This work was supported by National Institutes of Allergy and Infectious Diseases Grant P01 A1078894 to C.A.G.

<ol>
	<li>Nathan, C., Ding, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonresolving+Inflammation.">Nonresolving Inflammation.</a> Cell. 140 (6), 871-882 (2010).</li><li>Karin, M., Lawrence, T., Nizet, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Innate+immunity+gone+awry:+linking+microbial+infections+to+chronic+inflammation+and.">Innate immunity gone awry: linking microbial infections to chronic inflammation and.</a> 124, 823-835 (2006).</li><li>Connor, S. M., Taylor, C. E., Hughes, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Emerging+infectious+determinants+of+chronic+diseases.">Emerging infectious determinants of chronic diseases.</a> Emerging Infectious Diseases. 12 (7), 1051-1057 (2006).</li><li>Barth, K., Remick, D. G., Genco, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disruption+of+immune+regulation+by+microbial+pathogens+and+resulting+chronic+inflammation.">Disruption of immune regulation by microbial pathogens and resulting chronic inflammation.</a> Journal of Cellular Physiology. , (2012).</li><li>Hayashi, C., Gudino, C. V., Gibson, F. C., Genco, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review:+Pathogen-induced+inflammation+at+sites+distant+from+oral+infection:+bacterial+persistence+and+induction+of+cell-specific+innate+immune+inflammatory+pathways.">Review: Pathogen-induced inflammation at sites distant from oral infection: bacterial persistence and induction of cell-specific innate immune inflammatory pathways.</a> Molecular Oral Microbiology. 25 (5), 305-316 (2010).</li><li>Gibson, F. C., Ukai, T., Genco, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engagement+of+specific+innate+immune+signaling+pathways+during+Porphyromonas+gingivalis+induced+chronic+inflammation+and+atherosclerosis.">Engagement of specific innate immune signaling pathways during Porphyromonas gingivalis induced chronic inflammation and atherosclerosis.</a> Frontiers in Bioscience: a Journal and Virtual Library. 13, 2041-2059 (2008).</li><li>Pihlstrom, B. L., Michalowicz, B. S., Johnson, N. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Periodontal+diseases.">Periodontal diseases.</a> Lancet. 366 (9499), 1809-1820 (2005).</li><li>Baker, P. J., Evans, R. T., Roopenian, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+infection+with+Porphyromonas+gingivalis+and+induced+alveolar+bone+loss+in+immunocompetent+and+severe+combined+immunodeficient+mice.">Oral infection with Porphyromonas gingivalis and induced alveolar bone loss in immunocompetent and severe combined immunodeficient mice.</a> Archives of Oral Biology. 39 (12), 1035-1040 (1994).</li><li>Baker, P. J., Carter, S., Dixon, M., Evans, R. T., Roopenian, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serum+antibody+response+to+oral+infection+precedes+but+does+not+prevent+Porphyromonas+gingivalis-induced+alveolar+bone+loss+in+mice.">Serum antibody response to oral infection precedes but does not prevent Porphyromonas gingivalis-induced alveolar bone loss in mice.</a> Oral Microbiology and Immunology. 14 (3), 194-196 (1999).</li><li>Gibson, F. C., Hong, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Innate+immune+recognition+of+invasive+bacteria+accelerates+atherosclerosis+in+apolipoprotein+E-deficient+mice.">Innate immune recognition of invasive bacteria accelerates atherosclerosis in apolipoprotein E-deficient mice.