Gilad Bachrach - Profile on Academia.edu (original) (raw)

Papers by Gilad Bachrach

Fusobacterium nucleatum is an opportunistic bacterial pathogen and oncogenic microbe. Using host ... more Fusobacterium nucleatum is an opportunistic bacterial pathogen and oncogenic microbe. Using host sequencing data to systematically investigate Fusobacterium-host interactions in colorectal cancers (CRCs), we developed and orthogonally validated a multi-omics PAThogen CHaracterisation tool (PATCH) enabling gene-level annotations. In 1,020 CRC transcriptomes and 86 genomes from The Cancer Genome Atlas (TCGA), 9 Fusobacterium species were detected to gene-level resolution identifying carcinogenic virulence factors. PATCH uncovered the integration of Fusobacterium’s DNA into the host genome, specifically in non-coding regions and near Short Interspersed Elements. CRCs with integrated-Fusobacterium DNA revealed perturbations in host DNA damage response mechanisms, including deficiencies in chromosome segregation, increased microsatellite instability, elevated cytosolic DNA/RNA sensing signalling, and mutations in genes involved in oncogenic-related pathways. Fusobacterium-positive CRCs e...

Fusobacterium nucleatum and cancer

Periodontology 2000, 2022

Accumulating evidence demonstrates that the oral pathobiont Fusobacterium nucleatum is involved i... more Accumulating evidence demonstrates that the oral pathobiont Fusobacterium nucleatum is involved in the progression of an increasing number of tumors types. Thus far, the mechanisms underlying tumor exacerbation by F. nucleatum include the enhancement of proliferation, establishment of a tumor-promoting immune environment, induction of chemoresistance, and the activation of immune checkpoints. This review focuses on the mechanisms that mediate tumor-specific colonization by fusobacteria. Elucidating the mechanisms mediating fusobacterial tumor tropism and promotion might provide new insights for the development of novel approaches for tumor detection and treatment.

Frontiers in Cellular and Infection Microbiology, 2021

Recent studies on the oral, anaerobic, gram-negative bacterium Fusobacterium nucleatum revealed i... more Recent studies on the oral, anaerobic, gram-negative bacterium Fusobacterium nucleatum revealed its presence and involvement in colorectal, esophageal and breast cancer. We previously demonstrated that F. nucleatum binds and activates the human inhibitory receptors TIGIT and CEACAM1 leading to inhibition of T and NK cell anti-tumor immunity. CEACAM1 was found to be bound and activated by the fusobacterial trimeric autotransporter adhesin CbpF. Here we report the generation of a recombinant E. coli expressing full-length CbpF that efficiently binds and activates CEACAM1.

OncoImmunology, 2019

We previously showed that the colorectal cancer colonizing bacterium Fusobacterium nucleatum prot... more We previously showed that the colorectal cancer colonizing bacterium Fusobacterium nucleatum protects tumors from immune cell attack via binding of the fusbacterial Fap2 outer-membrane protein to TIGIT, a checkpoint inhibitory receptor expressed on T cells and NK cells. Helicobacter pylori, the causative agent for peptic ulcer disease, is associated with the development of gastric adenocarcinoma and MALT lymphoma. The HopQ outer-membrane adhesin of H. pylori was recently shown to bind carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) including CEACAM1, an inhibitory receptor expressed mainly by activated T and NK cells. Here we investigated the possibility that similar to Fap2, HopQ can also inhibit immune cell activities by interacting with CEACAM1. We used several approaches to confirm that HopQ indeed interacts with CEACAM1, and show that CEACAM1-mediated activation by HopQ, may inhibit NK and T cell functions.

Fusobacteria as a Bridge between Health and Disease: a Metatranscriptomic Approach

Oral Microbial Communities

Fusobacterium nucleatum is an oral anaerobe and the most common gram-negative isolate from both h... more Fusobacterium nucleatum is an oral anaerobe and the most common gram-negative isolate from both healthy and diseased oral sites. Association of F. nucleatum with gingivitis and with its progression to periodontal disease has been based on the fact that numbers of F. nucleatum organisms greatly increase in samples taken from diseased sites compared to those from healthy ones. The author feels that the sharing of both gram-positive and gram-negative properties might facilitate communication of fusobacteria with both gram-positive early colonizers and gram-negative late colonizers, an essential stage in the development of the periopathogenic dental biofilm. The species complexity of oral biofilms is probably the greatest hurdle in studying the fusobacterial role in oral health and disease. The author proposes that fusobacterial virulence relies on the presence of its adhesins and not on classical toxins and proteases. Microarrays can be designed to interact uniquely with F. nucleatum gene transcripts. These microarrays can be reacted with total RNAs extracted from dental biofilms sampled from healthy and diseased periodontal sites of increasing disease severity. In vitro studies have suggested that fusobacterial bridging coaggregation interactions are important for the shift in the composition of the microbial community associated with transition from health to disease. Ongoing introduction of tools for genetic manipulation of fusobacteria will enable the investigation of fusobacterial virulence-associated molecular elements. Integration species-specific and general molecular tools is expected to enable the study and the understanding of F. nucleatum's role in bridging from oral health to disease.

