Antibody responses to Porphyromonas gingivalis hemagglutinin A and outer membrane protein in chronic periodontitis

"Medicine food homology" plants promote periodontal health: antimicrobial, anti-inflammatory, and inhibition of bone resorption

"Medicine food homology" (MFH) is a term with a lengthy history. It refers to the fact that a lot of traditional natural products have both culinary and therapeutic benefits. The antibacterial, anti-inflammatory and anticancer effects of MFH plants and their secondary metabolites have been confirmed by numerous research. A bacterially generated inflammatory illness with a complicated pathophysiology, periodontitis causes the loss of the teeth's supporting tissues. Several MFH plants have recently been shown to have the ability to prevent and treat periodontitis, which is exhibited by blocking the disease's pathogens and the virulence factors that go along with them, lowering the host's inflammatory reactions and halting the loss of alveolar bone. To give a theoretical foundation for the creation of functional foods, oral care products and adjuvant therapies, this review has especially explored the potential medicinal benefit of MFH plants and their secondary metabolites in the prevention and treatment of periodontitis.

Variations in IgG antibody subclass responses to oral bacteria: Effects of periodontal disease and modifying factors

BACKGROUND AND OBJECTIVE

Local and systemic IgG antibodies or oral bacteria have been described with periodontitis. We extended these observations by assessing the impact of a range of intrinsic factors on serum IgG subclass antibodies to both commensal and pathogenic oral bacteria that would contribute to variations in immune protection or disease susceptibility in periodontitis have not been described.

METHODS

Subjects (n = 278) were classified as healthy, gingivitis, or periodontitis and categorized as mild, moderate, and severe periodontitis. Demographic stratification included sex, age, race/ethnicity, smoking, and obesity. Whole formalin-fixed bacteria were used as antigens to detect serum immunoglobulin (Ig)G subclass antibody levels using an ELISA.

RESULTS

The greatest differences in variations in IgG subclasses occurred in periodontitis versus health or gingivitis to bacteria considered oral pathogens (eg, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Treponema denticola) with IgG1, IgG2, and IgG4 increased by three- to sevenfold with Pg. Differences in subclass levels and distribution were also observed related to disease severity, particularly related to individual subclass responses to Pg. Examination of the overall population showed that females had elevated antibody, reflected by elevated IgG2 amounts/proportions. The older group of subjects demonstrated elevated antibody to multiple oral bacteria, lacking any particular subclass pattern. IgG2 antibody to Aa and Pg was increased in smokers. Multiple IgG subclass antibody levels to oral pathogens were significantly decreased in the obese subset within this population.

CONCLUSION

This investigation identified patterns of IgG subclass antibody responses to oral bacteria and demonstrated substantial effects of disease impacting the level and subclass distribution of antibody to an array of oral bacteria. Altered subclass antibody profiles most often in IgG2 levels and for antibody to P. gingivalis were found related to sex, age, disease severity, race/ethnicity, smoking, and obesity to both pathogens and commensal bacteria.

Heterogeneity of human serum antibody responses to P. gingivalis in periodontitis: Effects of age, race/ethnicity, and sex

Aging humans display an increased prevalence and severity of periodontitis, although the mechanisms underlying these findings remain poorly understood. This report examined antigenic diversity of P. gingivalis related to disease presence and patient demographics. Serum IgG antibody to P. gingivalis strains ATCC33277, FDC381, W50 (ATCC53978), W83, A7A1-28 (ATCC53977) and A7436 was measured in 426 participants [periodontally healthy (n = 61), gingivitis (N = 66) or various levels of periodontitis (N = 299)]. We hypothesized that antigenic diversity in P. gingivalis could contribute to a lack of "immunity" in the chronic infections of periodontal disease. Across the strains, the antibody levels in the oldest age group were lower than in the youngest groups, and severe periodontitis patients did not show higher antibody with aging. While 80 % of the periodontitis patients in any age group showed an elevated response to at least one of the P. gingivalis strains, the patterns of individual responses in the older group were also substantially different than the other age groups. Significantly greater numbers of older patients showed strain-specific antibody profiles to only 1 strain. The findings support that P. gingivalis may demonstrate antigenic diversity/drift within patients and could be one factor to help explain the inefficiency/ineffectiveness of the adaptive immune response in managing the infection.

