scholarly journals Neisseria gonorrhoeae subverts formin-dependent actin polymerization to colonize human macrophages

2021 ◽  
Vol 17 (12) ◽  
pp. e1010184
Author(s):  
Stanimir S. Ivanov ◽  
Reneau Castore ◽  
Maria Dolores Juarez Rodriguez ◽  
Magdalena Circu ◽  
Ana-Maria Dragoi
Keyword(s):  
Plasma Membrane ◽  
Neisseria Gonorrhoeae ◽  
Actin Polymerization ◽  
Bacterial Pathogens ◽  
Transmitted Disease ◽  
Bacterial Pathogen ◽  
Host Cells ◽  
Human Macrophages ◽  
Sexually Transmitted ◽  
Bacterial Replication

Dynamic reorganization of the actin cytoskeleton dictates plasma membrane morphogenesis and is frequently subverted by bacterial pathogens for entry and colonization of host cells. The human-adapted bacterial pathogen Neisseria gonorrhoeae can colonize and replicate when cultured with human macrophages, however the basic understanding of how this process occurs is incomplete. N. gonorrhoeae is the etiological agent of the sexually transmitted disease gonorrhea and tissue resident macrophages are present in the urogenital mucosa, which is colonized by the bacteria. We uncovered that when gonococci colonize macrophages, they can establish an intracellular or a cell surface-associated niche that support bacterial replication independently. Unlike other intracellular bacterial pathogens, which enter host cells as single bacterium, establish an intracellular niche and then replicate, gonococci invade human macrophages as a colony. Individual diplococci are rapidly phagocytosed by macrophages and transported to lysosomes for degradation. However, we found that surface-associated gonococcal colonies of various sizes can invade macrophages by triggering actin skeleton rearrangement resulting in plasma membrane invaginations that slowly engulf the colony. The resulting intracellular membrane-bound organelle supports robust bacterial replication. The gonococci-occupied vacuoles evaded fusion with the endosomal compartment and were enveloped by a network of actin filaments. We demonstrate that gonococcal colonies invade macrophages via a process mechanistically distinct from phagocytosis that is regulated by the actin nucleating factor FMNL3 and is independent of the Arp2/3 complex. Our work provides insights into the gonococci life-cycle in association with human macrophages and defines key host determinants for macrophage colonization.

scholarly journals Neisseria gonorrhoeae subverts formin-dependent actin polymerization to colonize human macrophages

2021 ◽  
Author(s):  
Stanimir S. Ivanov ◽  
Reneau Castore ◽  
Magdalena Circu ◽  
Ana-Maria Dragoi
Keyword(s):  
Plasma Membrane ◽  
Neisseria Gonorrhoeae ◽  
Actin Polymerization ◽  
Bacterial Pathogens ◽  
Transmitted Disease ◽  
Bacterial Pathogen ◽  
Host Cells ◽  
Human Macrophages ◽  
Sexually Transmitted ◽  
Bacterial Replication

ABSTRACTDynamic reorganization of the actin cytoskeleton dictates plasma membrane morphology and is frequently subverted by bacterial pathogens for entry and colonization of host cells. The human-adapted bacterial pathogen Neisseria gonorrhoeae can colonize and replicate when cultured with human macrophages, however the basic understanding of how this process occurs is incomplete. N. gonorrhoeae is the etiological agent of the sexually transmitted disease gonorrhea and tissue resident macrophages are present in the urogenital mucosa which is colonized by the bacteria. We uncovered that when gonococci colonize macrophages they can establish an intracellular or a cell surface-associated niche that support bacterial replication independently. Unlike other intracellular bacterial pathogens, which enter host cells as single bacterium, establish an intracellular niche and then replicate, gonococci invade human macrophages as a colony. Individual diplococci are rapidly phagocytosed by macrophages and transported to lysosomes for degradation. However, we found that surface-associated gonococcal colonies of various sizes can invade macrophages by triggering actin skeleton rearrangement resulting in plasma membrane invaginations that slowly engulf the colony. The resulting intracellular membrane-bound organelle supports robust bacterial replication. The gonococci-occupied vacuoles evaded fusion with the endosomal compartment and were enveloped by a network of actin filaments. We demonstrate that gonococcal colonies invade macrophages via a process mechanistically distinct from phagocytosis that is regulated by the actin nucleating factor FMNL3. Our work provides insights into the gonococci life-cycle in association with human macrophages and defines key host determinants for macrophage colonization.