Cell Reports

Highlights d Group A Streptococcus (GAS) ScpC cleaves LL-37 into two peptides d Cleavage reduces ... more Highlights d Group A Streptococcus (GAS) ScpC cleaves LL-37 into two peptides d Cleavage reduces activation of P2X7R and EGFR but maintains bactericidal activity d Non-cleavable analogs of LL-37 activate P2X7R and EGFR d P2X7R and EGFR activation is essential for the protection against GAS infections

Additional File 1: Figure S1

Effect of pH on bundling. 8 μM F-actin was bundled by 3–12 μM histatin-3 or 3–16 μM histatin-5 at... more Effect of pH on bundling. 8 μM F-actin was bundled by 3–12 μM histatin-3 or 3–16 μM histatin-5 at pH 6.5 and 7.4. Extent of bundling measured by low speed (20,800xg for 8 min) centrifugation and evaluated by densitometry of the SDS-PAGE of supernatants (unbundled actin) as described in Materials and Methods. (TIFF 192 kb)

Infection and Immunity, 1994

A delayed-type hypersensitivity (DTH) reaction in the course of brucellosis in humans and animals... more A delayed-type hypersensitivity (DTH) reaction in the course of brucellosis in humans and animals can be revealed by the brucellin INRA (Brucellergen) skin test. Brucellergen is composed of more than 20 proteins of different molecular weights. A 12-kDa protein eliciting DTH in Brucella melitensis Rev1-sensitized guinea pigs was found to be a significant component for the allergenic properties of Brucellergen. Sequencing of the gene encoding this protein identified it as the L7/L12 ribosomal protein. The L7/L12 gene of B. melitensis was amplified by PCR and subcloned in the Escherichia coli pQE30 plasmid. The resulting recombinant protein did not produce a DTH reaction in sensitized animals. It was used to raise specific antibodies in a rabbit. Affinity chromatography with these antibodies was used to isolate a single protein from Brucellergen and from B. melitensis cytosol preparations which produced a DTH reaction in guinea pigs sensitized with B. melitensis Rev1. N-terminal amino ...

OncoImmunology, 2019

Fusobacterium nucleatum (F. nucleatum) is an oral anaerobe found to be enriched in colorectal can... more Fusobacterium nucleatum (F. nucleatum) is an oral anaerobe found to be enriched in colorectal cancer (CRC). Presence of F. nucleatum in CRC has been correlated with resistance to chemotherapy and poor prognosis. We previously demonstrated that the Fap2 outer-surface protein of F. nucleatum binds and activates the human inhibitory receptor TIGIT which is expressed by T and Natural Killer (NK) cells, and inhibits anti-tumor immunity. Here we show that F. nucleatum also binds and activates the human inhibitory receptor CEACAM1 leading to inhibition of T and NK cells activities. Our results suggest that using CEACAM1 and TIGIT inhibitors and specific targeting of fusobacteria should be considered for treating fusobacteria-colonized tumors ARTICLE HISTORY

Infection and immunity, 2015

Fusobacterium nucleatum is a common oral anaerobe involved in periodontitis that is known to tran... more Fusobacterium nucleatum is a common oral anaerobe involved in periodontitis that is known to translocate and cause intrauterine infections. In the oral environment, F. nucleatum adheres to a large diversity of species, facilitating their colonization and creating biological bridges that stabilize the multispecies dental biofilm. Many of these interactions (called coadherences or coaggregations) are galactose sensitive. Galactose-sensitive interactions are also involved in the binding of F. nucleatum to host cells. Hemagglutination of some F. nucleatum strains is also galactose sensitive, suggesting that a single galactose-sensitive adhesin might mediate the interaction of fusobacteria with many partners and targets. In order to identify the fusobacterial galactose-sensitive adhesin, a system for transposon mutagenesis in fusobacteria was created. The mutant library was screened for hemagglutination deficiency, and three clones were isolated. All three clones were found to harbor the...

