Inflammation and severe demyelination in the peripheral nervous system induced by the intraneural injection of recombinant mouse interleukin-12.
Inflammatory cytokines appear to be involved in damage to Schwann cells, myelin and axons, although the exact role of the different cytokines is uncertain. The direct injection model offers a new and simplified way of examining the mechanisms of early inflammation in the peripheral nervous system. The present study was performed to assess the direct effects of interleukin (IL)-12 on rat sciatic nerves injected with recombinant mouse IL-12. Histological and immunohistochemical examination 24 h after injection showed early inflammation as well as demyelination within the injected nerve fibres. By 4 days the inflammatory and demyelinating changes were significantly increased. Seven days after injection, the endoneurium still contained significant numbers of inflammatory cells and the demyelination was even more severe. Control rats injected with sterile phosphate-buffered saline exhibited no such inflammatory and demyelinating response. These changes are similar to those seen in inflammatory and demyelinating disorders of the peripheral nervous system and suggest that IL-12 could be relevant to the pathogenesis of demyelinating diseases such as Guillain-Barré syndrome.
Division of Geriatric Medicine, Karolinska Institute, Huddinge Hospital, Sweden.
S H
SH
Pelidou
G
G
Deretzi
L P
LP
Zou
C
C
Quiding
J
J
Zhu
D000818:Animals; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D003711:Demyelinating Diseases / Q000276:immunology*; D007267:Injections; D018664:Interleukin-12 / Q000008:administration & dosage / Q000276:immunology*; D008297:Male; D051379:Mice; D051381:Rats; D011917:Rats, Inbred Lew; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000276:immunology; D012584:Sciatic Nerve / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D013997:Time Factors
D011994:Recombinant Proteins; D018664:Interleukin-12