Effect of Factors Other Than Pathologic Status on Responsiveness of Peripheral Blood Mononuclear Cells from Patients With Chronic Periodontitis

Publisher Website
Google Scholar
Abstract
Studies were designed to assess factors other than pathologic status of the cell donor which affect the blastogenic responsiveness in vitro of peripheral blood mononuclear cells (PBMs) from normal donors and patients with periodontitis. Cultures were established and activated using phytohemagglutinin‐P (PHA) or homogenates of Actinomyces viscosus (AVIS), a gram‐positive plaque microorganism, and Fusobacterium nucleatum (FUSO), a gram‐negative plaque microorganism. Activation was assessed by measuring the incorporation of labeled precursor into DNA. The effects of incubation time, vessel shape, cell concentration, prostaglandin E2 and indomethacin on blastogenic responsiveness were studied.Blastogenic responsiveness became maximal after 5 to 8 days' activation with the bacterial substances, and after 3 days' activation with PHA. Radioactivity incorporated by cultures in microtest wells with flat, round and conical bottoms was 5.9, 7.8 and 10.6 × 103 cpm, respectively. Cultures of cells from all of the patients and normal subjects were activated by PHA, AVIS and FUSO, and cell concentration was a major determinant of the magnitude of the blastogenic response. Responsiveness of cultures from all patients and control subjects activated with AVIS and FUSO was inhibited significantly by Prostaglandin E‐2 (PGE2) at a concentration of 10 μm. Inhibition was generally 50% or greater. Indomethacin, an inhibitor of prostaglandin production, at a concentration of 0.5 μg/ml significantly enhanced responsiveness of AVIS‐ and FUSO‐activated cultures from control donors and patients, indicating that prostaglandins are produced endogenously, and that they affect cell responsiveness. The effect of PGE2 and indomethacin on PHA‐activated cultures was more variable and, where present, of a lesser magnitude than that observed for cultures activated with bacterial homogenates. In most cultures the effects were not statistically significant. Our data show that in studies of lymphocyte activation, the incubation time, culture‐vessel shape, cell concentration and presence of endogenous inhibitors need to be taken into account.
Funding Information
  • National Institutes of Health (DE‐02600 and DE‐07063)