Placental colonization by Fusobacterium nucleatum is mediated by binding of the Fap2 lectin to placentally displayed Gal-GalNAc

Cell Reports, 2022

Frontiers in Cellular and Infection Microbiology, 2021

F. nucleatum is an anaerobic bacterium that is associated with several tumor entities and promote... more F. nucleatum is an anaerobic bacterium that is associated with several tumor entities and promotes tumorigenesis. Recent evidence suggests that F. nucleatum binds the inhibitory receptor carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1) via the trimeric autotransporter adhesin CbpF. However, whether this binding is functional or whether other fusobacterial trimeric autotransporter adhesins are involved in CEACAM1 activation is unknown. In this study, using F. nucleatum mutants lacking the type 5c trimeric autotransporter adhesins fvcA (CbpF), fvcB, fvcC, and fvcD, we show that F. nucleatum CbpF binds and activates CEACAM1 and also binds carcinoembryonic antigen (CEA), a tumor-associated protein. We further find that CEACAM antibodies directed against the CEACAM N-terminal domain block the CbpF-CEACAM1 interaction. In functional assays, we demonstrate CbpF-dependent inhibition of CD4+ T cell response. Thus, we characterize an immune evasion mechanism in which F. nucleatum u...

Frontiers in Cellular and Infection Microbiology, 2020

Fusobacterium nucleatum is a common oral bacterium that is enriched in colorectal adenomas and ad... more Fusobacterium nucleatum is a common oral bacterium that is enriched in colorectal adenomas and adenocarcinomas (CRC). In humans, high fusobacterial CRC abundance is associated with chemoresistance and poor prognosis. In animal models, fusobacteria accelerate CRC progression. Targeting F. nucleatum may reduce fusobacteria cancer progression and therefore determining the origin of CRC F. nucleatum and the route by which it reaches colon tumors is of biologic and therapeutic importance. Arbitrarily primed PCR performed previously on matched same-patients CRC and saliva F. nucleatum isolates, suggested that CRC F. nucleatum may originate from the oral cavity. However, the origin of CRC fusobacteria as well as the route of their arrival to the tumor have not been well-established. Herein, we performed and analyzed whole genome sequencing of paired, same-patient oral, and CRC F. nucleatum isolates and confirmed that CRC-fusobacteria originate from the oral microbial reservoir. Oral fusobacteria may translocate to CRC by descending via the digestive tract or using the hematogenous route during frequent transient bacteremia caused by chewing, daily hygiene activities, or dental procedures. Using the orthotropic CT26 mouse model we previously showed that IV injected F. nucleatum colonize CRC. Here, we compared CRC colonization by gavage vs. intravenous inoculated F. nucleatum in the MC38 and CT26 mouse orthotropic CRC models. Under the tested conditions, hematogenous fusobacteria were more successful in CRC colonization than gavaged ones. Our results therefore provide evidence that the hematogenous route may be the preferred way by which oral fusobacteria reach colon tumors.

The Journal of Immunology, 2006

Periodontitis is a chronic inflammatory disease that leads to destruction of the attachment appar... more Periodontitis is a chronic inflammatory disease that leads to destruction of the attachment apparatus of the teeth. The presence of particular oral bacteria and the host inflammatory response contribute to disease progression. Porphyromonas gingivalis is a Gram-negative anaerobe considered to be a major periodontal pathogen. Isolated Ags from P. gingivalis activate innate immune cells through TLR2 or TLR4. We challenged TLR2-and TLR4-deficient mice with live P. gingivalis and studied the inflammatory response and bacterial survival. Wildtype and TLR4-deficient mice produced high levels of cytokines in response to P. gingivalis challenge, whereas cytokine levels were nearly absent or delayed in TLR2-deficient mice. Surprisingly, P. gingivalis was cleared far more rapidly in TLR2-deficient mice. In addition, TLR2deficient mice resisted bone loss following oral infection with P. gingivalis.

FEMS Microbiology Letters, 1994

DNA sequencing of the gene encoding a Brucella melitensis 12-kDa protein revealed that this prote... more DNA sequencing of the gene encoding a Brucella melitensis 12-kDa protein revealed that this protein was the ribosomal protein L7/L12. The B. melitensis L7/L12 DNA sequence was identical to that of the corresponding B. abortus gene, showing the near identity of these two organisms. When comparing the sequence of this protein to that of other organisms some domains were highly conserved, especially the C-terminus, which contrasted with the lack of conservation of the sequences at the N-terminus. The finding that the ribosomal protein L7/L12 of Brucella is an immunodominant antigen provides a new rationale to explain the activity of ribosomal vaccines.

