Conclusion
IL-21 and Rapamycin can be used concurrently to raise and maintain antigen specific Tscm cells in vitro for purposes of augmenting immunotherapy strategies against cancers.
Methods
We started by obtaining PBLs that screened negative for HLA-A2 molecules from healthy donors followed by co-culture with T2/AFP cells to generate AFP peptide specific tumor-reactive T cells. Controls, IL-21 and/or rapamycin were applied to samples in 24 well plates. Samples were harvested and stained with anti-human CD3, CD8, CD44, CD62L, and HLA-A2/AFP dimer followed by flow cytometry analysis. Cell viability was measured by Trypan blue exclusion assay. One Way ANOVA and independent t test were used to compare the mean differences among and between groups where P values less than 0.05 were considered significant.
Results
Our results show that rapamycin arrests the differentiation of, and expands AFP specific Tscm cells. Further, the expansion of Tscm cells is augmented in the presence of IL-21.