title: Adjuvant activity of peptidoglycan monomer and its metabolic products.
abstract: Peptidoglycan monomer (PGM) is a natural compound of bacterial origin. It is a non-toxic, non-pyrogenic, water-soluble immunostimulator potentiating humoral immune response to ovalbumin (OVA) in mice. It is fast degraded and its metabolic products-the pentapeptide (PP) and the disaccharide (DS)-are excreted from the mammalian organism upon parenteral administration. The present study investigates: (a). whether PGM could influence the long-living memory generation; (b). whether metabolic products retain adjuvant properties of the parent compound and contribute to its adjuvanticity. We report now that mice immunised twice with OVA+PGM had significantly higher anti-OVA IgG levels upon challenge with antigen alone 6 months later in comparison to control group immunised with OVA only. PP and DS were prepared enzymatically in vitro as apyrogenic and chemically pure compounds. When mice were immunised with OVA plus PP and DS, respectively, the level of anti-OVA IgGs in sera was not higher than in mice immunised with OVA alone, while PGM raised the level of specific antibodies. Results implicate that the adjuvant active molecule, capable of enhancing long-living memory generation, is PGM itself, and none of its metabolic products.
authors.affiliation: Research and Development Department, Institute of Immunology Inc, Rockefellerova 10, HR-10 000, Zagreb, Croatia. bhalassy@imz.hr
authors.forename: Beata
authors.initials: B
authors.lastname: Halassy
authors.forename: Marina
authors.initials: M
authors.lastname: Krstanović
authors.forename: Ruza
authors.initials: R
authors.lastname: Frkanec
authors.forename: Jelka
authors.initials: J
authors.lastname: Tomasić
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology*; D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D000941:Antigens / Q000008:administration & dosage; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008815:Mice, Inbred Strains; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology; D010457:Peptidoglycan
chemical_list: D000276:Adjuvants, Immunologic; D000941:Antigens; D007074:Immunoglobulin G; D010457:Peptidoglycan; D000119:Acetylmuramyl-Alanyl-Isoglutamine; C032972:peptidoglycan pentapeptide-mDap3; D010047:Ovalbumin