No abstract

We have previously described a T helper cell 2-type clone, A3, of rat T cells that provides help for antibody production to Actinobacillus actinomycetemcomitans in vitro and in vivo in normal (euthymic) isogeneic Rowett strain recipient rats. Adoptive transfer of this T helper cell clone to euthymic rats also protects them from periodontal bone loss induced by oral infection with A. actinomycetemcomitans. In the present study, to assess the cell requirement for protection, A3 clone T lymphocytes (10(6)) or naive lymph node (6 x 10(4)) T cells, or A3 plus naive lymph node T cells (6 x 10(4)) were adoptively transferred to groups (n = 7-9) of 30-day-old Rowett athymic nude (rnu/rnu) rats. All recipients were also immunized (intraperitoneally) with 10(7) killed A. actinomycetemcomitans on the day of T cell transfer and orally infected with these bacteria on each of the next 5 days. Recipients of the combined A3+lymph node T cell transfer showed significantly increased serum immunoglobulin G (IgG) and IgM antibody to A. actinomycetemcomitans and in vitro proliferation of spleen lymphocytes to A. actinomycetemcomitans as antigen compared with nude animals receiving lymph node T cells only. Although other possibilities are discussed, we inferred that these differences might be due to successful population of the congenitally athymic rats by A3 clone cells given with a small number of normal autologous naive lymph node T cells. The result of this co-transfer of naive T cells with the A3 clone cells seemed to be greatly increased antibody production and protection from periodontal bone loss.

No abstract

It is suggested that B cells can contribute to periodontal bone resorption and that antigen-triggering of B cells is required for the bone resorption.