scholarly journals Host-pathogen genetic interactions underlie tuberculosis susceptibility in genetically diverse mice

2020 ◽  
Author(s):  
Clare M. Smith ◽  
Richard E. Baker ◽  
Megan K. Proulx ◽  
Bibhuti B. Mishra ◽  
Jarukit E. Long ◽  
...  

AbstractThe outcome of an encounter with Mycobacterium tuberculosis (Mtb) depends on the pathogen’s ability to adapt to the heterogeneous immune response of the host. Understanding this interplay has proven difficult, largely because experimentally tractable small animal models do not recapitulate the heterogenous disease observed in natural infections. We leveraged the genetically diverse Collaborative Cross (CC) mouse panel in conjunction with a library of Mtb mutants to associate bacterial genetic requirements with host genetics and immunity. We report that CC strains vary dramatically in their susceptibility to infection and represent reproducible models of qualitatively distinct immune states. Global analysis of Mtb mutant fitness across the CC panel revealed that a large fraction of the pathogen’s genome is necessary for adaptation to specific host microenvironments. Both immunological and bacterial traits were associated with genetic variants distributed across the mouse genome, elucidating the complex genetic landscape that underlies host-pathogen interactions in a diverse population.

2007 ◽  
Vol 30 (4) ◽  
pp. 93
Author(s):  
I Sekirov ◽  
N Tam ◽  
M Robertson ◽  
C Lupp ◽  
B Finlay

Background: During our lifetimes we develop a very complex set of interactions with the multitude of microorganisms colonizing our bodies. In the gastrointestinal system, the microbiota is highly important for morphological development, nutrition, and protection against infectious diseases. The gastrointestinal pathogens, enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) and Salmonella enterica serovar Typhimurium (ST) are food-borne pathogens that cause much morbidity and mortality worldwide. Citrobacter rodentium (Cr) is a mouse pathogen that is used in small animal models to mimic EHEC and EPEC infections. Methods: We began to characterize the contribution of intestinal microbiota to the progression of these infections. Two main phyla comprise the majority of mouse intestinal microbiota: Bacteroidetes and Firmicutes. Bacteria from a number of additional phyla are also present in smaller numbers; among them γ-Proteobacteria class, belonging to Proteobacteria phylum, is note-worthy as this class harbours many intestinal pathogens, such as ST and Cr. The mouse intestinal microbiota was perturbed using tetracycline (Tet) and streptomycin (Sm) to increase the proportion of Bacteroidetes in the colonic microbiota, and using vancomycin (Vanc) to create a predominance of Firmicutes. The mice with this perturbed microbiota were infected with ST to investigate the resultant pathology and virulence characteristics, and any additional shifts in microbiota as a result of infection. Results: Treatment of mice with Sm and Vanc was found to decrease the resistance of mice to colonization with ST, while Tet-treated mice exhibited unchanged colonization resistance. Treatment of mice with gradually increasing doses of Sm, which gradually augmented the proportion of CFB bacteria in the microbiota, resulted in progressively increasing colonization of mice by ST, as well as a step-wise increase in the ST-induced typhlitis, associated with higher levels of inflammatory markers IL-6 and KC. The increasing levels of ST colonization following both Sm and Vanc treatment were associated with an increase in the proportion of γ-Proteobacteria in the cecal and colonic microbiota, as well as a decrease in the total bacterial numbers in both organs. Conclusions: It is evident that the intestinal microbiota plays a significant role in the host’s response to infection with enteric pathogens, and its composition and numbers are also affected by the offending bacteria. Elucidation of the details regarding the contribution of the microbiota to infectious disease progression will offer novel targets for the future design of superior prevention and treatment methods.


Author(s):  
Maite Ibáñez de Garayo ◽  
Wendi Liu ◽  
Nicole C. Rondeau ◽  
Christopher B. Damoci ◽  
JJ L. Miranda

AbstractRepurposing of currently used drugs for new indications benefits from known experience with those agents. Rational repurposing can be achieved when newly uncovered molecular activities are leveraged against diseases that utilize those mechanisms. Nitroxoline is an antibiotic with metal-chelating activity used to treat urinary tract infections. This small molecule also inhibits the function of bromodomain and extraterminal (BET) proteins that regulate oncogene expression in cancer. Lymphoproliferation driven by the Epstein–Barr virus (EBV) depends on these same proteins. We therefore tested the efficacy of nitroxoline against cell culture and small animal models of EBV-associated lymphoproliferation. Nitroxoline indeed reduces cell and tumor growth. Nitroxoline also acts faster than the prototype BET inhibitor JQ1. We suggest that this rational repurposing may hold translational promise.


