Detection of Mouse Mammary Tumor Virus (MMTV) Particles in an Immortalized T Cell Line Based on Electrical Parameters

Abstract

Label-free detection and characterization of cells producing virus particles is a highly desirable property that can pave the way for direct detection of virally infected cells in body fluids, tissues, and eventually in infected individuals. Identification of such properties can also provide a better understanding of the growth and/or evolution of virally infected cells in real-time experimental setups. This paper takes a closer look at the electrical properties of an immortalized T cell line capable of producing virus particles along with its non-virus producing control cell line using capacitance–voltage ( ${C}$ – ${V}$ ) measurements. In addition, two other important control cell lines were also included in which the ability of the cells to produce virus particles was abrogated by using genetic mutations. The conducted ${C}$ – ${V}$ measurements revealed that it is possible to electrically differentiate between these different cell lines. The cells producing wild-type (WT) virus particles could be distinguished from the control cells in which no DNA was introduced and, hence, were incapable of producing any virus particles. Interestingly, the cells in which two mutant DNAs were introduced that abrogated their ability to produce virus particles showed a similar electrical profile to each other, yet distinct from that of the cells producing the WT virus. These results clearly demonstrate that the electrical technique was able to distinguish between cells expressing virus particles versus cells that do not express virus particles. Data analysis revealed a twofold difference in the interaction capacitance between WT and mutant cells. Characterizing cells using electrical parameters are not laborious and lengthy, as is the case with conventional biochemical methods that typically take several days. Together, these data suggest that it is possible to electrically characterize and differentiate virally infected cells from uninfected cells. It is our hope that eventually these observations could be translated into label-free, electrical detection of virally infected cells in biological samples and individuals for diagnostic purposes.