Figure 3. Proliferation and survival of activated T cells in adoptive hosts.

Activated CD4⁺ or CD8⁺ CD44^hi T cells and B220⁺ B cells were sorted from SP and LN cells of immunized CD45.1 mice (BALB/c splenocytes, 3 × 10⁷) at 8-days. Sorted CD45.1 CD4⁺ and CD8⁺ CD44^hi T cells (1 × 10⁶) were CFSE labeled and transferred with or without B220⁺ B cells (1.5 × 10⁷) into µMT and wt adoptive hosts. At 2-weeks after transfer, CFSE dilution was analyzed on harvested SP and LN cells after gating on CD4⁺ or CD8⁺ CD45.1⁺ T cells. Representative histogram overlays of CFSE dilution in CD4⁺ or CD8⁺ CD45.1⁺ T cells from harvested spleens of µMT and wt adoptive hosts are shown (A). B. B cells help proliferation of activated CD4 T cells in adoptive hosts. Proliferation index is calculated using Flowjo software after gating on CD4⁺ or CD8⁺ CD45.1⁺ T cells (Mean ± SD; *, p < 0.05; n = 3 – 4 mice/grp). C. Apoptosis of activated T cells in adoptive hosts. Harvested SP and LN cells from µMT and wt adoptive hosts were examined for Annexin V⁺ staining after gating on CD4⁺ or CD8⁺ CD45.1⁺ T cells (Mean ± SD; n = 3 – 4 mice/grp). D. Bcl-2 expression in CD4⁺ and CD8⁺ CD45.1⁺ T cells in adoptive hosts. Representative histogram overlays of Bcl-2 expression are shown after intracellular staining and gating on harvested CD4⁺ or CD8⁺ CD45.1⁺ T cells from adoptive hosts. E. Bcl-2 expression is upregulated in developing CD8 memory T cells in adoptive hosts harboring co-transferred B cells. Median fluorescence intensity of Bcl-2 expression on CD8⁺ CD45.1⁺ T cells harvested from adoptive hosts is shown in comparison to isotype control (Mean ± SD; *, p < 0.05, n = 3 – 4 mice/grp).