CD14 and TLR4 Gene Polymorphisms in Adult Periodontitis

Bacterial deposits, smoking, and host genetic factors play a major role in an individual’s predisposition to periodontitis. Bacterial components are recognized by CD14 and toll-like receptor 4 (TLR4), resulting in a NF-κB-based inflammatory response. We hypothesized that functional CD14 and TLR4 polymorphisms contribute to periodontitis susceptibility. We aimed to investigate the occurrence of CD14-260C>T, TLR4 299Asp>Gly, and 399Thr>Ile gene polymorphisms in adult periodontititis. DNA was collected from 100 patients with severe periodontitis and from 99 periodontally healthy controls. The gene polymorphisms were determined by the PCR technique. The presence of the periodontal pathogens Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans, and whether the subjects smoked, was included in the analyses. The CD14-260T/T genotype was found in 34.0% of periodontitis patients and in 20.2% of controls. Logistic regression analysis adjusted for gender, age, smoking, and prevalence of P. gingivalis and A. actinomycetemcomitans showed an association between the CD14-260T/T genotype and periodontitis (P = 0.004, OR 3.0, 95% CI 1.4–6.9). We conclude that the CD14-260T/T genotype contributes to the susceptibility to severe periodontitis in Dutch Caucasians.

Decoy receptors block TRAIL sensitivity at a supracellular level: the role of stromal cells in controlling tumour TRAIL sensitivity

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a death ligand cytokine known for its cytotoxic activity against malignantly transformed cells. TRAIL induces cell death through binding to death receptors DR4 and DR5. The inhibitory decoy receptors (DcR1 and DcR2) co-expressed with death receptor 4 (DR4)/DR5 on the same cell can block the transmission of the apoptotic signal. Here, we show that DcRs also regulate TRAIL sensitivity at a supracellular level and thus represent a mechanism by which the microenvironment can diminish tumour TRAIL sensitivity. Mathematical modelling and layered or spheroid stroma-extracellular matrix-tumour cultures were used to model the tumour microenvironment. By engineering TRAIL to escape binding by DcRs, we found that DcRs do not only act in a cell-autonomous or cis-regulatory manner, but also exert trans-cellular regulation originating from stromal cells and affect tumour cells, highlighting the potent inhibitory effect of DcRs in the tumour tissue and the necessity of selective targeting of the two death-inducing TRAIL receptors to maximise efficacy.

CARD15 gene mutations in periodontitis

OBJECTIVES

The CARD15 gene encodes the Nod2 protein, which is involved in intracellular recognition of bacterial products like peptidoglycan, activates inflammation and regulates apoptosis through nuclear factor-kappa B, a transcription factor that plays a central role in the innate immunity. Two functional mutations, an insertion mutation at nucleotide 3020 (3020insC) and a missense mutation C2104T in the CARD15 gene (originally NOD2 gene) have been reported to be associated with Crohn's disease. Our aim was to investigate the occurrence of CARD15 gene polymorphisms in adult patients with periodontitis taking into account smoking and presence of putative periodontal pathogens as additional variables.

MATERIAL AND METHODS

A case-control study was performed in 104 Dutch Caucasian patients with severe adult periodontitis (54 non-smokers and 50 smokers, mean age 46 years) and in 97 ethnically matched, periodontal healthy controls (73 non-smokers and 24 smokers, mean age 40 years). DNA isolated from a mouthwash was typed with PCR technology. Presence of putative periodontal pathogens was established by culture technique.

RESULTS

Frequencies of the CARD15 3020insC and 2104T mutations were similar in the periodontitis group and in the control group (5.1% and 13.3%; 5.2% and 10.3%, respectively). The highest carrier frequency of CARD15 mutations was found in non-smoking patients without Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans (29.4% versus 17.4% in controls); however it did not reach statistical significance.

CONCLUSION

Our results suggest no role for CARD15 3020insC and C2104T mutations in adult periodontitis.

Genetic and serological markers to identify phenotypic subgroups in a Dutch Crohn' s disease population

BACKGROUND AND AIMS

Both genetic and microbial factors seem to play a pivotal role in the aetiopathogenesis of Crohn's disease. The CARD15 frameshift mutation might link host genetic factors and the indigenous microbial flora, since CARD15 expression is stimulated by peptidoglycan, thereby activating NF-kappaB. It is hypothesised that CARD15 mutation carriers have defective anti-microbial reactions, resulting in more penetrating lesions and antibody responses, which are now being used as highly specific markers for Crohn's disease. The serological marker anti-Saccharomyces cerevisiae antibody directed against cell wall oligomannosidic epitopes has high specificity for Crohn's disease. Perinuclear anti-neutrophil cytoplasmic antibodies have been found in a subgroup of Crohn's disease patients, mostly with colonic involvement.

