Adenovirus-specific human T cells are pervasive, polyfunctional, and cross-reactive.
Pre-existing immunity to adenovirus (Ad) reduces the efficacy of Ad-based vaccines. The goal of this study was to define the prevalence, magnitude, functionality and phenotype of Ad-specific human T cells directly ex vivo. To study the magnitude of T-cell responses to Ad, we developed a highly reproducible whole Ad vector stimulation assay for use with polychromatic flow cytometry. Ad-specific CD4(+) and CD8(+) T-cells were detected in all 17 human subjects tested and were capable of proliferating upon restimulation. Ad5-specific CD4(+) T cells were primarily monofunctional CD4(+) T cells that produced IL-2, IFN-gamma or TNFalpha and expressed the memory markers CD27 and CD45RO. In contrast, Ad5-specific CD8(+) T cells were more polyfunctional, expressing effector-like combinations of IFN-gamma, MIP1alpha and perforin, and generally lacked CD27 and CD45RO expression. Ad-specific CD4(+) and CD8(+) T-cell responses against chimpanzee-derived AdC6 and AdC7 were found in all subjects, indicating the commonality of cross-serotype reactivity of Ad-specific T cells. This cross-reactivity is due in part to extensive CD4(+) and CD8(+) T-cell recognition of hexon regions conserved between multiple Ad serotypes. The prevalence, cross-reactivity and effector-like functions of Ad-specific T cells in humans may affect the efficacy of Ad vector-based vaccines by eliminating vector infected cells even when rare serotype Ad vectors are employed.
Hutnick
Natalie A
NA
Microbiology Department, University of Pennsylvania, Philadelphia, PA 19104, United States.
Carnathan
Diane
D
Demers
Korey
K
Makedonas
George
G
Ertl
Hildegund C J
HC
Betts
Michael R
MR
D000260:Adenoviruses, Human / Q000276:immunology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D003429:Cross Reactions; D016207:Cytokines / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007111:Immunity, Cellular; D002679:Pan troglodytes; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D016207:Cytokines