Functional T cells in athymic nude mice.

After passage of spleen cells from nu/nu mice over a nylon wool column, concanavalin A-responsive cells can be detected in the presence of 2-mercaptoethanol, and specific cytotoxic T lymphocytes can be generated without exposure to interleukin 2 (IL-2). The spleen cells of the nu/nu mice born of nu/nu parents and nursed by nu/nu mothers had significantly fewer Thy-1+ T cells and a lesser capacity to generate cytotoxic T lymphocytes than did the conventionally bred nu/nu mice. Nonetheless, such cells were clearly present. IL-2 may act to cause these post-thymic T cells to proliferate. Therefore, it seems inappropriate to consider IL-2 as an inducer of the differentiation of T cells in the absence of thymic influence on the basis of the capacity of IL-2 to induce the appearance of a T-lymphocyte population in nu/nu mice.