Differential Effect of Non-Thermal Plasma RONS on Two Human Leukemic Cell Populations

• Main Authors: Hager Mohamed, Eric Gebski, Rufranshell Reyes, Samuel Beane, Brian Wigdahl, Fred C. Krebs, Katharina Stapelmann, Vandana Miller
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Cancers
• Subjects: oxidative stress; damage-associated molecular patterns (DAMPs); calreticulin; heat shock proteins; phagocytosis; plasma medicine
• Online Access: https://www.mdpi.com/2072-6694/13/10/2437

Non-thermal plasma application to cancer cells is known to induce oxidative stress, cytotoxicity and indirect immunostimulatory effects on antigen presenting cells (APCs). The purpose of this study was to evaluate the responses of two leukemic cell lines—Jurkat T lymphocytes and THP-1 monocytes—to NTP-generated reactive oxygen and nitrogen species (RONS). Both cell types depleted hydrogen peroxide, but THP-1 cells neutralized it almost immediately. Jurkat cells transiently blunted the frequency-dependent increase in nitrite concentrations in contrast to THP-1 cells, which exhibited no immediate effect. A direct relationship between frequency-dependent cytotoxicity and mitochondrial superoxide was observed only in Jurkat cells. Jurkat cells were very responsive to NTP in their display of calreticulin and heat shock proteins 70 and 90. In contrast, THP-1 cells were minimally responsive or unresponsive. Despite no NTP-dependent decrease in cell surface display of CD47 in either cell line, both cell types induced migration of and phagocytosis by APCs. Our results demonstrate that cells modulate the RONS-mediated changes in liquid chemistry, and, importantly, the resultant immunomodulatory effects of NTP can be independent of NTP-induced cytotoxicity.