</a> Circulation. 109 (22), 2801-2806 (2004).</li><li>Hayashi, C., Viereck, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Porphyromonas+gingivalis+accelerates+inflammatory+atherosclerosis+in+the+innominate+artery+of+ApoE+deficient+mice.">Porphyromonas gingivalis accelerates inflammatory atherosclerosis in the innominate artery of ApoE deficient mice.</a> Atherosclerosis. 215 (1), 52-59 (2011).</li><li>Hayashi, C., Madrigal, A. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogen-mediated+inflammatory+atherosclerosis+is+mediated+in+part+via+Toll-like+receptor+2-induced+inflammatory+responses.">Pathogen-mediated inflammatory atherosclerosis is mediated in part via Toll-like receptor 2-induced inflammatory responses.</a> Journal of Innate Immunity. 2 (4), 334-343 (2010).</li><li>Hayashi, C., Papadopoulos, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protective+role+for+TLR4+signaling+in+atherosclerosis+progression+as+revealed+by+infection+with+a+common+oral+pathogen.">Protective role for TLR4 signaling in atherosclerosis progression as revealed by infection with a common oral pathogen.</a> Journal of Immunology (Baltimore, Md.: 1950). 189 (7), 3681-3688 (2012).</li><li>Papadopoulos, G., Weinberg, E. O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Macrophage-Specific+TLR2+Signaling+Mediates+Pathogen-Induced+TNF-Dependent+Inflammatory+Oral+Bone+Loss.">Macrophage-Specific TLR2 Signaling Mediates Pathogen-Induced TNF-Dependent Inflammatory Oral Bone Loss.</a> The Journal of Immunology. , (2012).</li><li>Gibson, F. C., Hong , C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Innate+immune+recognition+of+invasive+bacteria+accelerates+atherosclerosis+in+apolipoprotein+E-deficient+mice.">Innate immune recognition of invasive bacteria accelerates atherosclerosis in apolipoprotein E-deficient mice.</a> Circulation. 109 (22), 2801-2806 (2004).</li><li>Miyamoto, T., Yumoto, H., Takahashi, Y., Davey, M., Gibson, F. C., Genco, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogen-accelerated+atherosclerosis+occurs+early+after+exposure+and+can+be+prevented+via+immunization.">Pathogen-accelerated atherosclerosis occurs early after exposure and can be prevented via immunization.</a> Infection and Immunity. 74 (2), 1376-1380 (2006).</li><li>Baker, P. J., Dixon, M., Roopenian, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+control+of+susceptibility+to+Porphyromonas+gingivalis-induced+alveolar+bone+loss+in+mice.">Genetic control of susceptibility to Porphyromonas gingivalis-induced alveolar bone loss in mice.</a> Infection and Immunity. 68 (10), 5864-5868 (2000).</li><li>Baker, P. J., Dixon, M., Evans, R. T., Roopenian, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterogeneity+of+Porphyromonas+gingivalis+strains+in+the+induction+of+alveolar+bone+loss+in+mice.">Heterogeneity of Porphyromonas gingivalis strains in the induction of alveolar bone loss in mice.</a> Oral Microbiology and Immunology. 15 (1), 27-32 (2000).</li><li>Daugherty, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+of+atherosclerosis.">Mouse models of atherosclerosis.</a> The American Journal of the Medical Sciences. 323 (1), 3-10 (2002).</li><li>Weinreb, D. B., Aguinaldo, J. G. S., Feig, J. E., Fisher, E. A., Fayad, Z. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-invasive+MRI+of+mouse+models+of+atherosclerosis.">Non-invasive MRI of mouse models of atherosclerosis.</a> NMR in Biomedicine. 20 (3), 256-264 (2007).</li></ol>

