Orally administered ovine serum immunoglobulins modulate dental plaque in cats.

The effects of orally administered ovine serum immunoglobulin on dental plaque and associated oral immunity in cats were investigated. The two treatment groups consisted of 1) cats that were fed unsupplemented kibble (control diet) and 2) cats that were fed the same kibble but coated with a freeze-dried ovine serum immunoglobulin preparation (ovine Ig) (test diet). The adult cats were randomly allocated to one of the two diets (n = 15) and received their respective kibble for a 28-day experimental period. When compared to the ovine Ig-supplemented kibble, cats consuming the unsupplemented kibble had significantly (p < 0.05) higher dental plaque scores. Cat IgA and IgG concentrations in the saliva and serum were significantly (p < 0.05) higher for cats fed the unsupplemented kibble when compared to cats receiving the ovine Ig supplement. Similarly, myeloperoxidase activity in the saliva was significantly (p < 0.05) higher for cats fed the unsupplemented kibble when compared to cats receiving the Ig-supplement. Orally administered ovine serum Ig positively influenced oral health and oral immunity in cats as evidenced by preventing an increase of dental plaque formation, salivary and serum IgA and IgG concentrations and salivary myeloperoxidase activity.

T cells, teeth and tissue destruction - what do T cells do in periodontal disease?

The microbial plaque biofilm resides adjacent to the tissue-destructive inflammatory infiltrate in periodontitis. Although not sufficient, this biofilm is necessary for this inflammatory response. Patients with periodontitis generate antibodies specific for bacteria in the biofilm - although the role of these antibodies is not clear, there is, undoubtedly, an adaptive immune response in periodontitis. T lymphocytes are central to adaptive immunity, and provide help for B cells to generate specific antibodies. T-cell receptor recognition of peptide antigen in the context of major histocompatibility complex can result in T-cell activation. The activation and differentiation of the T-cell can take many forms, and hence numerous types of T cells have been described. The role of adaptive immune responses, and the T-cell component thereof, in periodontitis remains relatively poorly defined. This review aims to broadly summarize findings about T cells and their role in periodontitis, focusing primarily on studies of human disease with a short discussion of some animal studies.

Acute stress effects on local Il-1beta responses to pathogens in a human in vivo model.

The combined effects of stress and antigen on interleukin-1beta (Il-1beta) have rarely been studied locally at the site of microbial challenges in vivo, so far. We here propose a model for the analysis of such effects in humans and examine its utility for acute stress trials. Twelve students (6 male, 6 female) refrained from oral hygiene in two antagonistic quadrants for 28 days to allow for increasing bacterial stimulation of the respective gingival sites due to accumulation of microbial plaque. Good oral hygiene was maintained in the remaining quadrants. At day 27 and 28 students were subjected to either stress ('public speech') or a control condition, in a cross-over design. Samples of gingival crevicular fluid (GCF) which emerges between the tooth surface and the gingival epithelium as transudate of healthy and exudate of inflamed gingival tissue, were taken immediately after stress and 60 min later for Il-1beta analysis. Salivary cortisol was assessed to prove the validity of the stress protocol. Stress induced a profound increase of salivary cortisol (p=.001). Repeated measures (stress x time x hygiene) ANOVA with gender as between factor revealed significant stress (p=.014) and hygiene (p=.038) effects on GCF-Il-1beta concentrations and tentatively significant hygiene x time (p = .097) and stress x time x hygiene x gender (p=.107) interactions. Stress induced an increase of Il-1beta as did plaque accumulation. The merits of the proposed model are discussed. It is concluded that it is well suited for the assessment of the effects of stress on inflammatory responses in vivo in humans.

Immunological properties of Actinomyces viscosus: comparison of blastogenic and adjuvant activities.

A water-soluble extract of Actinomyces viscosus was tested for its capacity to induce deoxyribonucleic acid synthesis in spleen cells from normal mice and to augment the in vitro antibody-forming cell (AFC) response to the T-cell-dependent antigen, sheep erythrocytes (SRBC) by T-cell-deficient adherent spleen cell monolayers from the same mice. Our results indicated that the water-soluble extract induced an in vitro blastogenic response, as assessed by tritiated thymidine incorporation into mouse spleen cells. The water-soluble extract also augmented the antibody response to SRBC. However, after fractionation of the water-soluble extract on Biogel P-300, not all of the fractions induced a blastogenic response and augmented an AFC response to SRBC. This difference in the ability of A. viscosus fractions to induce in vitro responses suggests that the water-soluble extract has multiple immunological properties. Chemical analysis of the water-soluble extract indicated an enrichment for amino acids and amino sugar common to peptidoglycan.