The Journal of Neuroscience, March 25, 2009, 29(12):3948-3955; doi:10.1523/JNEUROSCI.5595-08.2009
Previous Article | Next Article 
Neurobiology of Disease
Interferon-
Causes Neuronal Dysfunction in Encephalitis
Andrew R. Sas,1
Heather Bimonte-Nelson,3,4
C. Thetford Smothers,1
John Woodward,1 and
William R. Tyor1,2
Departments of 1Neurosciences and 2Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina 29425, 3Department of Psychology, Arizona State University, Tempe, Arizona 85287, and 4Arizona Alzheimer's Consortium, Phoenix, Arizona 85006
Correspondence should be addressed to Dr. William R. Tyor, Neurology Service, Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033. Email: william.tyor{at}va.gov
Interferon-
(IFN
) is a pleomorphic cytokine produced by nucleated cells in response to viral infection. In patients, treatment with IFN
has side effects including cognitive impairment resembling subcortical dementia, which is a hallmark of human immunodeficiency virus (HIV)-associated dementia (HAD). IFN
is increased in the CSF of HAD patients compared with HIV patients without dementia. In this study, blocking IFN
in a HIV encephalitis (HIVE) mouse model with intraperitoneal injections of IFN
neutralizing antibodies (NAbs) significantly improved cognitive function compared with untreated or control antibody-treated HIVE mice during water radial arm maze behavioral testing. Treatment with IFN
NAbs significantly decreased microgliosis and prevented loss of dendritic arborization in the brains of HIVE mice. Furthermore, treatment of primary neuron cultures with IFN
resulted in dose-dependent loss of dendritic arborization that was blocked with IFN
NAb treatment and partially blocked with NMDA antagonists [AP5 and MK801 (dizocilpine maleate)] indicating glutamate signaling is involved in IFN
-mediated neuronal damage. These results show that IFN
has a major role in the pathogenesis of HIVE in mice and is likely important in the development neurocognitive dysfunction in humans with HIV. Blocking IFN
could be important in improving cognitive and pathological developments in HAD patients and may be clinically important in other neuroinflammatory diseases as well.
Received Nov. 22, 2008;
revised Jan. 6, 2009;
accepted Feb. 20, 2009.
Correspondence should be addressed to Dr. William R. Tyor, Neurology Service, Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033. Email: william.tyor{at}va.gov