The authors declare that they have no competing financial interests.

The P. gingivalis oral infection model provides a valuable tool for the study of pathogen-induced chronic inflammation at local and systemic sites. This unique model permits the characterization of both host and pathogen specific mechanisms contributing to chronic inflammation and immunopathology. In addition, the model can be used to screen for novel therapeutic strategies, including immunization and pharmacological intervention. The steps outlined in this protocol describe the successful use of this model and ...

Chronic inflammation is a major driver of pathological tissue damage and a unifying characteristic of many chronic diseases in humans. These diseases include neoplastic, autoimmune, and chronic inflammatory diseases1. The etiology of many chronic diseases remains unclear but is understood to be complex and multifactorial, involving both genetic predisposition and the introduction of environmental factors. While the perpetuators of inflammation remain elusive, the cellular and molecular profiles of immune activation overlap considerably with those patterns observed in host responses to pathogens2. 
Mounting evidence implicates infection with microbial pathogens in the development and progression of chronic inflammation and its diverse clinical manifestations2,3. Pathogens can induce and sustain chronic inflammation directly by subverting the host immune system and establishing persistent infections4. In the absence of microbial persistence, infection can precipitate chronic inflammation from autoimmune reactions triggered by molecular mimicry to self-antigens, changes in self-antigens that render them immunogenic, or damage that releases previously masked host antigens. Rarely however have specific pathogens been identified as the universal cause of a particular chronic disease. Rather, the majority of available data suggests that pathogens use distinct mechanisms to elicit chronic inflammation with a wide spectrum of clinical manifestations and disease outcomes in the genetically susceptible host3. Thus, a detailed understanding of the mechanisms by which specific pathogens induce chronic inflammation may have major implications for public health, as well as treatment and prevention of many chronic diseases. 
Although the host and pathogen specific mechanisms contributing to the induction and maintenance of chronic inflammation are poorly understood, advances in modeling of pathogen-induced chronic inflammation have begun to further our understanding of these processes. The P. gingivalis oral infection model is a unique, well-characterized mouse model of pathogen-induced chronic inflammation that permits the analysis of host and pathogen specific mechanisms contributing to chronic inflammation at local (oral bone loss) and systemic sites (atherosclerosis)5,6. 
P. gingivalis is a Gram-negative, anaerobic oral pathogen implicated in human periodontal disease, an infection-driven chronic inflammatory disease characterized by the destruction of tooth supporting tissue7. In addition to pathology at the initial site of infection, accumulating evidence implicates P. gingivalis-induced chronic inflammation in the development and progression of systemic diseases including atherosclerosis5, a disease characterized by chronic inflammation of the arterial vessel wall. Oral infection of specific-pathogen free mice with P. gingivalis induces a local inflammatory response that results in destruction of tooth supporting alveolar bone8. P. gingivalis can be recovered from the mouths of infected mice up to 42 days post-infection8 and mice develop high levels of pathogen-specific serum antibody titers9. In an established mouse model of atherosclerosis using Apolipoprotein-E-/- mice (ApoE-/-), oral infection with P. gingivalis induces chronic inflammation that drives inflammatory plaque deposition within the aortic sinus10 and the innominate artery11. Progressive inflammation within the innominate artery of P. gingivalis-infected mice can be monitored in live animals using in vivo MRI. Histologically, arterial lesions from P. gingivalis-infected mice exhibit increased accumulation of lipids accompanied by activation of the vascular endothelium, an increased immune cell infiltrate, and elevated expression of inflammatory mediators12. Use of this model in knockout mice has elucidated the role of host signaling components and inflammatory mediators, as well as the cell specific interactions that drive P. gingivalis-induced immunopathology12&#8211;14. In addition, experiments utilizing defined bacterial mutants have identified critical P. gingivalis virulence factors contributing to chronic inflammation at local and systemic sites15. 
This article details methodologies for the assessment of P. gingivalis-induced chronic inflammation at local and systemic sites. We provide a detailed protocol for the analysis of alveolar bone loss by microCT using Amira software. In addition, we define the utility of serial in vivo live animal MRI for the assessment of progressive inflammation within the innominate artery. We include methodologies for the visualization and quantification of inflammatory plaque in arterial lesions, and describe their histological characterization. The use of transgenic mice and defined bacterial mutants makes this model particularly suitable for identifying both host and microbial factors involved in the initiation, progression, and outcome of disease. Additionally, the model can be used to screen for novel therapeutic strategies, including vaccination and pharmacological intervention.

<table><tbody><tr><td>Amira analysis software</td><td>Visualization Sciences Group</td><td></td><td></td></tr><tr><td>Anaerobic chamber DW Scientific Model MG500&amp;nbsp;</td><td>Microbiology International</td><td></td><td></td></tr><tr><td>BHI&amp;nbsp;</td><td>Becton-Dickinson&amp;nbsp;</td><td>211059</td><td></td></tr><tr><td>Hemin&amp;nbsp;</td><td>Sigma-Aldrich&amp;nbsp;</td><td>51280-5G</td><td></td></tr><tr><td>Menadione (Vitamin K)</td><td>Sigma-Aldrich&amp;nbsp;&amp;nbsp;</td><td>M5625-25G</td><td></td></tr><tr><td>Yeast Extract</td><td>Becton-Dickinson&amp;nbsp;</td><td>212750</td><td></td></tr><tr><td>Carboxymethyl cellulose (medium viscocity)&amp;nbsp;</td><td>Sigma-Aldrich&amp;nbsp;</td><td>C-4888</td><td></td></tr><tr><td>Sulfamethoxazole and trimethoprim oral suspension 200 mg/40 mg per 5 ml</td><td>Hi-Tech Pharmacal</td><td>NDC 50383-823-16</td><td></td></tr><tr><td>&amp;mu;CT 40&amp;nbsp;</td><td>Scanco</td><td></td><td></td></tr><tr><td>HistoChoice Tissue Fixative</td><td>Sigma-Aldrich&amp;nbsp;</td><td>H2904</td><td></td></tr><tr><td>Sudan IV</td><td>Sigma-Aldrich&amp;nbsp;</td><td>S4261-25G</td><td></td></tr><tr><td>Vertical-bore 11.7T Avance spectrometer&amp;nbsp;</td><td>Bruker</td><td></td><td></td></tr><tr><td>Paravision</td><td>Paravision</td><td></td><td></td></tr><tr><td>ImageJ</td><td>NIH</td><td></td><td></td></tr><tr><td>Rat anti-mouse F4/80</td><td>Serotec</td><td>MCA497R</td><td></td></tr><tr><td>Rat anti-mouse TLR2</td><td>eBioscience</td><td>13-9021-80</td><td></td></tr><tr><td>Leica S4 dissecting scope</td><td>Leica</td><td></td><td></td></tr><tr><td>Microm HM 550 cryostat</td><td>Microm</td><td></td><td></td></tr></tbody></table>

