Production and secretion of perforin in SN CD8⁺ T cells are low after <i>in vitro</i> reactivation.

<p>Lymphocytes isolated from peripheral blood (PBMC) and sentinel node (SN) were cultured for seven days with addition of autologous tumor homogenate. (<b>A</b>) Flow cytometry was done to phenotype the co-expression in CD8⁺ T cells from PBMC and SN before and after reactivation. The results were shown in dot plots and gated based on isotype control. The frequency of granzyme B and perforin expression was counted out of CD8⁺ T cells. Dot plots showed data from a representative cystectomized patient. (<b>B</b>) Intracellular perforin was measured by Median Fluorescence Intensity (MFI) post 7-day culture using flow cytometry from (A). The data are means with error bars indicating SEM. Mann-Whitney was used as the statistical test. (<b>C</b>) The concentrations (pg/ml) of secreted granzyme B and perforin after seven days of culture were analyzed by ELISA and compared between <i>in vitro</i> culture supernatants of PBMC and SN. The data are means with error bars indicating SEM. Mann-Whitney was used as the statistical test. *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001.