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

Brittany Lassiter,Stephen Beebe,Siqi Guo

doi:10.3390/cancers10030069

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.

Highlights

The liver is the largest internal organ in the body and serves a wide range of functions related to digestion, nutrient storage, metabolism, detoxification and immunity among others.The liver has a dual blood supply from the hepatic artery providing fresh oxygenated blood and from the hepatic portal vein from the digestive tract delivering intestinal nutrients, bacterial products, environmental toxins and drugs
To determine if Nano-pulse stimulation (NPS) induced an immune response after rat orthotopic N1-S1 hepatocellular carcinoma (HCC) tumors, CD4+ and CD8+ Tem cells (CD44+ CD62L−) and Tcm cells treatment of rat orthotopic N1-S1 HCC tumors, CD4+ and CD8+ Tem cells (CD44+ CD62L−) and Tcm (CD44+ CD62L+) were analyzed in blood (Figure 1) and spleen (Figure 2)
These results suggest that liver CD8+ T-cells that express CD314-NKG2D or CD161 are remarkable andrare areand shown in Figure relatively are likely less important for NPS-induced tumor elimination

Summary

Introduction

The liver is the largest internal organ in the body and serves a wide range of functions related to digestion, nutrient storage, metabolism, detoxification and immunity among others. The liver has a dual blood supply from the hepatic artery providing fresh oxygenated blood and from the hepatic portal vein from the digestive tract delivering intestinal nutrients, bacterial products, environmental toxins and drugs. Chronic hepatocyte injury and efferocytosis of dead and dying cells leads to production of pro-inflammatory cytokines, linking hepatocyte apoptosis and liver fibrosis [1,2,3,4]. In contrast to other homeostatic functions where programmed cell death is a silent, non-inflammatory process [5], programmed cell death and inflammation, as part of liver homeostasis, is unique to hepatocytes. Chronic liver inflammation promotes genetic instability that transforms cells, develops resistances to apoptosis and immune surveillance, and facilitates hepatocellular carcinoma (HCC) resistances to Cancers 2018, 10, 69; doi:10.3390/cancers10030069 www.mdpi.com/journal/cancers

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