title: Human placenta: relative content of antibodies of different classes and subclasses (IgG1-IgG4) containing lambda- and kappa-light chains and chimeric lambda-kappa-immunoglobulins.
abstract: The specific organ placenta is much more than a filter: it is an organ that protects, feeds and regulates the growth of the embryo. Affinity chromatography, ELISA, SDS-PAGE and matrix-assisted laser desorption ionization mass spectrometry were used. Using 10 intact human placentas deprived of blood, a quantitative analysis of average relative content [% of total immunoglobulins (Igs)] was carried out for the first time: (92.7), IgA (2.4), IgM (2.5), kappa-antibodies (51.4), lambda-antibodies (48.6), IgG1 (47.0), IgG2 (39.5), IgG3 (8.8) and IgG4 (4.3). It was shown for the first time that placenta contains sIgA (2.5%). In the classic paradigm, Igs represent products of clonal B-cell populations, each producing antibodies recognizing a single antigen. There is a common belief that IgGs in mammalian biological fluids are monovalent molecules having stable structures and two identical antigen-binding sites. However, similarly to human milk Igs, placenta antibodies undergo extensive half-molecule exchange and the IgG pool consists of 43.5 ± 15.0% kappa-kappa-IgGs and 41.6 ± 17.0% lambda-lambda-IgGs, while 15.0 ± 4.0% of the IgGs contained both kappa- and lambda-light chains. Kappa-kappa-IgGs and lambda-lambda-IgGs contained, respectively (%): IgG1 (47.7 and 34.4), IgG2 (36.3 and 44.5), IgG3 (7.4 and 11.8) and IgG4 (7.5 and 9.1), while chimeric kappa-lambda-IgGs consisted of (%): 43.5 IgG1, 41.0 IgG2, 5.6 IgG3 and 7.9 IgG4. Our data are indicative of the possibility of half-molecule exchange between placenta IgGs of various subclasses, raised against different antigens, which explains a very well-known polyspecificity and cross-reactivity of different human IgGs.
authors: SB RAS, Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia.
authors: Evgenii A
authors: EA
authors: Lekchnov
authors: SB RAS, Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia.
authors: Sergey E
authors: SE
authors: Sedykh
authors: Pacific Institute of Bioorganic Chemistry, Far East Division, Russian Academy of Sciences, Vladivostok 690022, Russia.
authors: Pavel S
authors: PS
authors: Dmitrenok
authors: SB RAS, Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia Novosibirsk State University, 2 Pirogova Street, Novosibirsk 630090, Russia.
authors: Valentina N
authors: VN
authors: Buneva
authors: SB RAS, Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentiev Avenue, Novosibirsk 630090, Russia Novosibirsk State University, 2 Pirogova Street, Novosibirsk 630090, Russia nevinsky@niboch.nsc.ru.
authors: Georgy A
authors: GA
authors: Nevinsky
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000032:analysis / Q000145:classification / Q000276:immunology; D007074:Immunoglobulin G / Q000032:analysis / Q000145:classification / Q000276:immunology*; D007147:Immunoglobulin Light Chains / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000276:immunology; D007146:Immunoglobulin lambda-Chains / Q000032:analysis / Q000145:classification / Q000276:immunology; D010920:Placenta / Q000276:immunology*; D011247:Pregnancy
chemical_list: D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains
keywords: IgGs containing lambda- and kappa-light chains; chimeric lambda-kappa-immunoglobulins; half-molecule exchange between IgGs; human placenta; relative content of antibodies of different classes and subclasses