a mouse model for pathogen-induced chronic inflammation at local and systemic sites

Chronic inflammation is a major driver of pathological tissue damage and a unifying characteristic of many chronic diseases in humans including neoplastic, autoimmune, and chronic inflammatory diseases. Emerging evidence implicates pathogen-induced chronic inflammation in the development and progression of chronic diseases with a wide variety of clinical manifestations. Due to the complex and multifactorial etiology of chronic disease, designing experiments for proof of causality and the establishment of mechanistic links is nearly impossible in humans. An advantage of using animal models is that both genetic and environmental factors that may influence the course of a particular disease can be controlled. Thus, designing relevant animal models of infection represents a key step in identifying host and pathogen specific mechanisms that contribute to chronic inflammation.
Here we describe a mouse model of pathogen-induced chronic inflammation at local and systemic sites following infection with the oral pathogen Porphyromonas gingivalis, a bacterium closely associated with human periodontal disease. Oral infection of specific-pathogen free mice induces a local inflammatory response resulting in destruction of tooth supporting alveolar bone, a hallmark of periodontal disease. In an established mouse model of atherosclerosis, infection with P. gingivalis accelerates inflammatory plaque deposition within the aortic sinus and innominate artery, accompanied by activation of the vascular endothelium, an increased immune cell infiltrate, and elevated expression of inflammatory mediators within lesions. We detail methodologies for the assessment of inflammation at local and systemic sites. The use of transgenic mice and defined bacterial mutants makes this model particularly suitable for identifying both host and microbial factors involved in the initiation, progression, and outcome of disease. Additionally, the model can be used to screen for novel therapeutic strategies, including vaccination and pharmacological intervention.

Using the appropriate mouse model and oral infection regimen, P. gingivalis induces chronic inflammation and immunopathology at local (oral cavity) and systemic sites (arteries) (Figure 1).
In mice, oral infection with P. gingivalis induces a local inflammatory response that drives the destruction of tooth supporting alveolar bone8. P. gingivalis-infected mice develop serum antibody responses to this organism that are predominantly of the ...

Watch this Scientific Journal Video about A Mouse Model for Pathogen-induced Chronic Inflammation at Local and Systemic Sites at JoVE.com

A Mouse Model for Pathogen-induced Chronic Inflammation at Local and Systemic Sites

Animal models have proven to be invaluable tools in defining host and pathogen specific mechanisms that contribute to the development of chronic inflammation. Here we describe a mouse model of oral infection with the human pathogen Porphyromonas gingivalis and detail methodologies to assess the progression of inflammation at local and systemic sites.

Chronic inflammation is a major driver of pathological tissue damage and a unifying characteristic of many chronic diseases in humans including ...

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Research

JoVE Journal

Immunology and Infection

17.5K Views.  Boston University School of Medicine. Animal models have proven to be invaluable tools in defining host and pathogen specific mechanisms that contribute to the development of chronic inflammation. Here we describe a mouse model of oral infection with the human pathogen Porphyromonas gingivalis and detail methodologies to assess the progression of inflammation at local and systemic sites.

