1
|
Dalla Santa S, Merlo A, Bobisse S, Ronconi E, Boldrin D, Milan G, Barbieri V, Marin O, Facchinetti A, Biasi G, Dolcetti R, Zanovello P, Rosato A. Functional avidity-driven activation-induced cell death shapes CTL immunodominance. THE JOURNAL OF IMMUNOLOGY 2014; 193:4704-11. [PMID: 25246498 DOI: 10.4049/jimmunol.1303203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immunodominance is a complex phenomenon that relies on a mere numerical concept, while being potentially influenced at every step of the immune response. We investigated the mechanisms leading to the establishment of CTL immunodominance in a retroviral model and found that the previously defined subdominant Env-specific CD8(+) T cells are endowed with an unexpectedly higher functional avidity than is the immunodominant Gag-recognizing counterpart. This high avidity, along with the Env Ag overload, results in a supraoptimal TCR engagement. The overstimulation makes Env-specific T lymphocytes more susceptible to apoptosis, thus hampering their expansion and leading to an unintentional "immune kamikazing." Therefore, Ag-dependent, hyperactivation-induced cell death can be regarded as a novel mechanism in the establishment of the immunodominance that restrains and opposes the expansion of high-avidity T cells in favor of lower-affinity populations.
Collapse
Affiliation(s)
| | - Anna Merlo
- Veneto Institute of Oncology, 35128 Padua, Italy
| | - Sara Bobisse
- Ludwig Center for Cancer Research, University of Lausanne, Biopôle III, 1066 Epalinges, Lausanne, Switzerland
| | - Elisa Ronconi
- Excellence Centre for Research, Transfer, and High Education, University of Florence, 50139 Florence, Italy
| | | | - Gabriella Milan
- Department of Medicine, University of Padua, 35128 Padua, Italy
| | - Vito Barbieri
- Department of Surgery, Oncology, and Gastroenterology, University of Padua, 35128 Padua, Italy
| | - Oriano Marin
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Antonella Facchinetti
- Department of Surgery, Oncology, and Gastroenterology, University of Padua, 35128 Padua, Italy
| | - Giovanni Biasi
- Department of Molecular Pathology, University of Marche, 60126 Ancona, Italy; and
| | | | - Paola Zanovello
- Veneto Institute of Oncology, 35128 Padua, Italy; Department of Surgery, Oncology, and Gastroenterology, University of Padua, 35128 Padua, Italy
| | - Antonio Rosato
- Veneto Institute of Oncology, 35128 Padua, Italy; Department of Surgery, Oncology, and Gastroenterology, University of Padua, 35128 Padua, Italy;
| |
Collapse
|