Analysis of interaction between the apicomplexan protozoan Toxoplasma gondii and host cells using label-free Raman spectroscopy

Abstract

Label-free imaging using Raman micro-spectroscopy (RMS) was used to characterize the spatio-temporal molecular changes of T. gondii tachyzoites and their host cell microenvironment. Raman spectral maps were recorded from isolated T. gondii tachyzoites and T. gondii-infected human retinal cells at 6 hr, 24 hr and 48 hr postinfection. Principal component analysis (PCA) of the Raman spectra of paraformaldehyde-fixed infected cells indicated a significant increase in the amount of lipids and proteins in the T. gondii tachyzoites as the infection progresses within host cells. These results were confirmed by experiments carried out on live T. gondii-infected cells and were correlated with an increase in the concentration of proteins and lipids required for the replication of this intracellular pathogen. These findings demonstrate the potential of RMS to characterize time-and spatially-dependent molecular interactions between intracellular pathogens and the host cells. Such information may be useful for discovery of pharmacological targets or screening compounds with potential neuroprotective activity for eminent effects of changes in brain infection control practices. 2

The application of Raman spectroscopy for the detection and identification of microorganisms

“…Also, viral pathogens were objects of investigation in a clinical context, as it was reported for rotavirus, cytomegalovirus, influenza strains, human papillomavirus (HPV), Varicella zoster virus, and Porcine teschovirus , as well as echovirus 1 . Additionally, by means of Raman spectroscopy, clinically relevant eukaryotic microorganisms were studied such as several pathogenic fungi, Candida , Candida and Aspergillus , dermatophytes of the genus Trichophyton , and the protozoa Toxoplasma gondii . Special features, such as the presence of pigments within the microorganism, can contribute to characteristic Raman spectroscopic signals, which can be utilized for identification and differentiation.…”

Fourier transform infrared and Raman‐based biochemical profiling of different grades of pure foetal‐type hepatoblastoma

“…Intensity ratios of Raman peaks 1303 cm −1 /1267 cm −1 and 1654 cm −1 /1445 cm −1 could be used to evaluate the levels of saturated and unsaturated lipids , respectively. The unsaturated‐to‐saturated lipids ratio was obtained by calculating the intensity ratio of (1303 cm −1 /1267 cm −1 )/(1654 cm −1 /1445 cm −1 ).…”

Induction and measurement of the early stage of a host‐parasite interaction using a combined optical trapping and Raman microspectroscopy system

“…[2] Therefore, understanding the metabolic and chemical alterations that accompany T. gondii infection has gained significant attention in the last few years. [10] Additionally, stable isotope labeling in culture (SILAC) was used to increase the molecular specificity of the Raman spectroscopy measurements, allowing monitoring the exchange of stable isotope-labeled phenylalanine ( L -Phe(D8)) between human retinal pigment epithelial cells (ARPE-19) and T. gondii [11] or Acanthamoeba castellanii. [8] RMS has been used to study the interaction of parasites and host cells, such as Neospora caninum [9] and T. gondii.…”