2021 ◽  
Vol 10 (14) ◽  
pp. 3142
Author(s):  
Batoul Wehbi ◽  
Virginie Pascal ◽  
Lina Zawil ◽  
Michel Cogné ◽  
Jean-Claude Aldigier

IgA nephropathy (IgAN) is the most common primary glomerulonephritis in the world. It was first described in 1968 by Jean Berger and Nicole Hinglais as the presence of intercapillary deposits of IgA. Despite this simple description, patients with IgAN may present very broad clinical features ranging from the isolated presence of IgA in the mesangium without clinical or biological manifestations to rapidly progressive kidney failure. These features are associated with a variety of histological lesions, from the discrete thickening of the mesangial matrix to diffuse cell proliferation. Immunofluorescence on IgAN kidney specimens shows the isolated presence of IgA or its inconsistent association with IgG and complement components. This clinical heterogeneity of IgAN clearly echoes its complex and multifactorial pathophysiology in humans, inviting further analyses of its various aspects through the use of experimental models. Small-animal models of IgAN provide the most pertinent strategies for studying the multifactorial aspects of IgAN pathogenesis and progression. Although only primates have the IgA1 subclass, several murine models have been developed in which various aspects of immune responses are deregulated and which are useful in the understanding of IgAN physiopathology as well as in the assessment of IgAN therapeutic approaches. In this manuscript, we review all murine IgAN models developed since 1968 and discuss their remarkable contribution to understanding the disease.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Peter Nordbeck ◽  
Leoni Bönhof ◽  
Karl-Heinz Hiller ◽  
Sabine Voll ◽  
Paula Arias ◽  
...  

Background: Surgical procedures in small animal models of heart disease, such as artificial ligation of the coronary arteries for experimental myocardial infarction, can evoke alterations in cardiac morphology and function. Such alterations might induce artificial early or long term effects in vivo that might account for a significant bias in basic cardiovascular research, and, therefore, could potentially question the meaning of respective studies in small animal models of heart disease. Methods: Female Wistar rats were matched for weight and distributed to sham left coronary artery ligation or untreated control. Cardiac parameters were then investigated in vivo by high-field MRI over time after the surgical procedure, determining left and right ventricular morphology and function. Additionally, the time course of several metabolic and inflammatory blood parameters was determined. Results: Rats after sham surgery showed a lower body weight for up to 8 weeks after the intervention compared to healthy controls. Left and right ventricular morphology and function were not different in absolute measures in both groups 1 week after surgery. However, there was a confined difference in several cardiac parameters normalized to the body weight (bw), such as myocardial mass (2.19±0.30/0.83±0.13 vs. 1.85±0.22/0.70±0.07 mg left/right per g bw, p<0.05), or enddiastolic ventricular volume (1.31±0.36/1.21±0.31 vs. 1.14±0.20/1.07±0.17 µl left/right per g bw, p<0.05). Vice versa, after 8 weeks, cardiac masses, volumes, and output showed a trend for lower values in the sham operated rats compared to the controls in absolute measures (782.2±57.2/260.2±33.2 vs. 805.9±84.8/310.4±48.5 mg, p<0.05 for left/right ventricular mass), but not normalized to body weight. Matching these findings, blood testing revealed prolonged metabolic and inflammatory changes after surgery not related to cardiac disease. Conclusion: There is a small distinct impact of cardio-thoracic surgical procedures on the global integrity of the organism, which in the long term also includes circumscribed repercussions on cardiac morphology and function. This impact has to be considered when analyzing data from respective studies and transferring the findings to conditions in patients.


2009 ◽  
Vol 2 (2) ◽  
pp. 138-144 ◽  
Author(s):  
Richard D. Patten ◽  
Monica R. Hall-Porter

Author(s):  
Zachary Fralish ◽  
Ethan M. Lotz ◽  
Taylor Chavez ◽  
Alastair Khodabukus ◽  
Nenad Bursac

The neuromuscular junction (NMJ) is a specialized cholinergic synaptic interface between a motor neuron and a skeletal muscle fiber that translates presynaptic electrical impulses into motor function. NMJ formation and maintenance require tightly regulated signaling and cellular communication among motor neurons, myogenic cells, and Schwann cells. Neuromuscular diseases (NMDs) can result in loss of NMJ function and motor input leading to paralysis or even death. Although small animal models have been instrumental in advancing our understanding of the NMJ structure and function, the complexities of studying this multi-tissue system in vivo and poor clinical outcomes of candidate therapies developed in small animal models has driven the need for in vitro models of functional human NMJ to complement animal studies. In this review, we discuss prevailing models of NMDs and highlight the current progress and ongoing challenges in developing human iPSC-derived (hiPSC) 3D cell culture models of functional NMJs. We first review in vivo development of motor neurons, skeletal muscle, Schwann cells, and the NMJ alongside current methods for directing the differentiation of relevant cell types from hiPSCs. We further compare the efficacy of modeling NMDs in animals and human cell culture systems in the context of five NMDs: amyotrophic lateral sclerosis, myasthenia gravis, Duchenne muscular dystrophy, myotonic dystrophy, and Pompe disease. Finally, we discuss further work necessary for hiPSC-derived NMJ models to function as effective personalized NMD platforms.


2018 ◽  
Vol 2 ◽  
pp. 2 ◽  
Author(s):  
Michele Obeid ◽  
Ramzy C. Khabbaz ◽  
Kelly D. Garcia ◽  
Kyle M. Schachtschneider ◽  
Ron C. Gaba

Animal models have become increasingly important in the study of hepatocellular carcinoma (HCC), as they serve as a critical bridge between laboratory-based discoveries and human clinical trials. Developing an ideal animal model for translational use is challenging, as the perfect model must be able to reproduce human disease genetically, anatomically, physiologically, and pathologically. This brief review provides an overview of the animal models currently available for translational liver cancer research, including rodent, rabbit, non-human primate, and pig models, with a focus on their respective benefits and shortcomings. While small animal models offer a solid starting point for investigation, large animal HCC models are becoming increasingly important for translation of preclinical results to clinical practice.


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