Mutations in ALMS1 and C6ORF89 in patient 1 generate immunogenic peptides. (A) Twenty-five missense mutations were identified in patient 1 CLL cells, from which 30 putative epitopes (from 25 unique peptides; 5 peptides were predicted to bind to >1 HLA allele) from 13 mutations were predicted to bind to patient 1’s MHC class I alleles. A total of 13 peptides from 8 mutations were experimentally confirmed as HLA binding. Posttransplant T cells (7 years) from patient 1 were stimulated weekly ex vivo for 4 weeks with 5 pools of 6 mutated peptides per pool (supplemental Table 4), and subsequently tested by the IFN-γ ELISPOT assay. (B) Increased IFN-γ secretion by T cells was detected against pool 2 peptides. Negative control, irrelevant tax peptide; positive control, PHA. (C) Of pool 2 peptides, patient 1 T cells were reactive to mutated ALMS1 and C6ORF89 peptides (right, averaged results from duplicate wells are displayed). (Left) The predicted and experimental IC50 scores (nM) of mutated and wild-type ALMS1 and C6ORF89 peptides.
