Activation of human T-helper/inducer cell, T-cytotoxic cell, B-cell, and natural killer (NK)-cells and induction of natural killer cell activity against K562 chronic myeloid leukemia cells with modified citrus pectin.

Cheppail Ramachandran,Arland Hotchkiss,Isaac Eliaz,Hoa Chau,Barry J Wilk,Steven J Melnick

doi:10.1186/1472-6882-11-59

Abstract

BackgroundModified citrus pectin (MCP) is known for its anti-cancer effects and its ability to be absorbed and circulated in the human body. In this report we tested the ability of MCP to induce the activation of human blood lymphocyte subsets like T, B and NK-cells.MethodsMCP treated human blood samples were incubated with specific antibody combinations and analyzed in a flow cytometer using a 3-color protocol. To test functionality of the activated NK-cells, isolated normal lymphocytes were treated with increasing concentrations of MCP. Log-phase PKH26-labeled K562 leukemic cells were added to the lymphocytes and incubated for 4 h. The mixture was stained with FITC-labeled active form of caspase 3 antibody and analyzed by a 2-color flow cytometry protocol. The percentage of K562 cells positive for PKH26 and FITC were calculated as the dead cells induced by NK-cells. Monosaccharide analysis of the MCP was performed by high-performance anion-exchange chromatography with pulse amperometric detection (HPAEC-PAD).ResultsMCP activated T-cytotoxic cells and B-cell in a dose-dependent manner, and induced significant dose-dependent activation of NK-cells. MCP-activated NK-cells demonstrated functionality in inducing cancer cell death. MCP consisted of oligogalacturonic acids with some containing 4,5-unsaturated non-reducing ends.ConclusionsMCP has immunostimulatory properties in human blood samples, including the activation of functional NK cells against K562 leukemic cells in culture. Unsaturated oligogalacturonic acids appear to be the immunostimulatory carbohydrates in MCP.

Highlights

Modified citrus pectin (MCP) is known for its anti-cancer effects and its ability to be absorbed and circulated in the human body
T-Lymphocyte Subset Activation The percent increases in T- helper/inducer lymphocyte and T-cytotoxic cell activation are shown in Figure 1 &2, respectively
Results show that MCP does not have a significant effect on T-helper/inducer cell activation as compared to positive controls like CD2/CD2R (p < 0.01) and PMA (p < 0.001)

Summary

Introduction

Modified citrus pectin (MCP) is known for its anti-cancer effects and its ability to be absorbed and circulated in the human body. Pectin is a complex carbohydrate soluble fiber Dietary fibers, such as pectin, have been shown to have positive effects on a wide spectrum of pathological conditions. Their positive influence on human health is explained by their anti-oxidative, hypocholesterolemic, and anticancer effects [1,2,3,4,5,6,7,8,9,10,11,12]. The effect on the immune system has been previously attributed to the down regulation of the inflammatory response, moderating the production from a medicinal herb enhances secretion of granulocyte colony-stimulating factor (G-CSF) by murine colonic MCE 301 cells [17]. The carbohydrate composition of pectin is very important in determining different immune responses

Methods

Results

Discussion

Conclusion