Immunodominant Antigens in Periodontal Disease: a Real or Illusive Concept?

Abstract

The humoral arm of the immune system provides protection from many medically significant pathogens. The antigenic epitopes of the pathogens which induce these responses, and the subsequent characteristics of the host response, have been extensively documented in the medical literature, and in many cases have resulted in the development and implementation of effective vaccines or diagnostic tests. There is a substantial body of literature on the humoral immune response in periodontal disease, which is targeted at micro-organisms present within periodontal pockets. However, the significance and specificity of the immune response in periodontal disease have proved difficult to elucidate, due to the large number of potential pathogens in the plaque biofilm and the apparent commensal nature of many of these opportunistic pathogens. This review addresses our current knowledge of the approaches and strategies which have been used to elucidate and examine the concept of immunodominant antigens in medical infections and, more recently, periodontal disease. An identification/understanding of the immunodominant antigens would be informative with respect to: (i) the relative importance of the implicated pathogens, (ii) new approaches to immunological diagnosis, (iii) specific bacterial virulence determinants, (iv) natural protective responses, and (v) the selection of potential vaccine candidate antigens. We conclude that immunodominance of antigens in periodontal disease may be relevant to our understanding of periodontal disease pathogenesis, but due to the complexity and diversity of the 'pathogenic microbial ecology', it is currently an enigmatic topic requiring a multidisciplinary approach linking clinical, microbiological, and immunological investigations. We also conclude, after assessing the literature available on the topic of immunodominance, that it is a term that, if used, must be clearly defined and understood, since it is often used loosely, leading to a general misinterpretation by readers of oral and medical literature.

Humoral immune response to Aggregatibacter actinomycetemcomitans leukotoxin

“…This is in line with previous findings from adult populations with periodontitis (21), while the presence of systemic leukotoxin antibodies is strongly associated with adolescents with periodontitis (22,24,30–32). The protective role of these antibodies in the pathogenesis of periodontal diseases is still not clear, and conflicting data exist in the literature (24,31,32). The localization of the infection and the physiological conditions in the periodontal pocket (proteolytic, anaerobic) might affect antibody function.…”

Human dendritic cells respond to Porphyromonas gingivalis LPS by promoting a Th2 effector response in vitro

“…reflective of the complexity of the polymicrobial oral infection [25] and the different stages of the disease process during cytokine sampling [13]. Also observed is the presence of P. gingivalis antigens, colocalized with immature DC in situ [18]; moreover, our laboratory has now observed, using double-immunofluorescence staining and laser confocal microscopy, the presence of dermal DC and mature CD83 + DC in close association with CD4 + T cells in situ [19].…”

Differential gender effects of a reduced‐calorie diet on systemic inflammatory and immune parameters in nonhuman primates

“…Periodontal disease provides a model of host–bacterial interactions, inflammation and adaptive immune responses that can be used to examine nutritional and aging changes in the oral cavity. In addition, ample evidence has demonstrated that these local oral infections also stimulate a systemic inflammatory and humoral immune response (50,53,58, 72–77).…”