Hemophore-like proteins produced by periodontopathogens are recognized by the host immune system and react differentially with IgG antibodies

ABSTRACT

Aims

Hemophore-like proteins sequester heme from host hemoproteins. We aimed to determine whether the host immune system can recognize not only Porphyromonas gingivalis HmuY but also its homologs expressed by other periodontopathogens, and how periodontitis influences the production of respective antibodies.

Methods

The reactivity of total bacterial antigens and purified proteins with serum IgG antibodies of 18 individuals with periodontitis and 17 individuals without periodontitis was examined by enzyme-linked immunosorbent assay (ELISA). To compare IgG reactivity between groups with and without periodontitis and within the various dilutions of sera, statistical analysis was performed using the Mann-Whitney U-test and two-way ANOVA test with the post-hoc Bonferroni test.

Results

Individuals with periodontitis produced IgG antibodies reacting more strongly not only with total P. gingivalis antigens (P = 0.0002; 1:400) and P. gingivalis HmuY (P = 0.0016; 1:100) but also with Prevotella intermedia PinA (P = 0.0059; 1:100), and with low efficiency with P. intermedia PinO (P = 0.0021; 1:100). No increase in the reactivity of IgG antibodies with Tannerella forsythia Tfo and P. gingivalis HusA was found in individuals with periodontitis.

Conclusions

Although hemophore-like proteins are structurally related, they are differentially recognized by the host immune system. Our findings point to specific antigens, mainly P. gingivalis HmuY and P. intermedia PinA, whose immunoreactivity could be further investigated to develop markers of periodontitis.

KEYWORDS:

• Periodontitis
• Serum IgG
• hemophore-like protein
• Porphyromonas gingivalis
• Prevotella intermedia
• Tannerella forsythia

Acknowledgments

We thank all study participants and medical and laboratory staff for their contribution to this study. We also thank Richard Ashcroft for English correction.

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contribution

All authors have made substantial contributions to the conception and design of the study. EKNS, ISGF, and SCT have been involved in examination of participants and samples collection. All authors have been involved in data collection, data analysis and data interpretation. TO and SCT have been involved in drafting the manuscript. All authors have been involved in revising of the manuscript and given final approval of the version to be published.

Data availability statement

All data generated in this study are included in this published article and are available from the corresponding author upon request.

Supplementary Material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/20002297.2023.2214455.

Additional information

Funding

This study was supported by the State of Bahia Research Support Foundation (RED0022/2014) (to SCT) and by the Subsidy of the Polish Ministry of Education and Science (501 10110) (to TO).