T-cell allorecognition of donor glutathione S-transferase T1 in plasma cell-rich rejection

Figure 1 Polyclonal response of T cells upon recall with peptides of the glutathione S-transferase T1 protein. Percentages of activation upon exposure to the different pools are represented. Three cell types showed activation at different levels. A: Only CD8⁺ lymphocytes of patients included in group 1 showed activation. The numbers in the figure represent the highest value obtained for each pathway when activation was induced by different pools of peptides; B: Activation of CD4⁺ lymphocytes was observed in patients of groups 1 and 3; C: CD4⁺CD8^low cells showed the highest percentage of activation. ¹Indicate that the analysis could not be performed in these patients.

Figure 2 Different areas of the glutathione S-transferase T1 protein induce different degrees of activation in patients’ cells. A: The majority of CD4⁺ T cells that showed some degree of activation recognized peptides in pools 5 (blue) and 3 (green) but never in pool 4 (purple); B: CD4⁺CD8^low cells became stimulated almost homogeneously with in pools 3 (green) and 4 (purple); C: CD8⁺ lymphocytes that showed activation recognized peptides in different pools but never in pool 4 (purple).

Figure 3 Representative plots showing CD4⁺CD8^low T lymphocyte activation in terms of cytokine production. Production of IL-4 and/or IFNγ was analyzed after exposure of the cells to the glutathione S-transferase T1 peptides. As an example, patient 3 had 78.85% of the double positive cells activated with pool 3 and 2.9% with pool 6. Patient 4 had 6.05% of cells activated with pool 3, whereas pool 5 did not have any effect. Patient 17 showed 21.21% of cell activation with pool 3, but no response was observed when the cells were cultured with pool 2. In all the cases, the cells produced both cytokines, indicating a Th0 type of response.