ProA is a secreted zinc metalloprotease of Legionella pneumophila causing lung damage in animal models of Legionnaires' disease. Here we demonstrate that ProA promotes infection of human lung tissue explants (HLTEs) and dissect the contribution to cell type specific replication and extracellular virulence mechanisms. For the first time, we reveal that co‐incubation of HLTEs with purified ProA causes

The spread of infection is directly determined by the ability of a pathogen to invade and infect host tissues. The process involves adherence due to host‐pathogen interactions and traversal into deeper tissues. Mycobacterium tuberculosis (Mtb) primarily infects the lung but is unique in its ability to infect almost any other organ of the human host including immune privileged sites such as the central

Porphyromonas gulae, an animal‐derived periodontal pathogen, expresses several virulence factors, including fimbria, lipopolysaccharide (LPS), and proteases. We previously reported that its invasive efficiency was dependent on fimbriae types. In addition, P. gulae LPS increased inflammatory responses via toll‐like receptors. The present study was conducted to investigate the involvement of P. gulae

Inflammasomes are cytosolic innate immune complexes, which assemble in mammalian cells in response to microbial components and endogenous danger signals. A major family of inflammasome activators is bacterial toxins. Inflammasome sensor proteins, such as the nucleotide‐binding oligomerisation domain‐like receptor (NLR) family members NLRP1b and NLRP3, and the tripartite motif family member Pyrin+ efflux

No abstract is available for this article.

Guanine‐quadruplexes (G4s) are non‐canonical DNA structures that can regulate key biological processes such as transcription, replication and telomere maintenance in several organisms including eukaryotes, prokaryotes and viruses. Recent reports have identified the presence of G4s within the AT‐rich genome of Plasmodium falciparum, the protozoan parasite causing malaria. In Plasmodium, potential G4‐forming

Salmonella Paratyphi A (SPtA) remains one of the leading causes of enteric (typhoid) fever. Yet, despite the recent increased rate of isolation from patients in Asia, our understanding of its pathogenesis is incomplete. Here we investigated inflammasome activation in human macrophages infected with SPtA. We found that SPtA induces GSDMD‐mediated pyroptosis via activation of caspase‐1, caspase‐4 and

With no available therapies, infections with Zika virus (ZIKV) constitute a major public health concern as they can lead to congenital microcephaly. In order to generate an intracellular environment favourable to viral replication, ZIKV induces endomembrane remodelling and the morphogenesis of replication factories via enigmatic mechanisms. In this study, we identified the AAA+ type ATPase valosin‐containing

The unfolded protein response (UPR), crucial for the maintenance of ER homeostasis, is tied to the regulation of multiple cellular processes in pathogenic fungi. Here we show that C. albicans relies on an ER‐resident protein, inositol‐requiring enzyme 1 (Ire1) for sensing ER stress and activating the UPR. Compromised Ire1 function impacts cellular processes that are dependent on functional secretory

Fungal spores are unique cells that mediate dispersal and survival in the environment. For pathogenic fungi encountering a susceptible host, these specialised structures may serve as infectious particles. The main causative agent of the opportunistic disease aspergillosis, Aspergillus fumigatus, produces asexual spores, the conidia, that become dissipated by air flows or water currents but also serve

In the published article of Rai et al. (2020), the authors found a mistake in the caption of Figure 4, panel E and would like to change the caption of Figure 4, panel E from “Hours post infection” to “Days of post infection”.

Pathogens are faced with a number of physical barriers upon entry in their animal host, whether it be the mucocilliary escalator of the respiratory tract or the acidic environment of the stomach. Following this, they must also overcome innate immune cells expressing pattern recognition receptors that are specialised in identifying and eliminating invading pathogens. During the course of co‐evolution

The obligate intracellular pathogen C. burnetii is the causative agent of the zoonosis Q fever. C. burnetii infection can have severe outcomes due to the development of chronic infection. To establish and maintain an infection, C. burnetii depends on a functional type IVB secretion system (T4BSS) and, thus, on the translocation of effector proteins into the host cell. Here, we showed that the C. burnetii

Autophagy, a process of degradation and recycling of macromolecules and organelles to maintain cellular homeostasis, has also been shown to help eliminate invading pathogens. Conversely, various pathogens including parasites have been shown to modulate/exploit host autophagy facilitating their intracellular infectious cycle. In this regard, Cryptosporidium parvum (CP), a protozoan parasite of small

