Exclusive TCRVbeta chain usage of ex vivo generated minor Histocompatibility antigen HA-1 specific cytotoxic T cells: implications for monitoring of immunotherapy of leukemia by TCRBV spectratyping.

Tissue expression of minor Histocompatibility antigens HA-1 and HA-2 is limited to the hematopoietic system. Therefore, ex vivo generated HA-1/HA-2 specific cytotoxic T lymphocytes (CTLs) can be applied for adoptive immunotherapy of relapsed leukemia after HLA-matched HA-1/HA-2 mismatched stem cell transplantation. Here we used T cell receptor beta variable chain (TCRBV) spectratyping and/or TCRBV sequencing to monitor the specific TCR usage in eleven HA-1/HA-2 CTLs that were induced ex vivo with peptide pulsed dendritic cells. The HA-2 induced CTLs used different TCRBV. In contrast, the development of HA-1 specific CTLs coincided with prominent skewing of TCRBV7 spectratypes. Sequencing of the TCRBV7 specific PCR products used by these ex vivo generated HA-1 CTLs revealed the exclusive usage of TCRBV7-9*03, identical to the TCRBV used by HA-1 specific CTLs induced in vivo after stem cell transplantation. Thus, monitoring of immunotherapy with HA-1 specific CTLs is now also feasible by TCRBV spectratyping.