title: Cross--reactivity of the V3-speciflc antibodies with the human C1q.
abstract: It has been previously shown that the sequence similarity between a portion of the envelope glycoprotein 120 (gp120) from the human immunodeficiency virus type-1 (HIV-1) and several types of human collagen and collagen-like molecules exists. That observation led to the suggestion that the antibodies against the third hypervariable region (V3) of HIV-1 gp120 (V3-specific antibodies) might have a role in the autoimmune phenomena observed in HIV-infected persons. In this study we have examined the cross-reactivity of the V3-specific antibodies purified from sera of HIV-infected individuals, sera obtained from the rheumatoid arthritis and systemic lupus crythematosus patients, as well as from the sera of healthy volunteers with the separate chains of a subcomponent of the first component of the human complement system, Clq. Our results show that the V3-specific antibodies are present in the sera of the HIV-infected individuals, patients suffering of the systemic autoimmune diseases as well as in the sera of healthy volunteers. Whereas these antibodies appeared in the HIV+-sera after antigen challenge, those present in the HIV- -sera probably represent the antibodies that are cross-reactive with the antigen. V3-reactive antibodies can be purified by affinity chromatography and they were highly specific for the V3-peptide. Additionally, they showed cross-reactivity with the separate chains of the human Clq as well as with the chicken collagen type VI. Possible physiological implications are discussed.
authors.affiliation: Institute of Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Germany. petm@medizin.uni-leipzig.de
authors.forename: M
authors.initials: M
authors.lastname: Petković
authors.forename: R
authors.initials: R
authors.lastname: Metlas
mesh_terms: D000595:Amino Acid Sequence; D000918:Antibody Specificity; D015922:Complement C1q / Q000276:immunology*; D003429:Cross Reactions; D015699:HIV Envelope Protein gp120 / Q000097:blood / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D010446:Peptide Fragments / Q000097:blood / Q000276:immunology*
chemical_list: D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D015922:Complement C1q