scholarly journals Neisseria gonorrhoeae–Induced Inflammatory Pyroptosis in Human Macrophages is Dependent on Intracellular Gonococci and Lipooligosaccharide

2018 ◽  
Vol 11 ◽  
pp. 117906601775090 ◽  
Author(s):  
Jessica Leigh Ritter ◽  
Caroline Attardo Genco
Keyword(s):  
Cell Death ◽  
Neisseria Gonorrhoeae ◽  
Transmitted Disease ◽  
Human Monocyte ◽  
Dependent Manner ◽  
Human Macrophages ◽  
Sexually Transmitted ◽  
Cell Death Pathways ◽  
Dependent Cell ◽  
Obligate Pathogen

Neisseria gonorrhoeae, the human obligate pathogen responsible for the sexually transmitted disease gonorrhea, has evolved several mechanisms to evade the host immune response. One such mechanism is the modulation of host cell death pathways. In this study, we defined cell death pathways induced by N gonorrhoeae in human monocyte-derived macrophages (MDMs). In a dose-dependent manner, N gonorrhoeae stimulation of MDMs resulted in caspase 1 and 4–dependent cell deaths, indicative of canonical and noncanonical pyroptosis, respectively. Internalization of bacteria or stimulation with lipooligosaccharide (LOS) specifically induced pyroptosis in MDMs and increased secretion of IL-1β. Collectively, our results demonstrate that N gonorrhoeae induces inflammatory pyroptosis in human macrophages due in part to intracellular LOS. We propose that this in turn may exacerbate inflammatory outcomes observed during mucosal infection.

scholarly journals Detection of Cytosolic Shigella flexneri via a C-Terminal Triple-Arginine Motif of GBP1 Inhibits Actin-Based Motility

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Anthony S. Piro ◽  
Dulcemaria Hernandez ◽  
Sarah Luoma ◽  
Eric M. Feeley ◽  
Ryan Finethy ◽  
...  
Keyword(s):  
Host Cell ◽  
Host Defense ◽  
Actin Polymerization ◽  
Bacterial Pathogens ◽  
Shigella Flexneri ◽  
Bacterial Species ◽  
Host Cells ◽  
Gram Negative Bacteria ◽  
Protein Motif ◽  
Gram Negative

ABSTRACT Dynamin-like guanylate binding proteins (GBPs) are gamma interferon (IFN-γ)-inducible host defense proteins that can associate with cytosol-invading bacterial pathogens. Mouse GBPs promote the lytic destruction of targeted bacteria in the host cell cytosol, but the antimicrobial function of human GBPs and the mechanism by which these proteins associate with cytosolic bacteria are poorly understood. Here, we demonstrate that human GBP1 is unique among the seven human GBP paralogs in its ability to associate with at least two cytosolic Gram-negative bacteria, Burkholderia thailandensis and Shigella flexneri. Rough lipopolysaccharide (LPS) mutants of S. flexneri colocalize with GBP1 less frequently than wild-type S. flexneri does, suggesting that host recognition of O antigen promotes GBP1 targeting to Gram-negative bacteria. The targeting of GBP1 to cytosolic bacteria, via a unique triple-arginine motif present in its C terminus, promotes the corecruitment of four additional GBP paralogs (GBP2, GBP3, GBP4, and GBP6). GBP1-decorated Shigella organisms replicate but fail to form actin tails, leading to their intracellular aggregation. Consequentially, the wild type but not the triple-arginine GBP1 mutant restricts S. flexneri cell-to-cell spread. Furthermore, human-adapted S. flexneri, through the action of one its secreted effectors, IpaH9.8, is more resistant to GBP1 targeting than the non-human-adapted bacillus B. thailandensis. These studies reveal that human GBP1 uniquely functions as an intracellular “glue trap,” inhibiting the cytosolic movement of normally actin-propelled Gram-negative bacteria. In response to this powerful human defense program, S. flexneri has evolved an effective counterdefense to restrict GBP1 recruitment. IMPORTANCE Several pathogenic bacterial species evolved to invade, reside in, and replicate inside the cytosol of their host cells. One adaptation common to most cytosolic bacterial pathogens is the ability to coopt the host’s actin polymerization machinery in order to generate force for intracellular movement. This actin-based motility enables Gram-negative bacteria, such as Shigella species, to propel themselves into neighboring cells, thereby spreading from host cell to host cell without exiting the intracellular environment. Here, we show that the human protein GBP1 acts as a cytosolic “glue trap,” capturing cytosolic Gram-negative bacteria through a unique protein motif and preventing disseminated infections in cell culture models. To escape from this GBP1-mediated host defense, Shigella employs a virulence factor that prevents or dislodges the association of GBP1 with cytosolic bacteria. Thus, therapeutic strategies to restore GBP1 binding to Shigella may lead to novel treatment options for shigellosis in the future. Several pathogenic bacterial species evolved to invade, reside in, and replicate inside the cytosol of their host cells. One adaptation common to most cytosolic bacterial pathogens is the ability to coopt the host’s actin polymerization machinery in order to generate force for intracellular movement. This actin-based motility enables Gram-negative bacteria, such as Shigella species, to propel themselves into neighboring cells, thereby spreading from host cell to host cell without exiting the intracellular environment. Here, we show that the human protein GBP1 acts as a cytosolic “glue trap,” capturing cytosolic Gram-negative bacteria through a unique protein motif and preventing disseminated infections in cell culture models. To escape from this GBP1-mediated host defense, Shigella employs a virulence factor that prevents or dislodges the association of GBP1 with cytosolic bacteria. Thus, therapeutic strategies to restore GBP1 binding to Shigella may lead to novel treatment options for shigellosis in the future.

