in the nonrosetteable fraction in regulating the ex- 
tent and duration of the IFN-7autosuperinduction 
response. The implications of these phenomena in 
autoimmune dysfunction are under investigation. 
B. Negative effectors of IFN--^ gene expression. 
A crude, murine-derived T cell suppressor factor 
(TSF) was shown to contain a strong downregu- 
lator of the IFN--/ gene expression, while having no 
effect on IL-2, IL-2 receptor (IL-2R), or actin expres- 
sion. TSF was subsequently found to contain mea- 
surable levels of transforming growth factor-^ (TGF- 
P), a factor recently reported to be similarly capable 
of suppressing biological expression of several 
human cytokines. Dr. Hardy's laboratory subse- 
quently examined the effect of TGF-P on IFN-7 gene 
expression by activated human PBLs, clearly dem- 
onstrating a powerful downregulatory effect on 
IFN-7 gene expression. Recent studies have impli- 
cated the monocytes as the key cellular element fa- 
cilitating this downregulatory effect. 
C. Structural and functional analyses of the IFN--^ 
gene. Previous structural studies from Dr. Hardy's 
laboratory had identified three regions of the hu- 
man IFN-7 gene, two upstream and one intronically 
located, and implicated them functionally, via inter- 
domain communication, in that gene's positive and 
negative regulation. By constructing and transfect- 
ing a number of reporter plasmid constructs into 
human and murine cell lines. Dr. Hardy and his col- 
leagues have functionally identified several cis-act- 
ing regulatory regions in the human IFN-7 gene. A 
tissue-nonspecific enhancer element has been lo- 
calized to a 230 bp fragment in the first intron of 
PUBLICATIONS 
the human IFN-7 gene. Tissue-nonspecific DNase I 
footprints have also been identified in this same 
fragment. It was demonstrated that the upstream 
2.3 kb of the IFN-7 gene, while inactive in fibro- 
blasts, can direct activation-specific upregulation of 
reporter constructs transiently transfected into mu- 
rine T cells. Deletion analyses localized the se- 
quences involved in the induction process to the 
proximal 5' 550 bp. Dr. Hardy's laboratory opti- 
mized electroporation conditions to allow transfec- 
tion of expression constructs directly into fully dif- 
ferentiated, primary human lymphocytes (and/or 
their isolated subfractions) . By this approach, sev- 
eral cis-acting genetic elements were identified in 
this proximal 5' region. A T cell-specific, constitutive 
enhancer was localized to the most proximal 215 
bp. Furthermore, a T cell-specific DNase I footprint 
was identified at position -172 to -156. Deletion 
analyses suggested dominant suppression of this 
enhancer region by more upstream negative regula- 
tory elements. The first functional confirmation of a 
T cell-specific, negative regulatory element was 
made in this laboratory, and its orientation depen- 
dency was demonstrated. These data support a 
model of cytokine gene induction that involves T 
cell-specific derepression of negative elements oth- 
erwise dominantly suppressing a potent, T cell- 
specific, constitutive enhancer. Clonal identifica- 
tion of T cell-specific trans-acting factors is under 
way. 
Dr. Hardy is also Assistant Professor of Medicine, 
Microbiology and Immunology, and Cell Biology, 
and Attending Physician at Baylor College of Medi- 
cine and affiliated hospitals. 
Books and Chapters of Books 
Hardy, K.J. 1989- Methods of molecular medicine. In Molecular Biology Course Syllabus: Proceedings of the 
45th Annual Meeting of the American Academy of Allergy and Immunology. Milwaukee: AAAI, pp 13-28. 
Hardy K.J. , Chrivia, J.C. , Smith, J.G., Rich, S., Young, H.A., and Sawada, T. 1989. Positive and negative effec- 
tors of 7 interferon gene regulation. In The Biology of the Interferon System 1988 (Kawade, Y, and 
Kobayashi, S., Eds.). Tokyo: Kodansha Scientific, pp 33-38. 
Young, H.A., Beckwith, M., Scott, A.N., Hardy K.J. , and Ciccarone, VC. 1989- Role of genomic DNA sequences 
in the control of interferon-7 gene expression. In The Biology of the Interferon System 1988 (Kawade, Y, 
and Kobayashi, S., Eds.). Tokyo: Kodansha Scientific, pp 19-24. 
Article 
Hardy, K.J., and Sawada, T. 1989. Human 7 interferon strongly upregulates its own gene expression in pe- 
ripheral blood lymphocytes, f Exp Med 170:1021-1026. 
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