title: A novel liposome immune lysis assay (LILA) for determination of CRP antigen using two monoclonal antibodies recognizing different antigenic determinants.
abstract: We have already developed the liposome immune lysis assay (LILA) for the determination of C-reactive protein (CRP) by employing an inhibition method and a sandwich method. We herein report a new LILA system involving the use of monoclonal antibodies-bearing liposomes. We established five monoclonal antibodies to CRP antigen, AC-1, -2, -3, -4, -5 which had the capacity to activate complement and form antigen-antibody complex. Each of these antibodies was covalently coupled to carboxyfluorescein-entrapped multilamellar liposomes. When the liposomes were incubated with CRP antigen in the presence of guinea pig complement, CRP antigen-dependent liposome lysis was observed but the sensitivity was not great enough for practical use. On the other hand, when liposomes coupling two monoclonal antibodies (AC-1, AC-2) which recognized distinct CRP antigenic determinants were employed in the assay, the sensitivity increased compared with that using only one monoclonal antibody, and the detectable concentration range was 5-300 ng/ml. These results indicated that the combination of two or more monoclonal antibodies which recognize distinct CRP antigenic determinants is effective for increasing the sensitivity of the assay.
authors.affiliation: Research Laboratory, Nissui Pharmaceutical Co., Ltd., Ibaraki, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Umeda
authors.forename: T
authors.initials: T
authors.lastname: Yasuda
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D002097:C-Reactive Protein / Q000032:analysis* / Q000276:immunology; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods*; D000939:Epitopes / Q000097:blood; D006801:Humans; D007124:Immunoenzyme Techniques; D008081:Liposomes; D051379:Mice
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D008081:Liposomes; D002097:C-Reactive Protein