Lymphocyte response to T-cell mitogen during experimental gingivitis in humans

Abstract

This study was conducted to evaluate the dose response relationships of peripheral blood lymphocytes (PBL) by stimulation of phytohemagglutinin (PHA) during the onset of oral inflammation. Eleven dental students underwent a 3-week experimental gingivitis program (Loe et al., 1965). At time zero, weeks 1, 2, and 3, and after 1 week of reinstituted oral hygiene (week 4), the plaque accumulations were evaluated, the degree of gingival inflammation was assessed, and a blood sample was taken. Quadruplicate microcultures each containing 2 x 105 PBL in 0.2 ml of tissue culture medium 199 and 10% fetal calf serum were stimulated with five concentrations of PHA (10 to 0.5 ,ug/ml) and incubated for 78 h at 37 C in 5% C02. [3H]thymidine was added to each culture for the final 8 h. The cultures were then harvested and counted by liquid scintillation, and stimulation indexes (SI) were determined. At time zero the maximum PBL response occurred at a PHA concentration of 5 ug/ml (SI = 100). During weeks 1, 2, and 3 the location of the maximum PBL response shifted to a lower PHA concentration (1.0 ,ug/ml) and increased to over SI = 400. The phenomenon of shifting of peak PHA responses to lower PHA concentrations could be observed after only 1 week of developing gingival inflammation. The PBL response returned to pre-experimental values after 1 week of reinstituted oral hygiene, which resolved the oral inflammation. The findings show that a dose response relationship exists between PHA concentrations and the PBL response. If these dose response changes seen during developing gingival inflammation are ignored, either a decrease, increase, or no change in PBL response can be shown depending upon the PHA concentration evaluated. Owing to the dose-dependent nature of this PBL response, it is advisable to routinely use dose response curves in order to properly evaluate the full responsiveness of PBL to mitogenic substances.

Learned and unlearned concepts in periodontal diagnostics: a 50‐year perspective

“…They demonstrated that clinically healthy gingiva will develop gingivitis if all oral-hygiene efforts are stopped and that gingivitis-affected gingiva can be returned to health by the resumption of standard oral-hygiene practices. The experimental gingivitis model was subsequently validated by several groups in the coming decades (1,23,28,34,106,107,127,131,151,157,168,169,179,199,200,222,223,238,245,257,274,277). In addition, the microbiology of naturally occurring gingivitis in the general population was shown to closely resemble that found in the experimental gingivitis studies (171,215,234).…”

The immunopathogenesis of progressive chronic inflammatory periodontal disease

“…It was not until the work of Ivanyi & Lehner (1970) that any evidence indicating a possible role for T-cell mediated mechanisms in periodontal disease existed-Since then, several groups have attempted to elucidate this role using both peripheral blood lymphocytes (Kiger et 1974, Horton et al 1974, Lang & 1976) and experimental animal model ^ (Nobreus et al 1974a, b. Levy et al 1976, Wilde et al 1977).…”

“…Factors which influence the transformation response include age (Girard et al 1977, Church & Dolby 1978, the source and preparation of antigen as well as the dose of antigen. The importance of dose response relationships was demonstrated by Lang & Smith (1976) who found that the response of peripheral blood lymphocytes to the mitogen phytohaemagglutinin (PHA) during the development of gingival inflammation could be shown to decrease, increase or remain the same depending upon the PHA concentration evaluated.…”

Immunologic observations in macaques with Shigella‐associated periodontal disease

“…It is not known why the monkeys with SAPD gave significantly higher blastogenic responses to PHA than did the control monkeys. However, heightened responsiveness to PHA has been observed during periods of increased gingival infiammation in studies of human experimental gingivitis (Lang & Smith 1976, Gaumer, Holm-Pedersen & Folke 1976. Since no significant differences were observed in -"Hthymidine incorporation by resting cells from control and SAPD monkeys, it is unlikely that the heightened responsiveness to PHA was an artifact.…”

“…Since no significant differences were observed in -"Hthymidine incorporation by resting cells from control and SAPD monkeys, it is unlikely that the heightened responsiveness to PHA was an artifact. Possible explanations for it include: (1) an increase in the number of circulating PHAresponsive T-lymphocytes; (2) an increased recruitment of responsive cells involving macrophages and/or B-lymphocytes, and (3) surface membrane changes in responsive cells, involving an increase in mitogen receptors (Lang & Smith 1976, Hadden, Hadden & Coffey 1976.…”