Nano-Pulse Stimulation Ablates Orthotopic Rat Hepatocellular Carcinoma and Induces Innate and Adaptive Memory Immune Mechanisms that Prevent Recurrence

Brittany P Lassiter; Siqi Guo; Stephen J Beebe

doi:10.3390/cancers10030069

Nano-Pulse Stimulation Ablates Orthotopic Rat Hepatocellular Carcinoma and Induces Innate and Adaptive Memory Immune Mechanisms that Prevent Recurrence

Cancers (Basel). 2018 Mar 13;10(3):69. doi: 10.3390/cancers10030069.

Authors

Brittany P Lassiter¹, Siqi Guo², Stephen J Beebe³

Affiliations

¹ Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA 23508, USA. blassite@odu.edu.
² Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA 23508, USA. s2guo@odu.edu.
³ Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA 23508, USA. sbeebe@odu.edu.

Abstract

Nano-pulse stimulation (NPS), previously called nsPEFs, induced a vaccine-like effect after ablation of orthotopic N1-S1 hepatocellular carcinoma (HCC), protecting rats from subsequent challenges with N1-S1 cells. To determine immunity, immune cell phenotypes were analyzed in naïve, treated and protected rats. NPS provides a positive, post-ablation immuno-therapeutic outcome by alleviating immunosuppressive T regulatory cells (Treg) in the tumor microenvironment (TME), allowing dendritic cell influx and inducing dynamic changes in natural killer cells (NKs), NKT-cells and T-lymphocytes in blood, spleen and liver. NPS induced specific increases in NKs and NKT-cells expressing CD8 and activation receptors CD314-NKG2D and CD161 (NK1.1) in the TME after treatment, as well as some variable changes in CD4+ and CD8+ effector (Tem) and central memory (Tem) lymphocytes in blood and spleen. After orthotopic challenge, CD8+ T-cells were cytotoxic, inducing apoptosis in N1-S1 cells; additionally, in contrast to post-treatment immune responses, CD4+ and CD8+ memory precursor effector cells (MPECs) and short-lived effector cells (SLECs) were present, while still including CD8+ CD161 NK cells, but not involving CD8+ CD314-NKG2D+ NKs. This immunity was N1-S1-specific and was sustained for at least 8 months. NPS vaccinates rats in vivo against HCC by activating innate and adaptive immune memory mechanisms that prevent HCC recurrence.

Keywords: NK cell receptors; NKT cells; T-regulatory cells; central memory T-cells; effector memory T-cells; memory precursor effector T-cells; short-lived effector T-cells.