Concepcion Conejero-Goldberg1, Ena Wang2, Chuli Yi1,

Terry Goldberg3, Francesco M. Marincola2, Lorraine

Jones-Brando4, Maree J. Webster1, Robert H. Yolken4,

and E. Fuller Torrey1



Medical Research Institute, 2Department of Transfusion Medicine,

National Institutes of Health, 3Clinical Brain Disorders Branch,

National Institutes of Health, 4Stanley Division of Developmental

Neurovirology, Johns Hopkins University School of Medicine




Microarray technology has

become an important tool in psychiatric research.  Evidence that links HERVs to

schizophrenia comes from the detection of increased expression of sequences

homologous to retroviruses in both cerebrospinal fluid and brain tissue from

patients with schizophrenia.


A unique array based

pathogen chip has been developed in our laboratory for the detection of viral

RNA expression levels or DNA prevalence from test samples.  A set of long

oligonucleotides (60-mer) was designed based on highly conserved regions within

viral families, as well as heterogenic regions characterized by individual

subfamilies.  In addition, by including oligonucleotides derived from genes

implicated in different stages of the infection, we were also able to

potentially define the stage of the viral infection.  To validate the viral

microarray we used virally infected cell cultures to detect and identify diverse

viruses and their infectious stage.


Total RNA from Brodmann

area 46, from 8 patients with schizophrenia and 10 unaffected controls was

linearly amplified using in vitro transcription in combination with a template

switch technique.  Samples were then examined by cohybridization of patient aRNA

labeled with Cy5 (red) with pooled control aRNA labeled with Cy3 (green) to the

pathogen microarray chip.  The expression of 51 genes displayed statistically

significant differences between schizophrenic cases and controls P<.05 b t-test).  Expression of 6 viral sequences differed between groups by X2

(using a 1 SD cut off).  All favored increased levels of expression in the

schizophrenia cases.  More specifically, we found evidence of increased

expression of a sequence homologous to the endogenous retrovirus HERVWE1 in the

schizophrenic group using both statistical methods.  Quantitative-PCR studies

are underway to validate these results.


These findings suggest that

this platform provides the capability to detect a broad spectrum of viruses in a

single assay while simultaneously discriminating among different stages of the

viruses.  This method may be applied to identify evidence of viral infection in

postmortem tissue from psychiatric patients as well as a wide range of other

diagnostic categories.