Intracellular bacteria such as Salmonella enterica are confronted with a broad array of defence mechanisms of their mammalian host cells. The ability to sense host cell‐imposed damages, and to mount efficient stress responses are crucial for survival and proliferation of intracellular pathogens. The various combinations of host defence mechanisms acting on intracellular bacteria and their individual

The Helicobacter pylori HtrA protein (HtrAHp) is an important virulence factor involved in the infection process by proteolysis of components of the tight (claudin‐8 and occludin) and adherens junctions (E‐cadherin) between epithelial cells. As a protease and chaperone, HtrAHp is involved in protein quality control, which is particularly important under stress conditions. HtrAHp contains a protease

The multifunctional protein enolase has repeatedly been identified on the surface of numerous cell types, including a variety of pathogenic microorganisms. In Candida albicans—one of the most common fungal pathogens in humans—a surface‐exposed enolase form has been previously demonstrated to play an important role in candidal pathogenicity. In our current study, the presence of enolase at the fungal

Gametogenesis, the formation of gametes from gametocytes, an essential step for malaria parasite transmission, is targeted by transmission‐blocking drugs and vaccines. We identified a conserved protein (PBANKA_0305900) in Plasmodium berghei, which encodes a protein of 22 kDa (thus named Pb22) and is expressed in both asexual stages and gametocytes. Its homologues are present in all Plasmodium species

Infection by Trypanosoma cruzi, the protozoan parasite that causes Chagas disease, depends on reactive oxygen species (ROS), which has been described to induce parasite proliferation in mammalian host cells. It is unknown how the parasite manages to increase host ROS levels. Here, we found that intracellular T. cruzi forms release in the host cytosol its major cyclophilin of 19 kDa (TcCyp19). Parasites

Toxoplasma gondii rapidly propagates through endodyogeny of tachyzoites, a process in which daughter parasites divide within the cell of the mother parasite. Recent studies have revealed that transcription factors with AP2‐domain participate in the process of cell division in T. gondii. However, the concise regulation of the division cycles by AP2 proteins is poorly understood. In this study, we evaluated

No abstract is available for this article.

In “Borrelia burgdorferi outer surface protein C (OspC) binds complement component C4b and confers bloodstream survival”, by Caine et al. (2017)which was published in volume 19, issue 12, September 2017, the authors wish to notify readers that we have not been able to reliably reproduce the data in Figure 5. The corresponding text “To determine if OspC is able to directly inhibit the complement cascade

Twenty years ago the Molecular Approaches to Malaria conference was conceived as a forum to present the very latest advances in malaria research and to consolidate and forge new collaborative links between international researchers. The 6th MAM conference, held in February 2020 in Australia, provided 5 days of stimulating scientific exchange and highlighted the incredible malaria research conducted

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M. tb), is the leading infectious cause of mortality worldwide. One of the key reasons for M. tb pathogenesis is the capability of M. tb to evade immune elimination and survive in macrophage, eventually causing chronic infection. However the pathogenicity mechanism of M. tb is not unclear yet, and thus diagnosis and therapy for TB remains a challenge

The eukaryotic cell cycle is typically divided into distinct phases with cytokinesis immediately following mitosis. To ensure proper cell division, each phase is tightly coordinated via feedback controls named checkpoints. During its asexual replication cycle, the malaria parasite Plasmodium falciparum undergoes multiple asynchronous rounds of mitosis with segregation of uncondensed chromosomes followed

1 INTRODUCTION Priscille did her PhD at the Institut Gustave Roussy on the pharmacology of HIV integrase and then continued her Post‐Doctoral research at the Institut Pasteur, Paris, France with Professor Stewart T. Cole. After becoming a fellow from INSERM, Priscille moved to the Institut Pasteur Korea, Seoul in 2006 and started her team with the support of the Avenir Program. In 2011, Priscille was

Toxoplasma gondii shows high dissemination and migration properties across biological barriers infecting immunologically privileged organs. Toxoplasma uses different routes for dissemination; however, the mechanisms are not fully understood. Herein, we studied the effects of proteases present in excretion/secretion products (ESPs) of Toxoplasma on MDCK cell monolayers. Ultrastructural analysis showed

No abstract is available for this article.

