tetano
Editor, Senior Moderator
Immunity. 2013 Feb 5. pii: S1074-7613(13)00052-6. doi: 10.1016/j.immuni.2012.10.021. [Epub ahead of print]
Virus-Specific CD4(+) Memory-Phenotype T Cells Are Abundant in Unexposed Adults.
Su LF, Kidd BA, Han A, Kotzin JJ, Davis MM.
Source
Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, CA 94304, USA.
Abstract
Although T cell memory is generally thought to require direct antigen exposure, we found an abundance of memory-phenotype cells (20%-90%, averaging over 50%) of CD4(+) T cells specific to viral antigens in adults who had never been infected. These cells express the appropriate memory markers and genes, rapidly produce cytokines, and have clonally expanded. In contrast, the same T cell receptor (TCR) specificities in newborns are almost entirely na?ve, which might explain the vulnerability of young children to infections. One mechanism for this phenomenon is TCR cross-reactivity to environmental antigens, and in support of this, we found extensive cross-recognition by HIV-1 and influenza-reactive T lymphocytes to other microbial peptides and expansion of one of these after influenza vaccination. Thus, the presence of these memory-phenotype T cells has significant implications for immunity to novel pathogens, child and adult health, and the influence of pathogen-rich versus hygienic environments.
Copyright ? 2013 Elsevier Inc. All rights reserved.
PMID:
23395677
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23395677
Virus-Specific CD4(+) Memory-Phenotype T Cells Are Abundant in Unexposed Adults.
Su LF, Kidd BA, Han A, Kotzin JJ, Davis MM.
Source
Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, CA 94304, USA.
Abstract
Although T cell memory is generally thought to require direct antigen exposure, we found an abundance of memory-phenotype cells (20%-90%, averaging over 50%) of CD4(+) T cells specific to viral antigens in adults who had never been infected. These cells express the appropriate memory markers and genes, rapidly produce cytokines, and have clonally expanded. In contrast, the same T cell receptor (TCR) specificities in newborns are almost entirely na?ve, which might explain the vulnerability of young children to infections. One mechanism for this phenomenon is TCR cross-reactivity to environmental antigens, and in support of this, we found extensive cross-recognition by HIV-1 and influenza-reactive T lymphocytes to other microbial peptides and expansion of one of these after influenza vaccination. Thus, the presence of these memory-phenotype T cells has significant implications for immunity to novel pathogens, child and adult health, and the influence of pathogen-rich versus hygienic environments.
Copyright ? 2013 Elsevier Inc. All rights reserved.
PMID:
23395677
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23395677