The phagocytic capacity of neurones.
Phagocytosis is defined as the ingestion of particulates over 0.5 microm in diameter and is associated with cells of the immune system such as macrophages or monocytes. Neurones are not generally recognized to be phagocytic. Using light, confocal, time-lapse and electron microscopy, we carried out a wide range of in-vitro and in-vivo experiments to examine the phagocytic capacity of different neuronal cell types. We demonstrated phagocytosis of material by neurones, including cell debris and synthetic particles up to 2.8 microm in diameter. We showed phagocytosis in different neuronal types, and demonstrated that debris can be transported from neurite extremities to cell bodies and persist within neurones. Flow cytometry analysis demonstrated the lack of certain complement receptors on neurones but the presence of others, including integrin receptors known to mediate macrophage phagocytosis, indicating that a restricted set of phagocytosis receptors may mediate this process. Neuronal phagocytosis occurs in vitro and in vivo, and we propose that this is a more widespread and significant process than previously recognized. Neuronal phagocytosis may explain certain inclusions in neurones during disease, cell-to-cell spread of disease, neuronal death during disease progression and provide a potential mechanism for therapeutic intervention through the delivery of particulate drug carriers.
Bowen
Samantha
S
Neuroscience Centre and Pathology Group, Queen Mary's School of Medicine and Dentistry, Institute of Pathology, Royal London Hospital, London, UK.
Ateh
Davidson D
DD
Deinhardt
Katrin
K
Bird
Margaret M
MM
Price
Karen M
KM
Baker
Cathy S
CS
Robson
Joanna C
JC
Swash
Michael
M
Shamsuddin
Wassim
W
Kawar
Shalini
S
El-Tawil
Tariq
T
Roos
Jesper
J
Hoyle
Andrew
A
Nickols
Carole D
CD
Knowles
Charles H
CH
Pullen
Anthony H
AH
Luthert
Phillip J
PJ
Weller
Roy O
RO
Hafezparast
Majid
M
Franklin
Robin J M
RJ
Revesz
Tamas
T
King
Rosalind H M
RH
Berninghausen
Otto
O
Fisher
Elizabeth M C
EM
Schiavo
Giampietro
G
Martin
Joanne E
JE
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D002642:Chick Embryo; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D005434:Flow Cytometry; D005727:Ganglia, Spinal / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D016023:Integrins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D009046:Motor Neurons / Q000378:metabolism / Q000648:ultrastructure; D009420:Nervous System / Q000378:metabolism* / Q000648:ultrastructure; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D010587:Phagocytosis / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000378:metabolism
D016023:Integrins; D011956:Receptors, Cell Surface