Tetraspanins, a wide family composed of 33 transmembrane proteins, are associated with different types of proteins through which they arbitrate important cellular processes such as fusion, adhesion, invasion, tissue differentiation and immunological responses. Tetraspanins share a comparable structural design, which consists of four hydrophobic transmembrane domains with cytoplasmic and extracellular

Infectious diseases are a leading cause of death worldwide with over 8 million fatalities accounted for in 2016. Solicitation of host immune defenses by vaccination is the treatment of choice to prevent these infections. It has long been thought that vaccine immunity was solely mediated by the adaptive immune system. However, over the past decade, numerous studies have shown that innate immune cells

The Macrobrachium rosenbergii nodavirus (MrNV), the causative agent of white‐tail disease (WTD) in many species of shrimp and prawn, has been shown to infect hemocytes and tissues such as the gills and muscles. However, little is known about the host surface molecules to which MrNV attach to initiate infection. Therefore, the present study investigated the role of glycans as binding molecules for virus

In “Fungal biotin homeostasis is essential for immune evasion after macrophage phagocytosis and virulence”, which was published in Volume 22, Issue 7 July 2020 e13197 (Sprenger et al., 2020), the authors would like to note that Figure 6a was incorrectly labelled. The amended version of Figure 6A can be found below.

The authors of the article by Hu et al. (2013) would like to report a mistake in Figure 6A. In the published version of Figure 6A, the panels of the “p53‐pho(S15)” and “p53‐pho(S46)” groups in THP‐1 cells were inadvertently shown with incorrect images. The amended version of Figure 6A can be found below. The error does not affect the results or conclusions of the article. The authors would like to

Candida albicans is a major fungal pathogen that can utilise hemin and haemoglobin as iron sources in the iron‐scarce host environment. While C. albicans is a heme prototroph, we show here that it can also efficiently utilise external heme as a cellular heme source. Using genetically encoded ratiometric fluorescent heme sensors, we show that heme extracted from haemoglobin and free hemin enter the

Due to the frequent mutations, influenza A virus (IAV) becomes resistant to anti‐viral drugs targeting influenza viral proteins. There are increasing interests in anti‐viral agents that target host cellular proteins required for virus replication. Tankyrase (TNKS) has poly (ADP‐ribose) polymerase activity and is a negative regulator of many host proteins. The objectives of this study are to study the

Detailed analysis of secondary envelopment of the herpesvirus human cytomegalovirus (HCMV) by transmission electron microscopy (TEM) is crucial for understanding the formation of infectious virions. Here, we present a convolutional neural network (CNN) that automatically recognises cytoplasmic capsids and distinguishes between three HCMV capsid envelopment stages in TEM images. 315 TEM images containing

About half the world's population is at risk of malaria, with Plasmodium falciparum malaria being responsible for the most malaria related deaths globally. Antimalarial drugs such as chloroquine and artemisinin are directed towards the proliferating intra‐erythrocytic stages of the parasite, which is responsible for all the clinical symptoms of the disease. These antimalarial drugs have been reported

Toxoplasma gondii infects virtually any nucleated cell and resides inside a non‐phagocytic vacuole surrounded by a parasitophorous vacuolar membrane (PVM). Pivotal to the restriction of T. gondii dissemination upon infection in murine cells is the recruitment of immunity regulated GTPases (IRGs) and guanylate binding proteins (GBPs) to the PVM that leads to pathogen elimination. The virulent T. gondii

Infections in humans occur in the context of complex niches where the pathogen interacts with both the host microenvironment and immune response, and the symbiotic microbial community. The polymicrobial nature of many human infections adds a further layer of complexity. The effect of co‐ or polymicrobial infections can result in enhanced severity due to pathogens cooperative interaction or reduced

Viruses confiscate cellular components of the ubiquitin‐proteasome system (UPS) to facilitate many aspects of the infectious cycle. The 26S proteasome is an ATP‐dependent, multisubunit proteolytic machine present in all eukaryotic cells. The proteasome executes the controlled degradation of functional proteins, as well as the hydrolysis of aberrantly folded polypeptides. There is growing evidence for

The initiation of Aspergillus fumigatus infection occurs via dormant conidia deposition into the airways. Therefore, conidial germination and subsequent hyphal extension and growth occur in a sustained heat shock (HS) environment promoted by the host. The cell wall integrity pathway (CWIP) and the essential eukaryotic chaperone Hsp90 are critical for fungi to survive HS. Although A. fumigatus is a

No abstract is available for this article.

