抄録
In order to examine the immunological characteristics of tonsillar (t) lymphocytes, plaque forming cell (PFC) of t lymphocytes was assayed in comparison with that of peripheral (p) blood lymphocytes from the same donor. Each t or p lymphocytes of 12 patients with chronic tonsillitis or tonsillar hypertrophy were first separated by Ficoll-Isopaque method. Further fractionation to T and B cells in both t and p lymphocytes (Tt or Bt and Tp or Bp) was done by the usual procedure using sheep red blood cell (SRBC) rosette formation. These lymphocytes were reconsituted with variuos combination between (Bt, Bp) and (Tt, Tp) and, followed by a culture for 7 days with Pokeweed mitogen (PWM). Antibody producing cells detectable by PFC assay of Gronowicz' method were then assayed in the culture cells. Results obtained are summarized as follows.
The maximum numbers of PFC were observed in a culture with 10μg/ml concentration of PWM and 2-mercaptoethanol (5×10-5 M) after 7 days at 37°C, showing the optimal condition for the assay. Population of B cells in t lymphocytes clearly showed much more dominant percentages than that of T cells. This pattern of T and B cell proportion completely differed from the one usualy observed in a population of p lymphocytes. Reconstituted culture of t lymphocytes (Tt+Bt) always gave higher values in IgG and IgM-PFC assay than that of p lymphocytes (Tp+Bp) with a ratio of 100: 18, 100: 11. This means that t lymphocytes generally have an higher activity of antibody production, though its activity occasionally shows individually positive in the case of t lynphocytes, whereas no PFC was seen in a few cases of p lymphocytes. In addition, background numbers of PFC in reconstituted culture of t lymphocytes without an addition of PWM showed much more values than those of p lymphocytes. Tonsillar T cells (Tt) obviously indicated higher activity of helper function for B cells differentiation than that of peripheral blood T cells (Tp). The similar higher function for T cell dependent differentiation of B cells was also found in tonsillar B cells (Bt), when compared with that in peripheral blood B cells (Bp).
From the above results, the author discussed the characteristic roles of tonsil which may contribute to immunological defense mechanisms as the first barrier against various exogeneous antigens.
