Figure 5.

Increased cytokine production by Pten^+/– SHIP^+/– (phosphatase with tensin homology/SH2-containing inositol phosphatase) cells was not attributable to differences in survival or spontaneous polarization of T-cell populations. AnnexinV/propidium iodide (PI) staining, followed by fluorescence-activated cell sorter (FACS) analysis, revealed no difference in survival between genotypes after stimulation with anti-CD3: (a) wild type; (b) SHIP^+/–; (c) Pten^+/–; and (d) Pten^+/– SHIP^+/–. Intracellular staining for interleukin-4 (IL-4) and interferon-γ (IFN-γ) was performed on CD4⁺ T cells stimulated with anti-CD3: (e) wild type; (f) SHIP^+/–; (g) Pten^+/–; and (h) Pten^+/– SHIP^+/–. The percentages of cells producing IL-4 and IFN-γ did not differ significantly between genotypes, and the Pten^+/– SHIP^+/– cells did not appear to be polarized towards a greater proportion of T helper 2 (Th2) cells, implying increased cytokine production on a per-cell basis. The results shown represent one experiment of five independent experiments carried out.