Identification of APOBEC3B as a potential target for the graft-versus-lymphoma effect by SEREX in a patient with mantle cell lymphoma.

Recently, a graft-versus-lymphoma (GVL) effect has been shown in patients allografted for mantle cell lymphoma (MCL), but the antigenic targets of this response remain unclear. We screened an MCL cDNA expression library with sera at GVL response after allogeneic haematopoietic stem cell transplantation and isolated five genes including APOBEC3B. Antibody responses to APOBEC3B were correlated with clinical response. Furthermore, APOBEC3B-specific T-cell response was induced with one of the HLA-A*0201 binding peptides. In addition, APOBEC3B mRNA appeared to be upregulated in some MCL. These findings warrant further investigation of APOBEC3B as a candidate gene eliciting an effective immune response against MCL.