Detection of HIV reactivation using Spatial Light Interference Microscopy (Conference Presentation)

Abstract

Quantitative phase imaging (QPI) has emerged as a non-destructive tool for label-free imaging which helps understand the underlying physiological phenomena [1-7]. In this paper, we establish a correlation between dry mass and the reactivation of Jurkat T-cells latently infected with HIV (JLAT). In a previous study [8], the marker for reactivation of HIV was green fluorescence protein (GFP). A positive correlation between cell diameter and the intensity of viral reactivation was established. Using QPI, we were able to deduce that a positive correlation between dry mass and intensity of reactivation of HIV exists. JLAT isoclone 9.2 cells were treated with tumor necrosis factor (TNF-α) before imaging. Time lapse imaging was done using Spatial Light Interference Microscopy (SLIM) [9-12] with dual channel measurements for phase and fluorescence. Output of the fluorescence channel was quantified for cell diameter and mean fluorescence intensity. SLIM channel provided phase distribution in the sample. This phase information was then used to extract the dry mass [13-15] of cells. Segmentation and tracking were done using MATLAB. Results show that in a cell population with diameter range of 4-28 µm and dry mass ranging from 0.5-3.5 pg, cells having diameter greater than 10 um and dry mass greater than 1.5 pg were reactivated which leads to the conclusion that for the larger cell diameters and dry masses, higher fluorescent intensity and frequency of reactivation events occur as shown in Fig. 1. Thus, through QPI, diameter and dry mass of cells can be used as a marker for reactivation of latent HIV.