestis▿ †

Pan, Ning J., Brady, Michael J., Leong, John M., Goguen, Jon D.

Yersinia pestis, the causative agent of plague, utilizes a plasmid-encoded type III secretion system (T3SS) to aid it with its resistance to host defenses. This system injects a set of effector...

Insulin receptor tyrosine kinase substrate links the E. coli O157:H7 actin assembly effectors Tir and EspFU during pedestal formation

Vingadassalom, Didier, Kazlauskas, Arunas, Skehan, Brian, Cheng, Hui-Chun, Magoun, Loranne, Robbins, Douglas, ...

Enterohemorrhagic Escherichia coli O157:H7 translocates 2 effectors to trigger localized actin assembly in mammalian cells, resulting in filamentous actin “pedestals.” One effector, the...