The human 60 kDa and microbial 65 kDa heat shock proteins (HSP) have been implicated in the pathogenesis of chronic periodontitis (P) and coronary heart disease (CHD). We have studied four male non-smoking cohorts of 81 subjects, matched for age. Group (a) consisted of a healthy group with minimal gingivitis ( n = = = = 18), group (b) were patients with P ( n = = = = 23), group (c) patients with CHD and minimal gingivitis ( n = = = = 20) and group (d) patients with CHD and P ( n = = = = 20). T cells separated from peripheral blood were found to be primed to both microbial HSP65 and human HSP60 but significant CD4, human leucocyte antigen (HLA) class II-restricted proliferative responses were found only with the human HSP60 in patients with P ( P < < < < 0·001) and CHD without ( P < < < < 0·001) or with ( P < < < < 0·00001) periodontitis. Dose-dependent inhibition of T cell proliferative responses was carried out to determine the receptors involved in recognition of HSP60 and HSP65. Monoclonal antibodies to CD14 showed inhibition of T cell proliferation stimulated by both HSP60 and HSP65, consistent with the role of CD14 as a receptor for these HSPs in P and CHD. The toll-like receptor 2 (TLR-) and TLR-4 were then studied and these showed that TLR-4 was recognized by microbial HSP65, whereas TLR-2 was recognised by human HSP60 in both P and CHD. However, a dissociation was found in the HSP60 and TLR4 interaction, as TLR4 appeared to have been recognized by HSP60 in P but not in CHD. The results suggest an autoimmune or cross-reactive CD4 + + + + class IIrestricted T cell response to the human HSP60 in P and CHD. Further studies are required to determine if there is a common epitope within HSP60 that stimulates T cell proliferation in P and CHD.

Chronic periodontitis (CP) is a chronic inflammatory condition which destroys the supporting tissues of teeth and increases in prevalence with age. Immune responses against heat shock proteins (HSP) can be cross-reactive among bacterial and human antigens. There is evidence that microbial HSP65 and human HSP60 are involved in periodontal disease. The aim of this study is to investigate immune responses to the human HSP60 and microbial HSP65 in patients with CP and relate these to the level of inflammation and smoking status. We collected serum samples from 30 patients with chronic gingivitis (CG) and 30 patients with CP. In each group, eight subjects were current smokers. ELISA was used to determine the levels of serum anti-HSP and C-reactive protein (CRP) in each group. Peripheral blood mononuclear cells were also isolated and stimulated with HSPs. Significant lymphoproliferation was seen in CP when stimulated with human HSP60. CRP and serum anti-human HSP60 IgG were elevated in CP compared to the CG, but not serum anti-microbial HSP 65 IgG. In view of the potential confounding effects of smoking in CP, a group of current smokers (n = 16) was also recruited to investigate whether smoking affects HSP immune responses. There was no significant difference in HSP-induced lymphoproliferation between smokers and non-smokers in either the CG or CP. There was a significant correlation between CRP and lymphoproliferative responses to Human HSP60 irrespective of smoking status. This study shows that serum anti-human HSP60 IgG and serum CRP are raised in untreated CP. In CP, serum CRP levels correlated significantly with human HSP60-induced lymphoproliferation, but not with anti-HSP antibody levels.