Airway CD8⁺ T cells induced by pulmonary DNA immunization mediate protective anti-viral immunity

Bivas-Benita M, Gillard GO, Bar L, White KA, Webby RJ, Hovav AH, Letvin NL. Mucosal Immunol. 2013 6:156-166

Speaker: Tung-Sheng Lin (林東昇)                               Time: 13:00~14:00,Apr.24,2013

Commentator: Dr. Ching-Chuan Liu (劉清泉醫師)     Place: Room 601

Abstract

Virus-specific CD8⁺ T cells play an important role in protection against a number of respiratory viruses. After virus clearance, CD8⁺ T cells develop a stable pools in lymphoid and peripheral tissues, including a large population of antigen-specific cells that is localized to the lung airways and lung parenchyma¹.Virus-specific memory T cells in the lung airways are believed to provide a first line against a secondary infection². Vaccination can induce protective immunity via CD8⁺ T cells against respiratory pathogens. Pulmonary immunization by plasmid DNA formulated with polymer polyethyleneimine (PEI-DNA) has been shown to induce protective immunity against pulmonary pathogens³. In this study, the authors aimed to study  the mechanisms that affect the persistence of antigen-specific CD8⁺ T cells following PEI-DNA immunization and the contribution of PEI-DNA-induced CD8⁺ T cells to protect mice from viral challenge. The results showed that the persistence of CD8⁺ T cells was not mediated by ongoing antigen presentation or antigen-specific CD8⁺ T cells proliferation. These vaccine-induced CD8⁺ T cells were involved in protective immunity against respiratory viral challenges. Furthermore, this protection was not dependent on the T cells recalling from peripheral sites. In conclusion, pulmonary PEI-DNA immunization induces antigen-specific CD8⁺ T cells which persist in the airway, and protect mice from respiratory pathogens.

References

1.      Kohlmeier JE, Woodland DL. (2009) Immunity to respiratory viruses. Annu. Rev. Immunol. 27: 61-82.

2.      Hogan RJ, Zhong W, Usherwood EJ, Cookenham T, Roberts AD, Woodland DL. (2001) Protection from respiratory virus infections can be mediate by antigen-specific CD4⁺ T cells that persist in the lungs. J. Exp. Med. 193: 981-986

3. Bivas-Benita M. et al. (2010) Efficient generation of mucosal and systemic antigen-specific CD8⁺ T-cell responses following pulmonary DNA immunization. J. Virol. 84: 5764-5774.