Video: A Mouse Model for Pathogen-induced Chronic Inflammation at Local and Systemic Sites

The Citrobacter rodentium Mouse Model: Studying Pathogen and Host Contributions to Infectious Colitis

This protocol outlines the steps required to produce a robust model of infectious disease and colitis, as well as the methods used to characterize Citrobacter rodentium infection in mice. C. rodentium is a gram negative, murine specific bacterial pathogen that is closely related to the clinically important human pathogens enteropathogenic E. coli and enterohemorrhagic E. coli. Upon infection with C. rodentium, immunocompetent mice suffer from modest and transient weight loss and diarrhea. Histologically, intestinal crypt elongation, immune cell infiltration, and goblet cell depletion are observed. Clearance of infection is achieved after 3 to 4 weeks. Measurement of intestinal epithelial barrier integrity, bacterial load, and histological damage at different time points after infection, allow the characterization of mouse strains susceptible to infection.
The virulence mechanisms by which bacterial pathogens colonize the intestinal tract of their hosts, as well as specific host responses that defend against such infections are poorly understood. Therefore the C. rodentium model of enteric bacterial infection serves as a valuable tool to aid in our understanding of these processes. Enteric bacteria have also been linked to Inflammatory Bowel Diseases (IBDs). It has been hypothesized that the maladaptive chronic inflammatory responses seen in IBD patients develop in genetically susceptible individuals following abnormal exposure of the intestinal mucosal immune system to enteric bacteria. Therefore, the study of models of infectious colitis offers significant potential for defining potentially pathogenic host responses to enteric bacteria. C. rodentium induced colitis is one such rare model that allows for the analysis of host responses to enteric bacteria, furthering our understanding of potential mechanisms of IBD pathogenesis; essential in the development of novel preventative and therapeutic treatments.

The Citrobacter rodentium Mouse Model: Studying Pathogen and Host Contributions to Infectious Colitis

Citrobacter rodentium infection provides a valuable model to study enteric bacterial infections as well as host immune responses and colitis in mice. This protocol outlines the measurement of barrier integrity, pathogen load and histological damage allowing for the thorough characterization of pathogen and host contributions to murine infectious colitis.

This protocol  outlines the steps required to produce a robust model of infectious disease and  colitis, as well as the methods used to characterize ...

Humanized Mouse Model to Study Bacterial Infections Targeting the Microvasculature

Neisseria meningitidis causes a severe, frequently fatal sepsis when it enters the human blood stream. Infection leads to extensive damage of the blood vessels resulting in vascular leak, the development of purpuric rashes and eventual tissue necrosis. Studying the pathogenesis of this infection was previously limited by the human specificity of the bacteria, which makes in vivo models difficult. In this protocol, we describe a humanized model for this infection in which human skin, containing dermal microvessels, is grafted onto immunocompromised mice. These vessels anastomose with the mouse circulation while maintaining their human characteristics. Once introduced into this model, N. meningitidis adhere exclusively to the human vessels, resulting in extensive vascular damage, inflammation and in some cases the development of purpuric rash. This protocol describes the grafting, infection and evaluation steps of this model in the context of N. meningitidis infection. The technique may be applied to numerous human specific pathogens that infect the blood stream.

Neisseria meningitidis is a human specific pathogen that infects blood vessels. In this protocol human microvessels are introduced into a mouse by grafting human skin onto immunocompromised mice. Bacteria adhere extensively to the human vessels, leading to vascular damage and development of the purpuric rash typically observed in human cases.

Neisseria meningitidis causes a severe, frequently fatal sepsis when it enters the human blood stream. Infection leads to extensive damage of the blood ...

Chronic Salmonella Infected Mouse Model

The bacterial infected mouse model is a powerful model system for studying areas such as infection, inflammation, immunology, signal transduction, and tumorigenesis. Many researchers have taken advantage of the colitis induced by Salmonella typhimurium for the studies on the early phase of inflammation and infection. However, only few reports are on the chronic infection in vivo. Mice with Salmonella persistent existence in the gastrointestinal tract allow us to explore the long-term host-bacterial interaction, signal transduction, and tumorigenesis. We have established a chronic bacterial infected mouse model with Salmonella typhimurium colonization in the mouse intestine over 6 months. To use this system, it is necessary for the researcher to learn how to prepare the bacterial culture and gavage the animals. We detail a methodology for prepare bacterial culture and gavage mice. We also show how to detect the Salmonella persistence in the gastrointestinal tract. Overall, this protocol will aid researchers using the bacterial infected mouse model to address fundamentally important biological and microbiological questions.

Chronic Salmonella Infected Mouse Model

Establish a chronic bacterial infected mouse model with persistent Salmonella typhimurium colonization in intestine for 27 weeks.

The bacterial infected mouse model is a powerful model system for studying areas such as infection, inflammation, immunology, signal transduction, and ...

