Type IV pilus retraction enables sustained bacteremia and plays a key role in the outcome of meningococcal sepsis in a humanized mouse model

Autor: Mathieu Coureuil, Taliah Schmitt, Xavier Nassif, Sandrine Bourdoulous, Mohamed El Behi, Daniel Euphrasie, Olivier Join-Lambert, Mathilde Audry, Sophia Schönherr-Hellec, Jean-Philippe Barnier
Přispěvatelé: Institut Necker Enfants-Malades (INEM - UM 111 (UMR 8253 / U1151)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), [Institut Cochin] Departement Infection, immunité, inflammation, Institut Cochin (IC UM3 (UMR 8104 / U1016)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Bourdoulous, Sandrine
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Bacterial Diseases
Bacterial Lethality
Physiology
Bacteremia
Mice
SCID

Meningococcal Disease
Pilus retraction
Neisseria meningitidis
Pathology and Laboratory Medicine
medicine.disease_cause
Bacterial Adhesion
Pilus
Mice
Medical Conditions
[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases
Medicine and Health Sciences
Biology (General)
Immune Response
0303 health sciences
Skin Transplantation
Bacterial Pathogens
Body Fluids
3. Good health
Infectious Diseases
Blood
Medical Microbiology
[SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases
Female
Fimbriae Proteins
Pathogens
Cellular Structures and Organelles
Anatomy
medicine.symptom
Neisseria
Research Article
Pathogen Motility
QH301-705.5
Virulence Factors
Immunology
Inflammation
Biology
Meningococcal disease
Microbiology
Sepsis
03 medical and health sciences
Signs and Symptoms
Virology
Genetics
medicine
Animals
Humans
Microbial Pathogens
Molecular Biology
030304 developmental biology
Bacteria
030306 microbiology
Organisms
Endothelial Cells
Biology and Life Sciences
Bacteriology
Cell Biology
RC581-607
medicine.disease
[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Meningococcal Infections
Disease Models
Animal

Pili and Fimbriae
Fimbriae
Bacterial

Humanized mouse
Parasitology
Immunologic diseases. Allergy
Clinical Medicine
[SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Zdroj: PLoS Pathogens
PLoS Pathogens, Public Library of Science, 2021, 17 (2), pp.e1009299. ⟨10.1371/journal.ppat.1009299⟩
PLoS Pathogens, 2021, 17 (2), pp.e1009299. ⟨10.1371/journal.ppat.1009299⟩
PLoS Pathogens, Vol 17, Iss 2, p e1009299 (2021)
ISSN: 1553-7366
1553-7374
DOI: 10.1371/journal.ppat.1009299⟩
Popis: Neisseria meningitidis (the meningococcus) remains a major cause of bacterial meningitis and fatal sepsis. This commensal bacterium of the human nasopharynx can cause invasive diseases when it leaves its niche and reaches the bloodstream. Blood-borne meningococci have the ability to adhere to human endothelial cells and rapidly colonize microvessels. This crucial step enables dissemination into tissues and promotes deregulated inflammation and coagulation, leading to extensive necrotic purpura in the most severe cases. Adhesion to blood vessels relies on type IV pili (TFP). These long filamentous structures are highly dynamic as they can rapidly elongate and retract by the antagonistic action of two ATPases, PilF and PilT. However, the consequences of TFP dynamics on the pathophysiology and the outcome of meningococcal sepsis in vivo have been poorly studied. Here, we show that human graft microvessels are replicative niches for meningococci, that seed the bloodstream and promote sustained bacteremia and lethality in a humanized mouse model. Intriguingly, although pilus-retraction deficient N. meningitidis strain (ΔpilT) efficiently colonizes human graft tissue, this mutant did not promote sustained bacteremia nor induce mouse lethality. This effect was not due to a decreased inflammatory response, nor defects in bacterial clearance by the innate immune system. Rather, TFP-retraction was necessary to promote the release of TFP-dependent contacts between bacteria and, in turn, the detachment from colonized microvessels. The resulting sustained bacteremia was directly correlated with lethality. Altogether, these results demonstrate that pilus retraction plays a key role in the occurrence and outcome of meningococcal sepsis by supporting sustained bacteremia. These findings open new perspectives on the role of circulating bacteria in the pathological alterations leading to lethal sepsis.
Author summary Invasive meningococcal diseases remain a major cause of fatal sepsis. A specific feature of Neisseria meningitidis is its ability to colonize the blood microvessels in a type IV pilus (TFP)-dependent mechanism. TFP are filamentous appendages that undergo retraction through a mechanism dependent on the PilT ATPase. Here, we assess the role of TFP retraction in the pathophysiology of meningococcal infection using a humanized model of SCID mice grafted with human skin. We show that human skin graft microvessels are replicative niches for N. meningitidis that promote sustained bacteremia and subsequent lethality. Intriguingly, although pilus retraction-deficient N. meningitidis (ΔpilT) efficiently colonizes human grafts, this mutant strain did not promote sustained bacteremia nor induce mouse lethality. This drastic decrease in virulence was not due to a decreased inflammatory response or to a defect in bacterial clearance by the innate immune system. Rather, we demonstrate that pilus retraction was crucial to obtain a sustained bacteremia by allowing the release of bacteria from colonized microvessels and that lethality was directly linked to sustained bacteremia. Altogether, these data demonstrate the important role of pilus retraction in meningococcal pathogenesis and infection outcome and open new questions regarding the impact of circulating bacteria on the host during lethal sepsis.
Databáze: OpenAIRE