Role of T lymphocytes in the response to TNP-AECM-Ficoll

The T cell dependence of the in vivo and in vitro immune response to TNP-Ficoll was re-examined. It was found that after extensive T cell depletion, the in vitro response to TNP-Ficoll was significantly reduced and could be restored with T cells. Despite the apparent T cell dependence, TNP-Ficoll was able to elicit responses by congenitally athymic BALB/c mice in vivo and by spleen cells from these mice in vitro. The in vitro response of normal spleen cells to TNP-Brucella abortus was occasionally diminished as a result of T cell depletion but never as drastically as the response to TNP-Ficoll. This difference in requirement for T cell influence correlates well with our prior classification of these antigens into TI-1 and TI-2 categories.