Changes in the TCR repertoire of T-cell subsets during culture of cytokine-induced killer cells

Cytokine-induced killer (CIK) cells are a group of highly heterogeneous T cells expressing diverse T-cell antigen receptors (TCRs), but possessing wide major histocompatibility complex (MHC)-unrestricted antitumour activity, which have been used in the treatment of many tumours. However, the clonal diversity of different T-cell subsets and whether there is a certain clonal preference during CIK culture remains to be clarified. We found that the proportion of oligoclones seen in some subfamilies of freshly isolated T cells decreased in varying degrees after culturing. This indicates that the diversity of T-cell clones had been restored to a certain extent. The diversity differed among different T-cell subsets, as some TCR subfamily oligoclones mainly appeared in CD3(+)CD56(+) cells, which also indicates the heterogeneity of the CIK cell composition.