scholarly journals Dynamics of Neisseria gonorrhoeae Attachment: Microcolony Development, Cortical Plaque Formation, and Cytoprotection

2007 ◽  
Vol 75 (10) ◽  
pp. 4743-4753 ◽  
Author(s):  
Dustin L. Higashi ◽  
Shaun W. Lee ◽  
Aurelie Snyder ◽  
Nathan J. Weyand ◽  
Antony Bakke ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Transmitted Disease ◽  
Virus Transmission ◽  
Twitching Motility ◽  
Sexually Transmitted ◽  
Type Iv ◽  
Immunodeficiency Virus ◽  
Live Cell Microscopy ◽  
Induced Apoptosis ◽  
First Time

ABSTRACT Neisseria gonorrhoeae is the bacterium that causes gonorrhea, a major sexually transmitted disease and a significant cofactor for human immunodeficiency virus transmission. The retactile N. gonorrhoeae type IV pilus (Tfp) mediates twitching motility and attachment. Using live-cell microscopy, we reveal for the first time the dynamics of twitching motility by N. gonorrhoeae in its natural environment, human epithelial cells. Bacteria aggregate into microcolonies on the cell surface and induce a massive remodeling of the microvillus architecture. Surprisingly, the microcolonies are motile, and they fuse to form progressively larger structures that undergo rapid reorganization, suggesting that bacteria communicate with each other during infection. As reported, actin plaques form beneath microcolonies. Here, we show that cortical plaques comigrate with motile microcolonies. These activities are dependent on pilT, the Tfp retraction locus. Cultures infected with a pilT mutant have significantly higher numbers of apoptotic cells than cultures infected with the wild-type strain. Inducing pilT expression with isopropyl-β-d-thiogalactopyranoside partially rescues cells from infection-induced apoptosis, demonstrating that Tfp retraction is intrinsically cytoprotective for the host. Tfp-mediated attachment is therefore a continuum of microcolony motility and force stimulation of host cell signaling, leading to a cytoprotective effect.

scholarly journals Early intracellular trafficking of Waddlia chondrophila in human macrophages

Microbiology ◽  
2010 ◽  
Vol 156 (2) ◽  
pp. 340-355 ◽  
Author(s):  
Antony Croxatto ◽  
Gilbert Greub
Keyword(s):  
Intracellular Trafficking ◽  
Brefeldin A ◽  
Endocytic Pathway ◽  
Host Cells ◽  
Simultaneous Treatment ◽  
Human Macrophages ◽  
Infected Cells ◽  
Endosomal Pathway ◽  
Bacterial Replication ◽  
Protein Disulfide

