Diversity and complexity of CD8+ T cell responses against a single epitope of adenovirus E1B

This study describes the characteristics of the immune responses against adenovirus in C57BL/6 mice. CTL responses could be induced against E1Bp of adenovirus type 5, when whole viruses were immunized. A panel of E1Bp-specific CTL clones showed a wide range of T cell avidity. Recognition of the E1Bp peptide and a panel of variant peptides containing a single alanine substitution by CTL clones revealed that the fine specificity of the CTL response was quite diverse, rather than being limited to a certain clonal preference. Moreover, the variant peptides with a substitution at the TCR contact residue had antagonistic properties to some of the CTL clones, while being agonistic to others, reflecting the extensive diversity of the T cells. These results imply that the functional diversity of T cells to even a single epitope should be considered in manipulating immunity to viruses and in developing adoptive immunotherapy for immunocompromised individuals.