Antimicrobial Agents and Chemotherapy, 2007

Antimicrobial peptides are short, positively charged, amphipathic peptides that possess a wide sp... more Antimicrobial peptides are short, positively charged, amphipathic peptides that possess a wide spectrum of antimicrobial activity and have an important role in the host's innate immunity. Lack of, or dysfunctions in, antimicrobial peptides have been correlated with infectious diseases, including periodontitis. Porphyromonas gingivalis , a gram-negative anaerobe and a major pathogen associated with periodontal diseases, is resistant to antimicrobial peptides of human and nonhuman origin, a feature that likely contributes to its virulence. Expressing a robust proteolytic activity, P. gingivalis hydrolyzes antimicrobial peptides. In this study, P. gingivalis inactivated three antimicrobial peptides, while a d -enantiomer was resistant to degradation. P. gingivalis was resistant to the protease-resistant d -enantiomer peptide, and importantly, a protease-deficient P. gingivalis mutant was also resistant to the antimicrobial peptide. Finally, the binding of a fluorescently labeled an...

Age and Ageing, 2003

Objectives: to determine the incidence and the dynamics of asymptomatic bacteriuria in ambulatory... more Objectives: to determine the incidence and the dynamics of asymptomatic bacteriuria in ambulatory nursing home residents, and to characterise bacteria according to their phenotype and genotype. Design: an 18 months prospective longitudinal study. Subjects: 42 nursing home residents (31 female, 11 males) without indwelling catheters. Methods: urine was sampled every 3 months. Antibiograms, biotyping and ribotyping were performed. Results: the cumulative percent of infection for females and males was 75% and 27% respectively. Osteoporosis was associated with bacteriuria. Ribotypes of consecutive Escherichia coli isolates indicated that each patient harboured a different strain. Conclusions: asymptomatic bacteriuria in the elderly is a dynamic and transient phenomenon. Osteoporosis is common among this population. Ribotyping is a powerful tool in the elucidation of the epidemiology of this bacteriuria.

Microbiology, 2000

A 92 kb cryptic Mycobacterium fortuitum plasmid, pMF1, was isolated from strain 110 and its restr... more A 92 kb cryptic Mycobacterium fortuitum plasmid, pMF1, was isolated from strain 110 and its restriction map constructed. A 42 kb HindIII fragment of pMF1 was found to support replication in mycobacteria and this fragment was cloned and sequenced to characterize the replication elements of the plasmid. Computer analysis identified a putative Rep protein (362 amino acids) with high homology to the putative Rep protein of the Mycobacterium celatum plasmid pCLP and limited homology, mostly in the N-terminal region, to the Rep proteins of Mycobacterium avium pLR7, M. fortuitum pJAZ38 and Mycobacterium scrofulaceum pMSC262. A region containing a putative ori site was located upstream of the rep gene ; this region displayed high homology at the nucleotide level with the predicted ori of pCLP and pJAZ38. A plasmid carrying the 42 kb HindIII fragment and a kanamycin resistance marker, designated pBP4, was maintained as a single-copy plasmid in Mycobacterium smegmatis and was stably inherited in the absence of antibiotic selection. Plasmid pBP4 was incompatible with the pJAZ38 replicon but was compatible with the widely used pAL5000 replicon, indicating that among the mycobacterial vectors now available there are two incompatibility groups. Significantly, the plasmid was able to replicate in the pathogen Mycobacterium tuberculosis, making it a useful tool for gene expression studies. To provide a choice of restriction sites and easy manipulation, a 21 kb fragment containing the minimal replication region was cloned to make the mycobacterial shuttle vector pBP10, which showed similar stability to pBP4.

Author response for "The inhibitory receptor CD300a is essential for neutrophil‐mediated clearance of urinary tract infection in mice

Nature Communications

Fusobacterium nucleatum is an oral anaerobe recently found to be prevalent in human colorectal ca... more Fusobacterium nucleatum is an oral anaerobe recently found to be prevalent in human colorectal cancer (CRC) where it is associated with poor treatment outcome. In mice, hematogenous F. nucleatum can colonize CRC tissue using its lectin Fap2, which attaches to tumor-displayed Gal-GalNAc. Here, we show that Gal-GalNAc levels increase as human breast cancer progresses, and that occurrence of F. nucleatum gDNA in breast cancer samples correlates with high Gal-GalNAc levels. We demonstrate Fap2-dependent binding of the bacterium to breast cancer samples, which is inhibited by GalNAc. Intravascularly inoculated Fap2-expressing F. nucleatum ATCC 23726 specifically colonize mice mammary tumors, whereas Fap2-deficient bacteria are impaired in tumor colonization. Inoculation with F. nucleatum suppresses accumulation of tumor infiltrating T cells and promotes tumor growth and metastatic progression, the latter two of which can be counteracted by antibiotic treatment. Thus, targeting F. nucleat...