Biology

Induction of Experimental Autoimmune Encephalomyelitis in Mice and Evaluation of the Disease-dependent Distribution of Immune Cells in Various Tissues

Multiple sclerosis is presumed to be an inflammatory autoimmune disease, which is characterized by lesion formation in the central nervous system (CNS) resulting in cognitive and motor impairment. Experimental autoimmune encephalomyelitis (EAE) is a useful animal model of MS, because it is also characterized by lesion formation in the CNS, motor impairment and is also driven by autoimmune and inflammatory reactions. One of the EAE models is induced with a peptide derived from the myelin oligodendrocyte protein (MOG)35-55 in mice. The EAE mice develop a progressive disease course. This course is divided into three phases: the preclinical phase (day 0 - 9), the disease onset (day 10 - 11) and the acute phase (day 12 - 14). MS and EAE are induced by autoreactive T cells that infiltrate the CNS. These T cells secrete chemokines and cytokines which lead to the recruitment of further immune cells. Therefore, the immune cell distribution in the spinal cord during the three disease phases was investigated. To highlight the time point of the disease at which the activation/proliferation/accumulation of T cells, B cells and monocytes starts, the immune cell distribution in lymph nodes, spleen and blood was also assessed. Furthermore, the levels of several cytokines (IL-1&#946;, IL-6, IL-23, TNF&#945;, IFN&#947;) in the three disease phases were determined, to gain insight into the inflammatory processes of the disease. In conclusion, the data provide an overview of the functional profile of immune cells during EAE pathology.

This manuscript describes the methods for induction and scoring of the experimental autoimmune encephalomyelitis (EAE) model, together with the assessment of immune cell distribution and mRNA cytokine levels in lymph nodes, spleen, blood and spinal cord using flow cytometry and quantitative PCR, respectively, at various disease phases.

Multiple sclerosis is presumed to be an inflammatory autoimmune disease, which is characterized by lesion formation in the central nervous system (CNS) ...

An IL-8 Transiently Transgenized Mouse Model for the In Vivo Long-term Monitoring of Inflammatory Responses

Airway inflammation is often associated with bacterial infections and represents a major determinant of lung disease. The in vivo determination of the pro-inflammatory capabilities of various factors is challenging and requires terminal procedures, such as bronchoalveolar lavage and the removal of lungs for in situ analysis, precluding longitudinal visualization in the same mouse. Here, lung inflammation is induced through the intratracheal instillation of Pseudomonas aeruginosa culture supernatant (SN) in transiently transgenized mice expressing the luciferase reporter gene under the control of a heterologous IL-8 bovine promoter. Luciferase expression in the lung is monitored by in vivo bioluminescent image (BLI) analysis over a 2.5- to 48-h timeframe following the instillation. The procedure can be repeated multiple times within 2 - 3 months, thus permitting the evaluation of the inflammatory response in the same mice without the need to terminate the animals. This approach permits the monitoring of pro- and anti-inflammatory factors acting in the lung in real time and appears suitable for functional and pharmacological studies.

An IL-8 Transiently Transgenized Mouse Model for the In Vivo Long-term Monitoring of Inflammatory Responses

The method described here allows for the visualization of IL-8 promoter-dependent inflammation activation in the lungs of mice through non-invasive bioluminescence imaging (BLI). The same animal can be subjected to BLI multiple times for up to two months from the time of delivery of the luciferase reporter construct.

Airway inflammation is often associated with bacterial infections and represents a major determinant of lung disease. The in vivo determination of the ...

The bm12 Inducible Model of Systemic Lupus Erythematosus (SLE) in C57BL/6 Mice

Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical and immunological manifestations. Several spontaneous and inducible animal models mirror common components of human disease, including the bm12 transfer model. Upon transfer of bm12 splenocytes or purified CD4 T cells, C57BL/6 mice rapidly develop large frequencies of T follicular helper cells (Tfh), germinal center (GC) B cells, and plasma cells followed by high levels of circulating anti-nuclear antibodies. Since this model utilizes mice on a pure C57BL/6 background, researchers can quickly and easily study disease progression in transgenic or knockout mouse strains in a relatively short period of time. Here we describe protocols for the induction of the model and the quantitation Tfh, GC B cells, and plasma cells by multi-color flow cytometry. Importantly, these protocols can also be used to characterize disease in most mouse models of SLE and identify Tfh, GC B cells, and plasma cells in other disease models.

