Mannose-binding lectin gene polymorphism in relation to periodontal infection.
OBJECTIVE
Mannose-binding lectin (MBL) plays an important role in innate immunity. MBL deficiency is usually caused by mutations in exon 1 of the MBL structural gene (MBL2). Our aim was to investigate MBL2 polymorphisms and their relation to salivary levels of periodontal inflammatory/tissue destruction markers and two major periodontitis-associated bacteria.


METHODS
Salivary samples from 222 subjects were available for genotyping by pyrosequencing. The subjects between 40 and 60 years of age and having a minimum of 20 teeth were divided into three periodontal groups: 80 had generalized periodontitis, 65 had localized periodontitis and 77 were periodontitis-free. A comparison between their MBL2 genotypes and salivary detection rates and levels of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis as well as interleukin -1β, matrix metalloproteinase -8, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 was performed.


RESULTS
The frequencies of the MBL2 wild-type (A/A), heterozygote variants (A/O) and homozygote variants (O/O) were 69.4%, 26.6% and 4%, respectively. In A. actinomycetemcomitans-positive subjects having homozygote or heterozygote MBL2 variants, the salivary concentrations of IL-1β (p = 0.010) were elevated and those of TIMP-1 (p = 0.001) were decreased. In addition their matrix metalloproteinase -8/TIMP-1 ratio was higher (p < 0.001) and they had more pocket teeth (p = 0.012) than subjects negative for A. actinomycetemcomitans.


CONCLUSIONS
Our findings indicate that the carriage of A. actinomycetemcomitans may facilitate extended periodontal inflammation and destruction in subjects with a variant form of human MBL2.
Institute of Dentistry, University of Turku, Turku, Finland.
A
A
Liukkonen
Department of Medical Microbiology and Immunology, University of Turku, Turku, Finland.
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Q
He
Institute of Dentistry, University of Turku, Turku, Finland.
U K
UK
Gürsoy
Department of Oral and Maxillofacial Diseases, University of Helsinki, Helsinki, Finland.
P J
PJ
Pussinen
Department of Medical Microbiology and Immunology, University of Turku, Turku, Finland.
K
K
Gröndahl-Yli-Hannuksela
Institute of Dentistry, University of Turku, Turku, Finland.
J
J
Liukkonen
Department of Oral and Maxillofacial Diseases, University of Helsinki, Helsinki, Finland.|Division of Periodontology, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden.
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T
Sorsa
Institute of Dentistry, University of Eastern Finland, Kuopio, Finland.|Unit of Living Conditions, Health and Wellbeing, Department of Environmental Health in Environmental Epidemiology Unit, National Institute for Health and Welfare (THL), Kuopio, Finland.|Department of Oral and Maxillofacial Surgery, Kuopio University Hospital, Kuopio, Finland.
A L
AL
Suominen
Institute of Dentistry, University of Turku, Turku, Finland.
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S
Huumonen
Institute of Dentistry, University of Turku, Turku, Finland.|Welfare Division, Oral Health Care, City of Turku, Turku, Finland.
E
E
Könönen
D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D060005:Genotyping Techniques; D006801:Humans; D053583:Interleukin-1beta / Q000032:analysis; D008297:Male; D037601:Mannose-Binding Lectin / Q000235:genetics*; D020784:Matrix Metalloproteinase 8 / Q000032:analysis; D008875:Middle Aged; D010518:Periodontitis / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D016966:Porphyromonas gingivalis; D012463:Saliva / Q000382:microbiology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis
D053583:Interleukin-1beta; C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D020784:Matrix Metalloproteinase 8
bacteria; genetic polymorphism; periodontitis; saliva