Sublingual vaccination with fusion protein consisting of the functional domain of hemagglutinin A of Porphyromonas gingivalis and Escherichia coli maltose-binding protein elicits protective immunity in the oral cavity

This study demonstrated that sublingual immunization with a fusion protein, 25k-hagA-MBP, which consists of a 25-kDa antigenic region of hemagglutinin A purified from Porphyromonas gingivalis fused to maltose-binding protein (MBP) originating from Escherichia coli as an adjuvant, elicited protective immune responses. Immunization with 25k-hagA-MBP induced high levels of antigen-specific serum IgG and IgA, as well as salivary IgA. High level titers of serum IgG and IgA were also induced for almost 1 year. In an IgG subclass analysis, sublingual immunization with 25k-hagA-MBP induced both IgG1 and IgG2b antibody responses. Additionally, numerous antigen-specific IgA antibody-forming cells were detected from the salivary gland 7 days after the final immunization. Mononuclear cells isolated from submandibular lymph nodes (SMLs) showed significant levels of proliferation upon restimulation with 25k-hagA-MBP. An analysis of cytokine responses showed that antigen-specific mononuclear cells isolated from SMLs produced significantly high levels of IL-4, IFN-γ, and TGF-β. These results indicate that sublingual immunization with 25k-hagA-MBP induces efficient protective immunity against P. gingivalis infection in the oral cavity via Th1-type and Th2-type cytokine production.

Association of the FcγRIIB-nt645+25A/G polymorphism with the expression level of the FcγRIIb receptor, the antibody response to Porphyromonas gingivalis and the severity of periodontitis

BACKGROUND AND OBJECTIVE

Human FcγRIIb is an immunoglobulin G (IgG) receptor that inhibits the activation of B lymphocytes through cross-linking with the B-cell receptor via immune complexes. This function acts as a negative regulator of antibody production. Our previous studies have demonstrated the gene polymorphisms in FcγRIIb to be associated with periodontitis. In this study, we presented a polymorphism--FcγRIIB-nt645+25A/G (rs2125685)--in intron 4 and analyzed its functional relevance to periodontitis. We examined whether the FcγRIIB-nt645+25A/G polymorphism is associated with periodontal parameters, the IgG response to the periodontopathic bacterium Porphyromonas gingivalis and/or the expression level of FcγRIIb on peripheral B lymphocytes.

MATERIAL AND METHODS

Thirty-two patients with chronic periodontitis were genotyped with nested PCR and by direct sequencing of genome DNA. The levels of serum IgG and of specific IgG subclasses for P. gingivalis sonicate and for the recombinant 40-kDa outer membrane protein (OMP) were determined. The expression levels of FcγRIIb on peripheral B lymphocytes from 19 healthy donors were measured by flow cytometry.

RESULTS

Patients with the FcγRIIB-nt645+25AA genotype showed significantly higher mean clinical attachment levels compared to patients with the FcγRIIB-nt645+25GG genotype (p = 0.003) and a significantly lower IgG response to P. gingivalis sonicate and to the 40-kDa OMP. The expression levels of FcγRIIb protein on the cell surface in peripheral B lymphocytes were higher in healthy donors with the FcγRIIB-nt645+25AA genotype than in those with the FcγRIIB-nt645+25GG genotype (p = 0.03).

CONCLUSION

The higher expression levels of FcγRIIb in subjects with the FcγRIIB-nt645+25AA genotype may induce a lower level of production of IgG against P. gingivalis and therefore more severe periodontitis.

Antibody responses to Porphyromonas gingivalis outer membrane protein in the first trimester

BACKGROUND

Porphyromonas gingivalis (Pg) is one of the most harmful periodontal pathogens and it has been reported that Pg is associated with preterm birth (PTB), intrauterine growth retardation (IUGR) and pregnancy-induced hypertension (PIH), discovered by animal experiments and clinical research. The relationship between adverse pregnancy outcomes and maternal antibody response to Pg is controversial. On the other hand, the serum C-reactive protein (CRP) has been recognised as a reliable serum marker of periodontal disease.

