STUDIES OF PROLIFERATIVE RESPONSES BY LONG-TERM-CRYOPRESERVED PERIPHERAL-BLOOD MONONUCLEAR-CELLS TO BACTERIAL COMPONENTS ASSOCIATED WITH PERIODONTITIS

Freezing techniques provide a means for repeating and extending immuno logical assays with frozen aliquots of an individual's peripheral bloo d mononuclear cell fraction. Lymphocytes which are stored frozen for a limited time retain their ability to respond to polyclonal B-cell act ivators, mitogens, and antigens of dental interest. Our studies extend these previous findings by determining lymphocyte functional activity following frozen storage for up to 100 weeks. In addition, the autolo gous immune response was measured by spontaneous lymphocyte proliferat ion following 0, 1, 10, 40, and 60 weeks of frozen storage. Peak respo nses for all individuals occurred at day 7 of incubation, The lymphocy te proliferative response to the superantigens toxic shock syndrome to xin-1 (TSST-1) and Staphylococcus enterotoxin A (SEA) were not changed after 100 weeks of frozen storage, Maximum responses varied among the individuals but occurred at equivalent stimulator concentrations. How ever, slopes generated from data obtained following 0, 4, 13, 20, 30, 50, 88, and 100 weeks of frozen storage showed no significant deviatio n from zero (P > 0.05) for all individuals tested. After 100 weeks of storage, the total changes in proliferative activity (counts per minut e per week) were -2.1% +/- 16.8% and -5.5% +/- 17.0% for TSST-1 and SE A, respectively, The lymphocyte proliferative responses to pokeweed mi togen, concanavalin A, and sonicates of two periodontal pathogens (Por phyromonas gingivalis and Actinobacillus actinomycetemcomitans) follow ing frozen storage were similar to those with TSST-1 and SEA. These re sults indicate that peripheral blood mononuclear cells stored frozen m ay serve as appropriate controls to monitor changes in the disease sta te during long-term periodontal treatment.