Fusobacterium nucleatum is an opportunistic bacterial pathogen and oncogenic microbe. Using host ... more Fusobacterium nucleatum is an opportunistic bacterial pathogen and oncogenic microbe. Using host sequencing data to systematically investigate Fusobacterium-host interactions in colorectal cancers (CRCs), we developed and orthogonally validated a multi-omics PAThogen CHaracterisation tool (PATCH) enabling gene-level annotations. In 1,020 CRC transcriptomes and 86 genomes from The Cancer Genome Atlas (TCGA), 9 Fusobacterium species were detected to gene-level resolution identifying carcinogenic virulence factors. PATCH uncovered the integration of Fusobacterium’s DNA into the host genome, specifically in non-coding regions and near Short Interspersed Elements. CRCs with integrated-Fusobacterium DNA revealed perturbations in host DNA damage response mechanisms, including deficiencies in chromosome segregation, increased microsatellite instability, elevated cytosolic DNA/RNA sensing signalling, and mutations in genes involved in oncogenic-related pathways. Fusobacterium-positive CRCs e...

Fusobacterium nucleatum and cancer

Periodontology 2000, 2022

Accumulating evidence demonstrates that the oral pathobiont Fusobacterium nucleatum is involved i... more Accumulating evidence demonstrates that the oral pathobiont Fusobacterium nucleatum is involved in the progression of an increasing number of tumors types. Thus far, the mechanisms underlying tumor exacerbation by F. nucleatum include the enhancement of proliferation, establishment of a tumor-promoting immune environment, induction of chemoresistance, and the activation of immune checkpoints. This review focuses on the mechanisms that mediate tumor-specific colonization by fusobacteria. Elucidating the mechanisms mediating fusobacterial tumor tropism and promotion might provide new insights for the development of novel approaches for tumor detection and treatment.

Frontiers in Cellular and Infection Microbiology, 2021

Recent studies on the oral, anaerobic, gram-negative bacterium Fusobacterium nucleatum revealed i... more Recent studies on the oral, anaerobic, gram-negative bacterium Fusobacterium nucleatum revealed its presence and involvement in colorectal, esophageal and breast cancer. We previously demonstrated that F. nucleatum binds and activates the human inhibitory receptors TIGIT and CEACAM1 leading to inhibition of T and NK cell anti-tumor immunity. CEACAM1 was found to be bound and activated by the fusobacterial trimeric autotransporter adhesin CbpF. Here we report the generation of a recombinant E. coli expressing full-length CbpF that efficiently binds and activates CEACAM1.

OncoImmunology, 2019

We previously showed that the colorectal cancer colonizing bacterium Fusobacterium nucleatum prot... more We previously showed that the colorectal cancer colonizing bacterium Fusobacterium nucleatum protects tumors from immune cell attack via binding of the fusbacterial Fap2 outer-membrane protein to TIGIT, a checkpoint inhibitory receptor expressed on T cells and NK cells. Helicobacter pylori, the causative agent for peptic ulcer disease, is associated with the development of gastric adenocarcinoma and MALT lymphoma. The HopQ outer-membrane adhesin of H. pylori was recently shown to bind carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) including CEACAM1, an inhibitory receptor expressed mainly by activated T and NK cells. Here we investigated the possibility that similar to Fap2, HopQ can also inhibit immune cell activities by interacting with CEACAM1. We used several approaches to confirm that HopQ indeed interacts with CEACAM1, and show that CEACAM1-mediated activation by HopQ, may inhibit NK and T cell functions.

Fusobacteria as a Bridge between Health and Disease: a Metatranscriptomic Approach

Oral Microbial Communities

Fusobacterium nucleatum is an oral anaerobe and the most common gram-negative isolate from both h... more Fusobacterium nucleatum is an oral anaerobe and the most common gram-negative isolate from both healthy and diseased oral sites. Association of F. nucleatum with gingivitis and with its progression to periodontal disease has been based on the fact that numbers of F. nucleatum organisms greatly increase in samples taken from diseased sites compared to those from healthy ones. The author feels that the sharing of both gram-positive and gram-negative properties might facilitate communication of fusobacteria with both gram-positive early colonizers and gram-negative late colonizers, an essential stage in the development of the periopathogenic dental biofilm. The species complexity of oral biofilms is probably the greatest hurdle in studying the fusobacterial role in oral health and disease. The author proposes that fusobacterial virulence relies on the presence of its adhesins and not on classical toxins and proteases. Microarrays can be designed to interact uniquely with F. nucleatum gene transcripts. These microarrays can be reacted with total RNAs extracted from dental biofilms sampled from healthy and diseased periodontal sites of increasing disease severity. In vitro studies have suggested that fusobacterial bridging coaggregation interactions are important for the shift in the composition of the microbial community associated with transition from health to disease. Ongoing introduction of tools for genetic manipulation of fusobacteria will enable the investigation of fusobacterial virulence-associated molecular elements. Integration species-specific and general molecular tools is expected to enable the study and the understanding of F. nucleatum's role in bridging from oral health to disease.

Cell Reports

Highlights d Group A Streptococcus (GAS) ScpC cleaves LL-37 into two peptides d Cleavage reduces ... more Highlights d Group A Streptococcus (GAS) ScpC cleaves LL-37 into two peptides d Cleavage reduces activation of P2X7R and EGFR but maintains bactericidal activity d Non-cleavable analogs of LL-37 activate P2X7R and EGFR d P2X7R and EGFR activation is essential for the protection against GAS infections

Additional File 1: Figure S1

Effect of pH on bundling. 8 μM F-actin was bundled by 3–12 μM histatin-3 or 3–16 μM histatin-5 at... more Effect of pH on bundling. 8 μM F-actin was bundled by 3–12 μM histatin-3 or 3–16 μM histatin-5 at pH 6.5 and 7.4. Extent of bundling measured by low speed (20,800xg for 8 min) centrifugation and evaluated by densitometry of the SDS-PAGE of supernatants (unbundled actin) as described in Materials and Methods. (TIFF 192 kb)

Infection and Immunity, 1994

A delayed-type hypersensitivity (DTH) reaction in the course of brucellosis in humans and animals... more A delayed-type hypersensitivity (DTH) reaction in the course of brucellosis in humans and animals can be revealed by the brucellin INRA (Brucellergen) skin test. Brucellergen is composed of more than 20 proteins of different molecular weights. A 12-kDa protein eliciting DTH in Brucella melitensis Rev1-sensitized guinea pigs was found to be a significant component for the allergenic properties of Brucellergen. Sequencing of the gene encoding this protein identified it as the L7/L12 ribosomal protein. The L7/L12 gene of B. melitensis was amplified by PCR and subcloned in the Escherichia coli pQE30 plasmid. The resulting recombinant protein did not produce a DTH reaction in sensitized animals. It was used to raise specific antibodies in a rabbit. Affinity chromatography with these antibodies was used to isolate a single protein from Brucellergen and from B. melitensis cytosol preparations which produced a DTH reaction in guinea pigs sensitized with B. melitensis Rev1. N-terminal amino ...

OncoImmunology, 2019

Fusobacterium nucleatum (F. nucleatum) is an oral anaerobe found to be enriched in colorectal can... more Fusobacterium nucleatum (F. nucleatum) is an oral anaerobe found to be enriched in colorectal cancer (CRC). Presence of F. nucleatum in CRC has been correlated with resistance to chemotherapy and poor prognosis. We previously demonstrated that the Fap2 outer-surface protein of F. nucleatum binds and activates the human inhibitory receptor TIGIT which is expressed by T and Natural Killer (NK) cells, and inhibits anti-tumor immunity. Here we show that F. nucleatum also binds and activates the human inhibitory receptor CEACAM1 leading to inhibition of T and NK cells activities. Our results suggest that using CEACAM1 and TIGIT inhibitors and specific targeting of fusobacteria should be considered for treating fusobacteria-colonized tumors ARTICLE HISTORY

Infection and immunity, 2015

Fusobacterium nucleatum is a common oral anaerobe involved in periodontitis that is known to tran... more Fusobacterium nucleatum is a common oral anaerobe involved in periodontitis that is known to translocate and cause intrauterine infections. In the oral environment, F. nucleatum adheres to a large diversity of species, facilitating their colonization and creating biological bridges that stabilize the multispecies dental biofilm. Many of these interactions (called coadherences or coaggregations) are galactose sensitive. Galactose-sensitive interactions are also involved in the binding of F. nucleatum to host cells. Hemagglutination of some F. nucleatum strains is also galactose sensitive, suggesting that a single galactose-sensitive adhesin might mediate the interaction of fusobacteria with many partners and targets. In order to identify the fusobacterial galactose-sensitive adhesin, a system for transposon mutagenesis in fusobacteria was created. The mutant library was screened for hemagglutination deficiency, and three clones were isolated. All three clones were found to harbor the...

Placental colonization by Fusobacterium nucleatum is mediated by binding of the Fap2 lectin to placentally displayed Gal-GalNAc

Cell Reports, 2022

Frontiers in Cellular and Infection Microbiology, 2021

F. nucleatum is an anaerobic bacterium that is associated with several tumor entities and promote... more F. nucleatum is an anaerobic bacterium that is associated with several tumor entities and promotes tumorigenesis. Recent evidence suggests that F. nucleatum binds the inhibitory receptor carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1) via the trimeric autotransporter adhesin CbpF. However, whether this binding is functional or whether other fusobacterial trimeric autotransporter adhesins are involved in CEACAM1 activation is unknown. In this study, using F. nucleatum mutants lacking the type 5c trimeric autotransporter adhesins fvcA (CbpF), fvcB, fvcC, and fvcD, we show that F. nucleatum CbpF binds and activates CEACAM1 and also binds carcinoembryonic antigen (CEA), a tumor-associated protein. We further find that CEACAM antibodies directed against the CEACAM N-terminal domain block the CbpF-CEACAM1 interaction. In functional assays, we demonstrate CbpF-dependent inhibition of CD4+ T cell response. Thus, we characterize an immune evasion mechanism in which F. nucleatum u...

Frontiers in Cellular and Infection Microbiology, 2020

Fusobacterium nucleatum is a common oral bacterium that is enriched in colorectal adenomas and ad... more Fusobacterium nucleatum is a common oral bacterium that is enriched in colorectal adenomas and adenocarcinomas (CRC). In humans, high fusobacterial CRC abundance is associated with chemoresistance and poor prognosis. In animal models, fusobacteria accelerate CRC progression. Targeting F. nucleatum may reduce fusobacteria cancer progression and therefore determining the origin of CRC F. nucleatum and the route by which it reaches colon tumors is of biologic and therapeutic importance. Arbitrarily primed PCR performed previously on matched same-patients CRC and saliva F. nucleatum isolates, suggested that CRC F. nucleatum may originate from the oral cavity. However, the origin of CRC fusobacteria as well as the route of their arrival to the tumor have not been well-established. Herein, we performed and analyzed whole genome sequencing of paired, same-patient oral, and CRC F. nucleatum isolates and confirmed that CRC-fusobacteria originate from the oral microbial reservoir. Oral fusobacteria may translocate to CRC by descending via the digestive tract or using the hematogenous route during frequent transient bacteremia caused by chewing, daily hygiene activities, or dental procedures. Using the orthotropic CT26 mouse model we previously showed that IV injected F. nucleatum colonize CRC. Here, we compared CRC colonization by gavage vs. intravenous inoculated F. nucleatum in the MC38 and CT26 mouse orthotropic CRC models. Under the tested conditions, hematogenous fusobacteria were more successful in CRC colonization than gavaged ones. Our results therefore provide evidence that the hematogenous route may be the preferred way by which oral fusobacteria reach colon tumors.

The Journal of Immunology, 2006

Periodontitis is a chronic inflammatory disease that leads to destruction of the attachment appar... more Periodontitis is a chronic inflammatory disease that leads to destruction of the attachment apparatus of the teeth. The presence of particular oral bacteria and the host inflammatory response contribute to disease progression. Porphyromonas gingivalis is a Gram-negative anaerobe considered to be a major periodontal pathogen. Isolated Ags from P. gingivalis activate innate immune cells through TLR2 or TLR4. We challenged TLR2-and TLR4-deficient mice with live P. gingivalis and studied the inflammatory response and bacterial survival. Wildtype and TLR4-deficient mice produced high levels of cytokines in response to P. gingivalis challenge, whereas cytokine levels were nearly absent or delayed in TLR2-deficient mice. Surprisingly, P. gingivalis was cleared far more rapidly in TLR2-deficient mice. In addition, TLR2deficient mice resisted bone loss following oral infection with P. gingivalis.

FEMS Microbiology Letters, 1994

DNA sequencing of the gene encoding a Brucella melitensis 12-kDa protein revealed that this prote... more DNA sequencing of the gene encoding a Brucella melitensis 12-kDa protein revealed that this protein was the ribosomal protein L7/L12. The B. melitensis L7/L12 DNA sequence was identical to that of the corresponding B. abortus gene, showing the near identity of these two organisms. When comparing the sequence of this protein to that of other organisms some domains were highly conserved, especially the C-terminus, which contrasted with the lack of conservation of the sequences at the N-terminus. The finding that the ribosomal protein L7/L12 of Brucella is an immunodominant antigen provides a new rationale to explain the activity of ribosomal vaccines.

