Journal of Clinical Immunology

, Volume 32, Issue 2, pp 330–339

PTX3 Is Located at the Membrane of Late Apoptotic Macrophages and Mediates the Phagocytosis of Macrophages

  • Tangmeng Guo
  • Li Ke
  • Benling Qi
  • Jingjing Wan
  • Jing Ge
  • Lijuan Bai
  • Bei Cheng
Article

DOI: 10.1007/s10875-011-9615-6

Cite this article as:
Guo, T., Ke, L., Qi, B. et al. J Clin Immunol (2012) 32: 330. doi:10.1007/s10875-011-9615-6

Abstract

Apoptotic macrophages are removed by neighboring phagocytes (efferocytosis), which is an important event in advanced atherosclerosis. Recent reports have elucidated some key molecular regulators in efferocytosis including complement C1q, MFGE8, and MERTK. However, it remains unknown whether the long pentraxin 3 (PTX3), which is an important molecule that is involved in apoptotic cell clearance in the immune response, plays a part in efferocytosis during advanced atherosclerosis. In this study, we modeled macrophage apoptosis in advanced plaques by incubating macrophages (peritoneal macrophages isolated from C57 mice) with free cholesterol (free cholesterol-induced apoptotic macrophages, FC-AMs). FC-AMs were added to a monolayer of fresh phagocytes to study the engulfment response. We observed that PTX3 was mainly located at the membrane of late apoptotic macrophages. The anti-PTX3 monoclonal Ab 16B5 inhibited the engulfment of late apoptotic macrophages by phagocytes in a dose-dependent manner (from 14.63% inhibition at 5 μg/ml to 26.19% inhibition at 50 μg/ml). These results suggest that PTX3 located at the membrane of late apoptotic macrophages mediates their phagocytosis by phagocytes in a cell model of advanced atherosclerosis.

Keywords

Apoptosis macrophage PTX3 efferocytosis vulnerable plaque 

Abbreviations

MFGE8

Milk fat globulin E8

MERTK

MER tyrosine kinase

FC-AMs

Free cholesterol-induced apoptotic macrophages

PTX3

Pentraxin 3

CRP

C-reactive protein

SAP

Serum amyloid-P

DCs

Dendritic cells

CVD

Cardiovascular disease

GAS6

Growth arrest-specific protein 6

DMEM

Dulbecco’s modified Eagle’s medium

ACAT

Acyl-CoA:cholesterol O-acyltransferase

NECDS

Non-enzymatic cell dissociation solution

PBS

Phosphate-buffered saline

UV-AMs

Ultraviolet-induced apoptotic macrophages

FACS

Fluorescence-activated cell sorter

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Tangmeng Guo
    • 1
  • Li Ke
    • 1
  • Benling Qi
    • 1
  • Jingjing Wan
    • 1
  • Jing Ge
    • 1
  • Lijuan Bai
    • 1
  • Bei Cheng
    • 1
  1. 1.Department of GeriatricsUnion Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina

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