Specific intracellular signature of SARS-CoV-2 infection using confocal Raman microscopy

Abstract

SARS-CoV-2 infection remains spread worldwide and requires a better understanding of virus-host interactions. Here, we analyzed biochemical modifications due to SARS-CoV-2 infection in cells by confocal Raman microscopy. Obtained results were compared with the infection with another RNA virus, the measles virus. Our results have demonstrated a virus-specific Raman molecular signature, reflecting intracellular modification during each infection. Advanced data analysis has been used to distinguish non-infected versus infected cells for two RNA viruses. Further, classification between non-infected and SARS-CoV-2 and measles virus-infected cells yielded an accuracy of 98.9 and 97.2 respectively, with a significant increase of the essential amino-acid tryptophan in SARS-CoV-2-infected cells. These results present proof of concept for the application of Raman spectroscopy to study virus-host interaction and to identify factors that contribute to the efficient SARS-CoV-2 infection and may thus provide novel insights on viral pathogenesis, targets of therapeutic intervention and development of new COVID-19 biomarkers.

Review of optical methods for noninvasive imaging of skin fibroblasts—From in vitro to ex vivo and in vivo visualization

“…As far as visualization of viruses action is concerned, the use of CRM for fibroblasts has not yet been implemented. Visualization of biochemical modifications of fibroblasts caused by SARS‐CoV‐2 infection using CRM made it possible to discover the changes in the cells [166]. Also, Raman spectrometers were used to identify and characterize murine fibroblast cell lines (NIH/3T3) and malignant fibroblast cells transformed by murine sarcoma virus (NIH‐MuSV) [167].…”

Advanced flow cytometry for biomedical applications

“…As extracellular microparticles, far from being inert cellular debris, play important roles in the physiological processes of malignancy, quantification of microparticle levels with high sensitivity and accuracy is a fundamental requirement that can be satisfied by advanced FC [70,71]. [73]. The method based on Raman microscopy holds the promise of various RNA virus detection in FC.…”

Raman spectroscopic cellomics for the detection of SARS‐CoV‐2‐associated neutrophil activation after TNF‐α stimulation

“… 3 High throughput screening RS (HTS‐RS) represents an innovative strategy for direct and non‐destructive detection of changes in the composition and phenotype of the white blood cells. 4 , 5 , 6 , 7 The principle of this technique is to irradiate a cell with laser light for a few seconds and record the inelastically scattered light as a spectrum. 4 Compared to traditional flow cytometry, this spectrum displays the sample's label‐free molecular signature, which is susceptible to change due to biological stimulations.…”

“… 4 Compared to traditional flow cytometry, this spectrum displays the sample's label‐free molecular signature, which is susceptible to change due to biological stimulations. 5 , 6 , 7 Machine learning approaches are applied to transfer the spectral into meaningful biological information. 8 …”

“…The tryptophan metabolism pathway plays a crucial role in inflammation and immune tolerance captured in Raman spectra. 7 …”