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M9630521.TXT
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1996-02-27
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Document 0521
DOCN M9630521
TI Human immunodeficiency virus type 1 envelope protein does not stimulate
either prostaglandin formation or the expression of prostaglandin H
synthase in THP-1 human monocytes/macrophages.
DT 9603
AU Hui R; Curtis JF; Sumner MT; Shears SB; Glasgow WC; Eling TE; Eicosanoid
Biochemistry Section, National Institute of; Environmental Health
Sciences, Research Triangle Park, North; Carolina 27709, USA.
SO J Virol. 1995 Dec;69(12):8020-6. Unique Identifier : AIDSLINE
MED/96079052
AB Prostaglandin E2 is observed at elevated levels during human
immunodeficiency virus (HIV) infection and thus may contribute to the
HIV-dependent immunosuppression. The mechanisms responsible for this
increase are not understood. Evidence indicates that the viral envelope
proteins perturb membrane signaling mediated by the CD4 receptor,
suggesting that the free envelope protein and/or the intact virus may be
responsible for the increase in prostaglandin E2 levels. In this study,
we have used THP-1 human monocytes and THP-1 cells differentiated by
12-O-tetradecanoylphorbol-13-acetate treatment into macrophages to
determine if the HIV envelope protein, gp120, or an anti-CD4 receptor
antibody stimulates prostaglandin formation by interacting with the CD4
receptor. Incubation of THP-1 cells with OKT4A antibody greatly
stimulated the CD4-p56lck receptor complex as estimated by enhanced
p56lck autophosphorylation, while the gp120 gave small but significant
responses. Monocytic THP-1 cells poorly metabolized arachidonic acid to
prostaglandin E2 and thromboxane B2 as measured by high-pressure liquid
chromatography analysis. Western blot (immunoblot) and Northern (RNA)
blot analyses revealed that unstimulated monocytes expressed little
prostaglandin H synthase 1 and 2 (PGHS-1 and -2). Incubation of the
monocytes with lipopolysaccharide, OKT4A, or gp120 did not increase the
formation of prostaglandins. The expression of PGHS-1 or PGHS-2 was also
not increased. Differentiation of the monocytes to macrophages by
12-O-tetradecanoylphorbol-13-acetate treatment resulted in increased
expression of PGHS-1 and increased formation of prostaglandins compared
with that for the monocytes. Lipopolysaccharide stimulation of the
macrophages increased the formation of prostaglandins and increased the
expression of PGHS-2 in the macrophages. However, OKT4A or gp120
preparation, at concentrations that stimulated p56lck
autophosphorylation, did not enhance the formation of prostaglandins or
the expression of PGHS-1 or PGHS-2. OKT4A and gp120 also did not
stimulate the release of arachidonic acid, indicating that phospholipase
A2 was not activated by the CD4 receptor in either the THP-1 monocytes
or macrophages. These results indicate that activation of the CD4-p56lck
receptor signal transduction pathway by the HIV envelope protein does
not increase prostaglandin formation.
DE src-Family Kinases/METABOLISM Animal Antibodies,
Monoclonal/PHARMACOLOGY Antigens, CD4/PHYSIOLOGY Cell Differentiation
Cell Line CHO Cells Dinoprostone/ISOLATION & PURIF/METABOLISM
Eicosanoids/METABOLISM Enzyme Activation Gene Expression Hamsters
Human HIV Envelope Protein gp120/BIOSYNTHESIS/ISOLATION & PURIF/
*PHARMACOLOGY *HIV-1/*PHYSIOLOGY Isoenzymes/BIOSYNTHESIS Kinetics
Macrophages/CYTOLOGY/*METABOLISM Monocytes/CYTOLOGY/*METABOLISM
Prostaglandin-Endoperoxide Synthase/*BIOSYNTHESIS
Prostaglandins/*METABOLISM Tetradecanoylphorbol Acetate/PHARMACOLOGY
Thromboxane B2/ISOLATION & PURIF/METABOLISM JOURNAL ARTICLE
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).