The bm12 Inducible Model of Systemic Lupus Erythematosus SLE in C57BL/6 Mice

The transfer of bm12 lymphocytes into a C57BL/6 recipient is an established model of systemic lupus erythematosus. Here we describe how to initiate disease using this model and how to characterize T follicular helper cells, germinal center B cells and plasma cells by flow cytometry.

Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical and immunological manifestations. Several spontaneous and inducible ...

Medicine

Bioluminescence and Near-infrared Imaging of Optic Neuritis and Brain Inflammation in the EAE Model of Multiple Sclerosis in Mice

Experimental autoimmune encephalomyelitis (EAE) in SJL/J mice is a model for relapsing-remitting multiple sclerosis (RRMS). Clinical EAE scores describing motor function deficits are basic readouts of the immune-mediated inflammation of the spinal cord. However, scores and body weight do not allow for an in vivo assessment of brain inflammation and optic neuritis. The latter is an early and frequent manifestation in about 2/3 of MS patients. Here, we show methods for bioluminescence and near-infrared live imaging to assess EAE evoked optic neuritis, brain inflammation, and blood-brain barrier (BBB) disruption in living mice using an in vivo imaging system. A bioluminescent substrate activated by oxidases primarily showed optic neuritis. The signal was specific and allowed the visualization of medication effects and disease time courses, which paralleled the clinical scores. Pegylated fluorescent nanoparticles that remained within the vasculature for extended periods of time were used to assess the BBB integrity. Near-infrared imaging revealed a BBB leak at the peak of the disease. The signal was the strongest around the eyes. A near-infrared substrate for matrix metalloproteinases was used to assess EAE-evoked inflammation. Auto-fluorescence interfered with the signal, requiring spectral unmixing for quantification. Overall, bioluminescence imaging was a reliable method to assess EAE-associated optic neuritis and medication effects and was superior to the near-infrared techniques in terms of signal specificity, robustness, ease of quantification, and cost.

We show a technique for in vivo live bioluminescence and near-infrared imaging of optic neuritis and encephalitis in the experimental autoimmune encephalomyelitis (EAE) model for multiple sclerosis in SJL/J mice.

Experimental autoimmune encephalomyelitis (EAE) in SJL/J mice is a model for relapsing-remitting multiple sclerosis (RRMS). Clinical EAE scores describing ...

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

Staphylococcus aureus (S. aureus)&#160;infections, including methicillin resistant stains, are an enormous burden on the healthcare system. With incidence rates of S. aureus infection climbing annually, there is a demand for additional research in its&#160;pathogenicity. Animal models of infectious disease advance our understanding of the host-pathogen response and lead to the development of effective therapeutics. Neutrophils play a primary role in the innate immune response that controls S. aureus infections by forming an abscess to wall off the infection and facilitate bacterial clearance; the number of neutrophils that infiltrate an S. aureus skin infection often correlates with disease outcome. LysM-EGFP mice, which possess the enhanced green fluorescent protein (EGFP) inserted in the Lysozyme M (LysM) promoter region (expressed primarily by neutrophils), when used in conjunction with in vivo whole animal fluorescence imaging (FLI) provide&#160;a means of quantifying neutrophil emigration noninvasively and longitudinally into wounded skin. When combined with a bioluminescent S. aureus strain and sequential in vivo whole animal bioluminescent imaging (BLI), it is possible to longitudinally monitor both the neutrophil recruitment dynamics and in vivo bacterial burden at the site of infection in anesthetized mice from onset of infection to resolution or death. Mice are more resistant to a number of virulence factors produced by S. aureus that facilitate effective colonization and infection in humans. Immunodeficient mice provide a more sensitive animal model to examine persistent S. aureus infections and the ability of therapeutics to boost innate immune responses. Herein, we characterize responses in LysM-EGFP mice that have been bred to MyD88-deficient mice (LysM-EGFP&#215;MyD88-/- mice) along with wild-type LysM-EGFP mice to investigate S. aureus skin wound infection. Multispectral simultaneous detection enabled study of neutrophil recruitment dynamics by using in vivo FLI, bacterial burden by using in vivo BLI, and wound healing longitudinally and noninvasively over time.

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

An approach is described for real-time detection of the innate immune response to cutaneous wounding and Staphylococcus aureus infection of mice. By comparing LysM-EGFP mice (which possess fluorescent neutrophils) with a LysM-EGFP crossbred immunodeficient mouse strain, we advance our understanding of infection and the development of approaches to combat infection.

