tetano
Editor, Senior Moderator
PLoS One. 2012;7(9):e46166. doi: 10.1371/journal.pone.0046166. Epub 2012 Sep 27.
Multiple Distinct Forms of CD8+ T Cell Cross-Reactivity and Specificities Revealed after 2009 H1N1 Influenza A Virus Infection in Mice.
Guo H, Topham DJ.
Source
Center for Infectious Diseases and Vaccine Immunology, Rochester General Hospital Research Institute, Rochester, New York, United States of America.
Abstract
Influenza primed mice are protected against lethal infection with H1N1 A/CA/04/E3/09 virus, and T depletion and serum transfer studies suggest a T-dependent mechanism. We therefore set out to investigate the quality of the cross-reactive T cell response to CA/E3/09 in mice primed with H3N2 influenza A/Hong Kong/X31 virus. Sequences of the immunodominant nucleoprotein (NP) NP366-374 and acid polymerase (PA) PA224-233 CD8 epitopes from X31 each differ from the CA/E3/09 virus by one amino acid: an M371V substitution at position 6 of the NP peptide, and an S224P substitution at position 1 of the PA peptide, raising questions about the role of these epitopes in protection. PA224-233 peptides from either virus could elicit IFN-γ spot forming cells from mice infected with X31, indicating cross-reactivity of these two peptides. However, no T cell responses to either PA224-233 peptide were detectable after primary CA/E3/09 infection, suggesting it is cryptic in this virus. In contrast, primary responses to the NP366 peptides were detectable after infection with either virus, but did not cross-react in vitro. Similarly, H2-D(b) tetramers of each NP epitope stained CD8+ T cells from each respective virus infection, but did not obviously cross-react. Early after lethal CA/E3/09 challenge, X31 primed mice had enhanced IFN-γ responses toward both NP366 peptides, as well as recall responses to a set of subdominant NP and PA peptides not detectable after primary X31 infection alone. Furthermore, dual-tetramer staining revealed an expanded population of CD8 T cells reactive to both NP366 variant peptides also not seen after the priming infection alone. These observations demonstrate unusual CD8+ T cell cross-reactivity and specificity are elicited after primary and secondary CA/E3/09 influenza virus infections.
PMID:
23029425
[PubMed - in process]
PMCID:
PMC3459832
Free full text
http://www.ncbi.nlm.nih.gov/pubmed/23029425
Multiple Distinct Forms of CD8+ T Cell Cross-Reactivity and Specificities Revealed after 2009 H1N1 Influenza A Virus Infection in Mice.
Guo H, Topham DJ.
Source
Center for Infectious Diseases and Vaccine Immunology, Rochester General Hospital Research Institute, Rochester, New York, United States of America.
Abstract
Influenza primed mice are protected against lethal infection with H1N1 A/CA/04/E3/09 virus, and T depletion and serum transfer studies suggest a T-dependent mechanism. We therefore set out to investigate the quality of the cross-reactive T cell response to CA/E3/09 in mice primed with H3N2 influenza A/Hong Kong/X31 virus. Sequences of the immunodominant nucleoprotein (NP) NP366-374 and acid polymerase (PA) PA224-233 CD8 epitopes from X31 each differ from the CA/E3/09 virus by one amino acid: an M371V substitution at position 6 of the NP peptide, and an S224P substitution at position 1 of the PA peptide, raising questions about the role of these epitopes in protection. PA224-233 peptides from either virus could elicit IFN-γ spot forming cells from mice infected with X31, indicating cross-reactivity of these two peptides. However, no T cell responses to either PA224-233 peptide were detectable after primary CA/E3/09 infection, suggesting it is cryptic in this virus. In contrast, primary responses to the NP366 peptides were detectable after infection with either virus, but did not cross-react in vitro. Similarly, H2-D(b) tetramers of each NP epitope stained CD8+ T cells from each respective virus infection, but did not obviously cross-react. Early after lethal CA/E3/09 challenge, X31 primed mice had enhanced IFN-γ responses toward both NP366 peptides, as well as recall responses to a set of subdominant NP and PA peptides not detectable after primary X31 infection alone. Furthermore, dual-tetramer staining revealed an expanded population of CD8 T cells reactive to both NP366 variant peptides also not seen after the priming infection alone. These observations demonstrate unusual CD8+ T cell cross-reactivity and specificity are elicited after primary and secondary CA/E3/09 influenza virus infections.
PMID:
23029425
[PubMed - in process]
PMCID:
PMC3459832
Free full text
http://www.ncbi.nlm.nih.gov/pubmed/23029425