Abstract
Respiratory diseases, such as pulmonary infections, are an important cause of morbidity and mortality worldwide. Preclinical studies often require invasive techniques to evaluate the extent of infection. Fibered confocal fluorescence microscopy (FCFM) is an emerging optical imaging technique that allows for real-time detection of fluorescently labeled cells within live animals, thereby bridging the gap between in vivo whole-body imaging methods and traditional histological examinations. Previously, the use of FCFM in preclinical lung research was limited to endpoint observations due to the invasive procedures required to access lungs. Here, we introduce a bronchoscopic FCFM approach that enabled in vivo visualization and morphological characterisation of fungal cells within lungs of mice suffering from pulmonary Aspergillus or Cryptococcus infections. The minimally invasive character of this approach allowed longitudinal monitoring of infection in free-breathing animals, thereby providing both visual and quantitative information on infection progression. Both the sensitivity and specificity of this technique were high during advanced stages of infection, allowing clear distinction between infected and non-infected animals. In conclusion, our study demonstrates the potential of this novel bronchoscopic FCFM approach to study pulmonary diseases, which can lead to novel insights in disease pathogenesis by allowing longitudinal in vivo microscopic examinations of the lungs.
Highlights
Respiratory diseases are a major cause of death and morbidity worldwide, with pulmonary infections resulting in over 3.5 million deaths per year[1]
To investigate the potential of Fibered confocal fluorescence microscopy (FCFM) to visualize individual fungal cells by using a fibre-optic probe, wild type (WT) and green fluorescent protein (GFP)-expressing A. fumigatus or C. gattii colonies were grown on solid Sabouraud agar and imaged by using the S-1500 probe
The images confirmed that A. fumigatus colonies were composed of densely packed hyphal structures (Fig. 1D), whereas C. gattii colonies contained a large number of round cells (Fig. 1E)
Summary
Respiratory diseases are a major cause of death and morbidity worldwide, with pulmonary infections resulting in over 3.5 million deaths per year[1]. Intravital microscopy is an optical imaging technique complementary to whole-body imaging methods which enables in situ visualization of cellular processes on a microscopic level based on detection of fluorescent signals[10] This method creates the opportunity for specific detection of pathogens in the complex biological context of intact tissues and organs. By using fibre-optic probes with small tip diameters, endoscopic insertion through natural openings like the large airways of the animal becomes feasible and allows studying pulmonary diseases. Such bronchoscopic approaches have mainly been limited to larger animal models such as pigs or rabbits[15,16]. The development of a similar bronchoscopic procedure in mice would be of primary interest to research given the large availability of established mouse models and immunological resources
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call