Beyond Good and Evil in the Oral Cavity: Insights into Host-Microbe Relationships Derived from Transcriptional Profiling of Gingival Cells

Abstract

In many instances, the encounter between host and microbial cells can be, through a longstanding evolutionary association, a balanced interaction whereby both cell types co-exist and inflict a minimal degree of harm on each other. In the oral cavity, despite the presence of large numbers of diverse organisms, health is the most frequent status. Disease will only ensue when the host-microbe balance is disrupted on a cellular and molecular level. With the advent of microarrays, it is now possible to monitor the responses of host cells to bacterial challenge in a global scale. However, microarray data are known to be inherently noisy, which is caused in part by their great sensitivity. Hence, we will address a number of important general considerations required to maximize the significance of microarray analysis in order to faithfully depict relevant host-microbe interactions. Several advantages and limitations of microarray analysis that may directly impact the significance of array data are highlighted and discussed. Further, this review revisits and contextualizes recent transcriptional profiles that were originally generated to specifically study intricate cellular interactions between gingival cells and four important plaque microorganisms. This is, to our knowledge, the first report that systematically investigates the cellular responses of a cell line to challenge by 4 different microorganisms. Of particular relevance to the oral cavity, the model bacteria span the entire spectrum of documented pathogenic potential from commensal to opportunistic to overtly pathogenic. These studies provide a molecular basis of the complex and dynamic interaction between the oral microflora and its host, which may lead, in the long run, to the development of novel, rational and practical therapeutic, prophylactic and diagnostic applications.

Periodontal disease in pediatric rheumatic diseases

“…In addition, bacteria or their products continually interact with gingival epithelium to stimulate a host response. 18 An inflammatory infiltrate (mainly comprised of neutrophils or polymorphonuclear leukocytes) is usually present, even in the absence of clinically obvious inflammation in order to maintain periodontal homeostasis. 19 The bacteria associated with PD comprise a group of Gram-negative anaerobic organisms, among which the socalled "red complex" pathogens, especially Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia, are more prominent.…”

Predictive modeling of gingivitis severity and susceptibility via oral microbiota

“…As a worldwide health concern, it affects most children and adolescents (Petersen et al, 2005;Kornman, 2008;Filoche et al, 2010;Jin et al, 2011). The disease is believed to result from buildup of plaque (Moore et al, 1987) and ensuing interactions between the plaque microbiota and host tissues (Handfield et al, 2008;Offenbacher et al, 2009). Although no apical migration of the junctional epithelium occurs, these tissues become erythematous and bleed upon probing.…”

Porphyromonas gingivalis-Induced Reactive Oxygen Species Activate JAK2 and Regulate Production of Inflammatory Cytokines through c-Jun

“…Porphyromonas gingivalis, a Gram-negative black-pigmented anaerobe, is a major pathogen in the initiation and progression of periodontitis (15)(16)(17)(18). While P. gingivalis can induce robust inflammatory responses, including the generation of a wide variety of cytokines and chemokines, the organism is also capable of subverting and stalling host immunity depending on the context (15,(19)(20)(21)(22)(23)(24). Moreover, phagocytosed P. gingivalis is resistant to oxidative burst killing by polymorphonuclear neutrophils, in part by producing antioxidant enzymes such as superoxide dismutase, thiol peroxidase, and rubrerythrin (25)(26)(27)(28).…”