Microsporidia are a large group of fungal‐related obligate intracellular parasites. They are responsible for infections in humans as well as in agriculturally and environmentally important animals. Although microsporidia are abundant in nature, many of the molecular mechanisms employed during infection have remained enigmatic. In this review, we highlight recent work showing how microsporidia invade

Extracellular vesicles (EVs) have emerged as a ubiquitous mechanism for transferring information between cells and organisms across all three kingdoms of life. Parasitic unicellular eukaryotes use EVs as vehicles for intercellular communication and host manipulation. Pathogenic protozoans are able to modulate the immune system of the host and establish infection by transferring a wide range of molecules

Shiga toxins (Stxs) produced by Stx‐producing Escherichia coli are the primarily virulence factors of hemolytic uremic syndrome and central nervous system (CNS) impairment. Although the precise mechanisms of toxin dissemination remain unclear, Stxs bind to extracellular vesicles (EVs). Exosomes, a subset of EVs, may play a key role in Stx‐mediated renal injury. To test this hypothesis, we isolated

During acute Pseudomonas aeruginosa infection, the inflammatory response is essential for bacterial clearance. Neutrophil recruitment can be initiated following the assembly of an inflammasome within sentinel macrophages, leading to activation of caspase‐1, which in turn triggers macrophage pyroptosis and IL‐1β/IL‐18 maturation. Inflammasome formation can be induced by a number of bacterial determinants

In 2019 we started a new annual meeting, aimed at bringing together researchers from across the United Kingdom studying cellular microbiology and the cell biology of host‐pathogen interactions. In contrast to large glamourous meetings, featuring the great and the good from across the world, we wanted to create a forum for early career researchers to present their work and enjoy lively discussion. In

“MiRNA‐218 regulates osteoclast differentiation and inflammation response in periodontitis rats through MMP9”, Cell. Microbiol. 2019;21:e12979, by Jie Guo, Xuemin Zeng, Jie Miao, Chunpeng Liu, Fulan Wei, Dongxu Liu, Zhong Zheng, Kang Ting, Chunling Wang, and Yi Liu.

Hepatitis B virus (HBV) infection is of global importance with over 2 billion people exposed to the virus during their lifetime and at risk of progressive liver disease, cirrhosis and hepatocellular carcinoma. HBV is a member of the Hepadnaviridae family that replicates via episomal copies of a covalently closed circular DNA (cccDNA) genome. The chromatinization of this small viral genome, with overlapping

The remarkable deformability of red blood cells (RBCs) depends on the viscoelasticity of the plasma membrane and cell contents and the surface area to volume (SA:V) ratio; however, it remains unclear which of these factors is the key determinant for passage through small capillaries. We used a microfluidic device to examine the traversal of normal, stiffened, swollen, parasitised and immature RBCs

Human and plant pathogenic fungi have a major impact on public health and agriculture. Although these fungi infect very diverse hosts and are often highly adapted to specific host niches, they share surprisingly similar mechanisms that mediate immune evasion, modulation of distinct host targets and exploitation of host nutrients, highlighting that successful strategies have evolved independently among

Malaria parasites are fast replicating unicellular organisms and require substantial amounts of folate for DNA synthesis. Despite the central role of this critical co‐factor for parasite survival, only little is known about intraparasitic folate trafficking in Plasmodium. Here, we report on the expression, subcellular localisation and function of the parasite's folate transporter 2 (FT2) during life

Rab small GTPases regulate membrane traffic between distinct cellular compartments of all eukaryotes in a tempo‐spatially specific fashion. Rab small GTPases are also involved in the regulation of cytoskeleton and signalling. Membrane traffic and cytoskeletal regulation play pivotal role in the pathogenesis of Entamoeba histolytica, which is a protozoan parasite responsible for human amebiasis. E.

Innate immune cells such as macrophages and neutrophils initiate protective inflammatory responses and engage antimicrobial responses to provide frontline defence against invading pathogens. These cells can both restrict the availability of certain transition metals that are essential for microbial growth and direct toxic concentrations of metals towards pathogens as antimicrobial responses. Zinc is

Endogenous carbohydrates released from the intestinal mucus represent a constant source of nutrients to the intestinal microbiota. Mucus‐derived carbohydrates can also be used as building blocks in the biosynthesis of bacterial cell wall components, thereby influencing host mucosal immunity. To assess the uptake of endogenous carbohydrates by gut microbes in healthy mice and during intestinal inflammation