Proliferation of T8-positive cytolytic T lymphocytes in response to thyroglobulin in @entity1 XXXX : analysis of cell interactions and culture requirements.

@entity1 @entity2743 @entity1669 @entity2621 @entity19 @entity1358
These experiments were designed to analyze the involvement of T-lymphocyte subpopulations in @entity1669 such as @entity2743 ( @entity2743 ) and @entity2621 ( @entity2621 ). In a first set of experiments, lymphocytes isolated from thyroid infiltrates or from peripheral blood of @entity2743 and @entity2621 @entity1 were analyzed for the expression of various surface antigens. While HLA-DR + T cells were numerous among thyroid infiltrating T lymphocytes in both groups of @entity1 , the proportions of T8 + cells (as defined by their reactivity with the B 9.4 monoclonal antibody specific for T8 surface molecule) were strikingly different in @entity2621 and @entity2743 . In the latter group of @entity1 only 19% of infiltrating T cells were T8 +, whereas these cells represented approximately 50% in four @entity2621 @entity1 . Given the previous demonstration that all T cells expressing T8 antigen are cytolytic T lymphocytes (CTL) or their precursors (CTL-P) in conjunction with the fact that lymphocytes from @entity2621 or @entity2743 @entity1 are known to proliferate in vitro in response to @entity1 tg (Htg), we further analyzed the T-cell subset(s) responsible for in vitro proliferation to Htg. In these experiments, peripheral blood T lymphocytes purified from @entity1 with @entity2743 or @entity2621 were cultured with 1 microgram/ml Htg and irradiated autologous T-depleted mononuclear cells as the source of @entity1358 ( @entity1358 ). The proportions of T8 + cells declined considerably during culture in @entity2743 @entity1 , but at Days 6 to 9, T8 + cells represented as much as 51% of cultured T lymphocytes from @entity1 with @entity2621 . Moreover, the majority of T8 + cells were medium-large size lymphoblasts. Removal of Htg at Day 6 resulted in both abrogation of proliferative responsiveness and in decreases of T8 + percentages. Further analysis of the cell interactions leading to T8 + cell proliferation in response to Htg showed that helper/inducer T cells, as defined by 5/9 antigen expression, were strictly required. Collectively, these features are reminiscent of the T-cell involvement in experimental @entity1669 of @entity19 and stress for the first time the potential role of CTL in tissue damage occurring in @entity2621 .
