Использование люциферазы в Изображение Бактериальные инфекции у мышей
Summary
Методы визуализации биолюминесценции бактериальных инфекций в живых животных, описаны. Патогенные изменен, чтобы выразить люциферазы позволяет оптическим целого изображения тела инфекций у животных. Экспериментальные модели на животных могут быть инфицированы люциферазы выражения патогенов и в результате течения заболевания визуализированы в реальном времени биолюминесценции изображений.
Abstract
Imaging is a valuable technique that can be used to monitor biological processes. In particular, the presence of cancer cells, stem cells, specific immune cell types, viral pathogens, parasites and bacteria can be followed in real-time within living animals 1-2. Application of bioluminescence imaging to the study of pathogens has advantages as compared to conventional strategies for analysis of infections in animal models3-4. Infections can be visualized within individual animals over time, without requiring euthanasia to determine the location and quantity of the pathogen. Optical imaging allows comprehensive examination of all tissues and organs, rather than sampling of sites previously known to be infected. In addition, the accuracy of inoculation into specific tissues can be directly determined prior to carrying forward animals that were unsuccessfully inoculated throughout the entire experiment. Variability between animals can be controlled for, since imaging allows each animal to be followed individually. Imaging has the potential to greatly reduce animal numbers needed because of the ability to obtain data from numerous time points without having to sample tissues to determine pathogen load3-4.
This protocol describes methods to visualize infections in live animals using bioluminescence imaging for recombinant strains of bacteria expressing luciferase. The click beetle (CBRLuc) and firefly luciferases (FFluc) utilize luciferin as a substrate5-6. The light produced by both CBRluc and FFluc has a broad wavelength from 500 nm to 700 nm, making these luciferases excellent reporters for the optical imaging in living animal models7-9. This is primarily because wavelengths of light greater than 600 nm are required to avoid absorption by hemoglobin and, thus, travel through mammalian tissue efficiently. Luciferase is genetically introduced into the bacteria to produce light signal10. Mice are pulmonary inoculated with bioluminescent bacteria intratracheally to allow monitoring of infections in real time. After luciferin injection, images are acquired using the IVIS Imaging System. During imaging, mice are anesthetized with isoflurane using an XGI-8 Gas Anethesia System. Images can be analyzed to localize and quantify the signal source, which represents the bacterial infection site(s) and number, respectively. After imaging, CFU determination is carried out on homogenized tissue to confirm the presence of bacteria. Several doses of bacteria are used to correlate bacterial numbers with luminescence. Imaging can be applied to study of pathogenesis and evaluation of the efficacy of antibacterial compounds and vaccines.
Protocol
Discussion
Хотя следующие протоколы, как правило, приводят к высоким качеством изображения, важно учитывать несколько ключевых вопросов, чтобы получить точные и согласованные данные из изображений исследований. Люминесценция изображения должны быть приобретены, которые насчитывает от 600 до 60000,…
Disclosures
The authors have nothing to disclose.
Acknowledgements
Авторы выражают благодарность Cirillo лаборатории членов за ценные обсуждения и помощь на протяжении всего этого исследования. Мы благодарим доктора Джошуа Хилл и лаборатории д-р Джеймс Сэмюэль за помощь во время съемок этого протокола. Эта работа финансировалась грантом 48523 от Фонда Билла и Мелинды Гейтс и предоставить AI47866 из Национального института здоровья.
Materials
| Material Name | Type | Company | Catalogue Number | Comment |
|---|---|---|---|---|
| Isoflurane | VETONE | 501027 | ||
| Ketamine | Butler animal health supply | |||
| Xylazine | MP Biomedical | 158307 | ||
| Luciferin | GMT | LUCK-100 | ||
| Fetal plus solution | VOR tech pharmaceutical | |||
| Cathether (22G x 1”) | TERUMO | OX2225CA | ||
| Guide wire | Hallowell EMC | 210A3491 | ||
| Octocope with speculum | Hallowell EMC | 000A3748 | ||
| Xenogen IVIS system | Caliper Life Sciences | |||
| XGI-8-gas Anesthsia System | Caliper Life Sciences | |||
| Living Imaging Software | Caliper Life Sciences | |||
| Transparent nose cones | Caliper Life Sciences | |||
| Light baffle divider | Caliper Life Sciences |
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