AIMS

To determine the significance of antibody responses to Pg affecting pregnancy outcomes in the first trimester.

METHODS

A case-control study was carried out on women with PTB (n = 58), IUGR (n = 91), PIH (n = 32) and without any complications (control, n = 98). The serum level of the CRP and IgG1 against 40-kDa outer membrane protein of Pg (anti-40-kDa OMP Pg-IgG1) in the first trimester was measured.

RESULTS

The IUGR group, and PTB patients whose placentas were diagnosed as chorioamnionitis or whose vaginal flora included Lactobacilli, showed a lower level of anti-40-kDa OMP Pg-IgG1 than the control group. There was no difference in the serum CRP level between each case group and control group.

CONCLUSIONS

These results suggest that a lack of humoral immunity against Pg in early pregnancy is associated with IUGR and some PTB.

Acyl chain specificity of the acyltransferases LpxA and LpxD and substrate availability contribute to lipid A fatty acid heterogeneity in Porphyromonas gingivalis

Porphyromonas gingivalis lipid A is heterogeneous with regard to the number, type, and placement of fatty acids. Analysis of lipid A by matrix-assisted laser desorption ionization-time of flight mass spectrometry reveals clusters of peaks differing by 14 mass units indicative of an altered distribution of the fatty acids generating different lipid A structures. To examine whether the transfer of hydroxy fatty acids with different chain lengths could account for the clustering of lipid A structures, P. gingivalis lpxA (lpxA(Pg)) and lpxD(Pg) were cloned and expressed in Escherichia coli strains in which the homologous gene was mutated. Lipid A from strains expressing either of the P. gingivalis transferases was found to contain 16-carbon hydroxy fatty acids in addition to the normal E. coli 14-carbon hydroxy fatty acids, demonstrating that these acyltransferases display a relaxed acyl chain length specificity. Both LpxA and LpxD, from either E. coli or P. gingivalis, were also able to incorporate odd-chain fatty acids into lipid A when grown in the presence of 1% propionic acid. This indicates that E. coli lipid A acyltransferases do not have an absolute specificity for 14-carbon hydroxy fatty acids but can transfer fatty acids differing by one carbon unit if the fatty acid substrates are available. We conclude that the relaxed specificity of the P. gingivalis lipid A acyltransferases and the substrate availability account for the lipid A structural clusters that differ by 14 mass units observed in P. gingivalis lipopolysaccharide preparations.

Serum antibody levels in smoker and non-smoker saudi subjects with chronic periodontitis

BACKGROUND

Cigarette smoking is a significant risk factor for the initiation and progression of periodontal disease. Studies have shown altered serum and gingival crevicular fluid inflammatory cytokine profiles, immune cell function, and altered proteolytic regulation in smokers. The observations are not consistent, and to date, there is no clear mechanism to explain how smoking may affect periodontal disease. Hence, the present study was undertaken to assess the alterations of serum immunoglobulin levels in smokers with periodontitis and its potential role as a risk indicator of the disease process.

METHODS

In this study, 30 patients who smoked and 30 patients who did not smoke with chronic periodontitis and 30 healthy subjects were enrolled. Serum immunoglobulin (Ig) G, IgA, and IgM levels were estimated with immunoturbidimetric assay. The IgG subclass (IgG1, IgG2, IgG3, and IgG4) levels were performed using single radial immunodiffusion assay.

RESULTS

Levels of serum IgG and IgA were significantly lower in smokers compared to non-smokers and healthy controls (P <0.001). Although IgM levels were low in smokers, it was not significant. Of the four subclasses of IgG studied, the IgG2 was found to be significantly lower among smokers with periodontitis.

CONCLUSIONS

Current observations indicate that cigarette smoking may be associated with the suppression of B-cell function and immunoglobulin production. The alteration of antibody levels further explains the potential mechanism by which smoking exacerbates periodontal disease. Further studies at the molecular level may highlight the specific mechanism by which tobacco can interact with cells of the immune system and its impact on periodontal disease process.