Tweet
J Virol. 2011 Apr 27. [Epub ahead of print]
Functional Macroautophagy Induction by Influenza A Virus Without a Contribution to MHC-Class II Restricted Presentation.
Comber JD, Robinson TM, Siciliano NA, Snook AE, Eisenlohr LC.
Source
Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA.
Abstract
MHC class II presented peptides can be derived from both exogenous (extracellular) and endogenous (biosynthesized) sources of antigen. Although several endogenous antigen processing pathways have been reported, little is known about their relative contributions to global CD4(+) T cell responses against complex antigens. Using influenza for this purpose, we assessed the role of macroautophagy, a process in which cytosolic proteins are delivered to the lysosome by de novo vesicle formation and membrane fusion. Influenza infection triggered productive macroautophagy and autophagy-dependent presentation was readily observed with model antigens that naturally traffic to the autophagosome. Furthermore, treatments that enhance or inhibit macroautophagy modulated the level of presentation from these model antigens. However, validated ELISpot assays of influenza-specific CD4(+) T cells from infected mice using a variety of antigen presenting cells, including primary dendritic cells, revealed no detectable macroautophagy-dependent component. In contrast, the contribution of proteasome-dependent endogenous antigen processing to the global influenza CD4(+) response was readily appreciated. The contribution of macroautophagy to the MHC class II restricted response may vary depending upon the pathogen.
PMID:
21525345
[PubMed - as supplied by publisher]
Functional Macroautophagy Induction by Influenza A Virus Without a Contribution to MHC-Class II Restricted Presentation.
Comber JD, Robinson TM, Siciliano NA, Snook AE, Eisenlohr LC.
Source
Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA.
Abstract
MHC class II presented peptides can be derived from both exogenous (extracellular) and endogenous (biosynthesized) sources of antigen. Although several endogenous antigen processing pathways have been reported, little is known about their relative contributions to global CD4(+) T cell responses against complex antigens. Using influenza for this purpose, we assessed the role of macroautophagy, a process in which cytosolic proteins are delivered to the lysosome by de novo vesicle formation and membrane fusion. Influenza infection triggered productive macroautophagy and autophagy-dependent presentation was readily observed with model antigens that naturally traffic to the autophagosome. Furthermore, treatments that enhance or inhibit macroautophagy modulated the level of presentation from these model antigens. However, validated ELISpot assays of influenza-specific CD4(+) T cells from infected mice using a variety of antigen presenting cells, including primary dendritic cells, revealed no detectable macroautophagy-dependent component. In contrast, the contribution of proteasome-dependent endogenous antigen processing to the global influenza CD4(+) response was readily appreciated. The contribution of macroautophagy to the MHC class II restricted response may vary depending upon the pathogen.
PMID:
21525345
[PubMed - as supplied by publisher]