METHODS

We investigated the incidence of two CARD15 mutations (3020insC and 2722G>C), anti-S. cerevisiae antibody, and perinuclear anti-neutrophil cytoplasmic antibody in 108 (73F/35M) patients with Crohn's disease with a mean duration of disease since diagnosis of 16 (1-41) years in relation to their phenotype, according to the Vienna classification.

RESULTS

The prevalence of CARD15 frameshift mutation was 21%. Of all patients, 62% were anti-S. cerevisiae antibody positive, and 9% had perinuclear anti-neutrophil cytoplasmic antibodies. The prevalence of both anti-S. cerevisiae antibodies and perinuclear anti-neutrophil cytoplasmic antibodies was higher in the mutation carriers compared to non-carriers. Remarkably, all patients with a CARD15 mutation and positive anti-S. cerevisiae antibody had ileal disease. Carriership of the mutation was significantly associated with penetrating behaviour of the disease and weakly associated with stricturing behaviour. Furthermore, anti-S. cerevisiae antibody was associated with ileal disease involvement. Finally, most perinuclear anti-neutrophil cytoplasmic antibody positive patients showed ulcerative-like behaviour of disease (by means of colonic localisation).

CONCLUSIONS

Genetic and serologic markers might be useful in defining patient subgroups. This may result in a more accurate prediction of disease behaviour, prognosis and therapeutic approach.

Prevalence of mutations of the NOD2/CARD15 gene and relation to phenotype in Spanish patients with Crohn disease

BACKGROUND

We assessed the prevalence of R702W, G908R, and L1007fs coding mutations in the NOD2/CARD15 gene and the genotype-phenotype relation in Spanish patients with Crohn disease.

METHODS

A cohort of 204 unrelated patients with Crohn disease and 140 healthy controls were studied. The phenotype was established before commencement of genotyping. Genotyping of the R702W, G908R, and L1007fs gene polymorphisms of NOD2/CARD15 was performed by two independent laboratories using different techniques. In the case of discordant results, specific sequencing of DNA strands was performed.

RESULTS

At least one mutation was present in 32.8% of patients compared to 10.7% in controls (OR = 4.08, 95% CI 2.21 to 7.50). In patients with Crohn disease, the frequency of R702W, G908R, and L1007fs carriers was 13.7%, 8.3%, and 14.2%, respectively. Compound heterozygotes and homozygotes occurred in 3.4% and 2.9% of patients and in none of the controls. The correlation of genotype-Vienna classification showed a significant association with ileal disease (RR = 1.61, 95% CI 1.21-2.15, P = 0.001) and an inverse association with colonic localization (RR = 0.29, 95% CI 0.11-0.80, P = 0.007). There was a significant association between G908R carriership and previous appendectomy, surgical interventions, and stricturing behavior. A gene-dosage effect on phenotypic characteristics was not observed.

CONCLUSIONS

In a Spanish population from Madrid, mutations of the NOD2/CARD15 gene were a marker of susceptibility to Crohn disease and were associated with ileal disease. Carriers of the G908R mutation showed a stricturing disease behavior, history of appendectomy, and surgical interventions over the course of the disease.

CARD15 gene mutations are not associated with ankylosing spondylitis

An insertion mutation at nucleotide 3020 (3020insC) and a missense mutation G2722C in the CARD15 gene on chromosome 16p have been reported to be associated with Crohn's disease (CD). The protein encoded by the CARD15 gene is expressed in peripheral monocytes and regulates apoptosis and NF-kappaB activation, factors which play an important role in inflammation. Since CD and ankylosing spondylitis (AS) are interrelated disorders, we have investigated whether these mutations in the CARD15 gene are also associated with AS. We studied 113 unrelated AS patients and 152 unrelated healthy controls. No significant differences were found between patients and controls in the prevalence of the insertion 3020insC mutation and the G2722C missense mutation, OR = 1.36, 95% CI: 0.27-6.84, P = 0.70 and OR = 0.58; 95% CI: 0.18-1.94; P = 0.38, respectively. We conclude that the insertion 3020insC mutation and the G2722C missense mutation in the CARD15 gene are not involved in the susceptibility to AS.