       Document 0741
 DOCN  M9620741
 TI    Intracellular calcium release induced by human immunodeficiency virus
       type 1 (HIV-1) surface envelope glycoprotein in human intestinal
       epithelial cells: a putative mechanism for HIV-1 enteropathy.
 DT    9602
 AU    Dayanithi G; Yahi N; Baghdiguian S; Fantini J; Laboratoire de
       Neurobiologie Endocrinologique, CNRS URA 1197,; Universite Montpellier
       2, France.
 SO    Cell Calcium. 1995 Jul;18(1):9-18. Unique Identifier : AIDSLINE
       MED/96000449
 AB    Intracellular Ca2+ ([Ca2+]i) was measured in single human epithelial
       intestinal HT-29-D4 cells with the Ca2+ probe Fura-2 and digital imaging
       microscopy. Treatment of these cells with HIV-1 surface envelope
       glycoprotein gp120 (or a soluble form of its precursor gp160) induced an
       important increase of [Ca2+]i. This effect was abolished by
       preincubation of the viral glycoprotein with neutralizing antibodies
       specific for the V3 domain of gp120. These antibodies inhibited the
       binding of both gp120 and gp160 to galactosylceramide (GalCer), the
       alternative HIV-1 receptor in HT-29-D4 cells. Moreover, treatment of
       HT-29-D4 cells with an anti-GalCer mAb induced an increase in [Ca2+]i
       and rendered the cells insensitive to HIV-1 glycoprotein stimulation.
       The calcium response resulted from release of Ca2+ from
       caffeine-sensitive intracellular stores. Finally, the viral glycoprotein
       specifically abrogated the calcium response to the neuropeptide agonist
       neurotensin, a stimulator of chloride secretion via inositol
       trisphosphate-mediated calcium mobilization. Reciprocally, after
       neurotensin stimulation, the cells did not respond to gp120, showing
       that neurotensin and gp120 stimulate a common pathway of [Ca2+]i
       mobilization. These results suggest that HIV-1 may directly alter ion
       secretion in the intestine and thus be the causative agent of the watery
       diarrhea associated with HIV-1 infection.
 DE    Calcium/*METABOLISM  Cell Line  Enteritis/ETIOLOGY
       Epithelium/CYTOLOGY/DRUG EFFECTS/METABOLISM
       Galactosylceramides/METABOLISM  Gene Products, env/PHARMACOLOGY  Human
       HIV Envelope Protein gp120/*PHARMACOLOGY  HIV Infections/COMPLICATIONS
       HIV-1/*PATHOGENICITY  Intestines/*DRUG EFFECTS/*METABOLISM
       Intracellular Fluid/METABOLISM  Protein Precursors/PHARMACOLOGY
       Recombinant Proteins/PHARMACOLOGY  Support, Non-U.S. Gov't  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