Staphylococcus aureus (S. aureus)&#160;infections, including methicillin resistant stains, are an enormous burden on the healthcare system. With incidence ...

Mouse Footpad Inoculation Model to Study Viral-Induced Neuroinflammatory Responses

This protocol describes a footpad inoculation model used to study the initiation and development of neuroinflammatory responses during alphaherpesvirus infection in mice. As alphaherpesviruses are main invaders of the peripheral nervous system (PNS), this model is suitable to characterize the kinetics of viral replication, its spread from the PNS to CNS, and associated neuroinflammatory responses. The footpad inoculation model allows virus particles to spread from a primary infection site in the footpad epidermis to sensory and sympathetic nerve fibers that innervate the epidermis, sweat glands, and dermis. The infection spreads via the sciatic nerve to the dorsal root ganglia (DRG) and ultimately through the spinal cord to the brain. Here, a mouse footpad is inoculated with pseudorabies virus (PRV), an alphaherpesvirus closely related to herpes simplex virus (HSV) and varicella-zoster virus (VZV). This model demonstrates that PRV infection induces severe inflammation, characterized by neutrophil infiltration in the footpad and DRG. High concentrations of inflammatory cytokines are subsequently detected in homogenized tissues by ELISA. In addition, a strong correlation is observed between PRV gene and protein expression (via qPCR and IF staining) in DRG and the production of pro-inflammatory cytokines. Therefore, the footpad inoculation model provides a better understanding of the processes underlying alphaherpesvirus-induced neuropathies and may lead to the development of innovative therapeutic strategies. In addition, the model can guide research on peripheral neuropathies, such as multiple sclerosis and associated viral-induced damage to the PNS. Ultimately, it can serve as a cost-effective in vivo tool for drug development.

The footpad inoculation model is a valuable tool for characterizing viral-induced neuroinflammatory responses in vivo. In particular, it provides a clear assessment of viral kinetics and associated immunopathological processes initiated in the peripheral nervous system.

This protocol describes a footpad inoculation model used to study the initiation and development of neuroinflammatory responses during alphaherpesvirus ...

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness

Streptococcus pneumoniae (pneumococcus) is an asymptomatic colonizer of the nasopharynx in most individuals but can progress to a pulmonary and systemic pathogen upon influenza A virus (IAV) infection. Advanced age enhances host susceptibility to secondary pneumococcal pneumonia and is associated with worsened disease outcomes. The host factors driving those processes are not well defined, in part due to a lack of animal models that reproduce the transition from asymptomatic colonization to severe clinical disease. 
This paper describes a novel mouse model that recreates the transition of pneumococci from asymptomatic carriage to disease upon viral infection. In this model, mice are first intranasally inoculated with biofilm-grown pneumococci to establish asymptomatic carriage, followed by IAV infection of both the nasopharynx and lungs. This results in bacterial dissemination to the lungs, pulmonary inflammation, and obvious signs of illness that can progress to lethality. The degree of disease is dependent on the bacterial strain and host factors. 
Importantly, this model reproduces the susceptibility of aging, because compared to young mice, old mice display more severe clinical illness and succumb to disease more frequently. By separating carriage and disease into distinct steps and providing the opportunity to analyze the genetic variants of both the pathogen and the host, this S. pneumoniae/IAV co-infection model permits the detailed examination of the interactions of an important pathobiont with the host at different phases of disease progression. This model can also serve as an important tool for identifying potential therapeutic targets against secondary pneumococcal pneumonia in susceptible hosts.

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness

This paper describes a novel mouse model for the transition of pneumococcus from an asymptomatic colonizer to a disease-causing pathogen during viral infection. This model can be readily adapted to study polymicrobial and host-pathogen interactions during the different phases of disease progression and across various hosts.

Streptococcus pneumoniae (pneumococcus) is an asymptomatic colonizer of the nasopharynx in most individuals but can progress to a pulmonary and systemic ...

A Mouse Model for Pathogen-induced Chronic Inflammation at Local and Systemic Sites

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The bm12 Inducible Model of Systemic Lupus Erythematosus (SLE) in C57BL/6 Mice

Bioluminescence and Near-infrared Imaging of Optic Neuritis and Brain Inflammation in the EAE Model of Multiple Sclerosis in Mice

A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection

Mouse Footpad Inoculation Model to Study Viral-Induced Neuroinflammatory Responses

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness