In Vitro and In Vivo Model Systems for Studying Enteropathogenic Escherichia coli Infections

Abstract High throughput in vivo laboratory models is need for screening and identification of effective therapeutic agents to overcome microbial drug-resistance. This study was undertaken to evaluate in vivo antimicrobial efficacy of short-chain antimicrobial peptide- Cecropin A (1–7)-Melittin (CAMA) against three multi- drug resistant enteroaggregative Escherichia coli (MDR-EAEC) field isolates in a Galleria mellonella larval model. The minimum inhibitory concentration (MIC; 2.0 mg/L) and minimum bactericidal concentration (MBC; 4.0 mg/L) of CAMA were determined by microdilution assay. CAMA was found to be stable at high temperatures, physiological concentration of cationic salts and proteases; safe with sheep erythrocytes, secondary cell lines and commensal lactobacilli at lower MICs; and exhibited membrane permeabilisation. In vitro time-kill assay revealed concentration- and time-dependent clearance of MDR-EAEC in CAMA-treated groups at 30 min. CAMA- treated G. mellonella larvae exhibited an increased survival rate, reduced MDR-EAEC counts, immunomodulatory effect and proved non-toxic which concurred with histopathological findings. CAMA exhibited either an equal or better efficacy than the tested antibiotic control, meropenem. This study highlights the possibility of G. mellonella larvae as an excellent in vivo model for investigating the host-pathogen interaction, including the efficacy of antimicrobials against MDR-EAEC strains.

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Diet, Obesity, and Cancer Progression: Are Adipocytes the Link?

Lipid Insights ◽

10.4137/lpi.s10871 ◽

2013 ◽

Vol 6 ◽

pp. LPI.S10871 ◽

Cited By ~ 11

Author(s):

Paul Toren ◽

Benjamin C. Mora ◽

Vasundara Venkateswaran

Keyword(s):

Tumor Microenvironment ◽

Cancer Progression ◽

Tumor Biology ◽

Model Systems ◽

In Vivo Model ◽

Diet Induced Obesity ◽

Breast And Prostate Cancer ◽

Obesity And Cancer

Obesity has been linked to more aggressive characteristics of several cancers, including breast and prostate cancer. Adipose tissue appears to contribute to paracrine interactions in the tumor microenvironment. In particular, cancer-associated adipocytes interact reciprocally with cancer cells and influence cancer progression. Adipokines secreted from adipocytes likely form a key component of the paracrine signaling in the tumor microenvironment. In vitro coculture models allow for the assessment of specific adipokines in this interaction. Furthermore, micronutrients and macronutrients present in the diet may alter the secretion of adipokines from adipocytes. The effect of dietary fat and specific fatty acids on cancer progression in several in vivo model systems and cancer types is reviewed. The more common approaches of caloric restriction or diet-induced obesity in animal models establish that such dietary changes modulate tumor biology. This review seeks to explore available evidence regarding how diet may modulate tumor characteristics through changes in the role of adipocytes in the tumor microenvironment.

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In Vitro and In Vivo Model Systems of Cholangiocarcinoma

Diagnosis and Management of Cholangiocarcinoma ◽

10.1007/978-3-030-70936-5_22 ◽

2021 ◽

pp. 471-494

Author(s):

Giovanni Brandi ◽

Simona Tavolari

Keyword(s):

Model Systems ◽

In Vivo Model

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Unbiased in vivo preclinical evaluation of anticancer drugs identifies effective therapy for the treatment of pancreatic adenocarcinoma

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1920240117 ◽

2020 ◽

Vol 117 (48) ◽

pp. 30670-30678

Author(s):

Olivera Grbovic-Huezo ◽

Kenneth L. Pitter ◽

Nicolas Lecomte ◽

Joseph Saglimbeni ◽

Gokce Askan ◽

...

Keyword(s):

Large Scale ◽

Single Agent ◽

Model Systems ◽

Ductal Adenocarcinoma ◽

In Vivo Model ◽

Cancer Therapies ◽

Hsp90 Inhibition ◽

Dismal Prognosis

Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at an advanced stage, which limits surgical options and portends a dismal prognosis. Current oncologic PDAC therapies confer marginal benefit and, thus, a significant unmet clinical need exists for new therapeutic strategies. To identify effective PDAC therapies, we leveraged a syngeneic orthotopic PDAC transplant mouse model to perform a large-scale, in vivo screen of 16 single-agent and 41 two-drug targeted therapy combinations in mice. Among 57 drug conditions screened, combined inhibition of heat shock protein (Hsp)-90 and MEK was found to produce robust suppression of tumor growth, leading to an 80% increase in the survival of PDAC-bearing mice with no significant toxicity. Mechanistically, we observed that single-agent MEK inhibition led to compensatory activation of resistance pathways, including components of the PI3K/AKT/mTOR signaling axis, which was overcome with the addition of HSP90 inhibition. The combination of HSP90(i) + MEK(i) was also active in vitro in established human PDAC cell lines and in vivo in patient-derived organoid PDAC transplant models. These findings encourage the clinical development of HSP90(i) + MEK(i) combination therapy and highlight the power of clinically relevant in vivo model systems for identifying cancer therapies.

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Localized adherence by enteropathogenic Escherichia coli is an inducible phenotype associated with the expression of new outer membrane proteins.

Journal of Experimental Medicine ◽

10.1084/jem.174.5.1167 ◽

1991 ◽

Vol 174 (5) ◽

pp. 1167-1177 ◽

Cited By ~ 64

Author(s):

J Vuopio-Varkila ◽

G K Schoolnik

Keyword(s):

Escherichia Coli ◽

Membrane Proteins ◽

Outer Membrane ◽

De Novo ◽

Outer Membrane Proteins ◽

Temporal Correlation ◽

Enteropathogenic Escherichia Coli ◽

E Coli

Enteropathogenic Escherichia coli grow as discrete colonies on the mucous membranes of the small intestine. A similar pattern can be demonstrated in vitro; termed localized adherence (LA), it is characterized by the presence of circumscribed clusters of bacteria attached to the surfaces of cultured epithelial cells. The LA phenotype was studied using B171, an O111:NM enteropathogenic E. coli (EPEC) strain, and HEp-2 cell monolayers. LA could be detected 30-60 min after exposure of HEp-2 cells to B171. However, bacteria transferred from infected HEp-2 cells to fresh monolayers exhibited LA within 15 min, indicating that LA is an inducible phenotype. Induction of the LA phenotype was found to be associated with de novo protein synthesis and changes in the outer membrane proteins, including the production of a new 18.5-kD polypeptide. A partial NH2-terminal amino acid sequence of this polypeptide was obtained and showed it to be identical through residue 12 to the recently described bundle-forming pilus subunit of EPEC. Expression of the 18.5-kD polypeptide required the 57-megadalton enteropathogenic E. coli adherence plasmid previously shown to be required for the LA phenotype in vitro and full virulence in vivo. This observation, the correspondence of the 18.5-kD polypeptide to an EPEC-specific pilus protein, and the temporal correlation of its expression with the development of the LA phenotype suggest that it may contribute to the EPEC colonial mode of growth.

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Monoclonal and Single Domain Antibodies Targeting β-Integrin Subunits Block Sexual Transmission of HIV-1 in In Vitro and In Vivo Model Systems

JAIDS Journal of Acquired Immune Deficiency Syndromes ◽

10.1097/qai.0000000000000609 ◽

2015 ◽

Vol 69 (3) ◽

pp. 278-285 ◽

Cited By ~ 4

Author(s):

Janet Tai Guedon ◽

Kun Luo ◽

Hong Zhang ◽

Richard B. Markham

Keyword(s):

Sexual Transmission ◽

Single Domain ◽

Model Systems ◽

In Vivo Model ◽

Single Domain Antibodies ◽

Sexual Transmission Of Hiv ◽

Hiv 1

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Enteropathogenic Escherichia coli (EPEC) infection inhibits intestinal vitamin C transporter function and expression: in vitro and in vivo studies

The FASEB Journal ◽

10.1096/fasebj.2020.34.s1.03680 ◽

2020 ◽

Vol 34 (S1) ◽

pp. 1-1

Author(s):

Christopher W. Heskett ◽

Trevor Teafatiller ◽

Carly Hennessey ◽

Melanie G. Gareau ◽

Jonathan S. Marchant ◽

...

Keyword(s):

Escherichia Coli ◽

Vitamin C ◽

In Vivo Studies ◽

Enteropathogenic Escherichia Coli

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ENHANCED FLUORESCENCE IMAGING WITH DMSO-MEDIATED OPTICAL CLEARING

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545810001015 ◽

2010 ◽

Vol 03 (03) ◽

pp. 153-158 ◽

Cited By ~ 10

Author(s):

SANJEEV KARMA ◽

JAMES HOMAN ◽

CHARLES STOIANOVICI ◽

BERNARD CHOI

Keyword(s):

Fluorescence Emission ◽

Model Systems ◽

In Vivo Studies ◽

In Vivo Model ◽

Fluorescence Signal ◽

Optical Clearing ◽

Treated Site

Recent studies have demonstrated that topical application of glycerol on intact skin does not affect its optical scattering properties. Investigators from our research group recently revisited the use of dimethyl sulfoxide (DMSO) as an agent with optical clearing potential. We address the use of optical clearing to enhance quantitation of subsurface fluorescence emission. We employed both in vitro and in vivo model systems to study the effect of topical DMSO application on fluorescence emission. Our in vitro experiments performed on a tissue-simulating phantom suggest that DMSO-mediated optical clearing enables enhanced characterization of subsurface fluorophores. With topical DMSO application, a marked increase in fluorescence emission was observed. After 30 min, the fluorescence signal at the DMSO-treated site was 9× greater than the contralateral saline-treated site. This ratio increased to 13× at 105 min after agent application. In summary, DMSO is an effective optical clearing agent for improved fluorescence emission quantitation and warrants further study in preclinical in vivo studies. Based on outcomes from previous clinical studies on the toxicity profile of DMSO, we postulate that clinical application of DMSO as an optical clearing agent, can be performed safely, although further study is warranted.

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