Antimicrobial Agents and Chemotherapy, 2007

Antimicrobial peptides are short, positively charged, amphipathic peptides that possess a wide sp... more Antimicrobial peptides are short, positively charged, amphipathic peptides that possess a wide spectrum of antimicrobial activity and have an important role in the host's innate immunity. Lack of, or dysfunctions in, antimicrobial peptides have been correlated with infectious diseases, including periodontitis. Porphyromonas gingivalis , a gram-negative anaerobe and a major pathogen associated with periodontal diseases, is resistant to antimicrobial peptides of human and nonhuman origin, a feature that likely contributes to its virulence. Expressing a robust proteolytic activity, P. gingivalis hydrolyzes antimicrobial peptides. In this study, P. gingivalis inactivated three antimicrobial peptides, while a d -enantiomer was resistant to degradation. P. gingivalis was resistant to the protease-resistant d -enantiomer peptide, and importantly, a protease-deficient P. gingivalis mutant was also resistant to the antimicrobial peptide. Finally, the binding of a fluorescently labeled an...

Age and Ageing, 2003

Objectives: to determine the incidence and the dynamics of asymptomatic bacteriuria in ambulatory... more Objectives: to determine the incidence and the dynamics of asymptomatic bacteriuria in ambulatory nursing home residents, and to characterise bacteria according to their phenotype and genotype. Design: an 18 months prospective longitudinal study. Subjects: 42 nursing home residents (31 female, 11 males) without indwelling catheters. Methods: urine was sampled every 3 months. Antibiograms, biotyping and ribotyping were performed. Results: the cumulative percent of infection for females and males was 75% and 27% respectively. Osteoporosis was associated with bacteriuria. Ribotypes of consecutive Escherichia coli isolates indicated that each patient harboured a different strain. Conclusions: asymptomatic bacteriuria in the elderly is a dynamic and transient phenomenon. Osteoporosis is common among this population. Ribotyping is a powerful tool in the elucidation of the epidemiology of this bacteriuria.

Microbiology, 2000

A 92 kb cryptic Mycobacterium fortuitum plasmid, pMF1, was isolated from strain 110 and its restr... more A 92 kb cryptic Mycobacterium fortuitum plasmid, pMF1, was isolated from strain 110 and its restriction map constructed. A 42 kb HindIII fragment of pMF1 was found to support replication in mycobacteria and this fragment was cloned and sequenced to characterize the replication elements of the plasmid. Computer analysis identified a putative Rep protein (362 amino acids) with high homology to the putative Rep protein of the Mycobacterium celatum plasmid pCLP and limited homology, mostly in the N-terminal region, to the Rep proteins of Mycobacterium avium pLR7, M. fortuitum pJAZ38 and Mycobacterium scrofulaceum pMSC262. A region containing a putative ori site was located upstream of the rep gene ; this region displayed high homology at the nucleotide level with the predicted ori of pCLP and pJAZ38. A plasmid carrying the 42 kb HindIII fragment and a kanamycin resistance marker, designated pBP4, was maintained as a single-copy plasmid in Mycobacterium smegmatis and was stably inherited in the absence of antibiotic selection. Plasmid pBP4 was incompatible with the pJAZ38 replicon but was compatible with the widely used pAL5000 replicon, indicating that among the mycobacterial vectors now available there are two incompatibility groups. Significantly, the plasmid was able to replicate in the pathogen Mycobacterium tuberculosis, making it a useful tool for gene expression studies. To provide a choice of restriction sites and easy manipulation, a 21 kb fragment containing the minimal replication region was cloned to make the mycobacterial shuttle vector pBP10, which showed similar stability to pBP4.

Author response for "The inhibitory receptor CD300a is essential for neutrophil‐mediated clearance of urinary tract infection in mice

Nature Communications

Fusobacterium nucleatum is an oral anaerobe recently found to be prevalent in human colorectal ca... more Fusobacterium nucleatum is an oral anaerobe recently found to be prevalent in human colorectal cancer (CRC) where it is associated with poor treatment outcome. In mice, hematogenous F. nucleatum can colonize CRC tissue using its lectin Fap2, which attaches to tumor-displayed Gal-GalNAc. Here, we show that Gal-GalNAc levels increase as human breast cancer progresses, and that occurrence of F. nucleatum gDNA in breast cancer samples correlates with high Gal-GalNAc levels. We demonstrate Fap2-dependent binding of the bacterium to breast cancer samples, which is inhibited by GalNAc. Intravascularly inoculated Fap2-expressing F. nucleatum ATCC 23726 specifically colonize mice mammary tumors, whereas Fap2-deficient bacteria are impaired in tumor colonization. Inoculation with F. nucleatum suppresses accumulation of tumor infiltrating T cells and promotes tumor growth and metastatic progression, the latter two of which can be counteracted by antibiotic treatment. Thus, targeting F. nucleat...