Human Milk Compounds Inhibiting Adhesion of Mutans Streptococci to Host Ligand-Coated Hydroxyapatite in vitroDanielsson Niemi L. · Hernell O. · Johansson I.
Departments of aOdontology/Cariology and bClinical Sciences/Pediatrics, Umeå University, Umeå, Sweden
Acquisition of mutans streptococci at an early age is a risk factor for later caries development. Following our recent finding that human milk may inhibit adhesion of Streptococcus mutans the aim of the present study was to identify compounds in human milk preventing adhesion of mutans streptococci to saliva- or gp340-coated hydroxyapatite (s-HA and gp340-HA) using an in vitro model system. Superdex 200 fractions of human milk and purified proteins were screened for binding inhibition of the S. mutans strain Ingbritt. Avid inhibition was seen to both s-HA and gp340-HA for caseins, lactoferrin, IgA and IgG, and moderate inhibition for α-lactalbumin and bile salt-stimulated lipase, whereas albumin and lysozyme had no effect. The inhibitory epitope in β-casein was delineated to its C-terminal LLNQELLNPTHQIYPVTQPLAPVHNPISV stretch by use of synthetic peptides. Similarly, a peptide (SCKFDEYFSQSCA) corresponding to the human lactoferrin stretch that is highly homologous to the previously shown inhibitory stretch of bovine lactoferrin was found to inhibit S. mutans Ingbritt binding. Inhibition by human milk, IgA, and the inhibitory β-casein peptide was universal among 4 strains of S. mutans (Ingbritt, NG8, LT11, JBP) and 2 strains of S. sobrinus (6715 and OMZ176). IgG inhibited 4, α-lactalbumin 3 and lactoferrin 2 of these 6 strains. It was also confirmed that none of the milk components coated on HA mediated S. mutans Ingbritt adhesion, which was consistent with the finding that no milk protein was recognized on Western blots by gp340/DMBT1 monoclonal antibodies.
Prof. I. Johansson
Department of Odontology
SE–901 87 Umeå (Sweden)
Tel. +46 90 785 6035, Fax +46 90 770 580, E-Mail email@example.com
Received: December 5, 2008
Accepted after revision: February 20, 2009
Published online: April 23, 2009
Number of Print Pages : 8
Number of Figures : 3, Number of Tables : 1, Number of References : 38
Vol. 43, No. 3, Year 2009 (Cover Date: May 2009)
Journal Editor: Shellis R.P. (Bristol)
ISSN: 0008-6568 (Print), eISSN: 1421-976X (Online)
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