Fig. 5.

Splenic T cell proliferation in response to TPO requires irradiated ‘feeder’ splenocytes from TPO⁺ class II⁺ fibroblast-injected mice. (a) Protocol for studying proliferation to TPO by B-depleted spleen cells containing T cells and macrophages (‘Responders’). These cells were co-cultured with irradiated unseparated spleen cells from TPO fibroblast-injected mice or from control mice. (b,c) ³H-TdR uptake by B-depleted responder splenocytes. Responder cells from three mice were pooled (mice t and u, (b); mice h, t and u, (c)) and cultured with irradiated spleen cells from TPO fibroblast-injected mice or control mice with or without TPO. Data are the mean ± s.e.m. ct/min. Values significantly different from cultures without TPO: *P < 0.03 (t = 2.59, (b)); *P < 0.01 (t = 3.12, (c)).