Waddlia chondrophila is an obligate intracellular bacterium considered as a potential agent of abortion in both humans and bovines. This member of the order Chlamydiales multiplies rapidly within human macrophages and induces lysis of the infected cells. To understand how this Chlamydia-like micro-organism invades and proliferates within host cells, we investigated its trafficking within monocyte-derived human macrophages. Vacuoles containing W. chondrophila acquired the early endosomal marker EEA1 during the first 30 min following uptake. However, the live W. chondrophila-containing vacuoles never co-localized with late endosome and lysosome markers. Instead of interacting with the endosomal pathway, W. chondrophila immediately co-localized with mitochondria and, shortly after, with endoplasmic reticulum- (ER-) resident proteins such as calnexin and protein disulfide isomerase. The acquisition of mitochondria and ER markers corresponds to the beginning of bacterial replication. It is noteworthy that mitochondrion recruitment to W. chondrophila inclusions is prevented only by simultaneous treatment with the microtubule and actin cytoskeleton-disrupting agents nocodazole and cytochalasin D. In addition, brefeldin A inhibits the replication of W. chondrophila, supporting a role for COPI-dependent trafficking in the biogenesis of the bacterial replicating vacuole. W. chondrophila probably survives within human macrophages by evading the endocytic pathway and by associating with mitochondria and the ER. The intracellular trafficking of W. chondrophila in human macrophages represents a novel route that differs strongly from that used by other members of the order Chlamydiales.

scholarly journals RpoH Mediates the Expression of Some, but Not All, Genes Induced in Neisseria gonorrhoeae Adherent to Epithelial Cells

2006 ◽  
Vol 74 (5) ◽  
pp. 2767-2776 ◽  
Author(s):  
Ying Du ◽  
Cindy Grove Arvidson
Keyword(s):  
Epithelial Cells ◽  
Neisseria Gonorrhoeae ◽  
Host Cell ◽  
Infection Process ◽  
Host Cells ◽  
Cell Contact ◽  
Transmitted Infection ◽  
New Host ◽  
Sexually Transmitted ◽  
Cell Induction

ABSTRACT Neisseria gonorrhoeae (gonococcus [GC]), is highly adapted to the human host, the only known reservoir for gonococcal infection. However, since it is sexually transmitted, infection of a new host likely requires a regulatory response on the part of the gonococcus to respond to this significant change in environment. We previously showed that adherence of gonococci to epithelial cells results in changes of gene expression in the bacteria that presumably prepare them for subsequent steps in the infection process. Expression of the heat shock sigma factor gene, rpoH, was shown to be important for the invasion step, as gonococci depleted for rpoH were reduced in their ability to invade epithelial cells. Here, we show that of the genes induced in adherent gonococci, two are part of the gonococcal RpoH regulon. When RpoH is depleted, expression of these genes is no longer induced by host cell contact, indicating that RpoH is mediating the host cell induction response of these genes. One RpoH-dependent gene, NGO0376, is shown to be important for invasion of epithelial cells, consistent with earlier observations that RpoH is necessary for this step of infection. Two genes, NGO1684 and NGO0340, while greatly induced by host cell contact, were found to be RpoH independent, indicating that more than one regulator is involved in the response to host cell contact. Furthermore, NGO0340, but not NGO1684, was shown to be important for both adherence and invasion of epithelial cells, suggesting a complex regulatory network in the response of gonococci to contact with host cells.

Immunoperoxidase Labeling Demonstrates an Early Divergence of Chlamydia Trachomatis from the Endosomal-Lysosomal Pathway

1998 ◽  
Vol 4 (S2) ◽  
pp. 1032-1033
Author(s):  
Elizabeth R. Fischer ◽  
Marci A. Scidmore-Carlson ◽  
Ted Hackstadt
Keyword(s):  
Chlamydia Trachomatis ◽  
Transmitted Disease ◽  
Primary Source ◽  
Host Cells ◽  
Elementary Body ◽  
Sexually Transmitted ◽  
Obligate Intracellular ◽  
Survival And Growth ◽  
Immunoperoxidase Labeling ◽  
Preventable Blindness

Chlamydia trachomatis is responsible for several significant human diseases including trachoma, the primary source of preventable blindness in developing countries, and is the most common cause of sexually transmitted disease. C. trachomatis is an obligate intracellular prokaryote (ICP) relying on eukaryotic host cells for growth and replication. Typically, microorganisms engulfed by host cells, are trafficked through maturing endosomes to the lysosomal pathway and ultimately destroyed. Survival in a host cell requires the invading organism to either adapt or modify their host environment to avoid fusion with lysosomal vesicles. Organisms such as Mycobacterium tuberculosis have evolved mechanisms to arrest maturation of the endosomes, such that they avoid lysosomal fusion.3 C trachomatis has developed alternative strategies for successful intracellular survival and growth.C. trachomatis exists in two morphologically and functionally distinct forms which multiply in vacuoles termed inclusions. A small dense form known as the elementary body (EB), is the stable extracellular stage of the life cycle capable of attachment and entry into host cells.

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