Figure 4.

Role of ICAM‐1 in the activation of naive T cells. Nylon wool‐purified T cells were isolated from the spleens of naive ICAM‐1^+/+ mice. The T cells (2 × l0⁵/well) were stimulated with 10 µg/ml of chlamydial antigen and 2 × l0⁵ cells/well of APCs from either ICAM‐1^–/– or ICAM‐1^+/+ mice. At the indicated time of incubation the amounts of IL‐2 in the culture supernatants were measured by ELISA as described in the Materials and Methods section. The concentrations of IL‐2 are expressed as the mean (pg/ml) of results from different experiments. Cultures containing T cells and APCs but without chlamydial antigen did not show any measurable amounts of IL‐2 and so the data are not presented.