Document 0776
 DOCN  M9440776
 TI    The envelope glycoprotein of HIV-1 gp120 and human complement protein
       C1q bind to the same peptides derived from three different regions of
       gp41, the transmembrane glycoprotein of HIV-1, and share antigenic
       homology.
 DT    9404
 AU    Stoiber H; Thielens NM; Ebenbichler C; Arlaud GJ; Dierich MP; Institut
       fur Hygiene, Leopold-Franzens-University, Innsbruck,; Austria.
 SO    Eur J Immunol. 1994 Feb;24(2):294-300. Unique Identifier : AIDSLINE
       MED/94130941
 AB    gp41, the transmembrane glycoprotein of HIV-1, has been shown to be
       non-covalently associated with gp120. We have shown that it also binds
       human C1q. To analyze the interaction site(s) of gp41 with these two
       molecules, we established an enzyme-linked immunosorbent assay (ELISA)
       system using recombinant soluble gp41 [amino acids (aa) 539-684] and
       peptides thereof. In the cell-external part of gp41 three sites (aa
       526-538, aa 590-613 and aa 625-655) were found to bind both gp120 and
       C1q. That gp120 and C1q use the same sites was evidenced by the fact
       that these proteins competed with each other for the same sites in
       recombinant soluble gp41 and gp41 peptides. It could be demonstrated by
       ELISA, that rabbit antibodies against human C1q recognized gp120, and
       rabbit antibodies against gp120 cross-reacted with C1q. Rabbit
       anti-gp120, HIV-1-positive human sera and anti-gp120 obtained from such
       sera agglutinated sensitized sheep erythrocytes with human C1q (EAC1q).
       These data suggest that in addition to functional homology between C1q
       and gp120 structural homology between these two molecules exists. This
       molecular mimicry might become the basis for immunologically relevant
       autoimmune phenomena.
 DE    Antigenic Determinants  Binding Sites  Complement
       1q/*IMMUNOLOGY/METABOLISM  Human  HIV Envelope Protein
       gp120/*IMMUNOLOGY/METABOLISM  HIV Envelope Protein
       gp41/*IMMUNOLOGY/METABOLISM  HIV Seropositivity/IMMUNOLOGY  In Vitro
       Peptides/CHEMISTRY/IMMUNOLOGY  Protein Binding  Recombinant Proteins
       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).