tetano
Editor, Senior Moderator
J Virol. 2015 Dec 30. pii: JVI.02546-15. [Epub ahead of print]
[h=1]Plasmacytoid dendritic cells require direct infection to sustain the pulmonary influenza A virus-specific CD8 T cell response.[/h] Hemann EA[SUP]1[/SUP], Sjaastad LE[SUP]2[/SUP], Langlois RA[SUP]3[/SUP], Legge KL[SUP]4[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Following influenza A virus infection (IAV) development of a robust IAV-specific CD8 T cell response is required for clearance of primary infection and enhances memory protection. Following IAV infection, plasmacytoid dendritic cells (pDC) or CD8α[SUP]+[/SUP] DC regulated pulmonary effector CD8 T cell responses within the lung. Without this DC: T cell interaction, insufficient effector CD8 T cells are maintained in the lungs, leading to enhanced morbidity and mortality. Previous studies have demonstrated pDC are capable of classical- or cross-presentation of IAV antigens and could potentially regulate IAV-specific CD8 T cell responses through either mechanism. Our results demonstrate pDC from the lungs of donor mice infected with an IAV that is not able to replicate in hematopoietic cells (142t-IAV), unlike donor pDC isolated from the lungs of control infected mice, are not able to rescue the host IAV-specific CD8 T cell response from apoptosis. This indicates pDC must utilize the direct presentation pathway for this rescue. This inability to of pDC from 142t-IAV donors to rescue the IAV-specific CD8 T cell response is not due to differences in the overall ability of the 142t-IAV to replicate within the lungs, generate defective viral genomes or differences in levels of costimulatory molecules required for this interaction. We further demonstrate that bypassing the antigen presentation pathway by coating the 142t-IAV pDC with IAV peptide epitopes restores their ability to rescue the IAV-specific CD8 T cell response.
[h=4]IMPORTANCE:[/h] IAV continues to be a global health burden that infects 5-20% of the global population annual. Continued investigation into the mechanisms that mediate protective immune responses against IAV is important to improving current vaccination and antiviral strategies antagonistic towards IAV. Our findings presented in this manuscript demonstrate a key requirement for pDC promotion of effector CD8 T cell survival: that rather than utilize cross-presentation, pDC must be infected and utilize the endogenous pathway for presentation of antigens to CD8 T cells during in vivo IAV infections. This suggests that targeting presentation via the endogenous pathway in pDC could be important for the development of unique antiviral cellular therapies.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 26719269 [PubMed - as supplied by publisher]
[h=1]Plasmacytoid dendritic cells require direct infection to sustain the pulmonary influenza A virus-specific CD8 T cell response.[/h] Hemann EA[SUP]1[/SUP], Sjaastad LE[SUP]2[/SUP], Langlois RA[SUP]3[/SUP], Legge KL[SUP]4[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Following influenza A virus infection (IAV) development of a robust IAV-specific CD8 T cell response is required for clearance of primary infection and enhances memory protection. Following IAV infection, plasmacytoid dendritic cells (pDC) or CD8α[SUP]+[/SUP] DC regulated pulmonary effector CD8 T cell responses within the lung. Without this DC: T cell interaction, insufficient effector CD8 T cells are maintained in the lungs, leading to enhanced morbidity and mortality. Previous studies have demonstrated pDC are capable of classical- or cross-presentation of IAV antigens and could potentially regulate IAV-specific CD8 T cell responses through either mechanism. Our results demonstrate pDC from the lungs of donor mice infected with an IAV that is not able to replicate in hematopoietic cells (142t-IAV), unlike donor pDC isolated from the lungs of control infected mice, are not able to rescue the host IAV-specific CD8 T cell response from apoptosis. This indicates pDC must utilize the direct presentation pathway for this rescue. This inability to of pDC from 142t-IAV donors to rescue the IAV-specific CD8 T cell response is not due to differences in the overall ability of the 142t-IAV to replicate within the lungs, generate defective viral genomes or differences in levels of costimulatory molecules required for this interaction. We further demonstrate that bypassing the antigen presentation pathway by coating the 142t-IAV pDC with IAV peptide epitopes restores their ability to rescue the IAV-specific CD8 T cell response.
[h=4]IMPORTANCE:[/h] IAV continues to be a global health burden that infects 5-20% of the global population annual. Continued investigation into the mechanisms that mediate protective immune responses against IAV is important to improving current vaccination and antiviral strategies antagonistic towards IAV. Our findings presented in this manuscript demonstrate a key requirement for pDC promotion of effector CD8 T cell survival: that rather than utilize cross-presentation, pDC must be infected and utilize the endogenous pathway for presentation of antigens to CD8 T cells during in vivo IAV infections. This suggests that targeting presentation via the endogenous pathway in pDC could be important for the development of unique antiviral cellular therapies.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 26719269 [PubMed - as supplied by publisher]