Document 3245
 DOCN  M94A3245
 TI    Identification of a complement activating site in gp120.
 DT    9412
 AU    Susal C; Kirschfink M; Kropelin M; Daniel V; Opelz G; Institute of
       Immunology, University of Heidelberg, Germany.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):12 (abstract no. 023A). Unique
       Identifier : AIDSLINE ICA10/94369330
 AB    OBJECTIVE: We showed recently that rgp120 of HIV-1, either attached to
       microtiter plates or bound to normal CD4+ cells, activates the human
       complement system in the absence of anti-gp120 antibodies. This may
       represent a mechanism for the elimination of uninfected CD4+ cells by
       the reticuloendothelial system and play a role in the enhancement of
       infection by HIV-1. In the current study we attempted to identify
       complement activation sites in gp120. METHODS: Equal amounts of 21
       different gp120-peptides were attached to microtiter plates. After
       incubation with normal, anti-gp120 neg. human serum (n = 10) deposition
       of complement proteins was assessed by ELISA. RESULTS: Complement
       proteins C4, C3d, C5b-9 and properdin were found to bind to a peptide
       covering positions 228-246 when incubated with any normal human serum.
       Complement activation by the peptide was as strong as by aggregated IgG,
       by complete rgp120, as well as by the previously described complement
       activating gp41-peptide 609-623. Activation of complement occurred
       primarily via the classical pathway and was abrogated in the presence of
       EDTA, Mg/EGTA or C4-deficient human serum. Peptides partly overlapping
       the sequence 228-246 activated complement to a lesser extent.
       CONCLUSIONS: Our data indicate that a specific site in gp120 is able to
       activate complement in normal human serum via the classical pathway in
       the absence of anti-gp120 and independent of glycosylation.
 DE    Complement/ISOLATION & PURIF  *Complement Activation  Complement
       Pathway, Classical  Enzyme-Linked Immunosorbent Assay  Human  HIV
       Envelope Protein gp120/*IMMUNOLOGY  HIV Envelope Protein gp41/IMMUNOLOGY
       HIV-1/*IMMUNOLOGY  MEETING ABSTRACT

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